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JPSS-1/NOAA-20

Dec 29, 2017

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The Joint Polar Satellite System (JPSS) is a collaborative program between NOAA (National Oceanic and Atmospheric Administration) and NASA (National Aeronautics and Space Administration), alongside other international partners. NOAA-20, formerly known as JPSS-1, is the first satellite in this program, aimed at providing the next generation, operational, polar-orbiting, environmental satellite system for the United States. Launched in November 2017 with a seven year design lifetime, NOAA-20 is primarily used for meteorological and climate applications. JPSS aims to increase timeliness and accuracy of severe weather event forecasts, provide advanced atmospheric temperature, moisture and pressure profiles from space and provide advanced imaging capability to analyse fires, volcanoes, gulf oil tracking and other adverse incidents.

Quick facts

Overview

Mission typeEO
AgencyNASA, NOAA, EUMETSAT
Mission statusOperational (nominal)
Launch date18 Nov 2017
Measurement domainAtmosphere, Ocean, Land, Snow & Ice
Measurement categoryCloud type, amount and cloud top temperature, Liquid water and precipitation rate, Atmospheric Temperature Fields, Cloud particle properties and profile, Ocean colour/biology, Aerosols, Multi-purpose imagery (ocean), Radiation budget, Multi-purpose imagery (land), Surface temperature (land), Vegetation, Albedo and reflectance, Surface temperature (ocean), Atmospheric Humidity Fields, Ozone, Trace gases (excluding ozone), Sea ice cover, edge and thickness, Soil moisture, Snow cover, edge and depth, Ocean surface winds, Atmospheric Winds
Measurement detailedCloud top height, Precipitation Profile (liquid or solid), Atmospheric pressure (over sea surface), Ocean imagery and water leaving spectral radiance, Aerosol absorption optical depth (column/profile), Ocean chlorophyll concentration, Downward long-wave irradiance at Earth surface, Cloud cover, Cloud optical depth, Precipitation intensity at the surface (liquid or solid), Aerosol optical depth (column/profile), Cloud type, Cloud imagery, Cloud base height, Land surface imagery, Upward short-wave irradiance at TOA, Upward long-wave irradiance at TOA, Fire temperature, Vegetation type, Fire fractional cover, Earth surface albedo, Downwelling (Incoming) solar radiation at TOA, Leaf Area Index (LAI), Land cover, Atmospheric specific humidity (column/profile), O3 Mole Fraction, Atmospheric temperature (column/profile), Land surface temperature, Sea surface temperature, Sea-ice cover, Snow cover, Soil moisture at the surface, Wind speed over sea surface (horizontal), Normalized Differential Vegetation Index (NDVI), CO2 Mole Fraction, Sea-ice type, Soil type, Downward short-wave irradiance at Earth surface, Sea-ice surface temperature, Long-wave Earth surface emissivity, Atmospheric pressure (over land surface), Upwelling (Outgoing) long-wave radiation at Earth surface, Wind vector over land surface (horizontal)
InstrumentsCERES, OMPS, ATMS, CrIS, VIIRS
Instrument typeImaging multi-spectral radiometers (vis/IR), Earth radiation budget radiometers, Atmospheric chemistry, Atmospheric temperature and humidity sounders
CEOS EO HandbookSee JPSS-1/NOAA-20 summary

NOAA-20 Satellite (Image credit: NOAA)


 

Summary

Mission Capabilities

NOAA-20 has five instruments onboard: the Advanced Technology Microwave Sounder (ATMS), the Cross-track Infrared Sounder (CrIS), the Ozone Mapping and Profiler Suite (OMPS), the Visible Infrared Imaging Radiometer Suite (VIIRS) and Clouds and the Earth’s Radiant Energy System (CERES). These instruments offer a higher spatial and spectral resolution than their predecessors, NOAA’s Polar-orbiting Operational Environmental Satellites (POES), which translates to greater detail on spectra and atmospheric parameters.

CrIS and ATMS work together to measure high-resolution profiles of temperature and moisture to provide data for Numerical Weather Prediction (NWP) models. VIIRS contributes to improved weather forecasting by measuring clouds and the nature of cloud content, which helps to better predict rainfall. It is also able to track long-term data on land vegetation, ocean surface features like sea surface temperature and sea ice concentration, and track fires, flooding and drought instantaneously. CERES measures the balance of sunlight, the heat in the Earth’s system and how these parameters change over time, which can be used for evaluating the effects and climatic impact of natural disasters. This mission continues the Earth radiation budget data record of other CERES instruments on Terra, Aqua, and other satellites. OMPS takes accurate long-term measurements of the Earth’s ozone layer and builds on decades of ozone observations. When combined with cloud predictions, OMPS data helps create the Ultraviolet Index, a guide to safe levels of sunlight exposure.

Performance Specifications

ATMS is a 22-channel passive microwave radiometer with a nadir spatial resolution of 15.8 - 74.8 km and a swath width of around 2600 km. It is able to cover bands from 23 GHz to 183 GHz to provide high spatial resolution microwave measurements of temperature and moisture in both clear and cloudy conditions. CrIS is a spectrometer with 2211 spectral channels over bands ranging from 3.92 μm to 15.38 μm with a nadir spatial resolution field of view (FOV) of 14 km diameter and a 1 km vertical layer. The vertical layer is able to measure 3-dimensional, high resolution temperature profiles at a swath width of 2200 km. VIIRS measures in 22 spectral bands ranging from 412 nm to 12 μm at a spatial resolution of 400 m and a swath width of 3000 km for the measurement of clouds and the nature of cloud content. CERES is a multi channel radiometer that  records data in three channels, from 0.3μm to more than 50 μm, at a spatial resolution of 20 km. OMPS consists of a mapper and a profiler each with their own characteristics. The mapper measures between 0.3-0.38 μm at a nadir spatial resolution of 50 km and swath width of 2800 km and the profiler measures between 0.25 - 0.31 μm at a spatial resolution of 250 km.

NOAA-20 is in a sun-synchronous orbit with an orbital inclination of 98.75°, an altitude of 833 km and an orbital period of 101.5 minutes.

Space & Hardware Components

Built by Ball Aerospace and Technologies Corporation (BATC), the NOAA-20 satellite bus was based upon the proven Ball Configurable Platform (BCP) 2000 heritage architecture and the Suomi-National Polar-orbiting Program (Suomi-NPP) design. ATMS and CERES were built by Northrop Grumman Electronic Systems, CrIS was built by Harris, and VIIRS was built by Raytheon and OMPS by BATC. The primary Stored Mission Data (SMD) link is via a gimbaled Ka-band antenna providing 300 Mbit/s downlink to the Common Ground System (CGS) receiving stations in Norway, Antarctica, Alaska, and New Mexico. The Attitude Determination and Control Subsystem (ADCS) provides attitude knowledge of the spacecraft. The propulsion system onboard features eight 22 N thrusters which use a mono-propellant hydrazine system. NOAA-20 will be joined by four more JPSS missions over the 2020s and 2030s  to provide data continuity well into the future.

JPSS-1 (Joint Polar Satellite System-1) / NOAA-20 and JPSS-2 series

Spacecraft     Launch    Mission Status     Sensor Complement    Ground Segment    References

 

JPSS is the next generation polar-orbiting operational environmental satellite system series of the USA, procured by NOAA (National Oceanic and Atmospheric Administration) through NASA, with the following major objectives: 1) 2) 3) 4) 5) 6)

• Increase timeliness and accuracy of severe weather event forecasts

• Provide advanced atmospheric temperature, moisture and pressure profiles from space

• Provide advanced imaging capability to analyze fires, volcanoes, Gulf oil tracking and other adverse incidents

• Direct broadcast data to field terminals at hour scale latency

• Maintain continuity of climate observations and critical environmental data from the polar orbit.

1) JPSS consists of three satellites (Suomi-NPP, JPSS-1, JPSS-2), ground system and operations through 2025

- The JPSS mission is to provide global imagery and atmospheric measurements using polar-orbiting satellites

2) JPSS is a partnership between NOAA and NASA

- NOAA has final decision authority and is responsible for overall program commitment

- JPSS Program is the subset of JPSS managed by NASA

- NASA is the acquisition agent for the flight system (satellite, instruments and launch vehicle), ground system, leads program systems engineering, and program safety and mission assurance

- NOAA is responsible for operations, data exploitation and archiving, infrastructure.

3) The partnership is governed by the NOAA and NASA JPSS Management Control Plan

- The JPSS Program is executed in accordance with NPR 7120.5D (NASA Procedural Requirements) as a loosely-coupled program

4) NASA Categorization for JPSS-1 and JPSS-2

- Mission Category 1

- Risk Class B Mission

- Category 2 Expendable Launch Vehicle

JPSS represents significant technological and scientific advances in environmental monitoring and will help advance environmental, weather, climate, and oceanographic science. JPSS's primary user, NOAA's NWS (National Weather Service), will use the JPSS data in models for medium- and long-term weather forecasting. JPSS will allow scientists and forecasters to monitor and predict weather patterns with increased speed and accuracy and is the key for continuity of long-standing climate measurements, allowing the study of long-term climate trends. JPSS will improve and extend climate measurements for 30 different EDRs (Environmental Data Records) of the atmosphere, land, ocean, climate and space environment. 7)

 

Background

Since the 1960's the United States has operated two separate polar-orbiting environmental satellite programs:

- NOAA's POES (Polar-orbiting Operational Environmental Satellite) series

- USAF's DMSP (Defense Metrological Satellite Program) series.

• In 1994, the NPOESS (National Polar-orbiting Environmental Satellite System) program was created (under a Presidential Decision Directive) with the expectation that combining the civil (POES) and military (DMSP) programs would reduce duplication and result in cost savings

• A tri-agency IPO (Integrated Program Office) was formed to manage the program

- NOAA was responsible for overall program management of the converged system and satellite operations

- USAF (United States Air Force) was responsible for acquisition

- NASA responsible for technology insertion.

• Program was to launch NPP (NPOESS Preparatory Project) to reduce risk

• The first NPOESS contract awarded in 2002

- Program estimated to cost $7 billion through 2018

- Scope of program included six satellites (three orbits) each hosting up to 13 instruments, and a ground system.

• NPOESS program encountered significant challenges

- Technical challenges in VIIRS sensor development

- Program cost growth

- Schedule delays

• By 2005, the cost had increased to $10 billion and the first launch had to be delayed from 2008 to 2010

• A decision to restructure the program was made in 2006

- Driven by a Nunn-McCurdy breach

- Satellites reduced from six to four (in two orbits) – EUMETSAT would provide mid-morning orbit

- Number of instruments reduced from 13 to nine

• Even after restructure, program continued to encounter issues

- Technical issues continued with VIIRS

- Management challenges with governance structure

- Cost increases – expected to exceed $14 billion

- Further schedule delays. The major challenge of NPOESS was jointly executing the program between three agencies of different size with divergent objectives and different acquisition procedures.

• In 2009, EOP/OSTP (Executive Office of the President/Office of Science and Technology Policy) led a task force to investigate management and acquisition options that would improve NPOESS. An IRT (Independent Review Team) concluded that the current NPOESS program, in the absence of managerial and funding adjustments, has a low probability of success and data continuity is at extreme risk. The Office of Science and Technology, with the Office of Management and Budget and the National Security Council, as well as representatives from each agency, examined various options to increase the probability of success and reduce the risk to data continuity.

In February 2010, with the release of the FY2011 President's Budget, OSTP announced the restructure of the NPOESS program – specifically, NOAA and DoD would be responsible for different orbits. 8) 9) 10)

- NOAA responsible for the afternoon orbit - JPSS

- DoD responsible for the early morning orbit - DWSS (Defense Weather Satellite System)

- Partnership with EUMETSAT would continue for mid-morning orbit

- Both agencies would share a common ground system.

• Restructure codified and executed through:

- National Space Policy

- Administration's Implementation Plan for Polar-orbiting Environmental Satellites

- NPOESS Deputies Meeting Summary

- Series of DoD Acquisition Decision Memorandums: Continued support to NPP; Close out of the IPO; Transfer of sensors and ground system from DoD to NOAA/NASA; Identified sensor suite on DWSS.

The Administration decision for the restructured JPSS (Joint Polar Satellite System) will continue the development of critical Earth observing instruments required for improving weather forecasts, climate monitoring, and warning lead times of severe storms. NASA’s role in the restructured program will be modeled after the procurement structure of the successful POES (Polar Operational Environmental Satellite) and GOES (Geostationary Operational Environmental Satellite) programs, where NASA and NOAA have a long and effective partnership. The partner agencies are committed to maintaining collaborations towards the goal of continuity of Earth observations from space.

Note: Since this transition, the DWSS satellite program has been canceled and replaced with the WFO (Weather Follow On) program. As part of the restructuring of the program, some responsibilities have been shifted to accomplish the environmental and climate observing missions. For JPSS, NASA’s Goddard Space Flight Center has the responsibility for the acquisition for the afternoon orbit satellites, along with the acquisition, system engineering and integration for the Ground System (GS) for the US next-generation of weather and climate satellites. After the start of the JPSS program, the DWSS, which was to be responsible for the early morning orbit satellites, was cancelled due to lack of funding. EUMETSAT (European Organization for the Exploitation of Meteorological Satellites) will be relied on for the mid-morning orbit satellites of the MetOp series (Ref. 129).

• The JPSS program successfully completed two key reviews in July 2013 at NASA/GSFC. The JPSS program is continuing on schedule and on budget toward the March 2017 launch of the JPSS-1 polar-orbiting weather satellite. NASA is developing and acquiring the JPSS-1 mission for NOAA (National Oceanic and Atmospheric Administration). 11)

 

Figure 1: JPSS implements US civil commitment inter-agency and international agreements to afford a 3-orbit global coverage (image credit: NOAA, NASA)
Figure 1: JPSS implements US civil commitment inter-agency and international agreements to afford a 3-orbit global coverage (image credit: NOAA, NASA)
Figure 2: JPSS overview (image credit: NOAA, NASA, Ref. 1)
Figure 2: JPSS overview (image credit: NOAA, NASA, Ref. 1)

The restructured Joint Polar Satellite System is planned to provide launch readiness capability in FY 2015 and FY 2018 (with launches of JPSS-1 in 2017 and JPSS-2 in 2022, respectively) in order to minimize any potential loss of continuity of data for the afternoon orbit in the event of an on orbit or launch failure of other components in the system. Final readiness dates will not be baselined until all transition activities are completed.

The United States JPSS (Joint Polar Satellite System) is the new generation of POES (Polar Operational Environmental Satellites) in the early afternoon sun-synchronous orbit. The Joint NOAA/NASA Suomi-NPP (National Polar Partnership ) mission is the first of the JPSS missions. It has achieved nearly four years of successful on-orbit observations and was declared primary satellite for weather in May of 2014. 12)

JPSS overview — it is integral to 3-orbit global polar coverage as outlined in Figure 1

• JPSS is the next generation of U.S. civil operational polar-orbiting satellites, and includes Suomi NPP

• The JPSS program, including agreements with EUMETSAT, JAXA and DoD.

• NOAA plans and directs the program, while NASA acts as the acquisition agent for flight and elements of the ground system.

• JPSS provides operational continuity of satellite-based observations and products beyond the current NOAA Polar-orbiting satellites series.

• The JPSS program is on budget and on schedule to launch the next satellite, JPSS-1, in 2017 and after successful launch becomes NOAA-20

• JPSS implements U.S. Space Policy and international agreements to ensure global coverage.

• NOAA’s polar satellite covers the afternoon orbit, EUMETSAT’s satellite MetOp covers the mid-morning orbit and DoD covers the early morning orbit.

• The data from these three orbits are fundamental to the 3-7 day forecast to provide advanced warning of severe weather, as well as environmental monitoring .

• JAXA provides microwave imagery used for a variety of applications; most importantly of precipitation in areas not covered by radar.

 

Figure 3: NOAA & Partner polar weather satellite programs - continuity of weather observations, as of April 2015 (image credit: NOAA) 13)
Figure 3: NOAA & Partner polar weather satellite programs - continuity of weather observations, as of April 2015 (image credit: NOAA) 13)
Figure 4: NOAA POES continuity of weather observations (image credit: NOAA)
Figure 4: NOAA POES continuity of weather observations (image credit: NOAA)
Figure 5: Simplified schematic composition of the JPSS system (image credit: NASA, NOAA)
Figure 5: Simplified schematic composition of the JPSS system (image credit: NASA, NOAA)

 

 


 

Spacecraft

The JPSS spacecraft are procured at NASA/GSFC. NASA in turn awarded a contract to BATC (Ball Aerospace and Technologies Corporation) of Boulder, CO to design and develop the JPSS-1 spacecraft bus, the OMPS (Ozone Mapping and Profiler Suite) instrument, integrating all instruments, and performing satellite-level testing and launch support. 14) 15)

JPSS-1, a clone of the Suomi-NPP (also referred to as SNPP) satellite, employs the BCP-2000 (Ball Commercial Platform -2000) spacecraft bus.

• 3-axis stabilized (50 arcsec control, 21 arcsec knowledge, and 75 m position)

• Launch mass of 2540 kg

• Power: 1932 W (BOL)

• For JPSS-1, Ball is converting the NPP spacecraft design from IEEE 1394 (FireWire) to a SpaceWire databus protocol for use by the CrIS and the VIIRS instruments.

• Ka-band 300 Mbit/s downlink. In addition, a backup Ka-band SMD (Science Mission Data) downlink is added for TDRSS (Tracking and Data Relay Satellite System) transmissions (to improve future latency issues). 16)

• X-band 15 Mbit/s HRD (High Rate Data) direct broadcast to users

• Lifetime: 7 years

Figure 6: Illustration of the deployed JPSS-1 spacecraft (image credit: NASA, NOAA) 17)
Figure 6: Illustration of the deployed JPSS-1 spacecraft (image credit: NASA, NOAA) 17)
Figure 7: JPSS-1 spacecraft zenith deck layout (left) and nadir deck layout (right), image credit: BATC 18)
Figure 7: JPSS-1 spacecraft zenith deck layout (left) and nadir deck layout (right), image credit: BATC 18)

 

JPSS Series Development Status

• September 3, 2020: VIIRS (Visible Infrared Imaging Radiometer Suite), the first instrument for NOAA’s next polar-orbiting weather satellite, arrived at Northrop Grumman’s spacecraft facility in Gilbert, Arizona, last week to be integrated with JPSS-2 ( Joint Polar Satellite System-2). 19)

- The third satellite of the JPSS series, NOAA’s JPSS-2 is preparing for launch in 2022 to continue the critical flow of weather and environmental data to users like the National Weather Service, the National Hurricane Center and more. The VIIRS instrument is the eyes of JPSS. It produces infrared images of hurricanes; identifies snow and ice cover, clouds, fog and dust; and helps locate and map wildfires. Its DNB (Day-Night Band), the satellite’s eyes at night, can distinguish between city lights, moonlight, lightning, and auroras.

Figure 8: Engineers unpack the VIIRS instrument from its protective shipping container at Northrop Grumman’s spacecraft facility in Gilbert, Arizona (image credit: Northrop Grumman)
Figure 8: Engineers unpack the VIIRS instrument from its protective shipping container at Northrop Grumman’s spacecraft facility in Gilbert, Arizona (image credit: Northrop Grumman)

- A collaboration between NOAA and NASA, JPSS is the United States’ most advanced series of polar-orbiting environmental satellites. It provides significant technological and scientific advancements for severe weather prediction and environmental monitoring. These data are critical to the timeliness and accuracy of forecasts three to seven days in advance of a severe weather event.

Figure 9: The VIIRS instrument photographed prior to shipping (image credit: Raytheon Intelligence & Space)
Figure 9: The VIIRS instrument photographed prior to shipping (image credit: Raytheon Intelligence & Space)

• May 6, 2020: The CrIS (Cross-Track Infrared Sounder) instrument, built to fly on the Joint Polar Satellite System (JPSS)-2 satellite, is ready to ship to the spacecraft. CrIS has passed all of its readiness tests, completing its pre-ship review. Pre-ship review is the final step before instruments are shipped to and integrated onto the spacecraft. CrIS is the future satellite’s final instrument to be ready for spacecraft integration. 20)

- The CrIS instrument is an advanced operational sounder that provides more accurate, detailed atmospheric temperature and moisture observations for weather and climate applications.

Figure 10: Photo of the CrIS instrument (image credit: L3Harris Technologies)
Figure 10: Photo of the CrIS instrument (image credit: L3Harris Technologies)

- CrIS is a key instrument currently flying on the NASA-NOAA Suomi NPP and NOAA-20 (or JPSS-1) satellites, the first two in the Joint Polar Satellite System’s series of polar-orbiting satellites. CrIS represents a significant enhancement over NOAA's legacy infrared sounder—the High-Resolution Infrared Radiation Sounder (HIRS).

- Data from the JPSS satellites feed daily weather models and tell us about atmospheric conditions needed to provide extreme weather forecasts several days in advance. CrIS will be among the instruments on the JPSS-2, -3 and -4 satellite missions. The CrIS instrument was developed and built by L3Harris Technologies.

• October 4, 2018: Last month, as satellites fed a steady stream of data into models tracking the paths of Hurricane Florence and Typhoon Mangkhut, the next in a fleet of satellites designed to monitor weather and climate cleared its CDR (Critical Design Review). 21)

- JPSS-2 (Joint Polar Satellite System-2) will join NOAA-20 (former JPSS-1) in a series of polar-orbiting satellites to monitor the Earth’s atmosphere, land and oceans. NASA builds the JPSS series of satellites, and NOAA will operate them.

- It will measure the temperature and moisture of our atmosphere, and the knowledge of that is really what drives the accuracy of our weather forecasts,” said Greg Mandt, NOAA director of the Joint Polar Satellite System program at NASA's Goddard Space Flight Center, Greenbelt, MD.

- Passing the CDR, a technical review, means that design and analysis of the satellite system, which includes its ground system and flight plan, is complete, and that the project is ready to continue in its next phases: fabrication, assembly, integration and testing.

- The CDR was conducted by a standing review board of 16 members, who are independent of the program and experts in various fields, including electrical and mechanical engineering, weather forecasting and science, ground systems, ground stations, and budgeting and schedule.

- Like its polar-orbiting cousins, JPSS-2 will scan our planet as it orbits from pole to pole, crossing the equator 14 times a day. In the process, its onboard instruments will snap pictures and capture data that will inform seven-day weather forecasts and extreme weather events.

Figure 11: Northrop Grumman Information Systems (NGIS) technicians install the flight harnesses onto the JPSS-2 structure on 9 August 2018 (image credit NGIS)
Figure 11: Northrop Grumman Information Systems (NGIS) technicians install the flight harnesses onto the JPSS-2 structure on 9 August 2018 (image credit NGIS)

- Polar sounders provide roughly 85 percent of the data used in forecast models. But weather is only part of the picture. The spacecraft’s instruments will also tell us about wildfires, volcanoes, atmospheric ozone, ice loss and sea surface temperatures.

- “In our ground segment design for JPSS-2, we have shown that we understand what changes are needed, and we are well prepared to go to implementation,” said Heather Kilcoyne, the NOAA ground segment project manager for JPSS at NASA Goddard. “It’s not enough to just have a satellite up there. Our design covers the changes needed end to end to ensure our products actually get used by forecasters and researchers.”

- The newest spacecraft will be nearly identical to its predecessor, NOAA-20. But, Mandt points out, the science the data feeds are always advancing. “Every year, there will be new applications discovered,” he said. “Even if the instruments are the same, the use of the data will continue to expand, and we’ll find new ways to use it to solve problems.”

- JPSS enables forecasters and scientists to monitor and predict weather patterns with greater accuracy and to study long-term climate trends by extending the more than 30-year satellite data record.

• July 17, 2018: NASA has awarded Raytheon's Intelligence, Information and Services business $59 million for additional work on NOAA's JPSS (Joint Polar Satellite System) CGS (Common Ground System) project. 22)

- The changes are necessary to launch America's next polar satellite, JPSS-2, in 2021. The project recently completed the critical design review for the work, and compatibility testing between the satellite and ground system will begin in early 2020. Svalbard, Norway, is the location of the northernmost Joint Polar Satellite System Common Ground System station.

- Developed by NASA for NOAA, the JPSS CGS collects and disseminates observations from polar-orbiting weather satellites from the United States, Europe and Japan. The new contract brings the total value to just under $2 billion. In addition to changes to the command and control system and orbital dynamics system that will maneuver the JPSS-2 satellite while in space, the contract also covers upgrades to the system's simulation and cyber security capabilities, as well as expansion of the system's wide area network and security incident response team.

Figure 12: Svalbard, Norway, is the location of the northernmost Joint Polar Satellite System CGS (Common Ground System) station (image credit: Raytheon)
Figure 12: Svalbard, Norway, is the location of the northernmost Joint Polar Satellite System CGS (Common Ground System) station (image credit: Raytheon)

• May 25, 2018: NASA has exercised options under the Rapid Spacecraft Acquisition III (Rapid III)contract for two additional Joint Polar Satellite System (JPSS) spacecraft to be built for the National Oceanic and Atmospheric Administration (NOAA). 23)

- Orbital ATK of Dulles, Virginia, will build NOAA’s Joint Polar Satellite System JPSS-3 and -4. The contract value is $460 million and the period of performance will extend through 2026. The work will be performed at Orbital ATK’s facility in Gilbert, Arizona.

- Orbital, which currently is developing the JPSS-2 spacecraft, will design, develop, fabricate, integrate, test and provide post-delivery support for the third and fourth spacecraft in the series.

• September 5, 2017: NOAA's JPSS-1 satellite arrived at Vandenberg Air Force Base in California on Sept. 1, 2017, to begin preparations for a November launch. 24)

- After its arrival, the JPSS-1 spacecraft was pulled from its shipping container, and is being prepared for encapsulation on top of the rocket that will take it to its polar orbit at an altitude of 824 km above Earth. JPSS-1 is the first in a series of NOAA’s four next-generation, polar-orbiting weather satellites.

Figure 13: Photo of JPSS-1, arriving at the Astrotech Processing Facility at Vandenberg Air Force Base in California (image credit: NASA, Michael A. Starobin)
Figure 13: Photo of JPSS-1, arriving at the Astrotech Processing Facility at Vandenberg Air Force Base in California (image credit: NASA, Michael A. Starobin)

• March 6, 2017: NASA’s Launch Services Program has selected United Launch Alliance’s (ULA’s) proven Atlas V vehicle to launch the Joint Polar Satellite System (JPSS-2) mission, the third in the nation's new generation polar-orbiting operational environmental satellite system—this award resulted from a competitive Launch Service Task Order evaluation under the NASA Launch Services II contract. 25)

- The JPSS-2 mission is scheduled to launch in the summer of 2021 from Space Launch Complex-3 at Vandenberg Air Force Base in California. This mission will launch aboard an Atlas V 401 vehicle.

• On 15 December 2016, Europe and the US achieved another milestone in the cooperation on meteorological satellite systems when Marc Cohen, EUMETSAT Associate Director for LEO Programs and Harry A. Cikanek III, NOAA Director, Joint Polar Satellite System signed the plan that will implement the JPS (Joint Polar System). 26)

- The Polar System PIP (Program Implementation Plan) encompasses the space and ground segments associated with EUMETSAT’s Polar System Second Generation (EPS-SG) and the JPSS ( Joint Polar Satellite System) of NOAA ( National Oceanic and Atmospheric Administration). It also regulates the use of assets and operations as well as access to third party mission products such as the Copernicus Earth Observation Program of the EU and the NOAA COSMIC (Constellation Observing System for Meteorology Ionosphere and Climate) missions and follow-on partnerships.

• July 7, 2016: As highlighted in a May 2016 report of GAO (Government Accounting Office), the NOAA JPSS program has continued to make progress in developing the JPSS-1 satellite for a March 2017 launch. However, the program has experienced technical challenges which have resulted in delays in interim milestones. In addition, NOAA faces the potential for a near-term gap in satellite coverage of 8 months before the JPSS-1 satellite is launched and completes post-launch testing (Figure 14). 27)

- However, uncertainties remained on the best timing for launching these satellites, in part because of the potential for some satellites already in orbit to last longer. NOAA did not provide sufficient evidence that it had evaluated the costs and benefits of launch scenarios for these new satellites based on updated life expectancies. Until this occurs, NOAA may not make the most efficient use of investments in the polar satellite program.

Figure 14: Timeline for a Potential Gap in Polar Satellite Data in the Afternoon Orbit. The GAO analysis is based on NOAA and NASA data (image credit: GAO)
Figure 14: Timeline for a Potential Gap in Polar Satellite Data in the Afternoon Orbit. The GAO analysis is based on NOAA and NASA data (image credit: GAO)

• NOAA’s JPSS-1 satellite, the second in the JPSS satellite series, is slated for launch in early 2017 aboard a Delta-2 launch vehicle from Vandenberg Air Force Base in California. To prepare, the spacecraft is currently going through an array of tests designed to simulate the extreme environments the satellite may experience during launch and while in orbit. During the testing period, JPSS-1 and its instruments will be subjected to a variety of harsh conditions, including acoustical bombardment, intense vibration, electromagnetic fields, thermal vacuum environments and ground system compatibility tests. 28)

- The tests are taking place at BATC where the spacecraft was assembled. The satellite will be placed inside a large vacuum chamber, where it will be exposed to a simulated space environment complete with extreme hot and cold temperatures ranging from 10 degrees Celsius above and below what it could experience in space. The satellite will also undergo vibration and acoustic testing to simulate the experience of launching into space aboard a rocket, and electromagnetic testing to ensure it is properly protected from electromagnetic phenomena in space, such as solar flares.

- JPSS-1 takes advantage of the successful technologies developed through the NOAA/NASA Suomi-NPP satellite and has a design life of seven years.

• April 22, 2016: On behalf of NOAA, NASA has awarded a sole source contract modification to Ball Aerospace & Technologies Corporation of Boulder, Colorado, for two OMPS (Ozone Mapping and Profiling Suite) instruments for flight on NOAA’s JPSS (Joint Polar Satellite System) Polar Follow On JPSS-3 and JPSS-4 missions. 29)

• March 17, 2016: On behalf of NOAA, NASA has awarded a sole source contract modification to Northrop Grumman, of Azusa, California, for two ATMS (Advanced Technology Microwave Sounder) instruments for NOAA's JPSS (Joint Polar Satellite System) Polar Follow On / JPSS-3 and JPSS-4 Missions. 30)

• February 11, 2016: The fifth and final instrument, the ATMS (Advanced Technology Microwave Sounder), an instrument critical to forecasting weather three to seven days in advance, has been integrated with the JPSS-1 satellite. This marks a very significant milestone for the JPSS program. Soon, the spacecraft will be prepared for the environmental testing phase which is the next step toward launch. 31)

- Compared with NOAA’s legacy microwave sounders, ATMS offers more channels and better resolution and collects a wider swath of data. ATMS will be operating in tandem with CrIS (Cross-track Infrared Sounder) aboard the JPSS-1 satellite. By working together to cover more of the electromagnetic spectrum (microwave and infrared), ATMS and CrIS will provide coverage of a broad range of weather conditions.

- ATMS is built by Northrop Grumman in Azusa, California and was delivered to BATC in Boulder, Colorado where it was integrated with the spacecraft. ATMS currently flies on the NOAA/NASA Suomi NPP satellite mission and will fly on the JPSS-1, JPSS-2, JPSS-3, and JPSS-4 satellite missions.

Figure 15: Ball Aerospace technicians lower the ATMS instrument onto the JPSS-1 spacecraft (image credit: BATC)
Figure 15: Ball Aerospace technicians lower the ATMS instrument onto the JPSS-1 spacecraft (image credit: BATC)

• Fall 2015: The solar panel array on NOAA’s polar-orbiting satellite JPSS-1 spacecraft successfully completed deployment testing at BATC. Engineers unfurled the three panels of the solar array on a special friction reducing floor that helps simulate deployment in the zero-gravity environment of space. The solar array is folded up at launch and deploys on orbit, resembling a giant black wing and generating more than 2775 W of power for NOAA’s JPSS-1 satellite. 32)

• June 30, 2015: BATC has powered the JPSS-1 satellite for the first time. Powering on of the satellite is a key milestone to delivery. Following powering on, the satellite performed within specifications. 33)

- Ball earlier completed integration of four of five JPSS-1 flight instruments. The latest milestone means the satellite is moving toward environmental testing by early 2016 with on-time delivery scheduled for late 2016.

Figure 16: JPSS-1 has been powered-on for the first time, advancing the polar-orbiting environmental satellite toward environmental testing and delivery in 2016 (image credit: BATC)
Figure 16: JPSS-1 has been powered-on for the first time, advancing the polar-orbiting environmental satellite toward environmental testing and delivery in 2016 (image credit: BATC)

• April 9, 2015: The CrIS (Cross-track Infrared Sounder) has been successfully integrated with the spacecraft. CrIS follows successful integration of the Ozone Mapping and Profiler Suite-Nadir (OMPS-N) instrument, the Clouds and the Earth's Radiant Energy System (CERES), and the Visible Infrared Imaging Radiometer Suite (VIIRS). 34)

- Following integration of the final instrument to fly on JPSS-1, ATMS (Advanced Technology Microwave Sounder) later this year, the JPSS-1 satellite will enter environmental testing. 35)

Figure 17: Photo of the CrIS instrument which is being moved into position just prior to integration with the JPSS-1 spacecraft (image credit: BATC)
Figure 17: Photo of the CrIS instrument which is being moved into position just prior to integration with the JPSS-1 spacecraft (image credit: BATC)

• March 10, 2015: The VIIRS (Visible Infrared Imaging Radiometer Suite) has been successfully integrated on- board NOAA’s Joint Polar Satellite System-1 (JPSS-1) satellite. The VIIRS instrument, built by the Raytheon Company in El Segundo, California, is the third instrument to be integrated on the spacecraft by Ball Aerospace & Technologies Corp. in Boulder, Colorado. 36)

• Feb. 18, 2015: The CrIS (Cross-track Infrared Sounder) has completed its pre-shipment review. The completion of the development of the CrIS instrument marks another important step in the on-time completion of the critical instruments for the JPSS-1 spacecraft. 37)

• June 17, 2014: The CERES (Clouds and the Earth's Radiant Energy System) instrument, was delivered to Ball Aerospace for spacecraft integration on June 17, 2014. 38)

• June 12, 2014: The OMPS instrument successfully completed its pre-shipment review. 39)

• April 25, 2014: CERES, the first of five instruments that will fly on JPSS-1, successfully completed pre-shipment review last week. 40)

• March 2014: BATC has applied power to the JPSS-1 spacecraft bus for the first time, a significant milestone for achieving on-time delivery to NOAA. Power-on is the first time that the spacecraft bus is operated as a system with the core EDPS (Electrical Power & Distribution System) and the integrated components of the C&DH (Command & Data Handling) subsystem. Power will be cycled on/off continuously over the next nine months of spacecraft integration and testing. 41)

• February 2014: BATC has successfully completed the SpaceWire interoperability test for the JPSS-1 satellite and has begun spacecraft bus integration. The scope of the test, conducted under both normal and fault conditions, proved the functionality of links using flight-like engineering models of key JPSS-1 spacecraft bus subsystems and engineering models for VIIRS and CrIS. The three additional JPSS-1 instruments include the ATMS , CERES, and the Ball Aerospace-built OMPS (Ozone Mapping and Profiler Suite). 42)

• In December 2012, a four-day delta Critical Design Review (dCDR) of work was conducted at BATC with representatives of NASA and NOAA and the instrument providers. With this successful review, the spacecraft has now been approved to proceed into implementation. 43)

• April 2014: CERES (Clouds and the Earth’s Radiant Energy System), the first of five instruments that will fly on JPSS-1, NOAA’s next polar orbiting environmental satellite, successfully completed pre-shipment review. 44)

Figure 18: JPSS-1 satellite, including instruments and other key components (image credit: NOAA, BATC)
Figure 18: JPSS-1 satellite, including instruments and other key components (image credit: NOAA, BATC)

 

Launch

The JPSS-1 spacecraft was launched on 18 November 2017 (09:47:36 UTC) on a Delta-2-7920 vehicle of ULA (United Launch Alliance) from VAFB, CA. 45) 46) 47) 48)

Orbit: Sun-synchronous orbit, altitude of 824 km, inclination = 98.7º, period = 101 minutes, ground track: 20 km repeat accuracy at the equator with 20 day repeat cycle, LTAN = 13:30 hours ±10 minutes.

Once in orbit, the JPSS-1 spacecraft will be known as NOAA- 20 (once in orbit). This naming ensures the satellite will be identified consistently with previous NOAA operational polar satellite missions dating back to 1978. The previous satellite launched in 2011, the NOAA/NASA Suomi NPP satellite, serves as a bridge from legacy missions to JPSS. 49)

JPSS-1 is the first in NOAA’s series of four, next-generation operational environmental satellites designed to circle the Earth in a polar orbit. JPSS represents significant technological and scientific advancements in observations used for severe weather prediction and environmental monitoring. This data is used by NOAA’s National Weather Service for numerical forecast models, ultimately helping emergency managers make timely decisions on life-saving early warnings and evacuations.

Secondary payloads (ELaNa-14, Ref. 47):

• RadFxSat (Radiation Effects Satellite, Fox-1B), a 1U CubeSat of AMSAT and Vanderbilt University, Nashville, TN, USA.

• EagleSat, a 1U CubeSat of ERAU (Embry-Riddle Aeronautical University), Prescott, AZ, USA.

• MakerSat-0, a 1U CubeSat of NNU (Northwest Nazarene University) and of Caldwell High School of Nampa, Idaho, USA.

• MiRaTA (Microwave Radiometer Technology Acceleration), a 3U CubeSat of MIT (Massachusetts Institute of Technology), Cambridge, MA, USA.

• BRRM (Buccaneer Risk Mitigation Mission), a 3U CubeSat technology mission of UNSW (University of New South Wales), Canberra, Australia and DST (Defence Science and Technology) group. The goal is to calibrate JORN (Jindalee Over-the-Horizon Radar Network).

 

Figure 19: NOAA has partnered with NASA to implement the Joint Polar Satellite System (JPSS). The JPSS Program constitutes the next series of U.S. civilian polar orbiting environmental remote sensing satellites and sensors that have been flown historically on polar satellites. These satellites will implement NOAA's requirements for collection of global multi-spectral radiometry and other specialized meteorological and oceanographic data, via remote sensing of land, sea, and the atmosphere. These data will support NOAA's mission for continuous observations of the Earth's environment necessary to understand and predict changes in weather, climate, oceans and coasts, which support the nation's economy, and protect lives and property. The JPSS-1 through JPSS-4 satellite series provides operational continuity of satellite-based observations and products from NOAA's POES and S-NPP satellites (video credit: NASA Scientific Visualization Studio, Published on 11December 2016)

 

 


 

Mission Status

• June 28, 2022: As spring 2022 turned the page to summer, the Black Sea turned from dark to vivid. The artists are abundant phytoplankton, which can paint the water with color so brilliant it becomes visible from space. 50)

Figure 20: The phytoplankton bloom is visible in this natural-color image acquired on June 20, 2022. The image blends data from the Visible Infrared Imaging Radiometer Suite (VIIRS) on the NOAA-20 satellite and the VIIRS on the Suomi NPP satellite to eliminate sunglint and the seam lines between satellite passes (image credit: NASA Earth Observatory image by Joshua Stevens, using VIIRS data from NASA EOSDIS LANCE, GIBS/Worldview, and the Joint Polar Satellite System (JPSS). Story by Kathryn Hansen)
Figure 20: The phytoplankton bloom is visible in this natural-color image acquired on June 20, 2022. The image blends data from the Visible Infrared Imaging Radiometer Suite (VIIRS) on the NOAA-20 satellite and the VIIRS on the Suomi NPP satellite to eliminate sunglint and the seam lines between satellite passes (image credit: NASA Earth Observatory image by Joshua Stevens, using VIIRS data from NASA EOSDIS LANCE, GIBS/Worldview, and the Joint Polar Satellite System (JPSS). Story by Kathryn Hansen)

- The turquoise swirls indicate the presence of phytoplankton tracing the flow of water currents and eddies. One type of phytoplankton commonly found in the Black Sea is coccolithophores—microscopic plankton that are plated with white calcium carbonate. When aggregated in large numbers, these reflective plates are easily visible from space and make the water appear bright, milky blue.

- In most years, the colorful work of coccolithophores tends to show up in satellite images in May and peak in June. Just one month before the VIIRS data were acquired, the Black Sea more closely resembled its name. For example, satellite images on May 20, 2022 show only a faint trace of milky blue water hugging the coastlines, while most of the sea appeared dark blue to black.

- But a dark Black Sea does not mean that it was devoid of phytoplankton; on the contrary, diatoms were likely present. This type of phytoplankton is common in these waters during spring and can darken the water more than brightening it. Research across the northeast part of the sea suggests that the seasonal changes—from smaller species of diatoms earlier in spring to coccolithophores in late spring and summer—are related to changes in the type and amount of nutrients that are available.

- Diatoms rapidly multiply in spring, when surface waters have abundant nitrogen and phosphorous. In late spring and early summer, when warmer temperatures and fewer storms leave the seawater more stratified, less nitrogen gets mixed into the surface waters—a condition in which coccolithophores are known to dominate. Later in the summer, larger species of diatoms usually show up. These phytoplankton take advantage of nutrients supplied by the occasional mixing that occurs as winds shift direction and storms pass by.

- The seasonal shift in the dominant species of phytoplankton can have a rippling effect on the structure of the food web in the Black Sea. For example, coccolithophores provide fodder for species like Noctiluca scintillans (sea sparkle), while small diatoms feed pelagic fish and large diatoms feed jellyfish.

• June 7, 2022: Winds pick up an estimated 100 million tons of dust from the Sahara Desert each year, and a sizable portion of it blows out over the North Atlantic Ocean. A fresh supply of dust was airlifted from the Sahara in early June 2022, and some of it appeared to be headed for the Americas. 51)

Figure 21: The VIIRS instrument on the NOAA-20 satellite acquired natural-color images (above) of dust on June 3 and 5, 2022, when the plumes were most distinct. NASA’s Earth Polychromatic Imaging Camera on NOAA’s DSCOVR satellite also acquired hemisphere-wide views of the event on June 3 and June 4. This image is of June 5 of NOAA-20 (image credit: NASA Earth Observatory image by Lauren Dauphin, using VIIRS data from NASA EOSDIS LANCE, GIBS/Worldview, and the Joint Polar Satellite System (JPSS). Story by Michael Carlowicz, with reporting from Sara Pratt and Kathryn Hansen)
Figure 21: The VIIRS instrument on the NOAA-20 satellite acquired natural-color images (above) of dust on June 3 and 5, 2022, when the plumes were most distinct. NASA’s Earth Polychromatic Imaging Camera on NOAA’s DSCOVR satellite also acquired hemisphere-wide views of the event on June 3 and June 4. This image is of June 5 of NOAA-20 (image credit: NASA Earth Observatory image by Lauren Dauphin, using VIIRS data from NASA EOSDIS LANCE, GIBS/Worldview, and the Joint Polar Satellite System (JPSS). Story by Michael Carlowicz, with reporting from Sara Pratt and Kathryn Hansen)

- NASA satellite sensors that track aerosol optical depth observed substantial increases in sunlight-reflecting particles over the region starting on May 29 and continuing to June 6. Natural-color satellite imagery from May 30 to June 6 showed the storm’s progression across the water.

- Dust plays a major role in Earth’s climate and biological systems. The airborne particles absorb and reflect sunlight—altering the amount of solar energy reaching the surface—and can also promote or reduce cloud and storm formation, depending on other atmospheric conditions. Dust can degrade air quality and have negative health effects, particularly for people with lung conditions. And dust—rich with iron and other minerals that plants and phytoplankton need—provides natural fertilizer for ocean ecosystems and lands downwind.

- The Sahara Desert is by far Earth’s largest source of airborne dust, and the storms can arise at any time of year. In winter and spring storms, Saharan dust often ends up fertilizing the nutrient-poor soils of the Amazon rainforest. Dust storms in the summer tend to loft material higher into the atmosphere, allowing plumes to travel thousands of kilometers on high-level winds. Those summer seasonal wind patterns can carry the dust from Africa to the Caribbean and the Gulf of Mexico. Plumes of dust recently reached Florida, Texas, and other southern U.S. states in mid-May 2022.

• June 1, 2022: Hurricane season in the eastern Pacific is off to an early and potent start. Though May storms are rare there, Hurricane Agatha struck western Mexico, near Puerto Escondido, bearing maximum sustained winds of 105 miles (169 kilometers) per hour on May 30, 2022. That made the category 2 storm the strongest May hurricane to make landfall along the Pacific coast of Mexico since modern record keeping began in 1949, according to the National Hurricane Center. 52)

Figure 22: The Visible Infrared Imaging Radiometer Suite (VIIRS) on the NOAA-20 satellite acquired this natural-color image of the storm at 1:35 p.m. local time (19:35 Universal Time) on May 30, 2022, a few hours before the storm made landfall. Agatha brought intense downpours and howling winds to several tourist beaches and fishing towns in an otherwise sparsely populated region before weakening rapidly as it moved northward over the mountainous terrain of southern Mexico (image credit: NASA Earth Observatory image by Lauren Dauphin, using VIIRS data from NASA EOSDIS LANCE, GIBS/Worldview, and the Joint Polar Satellite System (JPSS). Caption by Adam Voiland)
Figure 22: The Visible Infrared Imaging Radiometer Suite (VIIRS) on the NOAA-20 satellite acquired this natural-color image of the storm at 1:35 p.m. local time (19:35 Universal Time) on May 30, 2022, a few hours before the storm made landfall. Agatha brought intense downpours and howling winds to several tourist beaches and fishing towns in an otherwise sparsely populated region before weakening rapidly as it moved northward over the mountainous terrain of southern Mexico (image credit: NASA Earth Observatory image by Lauren Dauphin, using VIIRS data from NASA EOSDIS LANCE, GIBS/Worldview, and the Joint Polar Satellite System (JPSS). Caption by Adam Voiland)

- Prevailing trade winds typically steer west and out to sea, but in this case a low-pressure trough dipped far enough south to pull Agatha toward land, reported meteorologist Jeff Masters for Yale Climate Connections. Hurricane forecasters are watching the possibility that Agatha’s remnants will become more organized and strengthen over the Gulf of Mexico as they move toward Florida.

- NOAA and other federal and state agencies lead the forecasting of and response to hurricanes in the United States, with NASA playing a supporting role in developing experimental tools and providing key data to those agencies. NASA’s Earth Science Applied Sciences program works to streamline the flow of information to international science institutions, governments, and aid groups as they use and customize data products from freely available NASA data.

- The eastern Pacific hurricane season officially runs from May 15 through November 30. The peak months of the season are July through September. NOAA’s seasonal outlook for the eastern Pacific hurricane season in 2022 indicates that a below-normal season is likely, while the seasonal outlook for the Atlantic Ocean predicts a more active season than normal. The ongoing La Niña and resulting changes in vertical wind shear in key regions of hurricane formation and development are one of the key factors behind these forecasts.

• January 20, 2022: In mid-January 2022, dust from northwest Africa washed over the Canary Islands, causing skies to turn orange, visibility to drop, and air quality to decline. Such events, known to islanders as “la calima,” generally happen around this time of year as strong seasonal winds carry sand and dust away from the Sahara. 53)

Figure 23: The Visible Infrared Imaging Radiometer Suite (VIIRS) on the NOAA-20 satellite acquired an image (above) around 1:45 p.m. local time on January 14. At the time, Spain’s meteorological agency (AEMET) had issued a warning to the islands of Lanzarote and Fuerteventura for high winds and suspended dust. Later that evening, the warning was extended to Gran Canaria and Tenerife (image credit: NASA Earth Observatory image by Joshua Stevens, and Lauren Dauphin using VIIRS data from NASA EOSDIS LANCE, GIBS/Worldview, and the Joint Polar Satellite System (JPSS). Story by Kathryn Hansen)
Figure 23: The Visible Infrared Imaging Radiometer Suite (VIIRS) on the NOAA-20 satellite acquired an image (above) around 1:45 p.m. local time on January 14. At the time, Spain’s meteorological agency (AEMET) had issued a warning to the islands of Lanzarote and Fuerteventura for high winds and suspended dust. Later that evening, the warning was extended to Gran Canaria and Tenerife (image credit: NASA Earth Observatory image by Joshua Stevens, and Lauren Dauphin using VIIRS data from NASA EOSDIS LANCE, GIBS/Worldview, and the Joint Polar Satellite System (JPSS). Story by Kathryn Hansen)

- With the arrival of the dust, visibility dropped to 1.6 km (1 mile) at the airport on Gran Canaria and 1.8 km (1.2 miles) on Fuerteventura and Tenerife South, according to local news reports. The Ministry of Heath advised people, especially those with respiratory issues, to stay inside with doors and windows closed. Wind gusts reached 70 kilometers (40 miles) per hour.

- The storm was not much more than a hazy orange nuisance to people on the ground. But when viewed from space, interesting patterns emerge. Notice that the dust has organized into a series of linear bands close to the archipelago’s eastern islands. The dust is likely organizing along otherwise invisible waves in the atmosphere. In similar cases, such waves can be caused by the rise and fall of an air mass that has been disturbed.

Figure 24: Over the weekend, dust continued to stream from the African coast. The second image, acquired with VIIRS on the Suomi NPP satellite, shows dust engulfing the archipelago’s westernmost islands by January 15. Notice the plume of dust billowing beyond La Palma to the north-northwest. Forecasts suggest the dust will keep moving north this week toward Ireland, Scotland, and Iceland (image credit: NASA Earth Observatory)
Figure 24: Over the weekend, dust continued to stream from the African coast. The second image, acquired with VIIRS on the Suomi NPP satellite, shows dust engulfing the archipelago’s westernmost islands by January 15. Notice the plume of dust billowing beyond La Palma to the north-northwest. Forecasts suggest the dust will keep moving north this week toward Ireland, Scotland, and Iceland (image credit: NASA Earth Observatory)

- Large plumes of Saharan dust can arise at any time of year, but the dust tends to blow higher in the atmosphere during the summer. For example, dust from the historic “Godzilla” storm of June 2020 rose as high as 4 km (2.5 miles) and crossed the Atlantic Ocean. In contrast, lower altitude dust carried by the northeast trade winds frequently affects people in the Canaries during winter and spring.

• November 3, 2021: The U.S. and Canadian West have been hit with wave after wave of Pacific moisture in recent weeks, producing substantial amounts of rain and snow across the region. But between storm systems, clear skies opened up for nearly a thousand miles from the coast to the interior, giving satellites a rare cloud-free view the region’s major mountain ranges. 54)

Figure 25: The Visible Infrared Imaging Radiometer Suite (VIIRS) on the NOAA-20 satellite acquired this image during the widespread “unusually pleasant” weather on October 31, 2021. Snowcapped peaks are visible across numerous ranges and subranges, from the Coast Mountains in British Columbia to the Rockies in western Alberta (image credit: NASA Earth Observatory image by Lauren Dauphin, using VIIRS data from NASA EOSDIS LANCE, GIBS/Worldview, and the Suomi National Polar-orbiting Partnership. Story by Kathryn Hansen)
Figure 25: The Visible Infrared Imaging Radiometer Suite (VIIRS) on the NOAA-20 satellite acquired this image during the widespread “unusually pleasant” weather on October 31, 2021. Snowcapped peaks are visible across numerous ranges and subranges, from the Coast Mountains in British Columbia to the Rockies in western Alberta (image credit: NASA Earth Observatory image by Lauren Dauphin, using VIIRS data from NASA EOSDIS LANCE, GIBS/Worldview, and the Suomi National Polar-orbiting Partnership. Story by Kathryn Hansen)

- Some of the highest mountain peaks stay white year-round, capped with snow and glacial ice that survive summertime melting. But compared to August 2021, snow cover spanned a much larger area in late October following the series of storms. In the week prior to this image, atmospheric rivers carried copious amounts of rain to lowlands around Vancouver and heavy snow at higher elevations. East of the Rockies, Calgary received its first major snowfall of the season.

- The snow in Calgary is considered on-time for the season. And in Western Washington, meteorologist Cliff Mass noted “we are now in the season of moisture,” when the jet stream typically brings evenly spaced systems of rain. This is also the time of year when the Cascades usually start to accumulate snow. All of this moisture has eased drought in parts of the Pacific Northwest, and more rain, snow, and cold temperatures are expected throughout winter as La Niña returns for a second year in a row.

- But the seasonably cool and wet conditions have not healed the damage from a summer of extremes. Notably, trouble looms for some areas of “permanent” ice hit hard by high temperatures and smoky fires in the summer of 2021. With data from airborne surveys, scientists found a particularly extreme amount of melting on the Columbia Icefield—the largest ice mass in North America outside the Arctic Circle.

- In an interview with CBC Edmonton, glaciologist Brian Menounos of University of Northern British Columbia noted that the icefield this year saw its most extreme melting since the airborne surveys began in 2017. The terminus, or “foot,” of Saskatchewan Glacier thinned by about 10 meters (33 feet). Menounos attributed the exceptional melting to a summer heatwave as well as soot from fires, which can land on glaciers and accelerate melting. Scientists think Saskatchewan Glacier could be mostly gone by the end of the century.

Figure 26: The icefield is visible in this image, acquired on October 31, 2021, by the Operational Land Imager (OLI) on Landsat 8. The icefield spans the provinces of British Columbia and Alberta, as well as Jasper and Banff National Parks. Saskatchewan Glacier, the icefield’s largest outlet glacier, forms the headwaters of the North Saskatchewan River—an important source of freshwater for communities downstream. Clear skies between storm systems gave satellites a cloud-free view from the Coast Mountains in British Columbia to the Rockies in western Alberta (image credit: NASA Earth Observatory using Landsat data from the U.S. Geological Survey )
Figure 26: The icefield is visible in this image, acquired on October 31, 2021, by the Operational Land Imager (OLI) on Landsat 8. The icefield spans the provinces of British Columbia and Alberta, as well as Jasper and Banff National Parks. Saskatchewan Glacier, the icefield’s largest outlet glacier, forms the headwaters of the North Saskatchewan River—an important source of freshwater for communities downstream. Clear skies between storm systems gave satellites a cloud-free view from the Coast Mountains in British Columbia to the Rockies in western Alberta (image credit: NASA Earth Observatory using Landsat data from the U.S. Geological Survey )

• July 2, 2021: So far in 2021, British Columbia has already seen dangerous wildfires and heat. More than 40 wildfires were burning across the Canadian province by the end of June 2021, including a cluster of substantial blazes located about 200 km northeast of Vancouver. 55)

Figure 27: VIIRS (Visible Infrared Imaging Radiometer Suite) on the NOAA-20 satellite acquired this image around 2 p.m. local time (21:00 Universal Time) on June 30, 2021. By the morning of July 1, the McKay Creek fire (left) and the Sparks Lake fire (right) had burned an estimated 150 and 200 km2 (60 and 75 square miles), respectively. A smaller fire is visible just south of the town of Lytton (image credit: NASA Earth Observatory images by Lauren Dauphin and Joshua Stevens, using VIIRS data from NASA EOSDIS LANCE, GIBS/Worldview, and the Suomi National Polar-orbiting Partnership, Landsat data from the U.S. Geological Survey, and GEOS-5 data from the Global Modeling and Assimilation Office at NASA GSFC. Story by Kathryn Hansen)
Figure 27: VIIRS (Visible Infrared Imaging Radiometer Suite) on the NOAA-20 satellite acquired this image around 2 p.m. local time (21:00 Universal Time) on June 30, 2021. By the morning of July 1, the McKay Creek fire (left) and the Sparks Lake fire (right) had burned an estimated 150 and 200 km2 (60 and 75 square miles), respectively. A smaller fire is visible just south of the town of Lytton (image credit: NASA Earth Observatory images by Lauren Dauphin and Joshua Stevens, using VIIRS data from NASA EOSDIS LANCE, GIBS/Worldview, and the Suomi National Polar-orbiting Partnership, Landsat data from the U.S. Geological Survey, and GEOS-5 data from the Global Modeling and Assimilation Office at NASA GSFC. Story by Kathryn Hansen)

- Notice the bright white areas over the two larger fires. According to Michael Fromm, a meteorologist with the Naval Research Laboratory, these are the onset of pyrocumulonimbus (pyroCb) clouds—towering clouds created by the convection and heat rising from a fire. The clouds are a mixture of brown smoke and white ice, so they show up whiter than the dry smoke plumes to the west of each fire.

Figure 28: This image shows a detailed view of the McKay Creek fire, acquired by the Operational Land Imager (OLI) on Landsat-8 at about 12 p.m. local time (19:00 UTC) on June 30, 2021.The natural-color image was overlaid with shortwave-infrared light to highlight the active fire (image credit: NASA Earth Observatory)
Figure 28: This image shows a detailed view of the McKay Creek fire, acquired by the Operational Land Imager (OLI) on Landsat-8 at about 12 p.m. local time (19:00 UTC) on June 30, 2021.The natural-color image was overlaid with shortwave-infrared light to highlight the active fire (image credit: NASA Earth Observatory)

- Hours after these images were acquired, officials ordered a mandatory evacuation for Lytton as fire threatened the town. According to news reports, the fast-moving blaze quickly engulfed the town, destroying homes and injuring residents. The fire affecting Lytton was reportedly a new fire, and not the George Road fire already burning south of the town.

- The spate of fires has occurred during a streak of record-setting temperatures across the Pacific Northwest and western Canada. On June 29, 2021, Lytton hit 121°F (49.6°C)—the highest temperature on record anywhere in the country on any date.

- “The forests are vulnerable each summer, and big fires and pyroCbs have been seen there repeatedly,” Fromm said. “But there’s no doubt the extreme heat and substantial wind exacerbate the fire danger.”

Figure 29: The map shows air temperature anomalies across the western United States and Canada on June 29, 2021. The map is derived from the Goddard Earth Observing System (GEOS) model and depicts air temperatures at 2 meters (about 6.5 feet) above the ground. The darkest red areas are where air temperatures were 36°F (20°C) higher than the 2014-2020 average for the same day (image credit: NASA Earth Observatory)
Figure 29: The map shows air temperature anomalies across the western United States and Canada on June 29, 2021. The map is derived from the Goddard Earth Observing System (GEOS) model and depicts air temperatures at 2 meters (about 6.5 feet) above the ground. The darkest red areas are where air temperatures were 36°F (20°C) higher than the 2014-2020 average for the same day (image credit: NASA Earth Observatory)

- The GEOS model, like all weather and climate models, uses mathematical equations that represent physical processes (such as precipitation and cloud processes) to calculate what the atmosphere will do. Actual measurements of physical properties, like temperature, moisture, and winds, are routinely folded into the model to keep the simulation as close to observed reality as possible.

• April 26, 2021: With millions of hectares of corn, rice, and beans sown in Heilongjiang each year, the province in northeastern China is one of the country’s most important food-producing areas. For many Heilongjiang farmers, one of the first steps in raising this year’s crop involves burning off the remaining bits of last year’s plants to remove debris from the fields and get them ready for planting in May. 56)

Figure 30: Many farmers in northeastern China and eastern Russia use fire to clear fields and get them ready for planting. This practice sometimes leads to hazy, smoke-filled skies, as shown by this natural-color satellite image from the Visible Infrared Imaging Radiometer Suite (VIIRS) on the NOAA-NASA Suomi NPP satellite. Throughout the spring, VIIRS has detected large numbers of “hotspots” associated with fires. These hotspots appear red and orange in this image (image credit: NASA Earth Observatory image by Joshua Stevens, using VIIRS data from NASA EOSDIS LANCE, GIBS/Worldview, and the Joint Polar Satellite System (JPSS). Story by Adam Voiland)
Figure 30: Many farmers in northeastern China and eastern Russia use fire to clear fields and get them ready for planting. This practice sometimes leads to hazy, smoke-filled skies, as shown by this natural-color satellite image from the Visible Infrared Imaging Radiometer Suite (VIIRS) on the NOAA-NASA Suomi NPP satellite. Throughout the spring, VIIRS has detected large numbers of “hotspots” associated with fires. These hotspots appear red and orange in this image (image credit: NASA Earth Observatory image by Joshua Stevens, using VIIRS data from NASA EOSDIS LANCE, GIBS/Worldview, and the Joint Polar Satellite System (JPSS). Story by Adam Voiland)

- VIIRS began detecting sporadic fire activity in the region in mid-March 2021, as soon as warmer weather melted the snow cover. The number of fire detections then ballooned in mid-April, particularly around Harbin, as the spring burning season reached its peak.

- Most straw burning in this area used to happen in the fall, but satellite observations collected over several years show that there has been a strong shift toward spring fires since 2015. That was the year that local authorities enacted fall burning restrictions—part of an effort to limit air pollution—and started encouraging farmers to find other uses for leftover straw. Most crop fires in Heilongjiang now happen in March and April, a change that has coincided with a reduction in overall greenhouse gas and particulate pollution emissions from the area’s fires, according to one recent study.

- Fire activity has not been limited to China. Across the border in Russia, fires—many likely lit by farmers for similar reasons—have also been common along the Amur River. In some areas, including near Vladivostok, Russian authorities and news media reported significant numbers of grass and forests. While some of these likely began as crop fires that spread into forests, Russian authorities pointed to a mix of human activities‐ranging from cooking outdoors to stray cigarettes—for triggering wildfires.

• April 20, 2021: Surigae is not expected to make landfall, but the typhoon churning in the Western Pacific Ocean is already a significant storm. When the storm rapidly intensified to category 5 strength on April 17, 2021, it marked the earliest date in the year that any storm in the Northern Hemisphere had reached such intensity in modern record-keeping. 57)

- Surigae (known as Bising in the Philippines) is the first typhoon of the 2021 season in the northwest Pacific and the second named storm. According to the U.S. Joint Typhoon Warning Center (JTWC), the super typhoon reached sustained winds of 165 knots (190 miles/305 km/hr) in the early afternoon on April 17. According to the Japan Meteorological Agency, the central pressure inside the storm dropped to 895 millibars, one of the lowest readings ever recorded.

Figure 31: The super typhoon reached extreme intensity earlier in the year than any storm in the satellite era. This infrared satellite image was acquired around midday on April 19 with the Visible Infrared Imaging Radiometer Suite (VIIRS) on NOAA-20. Surigae’s clouds are shown using brightness temperature data, which is useful for distinguishing cooler cloud structures from the warmer surface below. Around that time the JTWC reported the typhoon had sustained winds of 120 knots (140 miles/220 km/hr), [image credit: NASA Earth Observatory images by Joshua Stevens, using VIIRS data from NASA EOSDIS LANCE, GIBS/Worldview and the Joint Polar Satellite System (JPSS). Story by Michael Carlowicz]
Figure 31: The super typhoon reached extreme intensity earlier in the year than any storm in the satellite era. This infrared satellite image was acquired around midday on April 19 with the Visible Infrared Imaging Radiometer Suite (VIIRS) on NOAA-20. Surigae’s clouds are shown using brightness temperature data, which is useful for distinguishing cooler cloud structures from the warmer surface below. Around that time the JTWC reported the typhoon had sustained winds of 120 knots (140 miles/220 km/hr), [image credit: NASA Earth Observatory images by Joshua Stevens, using VIIRS data from NASA EOSDIS LANCE, GIBS/Worldview and the Joint Polar Satellite System (JPSS). Story by Michael Carlowicz]

- The typhoon is expected to curve and stay offshore, but its outer bands have been lashing the central and northern Philippine islands with heavy rain, gusty winds, and coastal flooding. At least one person has died and nearly 100,000 have evacuated coastal areas.

Figure 32: This image was acquired in the early morning hours of April 18 with the VIIRS day-night band (DNB) on the NOAA-NASA Suomi NPP satellite. The DNB detects light in a range of wavelengths from green to near-infrared and uses filtering techniques to observe light signals such as city lights, fires, and reflected moonlight. The image shows atmospheric gravity waves propagating away from the eye of the storm (image credit: NASA Earth Observatory)
Figure 32: This image was acquired in the early morning hours of April 18 with the VIIRS day-night band (DNB) on the NOAA-NASA Suomi NPP satellite. The DNB detects light in a range of wavelengths from green to near-infrared and uses filtering techniques to observe light signals such as city lights, fires, and reflected moonlight. The image shows atmospheric gravity waves propagating away from the eye of the storm (image credit: NASA Earth Observatory)

- “The intense convection associated with strong tropical cyclones can generate gravity waves that propagate upward of 30 km or more in the atmosphere,” wrote Matthew Barlow, a climate scientist at the University of Massachusetts–Lowell. “These waves can look similar to a ripple in a pond because they have a similar physical mechanism, although at a vastly different scale.”

- Typhoon season in the Western Pacific generally peaks from July through October, according to the Philippine Atmospheric, Geophysical, and Astronomical Services Administration. On average, 20 tropical cyclones form in the region every year, and eight or nine cross the Philippines.

- “The large-scale environment for typhoon formation in the northwest Pacific is more favorable than it was last year,” noted meteorologist Jeff Masters. “More warm water is present, and La Niña is now fading toward neutral conditions.”

• February 23, 2021: There is nothing particularly unusual about Mount Etna flinging lava, volcanic ash, or molten rocks into the air. The Italian volcano ranks as one the most active in Europe and has been in a state of eruption since 2011. 58)

- Yet even experienced Etna watchers have been wowed by the intensity of the volcano’s unrest in February 2021. Starting on February 16, Etna’s Southeast Crater produced a string of intense lava fountains that continued sporadically for nearly a week. Southeast Crater is one of four summit craters on the volcano and the youngest; it formed in 1971.

- February 20-21 and February 22-23 brought particularly intense activity. At times, lava fountains soared as high as 1.5 km (0.9 miles), about 3 times the height of One World Trade Center, the tallest building in the United States. Columns of ash and small rock fragments (called lapilli) rose as high 10 km (6 miles) in altitude. Long lava flows poured down Etna's eastern flank.

Figure 33: Intense lava fountains and lava flows illuminated a volcanic plume spreading across Sicily during an unusually pitched night of activity at the Italian volcano. At 1:37 a.m. local time (00:37 Universal Time) on February 23, 2021, the Visible Infrared Imaging Radiometer Suite (VIIRS) on the NOAA-20 satellite captured an image showing one of several volcanic plumes Etna has produced recently. At the time, the partially illuminated plume was spreading northwest across Sicily. It deposited a layer of ash in Palermo before heading north toward Sardinia (image credit: NASA Earth Observatory image by Joshua Stevens, using VIIRS day-night band data from the Joint Polar Satellite System and Landsat data from the U.S. Geological Survey. Story by Adam Voiland)
Figure 33: Intense lava fountains and lava flows illuminated a volcanic plume spreading across Sicily during an unusually pitched night of activity at the Italian volcano. At 1:37 a.m. local time (00:37 Universal Time) on February 23, 2021, the Visible Infrared Imaging Radiometer Suite (VIIRS) on the NOAA-20 satellite captured an image showing one of several volcanic plumes Etna has produced recently. At the time, the partially illuminated plume was spreading northwest across Sicily. It deposited a layer of ash in Palermo before heading north toward Sardinia (image credit: NASA Earth Observatory image by Joshua Stevens, using VIIRS day-night band data from the Joint Polar Satellite System and Landsat data from the U.S. Geological Survey. Story by Adam Voiland)
Figure 34: On February 18, 2021, the Operational Land Imager (OLI) on Landsat-8 acquired this image, a natural-color view (OLI bands 4-3-2) of the volcano. At the time, lava from Southeast Crater was flowing southward and eastward from the summit. The natural-color image is overlaid with infrared data from OLI showing the location of warm areas associated with lava (image credit: NASA Earth Observatory)
Figure 34: On February 18, 2021, the Operational Land Imager (OLI) on Landsat-8 acquired this image, a natural-color view (OLI bands 4-3-2) of the volcano. At the time, lava from Southeast Crater was flowing southward and eastward from the summit. The natural-color image is overlaid with infrared data from OLI showing the location of warm areas associated with lava (image credit: NASA Earth Observatory)

- While the recent paroxysms have impressed geologists, they were not out of character for the restive volcano. Paroxysms of similar intensity have occurred at Mount Etna at least four times since 1989, and the volcano has produced roughly 250 paroxysms of various strengths since 1977, said Boris Behncke, also with INGV.

- While ash temporarily closed the nearby airport and meant extra sweeping for many people in northern Sicily, the February paroxysms caused little serious damage or disruption. As long as the paroxysms remain at this intensity and lava comes from the summit rather than the sides of the volcano, the risks poses to surrounding communities are small.

- But there is no guarantee that Etna will remain in its current eruptive stance forever. “Periods of intense activity are almost always followed by lateral eruptions that open up mouths on the flank of the volcano, at times at low elevations,” said Neri. “That means there is a concrete possibility that lava could directly affect an urbanized area, as has happened numerous times in the past.”

- Lava from Etna has occasionally caused problems for surrounding communities. In 1669, lava overwhelmed part of Catania. In 1983, engineers used dynamite to divert lava away from homes. And in 1992, the army had to build an earthen wall to protect a village.

• February 20, 2021: Each year more than 180 million tons of dust blow out from North Africa, lofted out of the Sahara Desert by strong seasonal winds. Perhaps most familiar are the huge, showy plumes that advance across the tropical Atlantic Ocean toward the Americas. But the dust goes elsewhere, too—settling back down in other parts of Africa or drifting north toward Europe. 59)

- While much of the plume appears west of Africa, a tendril of dust can be seen riding the winds toward Europe. According to a story by research meteorologist Marshall Shepherd, strong and persistent winds from the south drive Saharan dust toward Europe at least a few times a year.

- Forecasts from the Copernicus Atmosphere Monitoring Service indicated that most of the dust reaching Europe this weekend will likely be concentrated over Spain and France, but some may carry as far north as Norway. Parts of Spain might see “mud rain,” as the approaching dust plume combines with a weather front.

- The mid-February dust storm follows an intense event earlier in the month over southern and central Europe. Saharan dust from that storm coated the snow on the Pyrenees and Alps and turned skies orange in France.

- Dust can degrade air quality and accelerate the melting of snow cover. But it also plays a major role in Earth’s climate and biological systems, absorbing and reflecting solar energy and fertilizing ocean ecosystems with iron and other minerals that plants and phytoplankton need to grow.

Figure 35: A dramatic display of airborne dust particles was observed on February 18, 2021, by the Visible Infrared Imaging Radiometer Suite (VIIRS) on the NOAA-20 spacecraft. The dust appears widespread, but particularly stirred up over the Bodélé Depression in northeastern Chad (image credit: NASA Earth Observatory image by Lauren Dauphin, using VIIRS data from NASA EOSDIS LANCE, GIBS/Worldview, and the Suomi National Polar-orbiting Partnership. Story by Kathryn Hansen)
Figure 35: A dramatic display of airborne dust particles was observed on February 18, 2021, by the Visible Infrared Imaging Radiometer Suite (VIIRS) on the NOAA-20 spacecraft. The dust appears widespread, but particularly stirred up over the Bodélé Depression in northeastern Chad (image credit: NASA Earth Observatory image by Lauren Dauphin, using VIIRS data from NASA EOSDIS LANCE, GIBS/Worldview, and the Suomi National Polar-orbiting Partnership. Story by Kathryn Hansen)
Figure 36: This image, also acquired on February 18, 2021, shows the scale of the plume in relation to continents bordering the Atlantic Ocean. It was acquired by the NASA’s Earth Polychromatic Imaging Camera (EPIC) on NOAA’s DSCOVR satellite (image credit: NASA Earth Observatory image by Lauren Dauphin, using VIIRS data from NASA EOSDIS LANCE, GIBS/Worldview, and the Suomi National Polar-orbiting Partnership. Story by Kathryn Hansen)
Figure 36: This image, also acquired on February 18, 2021, shows the scale of the plume in relation to continents bordering the Atlantic Ocean. It was acquired by the NASA’s Earth Polychromatic Imaging Camera (EPIC) on NOAA’s DSCOVR satellite (image credit: NASA Earth Observatory image by Lauren Dauphin, using VIIRS data from NASA EOSDIS LANCE, GIBS/Worldview, and the Suomi National Polar-orbiting Partnership. Story by Kathryn Hansen)

• January 21,2021: Strong winds frequently whip up dust as they funnel through a break in the Tibesti and Ennedi massifs and across the Bodélé Depression, the lowest point (land elevation) in Chad. By one estimate, dust storms cloud the skies over the ancient lakebed roughly 100 days each year. 60)

Figure 37: On January 20, 2021, the VIIRS (Visible Infrared Imaging Radiometer Suite) on the NOAA-20 spacecraft captured striking imagery of one of those storms. The image shows dust from the Bodélé streaming through the gap in the mountains as it rides northeasterly winds (image credit: NASA Earth Observatory image by Lauren Dauphin, using VIIRS data from NASA EOSDIS LANCE, GIBS/Worldview, and the Suomi National Polar-orbiting Partnership. Story by Adam Voiland)
Figure 37: On January 20, 2021, the VIIRS (Visible Infrared Imaging Radiometer Suite) on the NOAA-20 spacecraft captured striking imagery of one of those storms. The image shows dust from the Bodélé streaming through the gap in the mountains as it rides northeasterly winds (image credit: NASA Earth Observatory image by Lauren Dauphin, using VIIRS data from NASA EOSDIS LANCE, GIBS/Worldview, and the Suomi National Polar-orbiting Partnership. Story by Adam Voiland)

- The dust itself is mostly comprised of particles of quartz and the remains of ancient diatoms — microscopic organisms that lived in ancient Lake Mega Chad. About 7,000 years ago, the lake spanned an area larger than all of the Great Lakes combined.

- Bodélé dust is of particular interest to scientists because diatoms are rich in phosphorous, a nutrient essential to plant growth. Since the Bodélé is such an abundant source of dust, and its plumes often cross the Atlantic Ocean, scientists have long thought that dust from this area fertilized the nutrient-limited soils of the Amazon rainforest.

- Recent research suggests that idea may not be entirely right. A more detailed analysis of data from several satellites and models indicates that much of the Bodélé dust settles over Africa or gets washed out of the atmosphere by rain before reaching South America. The researchers found that most of the dust that does reach the Amazon comes instead from El Djouf, a west African desert in Mauritania and Mali. That area is roughly 2500 kilometers (1,600 miles) west of Bodélé.

• September 30, 2020: Minnesota, Wisconsin, and Michigan are typically among the first parts of the contiguous United States to experience autumn color. Fall 2020 was no exception. 61)

Figure 38: Aided by a period of chilly weather, fall foliage was peaking in the region’s forests in late September. On September 22, 2020, the Visible Infrared Imaging Radiometer Suite (VIIRS) on NOAA-20 acquired this image of the area around Lake Superior, which is rich with aspen, birch, maple, basswood, and other deciduous hardwood trees (image credit: NASA Earth Observatory image by Joshua Stevens, using VIIRS data from NASA EOSDIS/LANCE and GIBS/Worldview and the Joint Polar Satellite System (JPSS). Caption by Adam Voiland)
Figure 38: Aided by a period of chilly weather, fall foliage was peaking in the region’s forests in late September. On September 22, 2020, the Visible Infrared Imaging Radiometer Suite (VIIRS) on NOAA-20 acquired this image of the area around Lake Superior, which is rich with aspen, birch, maple, basswood, and other deciduous hardwood trees (image credit: NASA Earth Observatory image by Joshua Stevens, using VIIRS data from NASA EOSDIS/LANCE and GIBS/Worldview and the Joint Polar Satellite System (JPSS). Caption by Adam Voiland)

- In autumn, the leaves on deciduous trees change colors as they lose chlorophyll, the molecule that plants use to synthesize food. Chlorophyll makes plants appear green because it absorbs red and blue sunlight as it strikes leaf surfaces. It is not a stable compound and plants have to continuously synthesize it to keep their leaves green — a process that requires ample sunlight and warm temperatures. When temperatures drop and days shorten, levels of chlorophyll drop as well.

- As green chlorophyll fades, other leaf pigments—carotenoids and anthocyanins—show off their colors. Carotenoids absorb blue-green and blue light, appearing yellow; anthocyanins absorb blue, blue-green, and green light, appearing red.

- As explained by the U.S. Forest Service, certain species of trees produce certain colors. Oaks generally turn red, brown, or russet; aspen and yellow-poplar turn golden. Maples differ by species. Red maple turns brilliant scarlet; sugar maple, orange-red; and black maple, yellow. Leaves of some trees, such as elms, simply become brown.

• February 15, 2019: An enormous dust cloud snaked over Australia in mid-February 2019, carried toward the southeast by strong, dry winds. The dust reddened the skies over Sydney and turned air quality “hazardous” over parts of New South Wales. 62)

- The dust cloud is visible in this map, produced with data collected on 13 February 2019, with the Ozone Mapping Profiler Suite (OMPS) on the NOAA-20 satellite. The map of Figure 39 shows relative aerosol concentrations, with lower concentrations in yellow and higher concentrations in dark orange-brown.

Figure 39: The OMPS instrument on NOAA-20 (JPSS-1) acquired this image on 13 February 2019 (image credit: NASA Earth Observatory image by Joshua Stevens, using NOAA-20 OMPS data courtesy of Colin Seftor (SSAI). Story by Kathryn Hansen)
Figure 39: The OMPS instrument on NOAA-20 (JPSS-1) acquired this image on 13 February 2019 (image credit: NASA Earth Observatory image by Joshua Stevens, using NOAA-20 OMPS data courtesy of Colin Seftor (SSAI). Story by Kathryn Hansen)

- That same day, the Visible Infrared Imaging Radiometer Suite (VIIRS) on the Suomi NPP satellite acquired this natural-color image of the dust. According to news reports, the dust plume stretched 1,300 kilometers over land, and another 1,000 kilometers offshore.

Figure 40: The VIIRS instrument on the Suomi NPP satellite of NASA acquired this image on 13 February 2019 (NASA Earth Observatory, image by Joshua Stevens, using Suomi VIIRS data from NASA EOSDIS/LANCE and GIBS/Worldview, story by Kathryn Hansen)
Figure 40: The VIIRS instrument on the Suomi NPP satellite of NASA acquired this image on 13 February 2019 (NASA Earth Observatory, image by Joshua Stevens, using Suomi VIIRS data from NASA EOSDIS/LANCE and GIBS/Worldview, story by Kathryn Hansen)

- Air quality monitoring stations around Sydney reported elevated levels of PM10—particles smaller than 10 µm that can enter the lungs and cause health problems. According to the New South Wales Office of Environment & Heritage, air in parts of the North West Slopes region reached hazardous levels—the worst level on the air quality index.

- Notice the smoke from fires mixing in with the dust plume. The Tingha Plateau bush fire, for example, remained out of control and had burned 125 km2 (48 square miles) by the morning of February 13, according to the New South Wales Rural Fire Service.

• November 6, 2018: By the time the U.S. Forest Service declared the Mendocino Complex Fire 100 percent contained on Sept.18, it had scorched more than 459,000 acres, destroyed 157 homes and forced thousands to evacuate. One firefighter was killed and four others injured. It was the largest recorded wildfire in California’s history. 63)

- As the fires burned, air quality reached “unhealthy” levels in large regions of California and Western Nevada, and wind carried smoke from California all the way to the East Coast.

- Knowing how smoke from wildfires travels through the atmosphere is critical for visibility, but also human health. Particulate matter from wildfire smoke can penetrate deep into the lungs and cause a range of health problems, according to the Environmental Protection Agency, “from burning eyes and a runny nose to aggravated chronic heart and lung diseases.”

- Wildfires and the smoke they emit are notoriously difficult to forecast. This is because there are so many variables to account for: lightning, weather, and, of course, human activity.

- “In the past, it was a challenge for the atmospheric models to know where the fire was, how active it was, and how much emissions it was putting into the atmosphere,” said Andy Edman, chief of the science technology infusion division for the western region of the National Weather Service.

Figure 41: Vertically integrated smoke” is all of the smoke in a vertical column, including smoke high in the Earth’s atmosphere. On the left is a natural-color image of the Western United States during the Mendocino Complex Fire on August 6 at approximately 2:00 pm PDT, using data from the VIIRS instrument on the Suomi-NPP satellite. On the right, the HRRR-Smoke (High Resolution Rapid Refresh-Smoke) model shows vertically integrated smoke at the same time (image credit: Lauren Dauphin/ NASA Earth Observatory)
Figure 41: Vertically integrated smoke” is all of the smoke in a vertical column, including smoke high in the Earth’s atmosphere. On the left is a natural-color image of the Western United States during the Mendocino Complex Fire on August 6 at approximately 2:00 pm PDT, using data from the VIIRS instrument on the Suomi-NPP satellite. On the right, the HRRR-Smoke (High Resolution Rapid Refresh-Smoke) model shows vertically integrated smoke at the same time (image credit: Lauren Dauphin/ NASA Earth Observatory)

- But a new experimental model that relies on data from the Joint Polar Satellite System’s Suomi-NPP and NOAA-20 (JPSS-1)polar-orbiting satellites, as well as Terra and Aqua, has proved remarkably good at simulating the behavior of wildfire smoke.

Figure 42: A 36-hour HRRR-Smoke forecast from August 6 shows vertically integrated smoke moving east across the United States during the Mendocino Complex Fire (image credit: Lauren Dauphin/ NASA Earth Observatory)
Figure 42: A 36-hour HRRR-Smoke forecast from August 6 shows vertically integrated smoke moving east across the United States during the Mendocino Complex Fire (image credit: Lauren Dauphin/ NASA Earth Observatory)

How it works

- The High-Resolution Rapid Refresh Smoke model, or HRRR-Smoke, builds on NOAA’s existing HRRR weather model, which forecasts rain, wind and thunderstorms.

- Central to HRRR-Smoke is an important metric called FRP (Fire Radiative Power). FRP is a measurement of the amount of heat released by a given fire, in megawatts, detected with the VIIRS instruments on Suomi-NPP and NOAA-20. A large fire, for example, might reach about 4,000 megawatts per pixel. Calculating a fire’s heat or intensity also helps scientists pinpoint its location.

- The model combines this FRP data with windspeed, rain and atmospheric temperature, along with information from vegetation maps. Sagebrush burns differently than a ponderosa pine, and the more the scientists know about what’s burning, the better the simulations.

- “Grass burns fast. And a dense forest has so much biomass to burn, so it’s going to produce much more smoke than a grassland,” said Eric James, a research associate with NOAA’s Earth Systems Research Laboratory and the Cooperative Institute for Research in Environmental Sciences at CU Boulder.

- These measurements are mapped to a three-dimensional grid that extends nearly 16 miles into the atmosphere. What results is a detailed forecast of the amount of smoke produced, the direction it’s traveling and its plume height. HRRR-Smoke spits out these forecasts four times a day, extending out to 36 hours.

- The forecasts are visualized as two plots: “Near-surface smoke” refers to the smoke about 8 m from the ground, the kind responsible for burning eyes and worsening asthma. “Vertically integrated smoke” is all of the smoke in a vertical column, including smoke high in the Earth’s atmosphere. That’s the smoke you see at sunrise and sunset.

“Near-surface smoke is one indicator of air pollution, but the smoke could also be at much higher altitudes,” said Ravan Ahmadov, the main developer of the HRRR smoke model, and a research scientist at NOAA’s Earth Systems Research Laboratory and the Cooperative Institute for Research in Environmental Sciences at CU Boulder. “That’s important to know, because the smoke could affect visibility for aviation.”

- Higher altitude smoke can also block incoming sunlight, which in turn can cool air temperatures and interfere with solar energy production. “The key advantages of HRRR-Smoke are the high spatial resolution and the tight coupling with a weather forecast model,” Ahmadov said.

- HRRR-Smoke is being used increasingly on the ground by forecasters and government agencies, but also by schools and sports teams. During California’s Ferguson fire, which burned from mid-July to mid-August, HRRR-Smoke simulations were consulted when the Department of Transportation made a decision to suspend Amtrak service and when the National Park Service closed parts of Yosemite National Park for three weeks. As fires burned south of Provo, Utah, schools opted to keep kids inside during recess and to cancel Friday night football games. In Oregon, a children’s swim coach moved outdoor swim practice to an indoor pool.

- If you have a child with asthma, you’ll know to take precautions,” Edman said. “When we can tell people that the smoke is going to move in and hang around for a day, they can take smart actions to anticipate the event.”

The Origin Story

- The origins of HRRR-Smoke date back four years. Advances were happening simultaneously in several fields, and everything converged in the back row of a meeting in Madison, Wisconsin.

- Scientists had recently developed the HRRR weather model, with its high-resolution representation of atmospheric convection. Convection describes the movement of energy from the Earth’s surface up into the atmosphere; convection that is sufficiently deep produces thunderstorms. Meanwhile, on the satellite front, scientists had zeroed in on fire radiative power from VIIRS. And atmospheric chemists were working to turn a fire’s intensity into an estimate of smoke emissions.

- “All these major advancements were happening at same time,” Edman said. “When you read the history of science, I think this is not uncommon. People say, you got this, I got that, why don’t we get together and make something happen?”

- The scientists acquired funding from the JPSS Satellite Proving Ground program, and they began holding meetings, running tests and working with forecasters.

- Fast forward to present day, and a small team, led by Ahmadov, runs the model around the clock from a NOAA research lab in Boulder, Colorado.

- The smoke forecast is a great example of the JPSS program’s “Proving Ground” initiatives, which seek to translate satellite observations into public services that ultimately affect decision making, said Mitch Goldberg, the chief program scientist for JPSS.

- “Satellites are expensive, but the societal and economic benefits are huge. So we engage with the community to help them realize the benefits of our data,” Goldberg said. “Let’s say someone’s decision is simply, ‘Do I leave my house and seek shelter?’ Or you have families wanting to know if the air quality is good or bad and if they can go outside. We try to work with services, such as smoke forecasts, which would communicate that.”

Next Steps

- The HRRR-Smoke model is still evolving. One limitation, Ahmadov said, is that each polar orbiting satellite passes over a single location in the continental United States twice a day, and fires can spread and evolve rapidly during the gaps in time.

- Ahmadov’s ultimate goal is to add smoke to the regular HRRR model and transition it to operations at the National Weather Service. And he hopes to eventually incorporate data from geostationary satellites like GOES-16 and GOES-17. These satellites have a lower spatial resolution but would scan the fires more often.

- In the next couple years, I think we’re going to see a lot of small, incremental improvements,” Edman said. “The model’s not perfect, but all the components came together this year, and the forecasts were pretty darn good.”

• July 2018: Since launch in November 2017, the VIIRS (Visible Infrared Imaging Radiometer Suite) on-board the NOAA-20 /JPSS-1 satellite has completed its initial intensive on-orbit check-outs and several key calibration and validation activities scheduled to help evaluate sensor at launch performance. 64)

- Like its predecessor aboard the Suomi NPP spacecraft launched in October 2011, the VIIRS collects data in 22 spectral bands. In addition to a day and night band (DNB), spectral bands (M1-M11 and I1-I3) with wavelengths from 0.41 to 2.2 µm are referred to as the reflective solar bands (RSB) and other bands (M12-16 and I4-I5) covering wavelengths from 3.7 to 12 µm are referred to as the thermal emissive bands (TEB). M1-M5, M7, and M13 can make observations at either high- or low-gain and the DNB is capable of collecting data at three different gain stages.

- As shown in Figure 43, the VIIRS on-orbit calibration is performed by the OBCs that include a solar diffuser (SD) and a solar diffuser stability monitor (SDSM) for the RSB and a blackbody (BB) for the TEB. Lunar observations are also made regularly as a supplement to instrument on-board calibration. The SD calibration is normally performed every orbit. The SDSM is currently operated on a daily basis. The BB warm-up/cool-down (WUCD), initially planned on a quarterly basis, will be executed less frequently in future operation. Like Suomi NPP, lunar observations will be scheduled 8-9 times per year at nearly identical phase angles (-51º). The first lunar calibration for N-20 VIIRS was performed on December 29, 2017 via a spacecraft roll maneuver.

Figure 43: VIIRS instrument and its on-board calibrators (OBCs), image credit: NASA, NOAA
Figure 43: VIIRS instrument and its on-board calibrators (OBCs), image credit: NASA, NOAA

- Since launch, a number of calibration improvements have been made. Using data collected during spacecraft yaw maneuvers, the SD and SDSM screen transmission functions are derived, updated and used for on-orbit calibration. Compared to pre-launch measurements, on-orbit yaw maneuver data provide fine details, both geometrically (more angles) and spectrally (more wavelengths). The TEB RVS characterized using pitch maneuver data shows good agreement with pre-launch results. DNB straylight correction strategy is based on lessons from Suomi NPP and needs extra effort to address effects in the extended zone (not in Suomi NPP). Similar to Suomi NPP, the lunar long-term trend will be used to support RSB solar calibration. From the perspective of long-term data records, the calibration consistency between Suomi NPP and N-20 VIIRS will likely be a major challenge and requires more studies.

• May 30, 2018: The NOAA-20 (JPSS-1) satellite is now operational. Advanced data will detect environmental hazards, improve weather forecasts. Weather forecasters officially have a new tool in their arsenal, as the first satellite in NOAA’s new Joint Polar Satellite System has passed rigorous testing and is now operational. 65)

- Launched in November 2017 as JPSS-1 and renamed NOAA-20 once it reached orbit, the satellite features the latest and best technology NOAA has ever flown in a polar orbit to capture more precise observations of the world’s atmosphere, land and waters. Data from the satellite’s advanced instruments will help improve the accuracy of 3-to-7 day forecasts.

- “Improved weather forecasts can save lives, protect property and provide businesses and communities valuable additional time to prepare in advance of dangerous weather events,” said Secretary of Commerce Wilbur Ross.

- NOAA-20 provides NOAA’s National Weather Service with global data for numerical weather prediction models used to develop timely and accurate U.S. weather forecasts. In addition, high-resolution imagery from the satellite’s VIIRS (Visible Infrared Imaging Radiometer Suite) will enable the satellite to detect fog, sea-ice formation and breaking in the Arctic, volcanic eruptions and wildfires in their very early stages. This advanced modeling and imagery information, shared with international and governmental partners, will help businesses, the emergency preparedness and response communities and individuals make the best decisions possible in the face of weather-related hazards.

- NOAA-20 joins Suomi NPP – the NOAA-NASA demonstration satellite launched in 2011 – giving the U.S. the benefit of two sophisticated spacecraft in nearly the same orbit. Each circles the Earth in a polar orbit 14 times a day, collecting global observations that form the basis for U.S. weather prediction.

- “NOAA-20 is especially beneficial for tracking developing storms in the Arctic, Alaska and Antarctica. Forecasts for these remote regions are critical for the U.S. fishing, energy, transportation and recreation industries, which operate in some of the harshest conditions on the planet,” said Neil Jacobs, Ph.D., assistant secretary of commerce for environmental observation and prediction.

- JPSS-2, the second in the series, is scheduled to be launched in 2021, followed by JPSS-3 in 2026 and JPSS-4 in 2031. JPSS satellites are designed to operate for seven years, with the potential for several more years. The JPSS mission will deliver its critical data and information for at least the next two decades to support a Weather-Ready Nation.

• April 20, 2018: NOAA's newest polar-orbiting satellite, NOAA-20 (JPSS-1), captured this magnificent view of the Earth's North Pole on April 12, 2018 (Figure 44). By passing over the pole 14 times a day, the satellite's VIIRS instrument was able to create this composite image of the planet, centered over the frozen Arctic, from 824 km above Earth. The outline of the North American continent is visible at the bottom of the Earth's disk, while the Sahara Desert and northern Africa appear on the right hand side. 66)

- Scientists use the data from NOAA-20's VIIRS sensor to create the "true-color" imagery shown here. While true-color images appear to be simple photographs of Earth, they are actually created by combining data from the three color channels on the satellite's VIIRS instrument sensitive to the red, green and blue (or RGB) wavelengths of light into a single composite image.

- As the backbone of the global satellite observing system, NOAA-20 circles the Earth from pole to pole and crosses the equator about 14 times daily, providing full global coverage twice a day. The satellite's instruments measure temperature, water vapor, ozone, precipitation, fire and volcanic eruptions, and can distinguish snow and ice cover under clouds. This data enables more accurate weather forecasting for the United States and the world.

Figure 44: NOAA-20 Shares New View of the North Pole for Earth Day (image credit: NOAA/NESDIS)
Figure 44: NOAA-20 Shares New View of the North Pole for Earth Day (image credit: NOAA/NESDIS)

• April 12, 2018: Ball Aerospace completed the handover of NOAA's advanced next-generation polar-orbiting weather satellite, the Joint Polar Satellite System (JPSS-1), to NASA following a successful satellite acceptance review. Launched on Nov. 18, 2017, JPSS-1, now known as NOAA-20, is the most advanced operational environmental system ever developed by government and industry, and significantly increases the timeliness and accuracy of forecasts three to seven days in advance of severe weather events. 67)

- The acceptance review confirmed the satellite met its on-orbit requirements, and the spacecraft and the five instruments are performing as expected. NOAA-20 is proceeding on schedule for operations handover from NASA to NOAA. NOAA will determine when the satellite data will be used in NOAA products and services.

- "Everyone on our planet is affected by weather – especially adverse weather – in some way, and relies on systems like JPSS that are part of our nation's critical infrastructure, just like roads and bridges," said Rob Strain, president, Ball Aerospace. "The NOAA-20 satellite, with its sophisticated instruments, is ready to deliver better, more accurate data for operational weather forecasting, which will help save lives and resources, protect property and support our economy, now and well into the future."

- NOAA-20 is now circling in the same orbital plane as the Ball-built Suomi National Polar-Orbiting Partnership (Suomi NPP) satellite, allowing important overlap in observational coverage to occur for critical instrument calibration and validation activities, which in turn lead to more accurate weather forecasting. NOAA-20 crosses the equator about 14 times daily - providing full global coverage twice a day, making precise measurements of the atmosphere, ocean and land surface, measurements that are critical for the nation's weather models and forecasters.

- Ball Aerospace designed and manufactured the NOAA-20 spacecraft and the Ozone Mapping and Profiler Suite-Nadir (OMPS-N) instrument; integrated all five of the satellite's instruments, including those built by industry partners Harris, Raytheon and Northrop Grumman; and performed satellite-level testing and launch support.

- The JPSS missions are funded by NOAA to provide global environmental data in low-Earth polar orbit. NASA is the acquisition agent for the flight systems, launch services and components of the ground segment. Ball is also under contract to build the OMPS instruments for NOAA's follow-on JPSS-2, JPSS-3 and JPSS-4 missions.

• March 23, 2018: It is the first category 5 cyclone of 2018 and the strongest to hit Darwin, Australia, since 1974. But so far, Cyclone Marcus has directed most of its fury into the Indian Ocean, rather than onto landmasses. 68)

- At 2 p.m. local time (06:00 UT) on March 21, 2018, VIIRS (Visible Infrared Imaging Radiometer Suite) on JPSS-1 (Joint Polar Satellite System–1) satellite acquired a natural-color image (Figure 45) of Cyclone Marcus off the northwest coast of Australia. At the time, the storm had sustained winds of 125 knots (145 miles/230 km/hour) according to estimates from the U.S. Joint Typhoon Warning Center. It was a category 5 storm on the Australian cyclone scale.

- The next day, the VIIRS instrument on Suomi NPP captured another view of the storm. Satellite estimates of wind speed suggested very little change, with the storm still at category 5 strength.

- Marcus first developed as a tropical storm on March 15, 2018, and reached category 2 cyclone strength on the Australian scale on March 17 (a strong tropical storm compared to Atlantic hurricanes). The cyclone blew through Darwin with wind gusts as high as 130 km/hour. The storm knocked out electricity for more than 20,000 people, and thousands of trees were destroyed, including many that were planted in the wake of Cyclone Tracy of 1974.

Figure 45: Natural color image of Cyclone Marcus off the northwest coast of Australia, acquired with VIIRS on JPSS-1 on 21 March 2018 (image credit: NASA image by Jeff Schmaltz, LANCE/EOSDIS Rapid Response. Story by Mike Carlowicz)
Figure 45: Natural color image of Cyclone Marcus off the northwest coast of Australia, acquired with VIIRS on JPSS-1 on 21 March 2018 (image credit: NASA image by Jeff Schmaltz, LANCE/EOSDIS Rapid Response. Story by Mike Carlowicz)

- Cyclone Marcus skirted Northern Territory and Western Australia as it moved westward over very warm water and reached category 4 strength by March 21. The map of Figure 46 shows the SSTs (Sea Surface Temperatures) in the equatorial Indian Ocean on March 21, 2018. The data were compiled by Coral Reef Watch, which blends observations from the Suomi NPP, MTSAT, Meteosat, and GOES satellites, and computer models. The dotted white line across the Indian Ocean shows the cutoff between waters above and below 27.8ºC, a threshold scientists believe to be necessary to fuel a cyclone. The yellow-to-red line represents the storm’s track.

- As of March 22, forecasters were calling for Marcus to remain at severe strength for another day, then weaken rapidly as it turns south toward cooler water. The remnants of the storm could make landfall around Perth as a tropical depression.

Figure 46: Coral Reef Watch SSTs blending observations from the Suomi NPP, MTSAT, Meteosat, and GOES satellites, and computer models. The dotted white line across the Indian Ocean shows the cutoff between waters above and below 27.8ºC, a threshold scientists believe to be necessary to fuel a cyclone. The yellow-to-red line represents the storm’s track (image credit: NASA Earth Observatory, image by Joshua Stevens, using SST data from Coral Reef Watch, and storm track information from Unisys, story by Mike Carlowicz)
Figure 46: Coral Reef Watch SSTs blending observations from the Suomi NPP, MTSAT, Meteosat, and GOES satellites, and computer models. The dotted white line across the Indian Ocean shows the cutoff between waters above and below 27.8ºC, a threshold scientists believe to be necessary to fuel a cyclone. The yellow-to-red line represents the storm’s track (image credit: NASA Earth Observatory, image by Joshua Stevens, using SST data from Coral Reef Watch, and storm track information from Unisys, story by Mike Carlowicz)

• January 16, 2018: The covers on the CERES FM6 (Clouds and the Earth's Radiant Energy System Flight Model 6) opened Jan. 5, allowing it to scan Earth for the first time. 69)

- CERES FM6 began scanning Earth at approximately 1:25 p.m. (EST) Jan. 5. On Jan. 10, scientists used those scans to produce the "first light" images.

- Built by Northrop Grumman, funded by NOAA and managed by NASA/LaRC (Langley Research Center) in Hampton, Virginia, in coordination with the JPSS program, CERES FM6 is the last in a series of instruments going back to the late 1990s that measure the solar energy reflected by Earth, the heat the planet emits, and the role of clouds in that process.

- “CERES FM6 is the seventh and final copy since we first launched the first CERES instrument in 1997. It is the most accurate broadband radiometer that NASA/NOAA have flown as a result of a more rigorous prelaunch calibration campaign than previous instruments," said CERES Project Scientist Kory Priestley. "We were able to take knowledge from on-orbit operations and apply it to this flight model. We’ve done a better job of building and characterizing the instrument, and with hope that will bear fruit as the mission is flown.”

- “The robustness of the CERES instruments already on-orbit, having exceeded their design lifetimes by a factor of two to three, is testament to the work of the dedicated team of engineers at Northrop Grumman,” Priestley said. “The scientific discoveries the community will make by utilizing these datasets will benefit humanity for decades to come.”

Figure 47: In this shortwave image from CERES FM6, the white and green shades represent thick cloud cover reflecting incoming solar energy back to space. Compare that with the darker blue regions, which have no cloud cover, to get a sense for just how much clouds can affect the balance of incoming and outgoing energy on Earth (image credit: NASA)
Figure 47: In this shortwave image from CERES FM6, the white and green shades represent thick cloud cover reflecting incoming solar energy back to space. Compare that with the darker blue regions, which have no cloud cover, to get a sense for just how much clouds can affect the balance of incoming and outgoing energy on Earth (image credit: NASA)
Figure 48: In this longwave image from CERES FM6, heat energy radiated from Earth is represented by shades of yellow, red, blue and white. Bright yellow regions are the hottest and emit the most energy out to space. Dark blue and bright white regions, which represent clouds, are much colder and emit the least energy (image credit: NASA)
Figure 48: In this longwave image from CERES FM6, heat energy radiated from Earth is represented by shades of yellow, red, blue and white. Bright yellow regions are the hottest and emit the most energy out to space. Dark blue and bright white regions, which represent clouds, are much colder and emit the least energy (image credit: NASA)

- Five other CERES instruments are flying on three other satellites. Their data helps scientists validate models that calculate the effect of clouds on planetary heating and cooling. The same data can also be helpful for improving near-term, seasonal forecasts influenced by weather events such as El Niño and La Niña. El Niño and La Niña are climatic fluctuations in the temperature of the tropical Pacific Ocean that can influence weather globally.

- "The successful launch of CERES FM6 and acquisition of initial data is fantastic news," said David Considine, program manager for NASA's Modeling, Analysis and Prediction program. "Its data will help us to understand the critical role that clouds play in the Earth system, and shows the value to the Nation of the NASA and NOAA collaboration leading to this achievement."

- The CERES data record extends back to 1997. Prior to CERES, the ERBE (Earth Radiation Budget Experiment) collected similar data beginning in 1984. The two NASA programs demonstrate NASA’s long-term involvement in measuring Earth's energy balance going back more than 30 years.

- “Northrop Grumman is proud to be a collaborative partner with NASA and NOAA on this successful CERES mission. Between the seven CERES instruments and their ERBE predecessors, we have had a relationship in Earth radiation budget measurements that now spans over three decades," said Northrop Grumman CERES Program Manager Sean Kelly. "The CERES instruments continue to reliably provide the climate data record necessary for monitoring, processing and analyzing critical data for the Earth science community. CERES is one of the most highly calibrated, highly reliable instruments on-orbit today."

• December 13, 2017: Twenty-five days after JPSS-1 (NOAA-20) was launched into Earth orbit, NOAA-20 sent back its first VIIRS (Visible Infrared Imaging Radiometer Suite) science data on December 13, 2017, as part of a series of instrument activation and checkouts that is taking place before the satellite goes into fully operational mode. VIIRS is one of the key five instruments onboard NOAA-20 that will improve day-to-day weather forecast and environmental monitoring, while extending the record of many long-term observations of Earth's climate. 70)

- This VIIRS true color image captured the aggressive wildfires across the Southern California region which forced thousands to flee their homes. As of Wednesday morning, December 13, 2017, the Thomas Fire was the fourth-largest fire in California history, and it continues to generate smoke and plumes as it enters its second week. The fire spanned more than 370 square miles (>95,800 hectares) and remains the strongest blaze for firefighters to battle in Ventura and Santa Barbara counties.

Figure 49: The NOAA-20 VIIRS first light image captures one of the largest wildfires in California history (image credit: NOAA Visualization Lab and NESDIS/STAR)
Figure 49: The NOAA-20 VIIRS first light image captures one of the largest wildfires in California history (image credit: NOAA Visualization Lab and NESDIS/STAR)

• November 30, 2017: Eleven days after JPSS-1 launched into Earth orbit, the satellite, now known as NOAA-20, has sent back its first ATMS (Advanced Technology Microwave Sounder) science data as part of a series of instrument startups and checkouts that will take place before the satellite goes into full operational mode. The NOAA-20 satellite carries five instruments that will improve day-to-day weather forecasting while extending the record of many long-term observations of Earth's climate. 71)

- ATMS receives 22 channels of radio waves from 23 to 183 gigahertz. Five water vapor channels, combined with other temperature sounding channels are used to provide the critical global atmospheric temperature and water vapor needed to provide accurate weather forecasts out to seven days. ATMS also maps global precipitation, snow and ice cover.

Figure 50: This image uses ATMS data to depict the location and abundance of water vapor (as associated with antenna temperatures) in the lower atmosphere, from the surface of the Earth to 5 kilometers altitude. Transparent/grey colors depict areas with less water vapor, while blue-green and purple colors represent abundant water in all phases (vapor, clouds, and precipitation) in low and middle latitudes. In the polar regions, purple depicts surface snow and ice. Water vapor distribution in space and time is a critical measurement for improving global weather forecasts. With detailed vertical information, forecasters can better identify the transport of water vapor associated with jet streams, which can fuel severe weather events (image credit: NOAA, NASA)
Figure 50: This image uses ATMS data to depict the location and abundance of water vapor (as associated with antenna temperatures) in the lower atmosphere, from the surface of the Earth to 5 kilometers altitude. Transparent/grey colors depict areas with less water vapor, while blue-green and purple colors represent abundant water in all phases (vapor, clouds, and precipitation) in low and middle latitudes. In the polar regions, purple depicts surface snow and ice. Water vapor distribution in space and time is a critical measurement for improving global weather forecasts. With detailed vertical information, forecasters can better identify the transport of water vapor associated with jet streams, which can fuel severe weather events (image credit: NOAA, NASA)

• November 21, 2017: JPSS-1 not only reached polar orbit on Saturday, November 18; it also officially became known as NOAA-20. 72)

• November 18, 2017: All CubeSats have been deployed! P-POD 1 released EagleSat-1, RadFXSat and MakerSat-0; Buccaneer deployed from P-POD 2; and MiRaTA deployed from P-POD 3. The CubeSats all are flying solo to begin their missions. 73)

- Orbit: All CubeSats were deployed into an elliptical sun-synchronous orbit with a perigee of 450 km and an apogee at 810 km, inclination = 97.2º.

• Approximately 63 minutes after launch the solar arrays on JPSS-1 deployed and the spacecraft was operating on its own power. JPSS-1 will be renamed NOAA-20 when it reaches its final orbit. Following a three-month checkout and validation of its five advanced instruments, the satellite will become operational. 74)

- JPSS-1 will join the joint NOAA/NASA Suomi National Polar-orbiting Partnership satellite in the same orbit and provide meteorologists with observations of atmospheric temperature and moisture, clouds, sea-surface temperature, ocean color, sea ice cover, volcanic ash, and fire detection. The data will improve weather forecasting, such as predicting a hurricane’s track, and will help agencies involved with post-storm recovery by visualizing storm damage and the geographic extent of power outages.

 

 


 

Sensor Complement

Contracts with instrument developers: NASA signed the final contract on June 19, 2012 with Raytheon Space and Airborne Systems of El Segundo, CA, for the VIIRS (Visible Infrared Imager Radiometer Suite) instrument. The ATMS (Advanced Technology Microwave Sounder) contract was signed with Northrop Grumman Electronic Systems of Azusa, CA, in April, 2012. NASA completed the JPSS-1 spacecraft and the OMPS (Ozone Mapping and Profiler Suite) instrument contract with Ball Aerospace in 2011. The contract to Raytheon Intelligence and Information Systems for the JPSS Ground System was also completed in 2011, as was the CrIS (Cross-track Infrared Sounder) instrument contract with ITT Exelis (Ref. 14). 75) 76)

Figure 51: JPSS-1 flight configuration and allocation of the instrument suite, identical to the one of NPP (image credit: NASA, NOAA) 77)
Figure 51: JPSS-1 flight configuration and allocation of the instrument suite, identical to the one of NPP (image credit: NASA, NOAA) 77)

Note: Due to JPSS-1 (NPP Clone) bus limitations, the JPSS FF-1 (JPSS Free Flyer-1) mission was developed, a complementary mission to the JPSS-1 satellite. It will fly the instruments, which were originally planned for the former NPOESS satellites, but could not be accommodated on the JPSS satellites.

JPSS Free Flyer-1 will accommodate the following instruments:

• TSIS (Total Solar Irradiance Sensor)

• A-DCS (Advanced Data Collection System)

• SARSAT (Search and Rescue) instruments.

Figure 52: The JPSS instruments (image credit: NOAA)
Figure 52: The JPSS instruments (image credit: NOAA)

 

ATMS (Advanced Technology Microwave Sounder)

ATMS, of Suomi-NPP heritage, provides sounding observations necessary to retrieve atmospheric temperature and moisture profiles for civilian operational weather forecasting, as well as continuity of these measurements for climate monitoring. In addition to temperature and moisture profiles, some of ATMS-derived products include integrated water vapor content, cloud liquid water content, precipitation rate, snow cover and sea ice concentration.

ATMS is the next generation cross-track microwave sounder that will combine the capabilities of current generation microwave temperature sounders AMSU-A, AMSU-B and AMSU-B/MHS, into a single instrument. The ATMS draws its heritage directly from AMSU-A/B, but with reduced volume, mass and power. The ATMS has 22 microwave channels to provide temperature and moisture sounding capabilities. Sounding data from CrIS and ATMS will be combined to construct atmospheric temperature profiles at 1 degree Kelvin accuracy for 1 km layers in the troposphere and moisture profiles accurate to 15% for 2 km layers. Higher (spatial, temporal and spectral) resolution and more accurate sounding data from CrIS and ATMS will support continuing advances in data assimilation systems and NWP models to improve short- to medium-range weather forecasts beyond three days. - The ATMS instrument was developed at Northrop Grumman Electronic Systems of Azusa, CA. 78)

Figure 53: Photo of the ATMS instrument (image credit: MIT/LL, NASA)
Figure 53: Photo of the ATMS instrument (image credit: MIT/LL, NASA)

ATMS instrument dimensions

70 cm x 60 cm x 40 cm

Instrument mass

75 kg

Operational average power (peak)

100 W (200 W)

Data rate

30 kbit/s

Absolute calibration accuracy

0.6 K

Maximum nonlinearity

0.35 K

Frequency stability

0.5 MHz

Pointing knowledge

0.03º

NEΔT

0.3/0.5/1.0/2.0 K

Swath width

~2600 km

Table 2: Summary of key instrument parameters 79)
Figure 54: Functional block diagram of ATMS (image credit: NASA)
Figure 54: Functional block diagram of ATMS (image credit: NASA)

Cannel

Center
frequency (GHz)

Max. bandwidth (GHz)

Center frequency stability (MHz)

Temp. sensitivity NEΔT (K)

Calibration accuracy (K)

Static beamwidth (º)

Quasi polarization

Characterization at nadir
(reference only)

1

23.8

0.27

10

0.9

2.0

5.2

QV

Window-water
Vapor 100 mm

2

31.4

0.18

10

0.9

2.0

5.2

QV

Window-water
Vapor 500 mm

3

50.3

0.18

10

1.20

1.5

2.2

QH

Window-surface
Emissivity

4

51.76

0.40

5

0.75

1.5

2.2

QH

Window-surface
Emissivity

5

52.8

0.40

5

0.75

1.5

2.2

QH

Surface air

6

53.596 ±0.115

0.17

5

0.75

1.5

2.2

QH

4 km ~700 mb

7

54.40

0.40

5

0.75

1.5

2.2

QH

9 km ~ 400 mb

8

54.94

0.40

10

0.75

1.5

2.2

QH

11 km ~ 250 mb

9

55.50

0.33

10

0.75

1.5

2.2

QH

13 km ~ 180 mb

10

57.290344

0.33

0.5

0.75

1.5

2.2

QH

17 km ~ 90 mb

11

57.290344 ±0.217

0.078

0.5

1.20

1.5

2.2

QH

19 km ~ 50 mb

12

57.290344 ±0.3222 ±0.048

0.036

1.2

1.20

1.5

2.2

QH

25 km ~ 25 mb

13

57.290344 ±0.3222
±0.022

0.016

1.6

1.50

1.5

2.2

QH

29 km ~ 10 mb

14

57.290344 ±0.3222
±0.010

0.008

0.5

2.40

1.5

2.2

QH

32 km ~ 6 mb

15

57.290344 ±0.3222
±0.0045

0.003

0.5

3.60

1.5

2.2

QH

37 km ~ 3 mb

16

87-91

2.0

200

0.5

2.0

2.2

QV

Window
H2O 150 mm

17

166.31

2.0

200

0.6

2.0

1.1

QH

H2O 18 mm

18

183.31±7.0

2.0

100

0.8

2.0

1.1

QH

H2O 8 mm

19

183.31±4.5

2.0

100

0.8

2.0

1.1

QH

H2O 4.5 mm

20

183.31±3.0

1.0

50

0.8

2.0

1.1

QH

H2O 2.5 mm

21

183.31±1.8

1.0

50

0.8

2.0

1.1

QH

H2O 1.2 mm

22

183.31±1.0

0.5

30

0.9

2.0

1.1

QH

H2O 0.5 mm

Table 3: Channel characteristics of ATMS

Instrument calibration: The instrument includes on-board calibration sources viewed by the reflectors during each scan cycle. The calibration of the ATMS is a so-called through-the-aperture type, two-point calibration subsystem. The warm reference point is a microwave blackbody target whose temperature is monitored. In addition, cold space is viewed during each scan cycle. Both calibrations provide for the highly accurate microwave sounding measurements required by the operational and science applications of ATMS data.

There are three antenna beamwidths. The temperature sounding channels are 2.2º (Nyquist-sampling in both along-scan & down-track directions) while the humidity channels are 1.1º. Channels 1 and 2 have a larger beam width of 5.2º. This is due to the limited volume available on the spacecraft for ATMS.

The ATMS post-launch calibration/validation:

• Tasks within the phases can be categorized:

- Sensor evaluation: interference, performance evaluation, etc.

- TDR/SDR verification: geolocation, accuracy, etc.

- SDR algorithm tunable parameters: bias correction, space view sector, etc.

• Activation phase: Sensor is turned on and a sensor functional evaluation is performed; ATMS is collecting science data

• Checkout phase: Performance evaluation and RFI evaluations

• Intensive Cal/Val: Verification of SDR attributes such as geolocation, resampling, brightness temperature accuracy (simultaneous nadir overpass, double difference, radiosondes/NWP simulations, aircraft verification campaigns), and satellite maneuvers.

Figure 55: Atmospheric transmission at microwave wavelengths (image credit: MIT/LL)
Figure 55: Atmospheric transmission at microwave wavelengths (image credit: MIT/LL)

ATMS provides 3 EDRs (Environmental Data Records) with CrIS:

• Atmospheric vertical moisture profile

• Atmospheric vertical temperature profile

• Pressure (surface/profile).

• Both ATMS and CrIS are critical for forecasting – at all scales – particularly for the 3-7 day weather forecast.

• ATMS provides rain and snow rates, ice and snow cover information, and snow water equivalent.

• CrIS provides soundings for real-time instability assessments, and trace gases for monitoring greenhouse gases and their transport.

• Both sensors have low noise and excellent long-term stability that will enable more accurate climate change monitoring.

• The sounding products (NUCAPS and MIRS) are available through the NOAA operational product generation system for global data and the CSPP Direct Readout Software.

Table 4: Summary of ATMS and CrIS applications 80)

NUCAPS (NOAA Unique CrIS/ATMS Processing System) was developed to generate (1) spectrally and spatially thinned radiances, (2) retrieved products such as profiles of temperature, moisture, trace gases and cloud-cleared radiances, and (3) global validation products such as radiosonde matchups and gridded radiances and profiles.

These products are derived from the CrIS (Cross-track Infrared Sounder) and ATMS (Advanced Technology Microwave Sounder) currently onboard the Suomi National Polar-orbiting Partnership (S-NPP) satellite and later will be available from the Joint Polar Satellite System (JPSS-1 and JPSS-2). 81)

 

CrIS (Cross-track Infrared Sounder)

CrIS is the first in a series of advanced operational sounders that will provide more accurate, detailed atmospheric temperature and moisture observations for weather and climate applications. This high-spectral resolution infrared instrument will take 3-D images of atmospheric temperatures, water vapor and trace gases. It will provide over 1,000 infrared spectral channels at an improved horizontal spatial resolution and measure temperature profiles with keen vertical resolution to an accuracy approaching 1 K (the absolute temperature scale). This information will help significantly to improve climate prediction, including both short-term weather "nowcasting" and longer-term forecasting. It will also provide a vital tool for NOAA to take the pulse of the planet continuously and assist in understanding major climate shifts. The CrIS instrument is developed by ITT Exelis, Fort Wayne, Indiana.

Figure 56: Photo of the CrIS instrument (image credit: NOAA) 82)
Figure 56: Photo of the CrIS instrument (image credit: NOAA) 82)

CrIS, of HIRS/4 (POES) and AIRS (Aqua) heritage, is a high-spectral and high-spatial resolution infrared sounder for atmospheric profiling applications. The overall objective is to perform daily measurements of Earth's upwelling infrared radiation to determine the vertical atmospheric distribution (surface to the top of the atmosphere) of temperature (profiles to better than 1 K accuracy in the lower troposphere and lesser accuracy at higher altitudes), moisture (profiles to better than 20-35% accuracy depending on altitude) and pressure (profiles to better than 1.0% accuracy ) with an associated 1.0 km vertical layer resolution. The Michelson interferometer sounder has 1305 spectral channels, it covers a spectral range of 650-2550 cm-1 (or 3.9 to 15.4 µm), with a spectral resolution of 0.6525 cm-1 (LWIR), and a ground spatial resolution (IFOV) of 14.0 km (from an orbital altitude of 833 km). Each scan (with an 8-second repeat interval) includes views of the internal calibration target (warm calibration point), and a deep space view (cold calibration point). The overall instrument data rate is <1.5Mbit/s. Only photovoltaic detectors are used in the CrIS instrument. The detectors are cooled to approximately 81K using a 4-stage passive cooler with no moving parts. They have a low-risk heritage design of over 50 space units. The IFOVs are arranged in a 3 x 3 array. The swath width is 2200 km (FOV of ±50º), with 30 Earth-scene views.

The CrIS optical system was designed to provide an optimum combination of optical performance and compact packaging. Its key subsystems include a step and settle two-axis scene selection module with image motion compensation capability, a full-aperture internal calibration source, a large-aperture Michelson interferometer, a three-element all reflective telescope, a cooled aft optics module, a multiple-stage passive cooler, and an attached electronics assembly. The interferometer uses a flat-mirror Michelson configuration equipped with a dynamic alignment system to minimize misalignments within the interferometer and has a maximum optical path difference of ±0.8 cm. 83)

The “unapodized spectral resolution” requirement is defined as I/(2L), where L is the maximum optical path difference from ZOND (Zero Path Difference) to MPD (Maximum optical Path Difference). The on-axis unapodized spectral resolution for each spectral band shall be ≤to the values given in Table 5. Since L determines the unapodized spectral resolution, the nominal value for L is also given in the table. 84)

Requirement/Spectral band

LWIR (TIR)

MWIR

SWIR

Channel center wavenumber range

650-1095 cm-1
15.38-9.14 µm

1210-1750 cm-1
8.26-5.71 µm

2155-2550 cm-1
4.64-3.92 µm

No of channels

713

433

159

Unapodized spectral resolution, nominal L

≤ 0.625, 0.8 cm

≤ 1.25, 0.4 cm

≤ 2.5, 0.2 cm

Absolute spectral uncertainty

< 10 (5) PPM

< 10 (5) PPM

< 10 (5) PPM

Characterize self-apodized ILS for each spectral bin

Yes

Yes

Yes

ILS (Instrument Line Shape) shape uncertainty

< 1.5% FWHM

< 1.5% FWHM

< 1.5% FWHM

ILS shape stability over 30 days

< 1% FWHM

< 1% FWHM

< 1% FWHM

Table 5: Spectral requirements of the CrIS instrument

Instrument: The CrIS instrument consists of 6 modular assemblies: optical bench, scanning telescope, interferometer, PV focal plane arrays, 4-stage passive cooler, and electronics. The optical bench provides a stable structure for mounting all of the other assemblies. The scanning telescope scans the Earth views, the ICT (Internal Calibration Target), and deep space, and focuses the IR energy into the interferometer. The interferometer sequentially "breaks" the IR energy into the spectral bands, much like the "rainbow" from a DVD surface. The PV detectors sense the sequenced IR energy (from the interferometer), and provide an electrical signal corresponding to the incoming IR energy. The 4-stage cooler is used to cool the detectors, and hence reduce any spurious detector noise. The electronics assembly controls the instrument. It also conditions and formats the telescope scan and detector signals for output to the spacecraft. 85) 86)

• 8 cm clear aperture

• A collimator is used to perform the spatial and spectral characterizations

• 4-stage split-patch passive cooler (81 K for LWIR patch temperature, 98 K for MWIR/SWIR patch)

• High-performance PV (photovoltaic) detectors

• 3 x 3 arrays (14 km IFOVs)

• Three spectral bands (SWIR, MWIR, TIR), co-registered so that the FOVs of each band see the radiance from the same region of the Earth's atmosphere

• All-reflective telescope

• Proven Bomem plane-mirror Michelson interferometer with dynamic alignment

• Deep-cavity internal calibration target based on MOPITT design

• Two-axis scene selection module with image motion compensation

• A modular design (allowing for future addition of an active cooler and >3 x 3 arrays

The flight configuration for the CrIS DPM (Detector Preamplifier Module) consists of three spectrally separate (SWIR, MWIR and LWIR) FPAAs (Focal Plane Array Assemblies), three (SWIR, MWIR and LWIR) signal flex cable assemblies, a warm signal flex cable/vacuum bulk head assembly, and the DPM warm electronics CCAs (Circuit Card Assemblies). The FPAAs are cooled to cryogenic temperature (98 K SWIR, MWIR, 81 K for LWIR) by the detector cooler module. The cryogenic portions of the DPM (FPAAs, and signal flex cable assemblies) mate to the ambient temperature portions of the DPM (warm signal flex cable assembly and the ambient temperature portions of the transimpedance amplifier, mounted within the CCAs) through the vacuum bulk head assembly mounted on the detector cooler assembly housing. 87)

Spectral bands
- SWIR
- MWIR
- TIR (also known as LWIR)

Total of 1305 channels
(2155 - 2550 cm-1) or 4.64 - 3.92 µm, 159 channels
(1210 - 1750 cm-1) or 8.62 - 5.7 µm, 433 channels
(650 - 1095 cm-1) or 15.3 - 9.1 µm, 713 channels

Spectral resolution:
- SWIR
- MWIR
- TIR


(<2.5 cm-1) or 5.4 nm (at 4.64 µm) to 38.4 nm (at 3.92 µm)
(<1.25 cm-1) or 92.8 nm (at 8.62 µm) to 40.6 nm (at 5.7 µm)
(<0.625 cm-1) or 146 nm (at 15.3 µm) to 51.7 nm (at 9.1 µm)

Band-to-band co-registration
IFOV motion (jitter)
Mapping accuracy

< 1.4%
< 50 µrad/axis
< 1.5 km

Number of IFOVs

3 x 3 at 14 km diameter for each band

IFOV diameter

14 km

Absolute radiometric uncertainty

<0.8% (SWIR), <0.6% (MWIR), <0.45% (TIR)

Radiometric stability

<0.65% (SWIR, <0.5% (MWIR), <0.4% (TIR)

Instrument size

71 cm x 88 cm x 94 cm

Instrument mass, average power, data rate

152 kg, 124 W, 1.5 Mbit/s (average), 1.5 Mbit/s (max)

Table 6: Key performance characteristics of CrIS

CrIS calibration: The calibration of the interferometer is accomplished with both LASER wavelength calibration, and also with a Neon bulb spectral calibration. The ICT (Internal Calibration Target) consists of a highly emissive, deep-cavity blackbody, utilizing a flight-proven, MOPITT (Measurement of Pollution in the Troposphere)-heritage design. Temperature knowledge of the ICT is better than 80mK. A passive vibration isolation system is included to allow instrument operation in a 50mG environment. The instrument optics are thermally decoupled from both the structure and the instrument electronics. The overall instrument design is modular, which allows for parallel assembly and rapid instrument integration.

The primary data product of the CrIS instrument are interferograms collected from 27 infrared detectors that cover 3 IR bands and 9 FOVs. 88)

Data of CrIS will be combined in particular with those of ATMS to construct atmospheric temperature profiles at 1 K accuracy for 1 km layers in the troposphere and moisture profiles accurate to 15% for 2 km layers. 89)

 

CERES (Clouds and the Earth's Radiant Energy System)

The CERES measurements seek to develop and improve weather forecast and climate models prediction. CERES will help provide measurements of the space and time distribution of the Earth's Radiation Budget (ERB) components, further developing a quantitative understanding of the links between the ERB and the properties of the atmosphere and surface that define the budget. The observations from CERES are essential to understanding the effect of clouds on the energy balance (energy coming in from the sun and radiating out from the earth), which is one of the largest sources of uncertainty in our modeling of the climate. NASA/LaRC is procuring the CERES instrumentation.

Background: The ERB measurements provided by the CERES instruments are key elements in the production of ERB Climate Data Records; these records that have been produced on a continuous basis for more than 20 years, including measurements from the ERBE (Earth Radiation Budget Experiment) prior to CERES. Maintaining the continuity of these measurements and the ERB records are part of an overarching NOAA program objective to sustain continuity and enhance Earth observation analysis, forecasting and climate monitoring capabilities from global polar-orbiting observations.

The level of measurement accuracy necessary to assess climate change and understand the interactions of natural and anthropogenic effects occurring on a decadal time scale requires that instruments making these measurements overlap on orbit for sufficient periods to achieve transfer of calibration from one instrument to the next. The CERES instruments currently operating on the EOS (Earth Observing System) Terra and Aqua missions have provided over 10 years of accurate measurements of the solar reflected and Earth emitted energy.

The CERES FM5 instrument is currently flown on the Suomi-NPP mission while the CERES FM6 instrument is planned for launch on the JPSS-1 mission. These missions should provide continuity of ERB measurements into the next decade.

Figure 57: Earth’s energy budget describes the balance between the radiant energy that reaches Earth from the sun and the energy that flows from Earth back out to space (image credit: NASA)
Figure 57: Earth’s energy budget describes the balance between the radiant energy that reaches Earth from the sun and the energy that flows from Earth back out to space (image credit: NASA)

CERES Flight Model (FM)

Mission

Launch

Comment

PFM (Proto-Flight Model)

TRMM (Tropical Rainfall Measuring Mission)

Nov. 27, 1997

PFM performed for 8 months, then PFM was turned off from Aug. 1998 to June 2002, when it was on to provide a comparison with CERES on Aqua

FM-1, -2

Terra (2 CERES instruments)

Dec. 19, 1999

SSO at 705 km altitude

FM-3, -4

Aqua (2 CERES instruments)

May 04, 2002

SSO at 705 km altitude

FM-5

Suomi-NPP

Oct. 28, 2011

SSO at 824 km altitude

FM-6

JPSS (Joint Polar Satellite System)-1

Planned 2017

SSO at 833 km altitude

CBERS Follow-on

JPSS (Joint Polar Satellite System)-2

Planned 2022

 

Table 7: CBERS instruments on NASA missions 90)
Figure 58: Overview of past, current and future missions with corresponding CERES instrument FM generations (image credit: NASA/LaRC) 91)
Figure 58: Overview of past, current and future missions with corresponding CERES instrument FM generations (image credit: NASA/LaRC) 91)

CERES instrument measures the reflected shortwave (SW) and Earth emitted radiances. The objectives are to continue a consistent database of accurately known fields of Earth’s reflected solar and Earth’s emitted thermal radiation. CERES satisfies four JPSS EDRs, in combination with other instruments. 92) 93) 94) 95) 96)

- Net solar radiation at TOA (Top of the Atmosphere)

- Downward longwave radiation at the surface

- Downward shortwave radiation at the surface

- Outgoing longwave radiation at TOA.

CERES instrument: The CERES instrument consists of three major subassemblies: 1) Cassegrain telescope, 2) baffle for stray light, and 3) detector assembly, consisting of an active and compensating element. Radiation enters the unit through the baffle, passes through the telescope and is imaged onto the IR detector. Uncooled infrared detection is employed.

Figure 59: Norman Loeb, principal investigator of NASA’s Radiation Budget Science Project, is pictured with a CERES model, which studies the clouds and monitor Earth's “energy budget” (image credit: NASA, David C. Bowman) 97)
Figure 59: Norman Loeb, principal investigator of NASA’s Radiation Budget Science Project, is pictured with a CERES model, which studies the clouds and monitor Earth's “energy budget” (image credit: NASA, David C. Bowman) 97)
Figure 60: Cross section of the CERES telescope (image credit: NASA/LaRC) 98)
Figure 60: Cross section of the CERES telescope (image credit: NASA/LaRC) 98)

A CERES instrument consists of 2 identical scanners: total mass of 114 kg , power = 100 W (average, 2 instruments), data rate = 20 kbit/s, duty cycle = 100%, thermal control by heaters and radiators, pointing knowledge = 180 arcsec. The design life is six years. CERES measures longwave (LW) and shortwave (SW) infrared radiation using thermistor bolometers to determine the Earth's radiation budget. There are three spectral channels in each radiometer:

- VNIR+SWIR: 0.3 - 5.0 µm (also referred to as SW channel); measurement of reflected sunlight to an accuracy of 1%.

- Atmospheric window: 8.0 - 12.0 µm (also referred to as LW channel); measurement of Earth-emitted radiation, this includes coverage of water vapor

-Total channel radiance in the spectral range of 0.35 - 125 µm;. reflected or emitted infrared radiation of the Earth-atmosphere system, measurement accuracy of 0.3%.

Limb-to-limb scanning with a nadir IFOV (Instantaneous Field of View) of 14 mrad, FOV = ±78º cross-track, 360º azimuth. Spatial resolution = 10-20 km at nadir. Each channel consists of a precision thermistor-bolometer detector located in a Cassegrain telescope.

Instrument calibration: CERES is a very precisely calibrated radiometer. The instrument is measuring emitted and reflected radiative energy from the surface of the Earth and the atmosphere. A variety of independent methods are used to verify calibration: 99)

• Internal calibration sources (blackbody, lamps)

• MAM (Mirror Attenuator Mosaic) solar diffuser plate. MAM is used to define in-orbit shifts or drifts in the sensor responses. The shortwave and total sensors are calibrated using the solar radiances reflected from the MAM's. Each MAM consists of baffle-solar diffuser plate systems, which guide incoming solar radiances into the instrument FOV of the shortwave and total sensor units.

• 3-channel deep convective cloud test

- Use night-time 8-12 µm window to predict longwave radiation (LW): cloud < 205 K

- Total - SW = LW vs Window predicted LW in daytime for same clouds <205 K temperatures

• 3-channel day/night tropical ocean test

• Instrument calibration:

- Rotate scan plane to align scanning instruments TRMM, Terra during orbital crossings (Haeffelin: reached 0.1% LW, window, 0.5% SW 95% configuration in 6 weeks of orbital crossings of Terra and TRMM)

- FM-1 and FM-2 instruments on Terra at nadir

Instrument heritage

Earth Radiation Budget Experiment (ERBE)

Prime contractor

Northrop Grumman Aerospace Systems

NASA center responsible

LaRC (Langley Research Center)

Three channels in each radiometer

Total radiance (0.3 to 200 µm); Shortwave (0.3 to 5 µm); Window (5 to 35 µm)

Swath

Limb to limb

Spatial resolution

24 km at nadir

Instrument mass, duty cycle

~54 kg/scanner, 100%

Instrument power

55 W (average) per scanner, 104 W (peak: biaxial mode) both scanners

Data rate

10.52 kbit/scanner (average)

Thermal control

Use of heaters and radiators

Thermal operating range

38±0.1ºC (detectors)

FOV (Field of View)

±78º cross-track, 360º azimuth

IFOV

14 mrad

Instrument pointing requirements (3σ)
Control
Knowledge
Stability


720 arcsec
180 arcsec
79 arcsec/6.6 sec

Instrument size

60 cm x 60 cm x 57.6 cm/unit

Table 8: CERES instrument parameters
Figure 61: Illustration of the CERES scanning radiometer (image credit: NASA/LaRC)
Figure 61: Illustration of the CERES scanning radiometer (image credit: NASA/LaRC)

Data products: CERES provides global radiative flux and cloud property datasets. The temporal resolutions range from Level 2 instantaneous measurements to Level 3 hourly, daily, and monthly averages. The spatial resolutions range from Level 2 satellite field-of-view footprint measurements to Level 3 gridded regional, zonal, and global averages.

Global CERES data allow scientists to validate models that calculate the effect of clouds in driving planetary heating or cooling. CERES data also help improve seasonal climate forecasts, including cloud and radiative aspects of large-scale climate events like El Niño and La Niña.

The CERES science team also uses high spatial resolution visible/infrared imager data to determine cloud properties including the amount, height, thickness, particle size, and phase of clouds using simultaneous measurements by other instruments, such as VIIRS (Visible Infrared Imaging Radiometer Suite). These measurements are critical for understanding cloud-radiation climate change and improving the prediction of global warming using climate models.

Data from CERES can also be used for assessing the radiative effects and climatic impact of natural disasters like volcanic eruptions, major floods, and droughts. The long-term data record from CERES will provide a basis for scientific understanding of cloud and climate feedback that determines climate variations and trends.

Figure 62: This map of India and the Middle East and Asia shows how much outgoing longwave radiation left Earth’s atmosphere between May 15-27, 2015, while the region was experiencing a heatwave. Measurements for this image were made by the CERES instrument on NASA’s Terra satellite. The image was created using the CERES SSF (Single Scanner Footprint) 1deg data product (image credit: NASA’s CERES Science Team)
Figure 62: This map of India and the Middle East and Asia shows how much outgoing longwave radiation left Earth’s atmosphere between May 15-27, 2015, while the region was experiencing a heatwave. Measurements for this image were made by the CERES instrument on NASA’s Terra satellite. The image was created using the CERES SSF (Single Scanner Footprint) 1deg data product (image credit: NASA’s CERES Science Team)

 

OMPS (Ozone Mapping and Profiler Suite)

Ozone in the atmosphere keeps the Sun's ultraviolet radiation from striking the Earth. The OMPS will measure the concentration of ozone in the atmosphere, providing information on how ozone concentration varies with altitude. Data from OMPS will continue three decades of climate measurements of this important parameter used in global climate models. The OMPS measurements also fulfill the U.S. treaty obligation to monitor global ozone concentrations with no gaps in coverage. OMPS is comprised of two sensors: (1) a nadir sensor, and (2) a limb sensor. Measurements from the nadir sensor are used to generate total column ozone measurements, while measurements from the limb sensor generate ozone profiles of the along-track limb scattered solar radiance.

OMPS is a limb- and nadir-viewing UV hyperspectral imaging spectrometer, designed and developed at BATC (Ball Aerospace & Technologies Corp.), Boulder, CO. The objective is to measure the total amount of ozone in the atmosphere and the ozone concentration variation with altitude. OMPS is of SBUV/2, TOMS and GOME heritage. Also, the OMPS limb-sounding concept/technology was already tested with ISIR (Infrared Spectral Imaging Radiometer) flown on Shuttle flight STS-85 (Aug. 7-19, 1997) and with SOLSE/LORE flown on STS-87 (Nov 19 - Dec. 5, 1997). The vertical resolution requirement demands an instrument design to include a limb-viewing sensor in addition to a heritage-based nadir-viewing sensor. 100) 101) 102) 103)

OMPS on JPSS consists of three spectrometers:

• Nadir total column spectrometer covers a 50 km x 2800 km cross-track swath

• Nadir Profile Spectrometer provides performance over (250 km x 250 km) cell

• Limb sensor provides 1 km vertical sampling along three slits enabling ozone profile retrieval (Not provided on JPSS-1) 104)

Basic requirement

Measurement parameter

Requirement

1) Global daily maps of the amount of ozone
in the vertical column of the atmosphere

Horizontal cell size
Range
Accuracy
Precision
Long-term stability

50 km @ nadir
50-650 Dobson Units (DU)
15 DU or better
3 DU+0.5% total ozone or better
1% over 7 years or better

2) Provision of volumetric ozone concentration
profiles in specified segments of a vertical column
of the atmosphere with a 4-day revisit time

Vertical cell size
Horizontal cell size
Vertical coverage
Range
Accuracy

Precision
Long-term stability

3 km
250 km
Tropopause height to 60 km
0.1 - 15 ppmv
Greater of (20%, 0.1 ppmv) below 15 km
Greater of (10%, 0.1 ppmv) above 15 km
3%, 15-50 km; 10% TH-15 and 50-60 km
2%

Table 9: Overall mission requirements for OMPS ozone observations 105)

The OMPS instrument design features two coregistered spectrometers in the OMPS nadir sensor. The grating spectrometer and focal plane for total column measurements provide 0.45 nm spectral sampling across the wavelength range of 300 to 380 nm. The IFOV for the nadir cell of the total column measurement is 49.5 km cross track with an along-track reporting interval of 50 km. The total FOV cross track is 110º to provide daily global coverage.

Nadir-viewing instrument: The nadir sensor wide-field telescope feeds two separate spectrometers, a) for total column observations (mapper) and b) for nadir profiling observations. The total column spectrometer (300-380 nm spectral range, resolution of 0.45 nm) has a 2800 km cross-track swath (FOV = 110º and an along-track slit width of 0.27º) divided into 35 IFOVs of nearly equal angular extent. The CCD pixel measurements from its cross-track spatial dimension are summed into 35 bins. The summed bins subtend 3.35º (50 km) at nadir and 2.84º at ±55º. The along-track resolution is 50 km at nadir due to spacecraft motion during the 7.6 second reporting period. Measurements from this spectrometer are used to generate total column ozone data with a resolution of about 50 km x 50 km at nadir.

The nadir profile spectrometer (250-310 nm) has a 250 km cross-track swath corresponding to a single cell (cross-track FOV = 16.6º, and 0.26º along-track slit width). Co-registration with the total column spectrometer provides the total ozone, surface and cloud cover information needed for nadir profile retrievals. All of the cross-track pixels are binned spatially to form a single cell of 250 km x 250 km. Some instrument parameters are: 106)

- The telescope is a three mirror, near telecentric, off-axis design. The FOV is allowed to curve backward (concave in the anti-ram direction) by 8.5º at 55º cross-track in order to maintain straight entrance slits for the spectrometers. The mirrors are made with a glass which matches the thermal expansion of Titanium, are coated with an enhanced aluminum, and have an rms surface roughness of < 15Å.

- Each of the 2 spectrometers has a CCD detector array, a split column frame transfer CCD 340 x 740 (column x row) operated in a backside illuminated configuration. The pixel pitch is 20 µm in the column (spectral) dimension and 25 µm in the row (spatial) dimension and every pixel in both the active and storage regions contains a lateral overflow antiblooming structure integrated into a 4-phase CCD architecture.

- Both spectrometers sample the spectrum at 0.42 nm, 1 nm FWHM end-to-end resolution

- Electronics: a) CCD preamplifier electronics in sensor housing, b) main electronics box performs A/D conversion and on-orbit pixel correction

- The OMPS nadir instrument has a mass of 12.5 kg and a size of 31 cm x 32 cm x 20 cm.

Polarization compensators are used to reduce polarization sensitivity for both Nadir instruments. Long-term calibration stability is monitored and corrected by periodic solar observations using a “Working” and “Reference” reflective diffuser system (similar to that successfully deployed on the TOMS sensors).

Figure 63: Photo of the OMPS instrument (image credit: BATC) 107)
Figure 63: Photo of the OMPS instrument (image credit: BATC) 107)

 

Parameter

Nadir Total Column (Nadir Mapper)

Nadir Profile (Nadir Profiler)

Spectral range

300-380 nm

250-310 nm

Spectral radiance range [photons/(s cm2 sr nm)]

9 el 3 (380 nm)
8 el 1 (308 nm)

2 el 3 (310 nm)
1.5 el 8 (252 nm)

Minimum SNR

1000

35 (252 nm)
400 (310 nm)

Integration time

7.6 s

38 s

Spectral resolution

1 nm FWHM
2.4 samples/FWHM

1 nm FWHM
2.4 samples/FWHM

FOV

110º x 1.0º (cross-track x along-track)

16.6º x 0.26º

Cell size

49 km x 50 km (nadir)

250 km x 250 km (single cell at nadir)

Revisit time

daily

 

Swath

2800 km

250 km

Table 10: Performance parameters of the OMPS spectrometers

 

VIIRS (Visible/Infrared Imager Radiometer Suite)

VIIRS will combine the radiometric accuracy of the AVHRR-3 (Advanced Very High Resolution Radiometer), which is currently flown on the NOAA polar orbiters with the high spatial resolution (0.56 km) of the OLS (Operational Linescan System) flown on DMSP. VIIRS will provide imagery of clouds under sunlit conditions in about a dozen bands, and will also provide coverage in a number of infrared bands for night and day cloud imaging applications.

VIIRS will have multi-band imaging capabilities to support the acquisition of high-resolution atmospheric imagery and generation of a variety of applied products, including visible and infrared imaging of hurricanes and detection of fires, smoke and atmospheric aerosols. VIIRS will also provide capabilities to produce higher-resolution and more accurate measurements of sea surface temperature than currently available from the heritage AVHRR-3 instrument on POES, as well as provide an operational capability for ocean-color observations and a variety of derived ocean-color products. The VIIRS instrument is developed by the Raytheon Company, El Segundo, CA. 108)

VIIRS is an advanced, modular, multi-channel imager and radiometer (of OLS, AVHRR-3, MODIS, and SeaWiFS heritage) with the objective to provide global observations (moderate spatial resolution) of land, ocean, and atmosphere parameters at high temporal resolution (daily). 109) 110) 111) 112) 113) 114) 115) 116) 117)

VIIRS is a multispectral (22-band) opto-mechanical radiometer, employing a cross-track rotating telescope fore-optics design (operating on the whiskbroom scanner principle), to cover a wide swath. The rotating telescope assembly (RTA of 20 cm diameter) concept of SeaWiFS heritage allows a low straylight performance. An observation scene is imaged onto three focal planes, separating the VNIR, SWIR/MWIR, and TIR energy - covering a spectral range of 0.4 - 12.5 µm. The VNIR FPA (Focal Plane Array) has nine spectral bands, the SWIR/MWIR FPA has eight spectral bands, and the TIR FPA four spectral bands. The integral DNB (Day Night Band) capability provides a very large dynamic range low-light capability in all VIIRS orbits. The detector line arrays [16 detectors in each array for the SWIR/MWIR and TIR bands, 32 detectors in the array for the VNIR and DNB (Pan) bands] of the whiskbroom scanner are oriented in the along-track direction. This arrangement provides a parallel coverage of 11.87 km along-track in one scan sweep (cross-track direction). The wide along-track coverage permits sufficient integration time for all cells in each scan sweep. One cross-track scan period of RTA is 1.786 s in length. The data quantization is 12 bits (14 bit A/C converters for lower noise).

Typical data products (types) of VIIRS include atmospheric, clouds, earth radiation budget, clear-air land/water surfaces, sea surface temperature, ocean color, and low-light visible imagery. A swath width of 3000 km is provided (corresponding to FOV=±55.84º) with a spatial resolution for imagery related products of no worse than 0.4 km to 0.8 km (nadir to edge-of-scan). The radiometric bands provide a resolution about twice in size to the imagery bands. Note: Most derived data products will be produced at somewhat coarser resolutions by aggregation of on-board data.

Figure 64: Photo of the VIIRS instrument (image credit: NASA, Raytheon, Ref. 114)
Figure 64: Photo of the VIIRS instrument (image credit: NASA, Raytheon, Ref. 114)

The VIIRS instrument design employs an all-reflective optics assembly taking advantage of recent optics advances: a) single 4 mirror imager, b) 2 dichroics and 1 fold, c) aluminum DPT-bolt together technology (DPT = Diamond Point Turning). A rotating off-axis and afocal TMA (Three Mirror Anastigmatic) telescope assembly is employed [Note: The telescope rotates 360º, thus scanning the Earth scene, and then internal calibration targets.]. The aperture of the imaging optics is 18.4 cm in diameter, the focal length is 114 cm (f/5.97). The VIIRS optical train consists of the fore optics (TMA), the aft optics [an all-reflective FMA (Four Mirror Anastigmat) imager], and the back-end optics, which include microlenses for the cooled focal planes.

A total of 22 spectral bands have been selected as defined in Table 11. VIIRS features band-to-band registration for all bands (optical alignment of all FPAs). A total of three focal planes and four FPAs (Focal Plane Arrays) cover the spectral range of the instrument, one FPA for DNB (Day-Night Band), one for VNIR, SWIR/MWIR, and TIR. The DNB spectral range of 0.5-0.9 µm CCD detector features four light-sensitive areas (3 with TDI, one without) and near-objective sample spacing.

The VNIR FPA employs a PIN (Positive Insulator Negative) diode array/ROIC (Readout Integrated Circuit) design collocated with the DNB monolithic CCD. All detectors in the SWIR/MWIR/TIR regions employ photovoltaic (PV) detectors with an element spacing of 12 µm. A ROIC (Readout Integrated Circuit) at each FPA provides improved noise levels and built-in offset correction. A cryogenic module (three-stage radiative cooler) provides FPA cooling.

A single-board instrument computer provides a processing capability including data aggregation, data compression [lossless (2:1 Rice compression) and lossy (JPEG) algorithms are used], and CCSDS data formatting.

Calibration is performed with three on-board calibrators: a) a solar diffuser (SD) provides full aperture solar calibration, b) a solar diffuser stability monitor, and c) a blackbody. Instrument calibration of VIIRS is based on that of the MODIS instrument: 118) 119) 120)

• VNIR: 1) View of a spectralon plate at the poles every few days; 2) Deep space view

• SWIR/MWIR/TIR: 1) View of blackbody every scan; 2) Deep space view

Figure 65: Major subsystems/components of VIIRS (functional block diagram)
Figure 65: Major subsystems/components of VIIRS (functional block diagram)
Figure 66: Schematic of VIIRS rotating TMA (Three Mirror Anastigmatic) telescope assembly
Figure 66: Schematic of VIIRS rotating TMA (Three Mirror Anastigmatic) telescope assembly

The VIIRS instrument has a mass of 252 kg, power of ~ 191 W (operational average), and a size of 134 cm x 141 cm x 85 cm. The data rate is 10.5 Mbit/s (high rate mode) and 8 Mbit/s (average rate) mode with 10:1 JPEG compression). The VIIRS instrument features a SBC (Single Board Computer) for all instrument operations and control; it communicates with the S/C via an IEEE 1394a cable interface.

Some operational features of VIIRS:

• All functions are individually commandable

• Macro commands (stored sequences, all macros are reprogrammable) simplify the commanding and reduce the uplink data

• Time-tagged commands allow delayed execution (provides for 30 days autonomous operations)

• The swath widths and locations are individually programmable by band (improved resolution views of selected target near nadir)

• Diagnostic mode features improved versatility.

Band

Center wave (µm)

Bandwidth (µm)

Comment (driving EDR observation requirements)

VNIR (Visible Near-Infrared) spectral region, use of Si detectors in FPA

DNB

0.70

0.40

Day Night Band, broad bandwidth maximizes signal (essential nighttime reflected band)

M1

0.412

0.02

Ocean color, suspended matter, net heat flux, mass loading

M2

0.445

0.018

Ocean color, suspended matter, net heat flux, mass loading

M3

0.488

0.02

Ocean color EVI, surface type, aerosols suspended matter, net heat flux, mass loading

M4

0.555

0.02

Ocean color, surface type, suspended matter, net heat flux, mass loading

I1

0.640

0.05

Imagery, NDVI, cloud mask/cover, cloud optical properties, surface type, albedo, snow/ice, soil moisture

M5

0.672

0.02

Ocean color, aerosols, suspended matter, net heat flux, littoral transport, mass loading

M6

0.746

0.015

Ocean color, mass loading

I2

0.865

0.039

Imagery NDVI (NDVI heritage band), snow/ice, surface type, albedo

M7

0.865

0.039

Ocean color, cloud mask/cover, aerosols, soil moisture, net heat flux, mass loading

SWIR (Short-Wave Infrared) spectral region, use of PV (Photovoltaic) HgCdTe detectors

M8

1.24

0.02

Cloud optical properties (essential over snow/ice), active fires

M9

1.378

0.015

Cloud mask/cover (thin cirrus detection), aerosols, net heat flux

M10

1.61

0.06

Aerosols, cloud optical properties, cloud mask/cover (cloud/snow detection), active fires, soil moisture, net heat flux

I3

1.61

0.06

Imagery snow/ice (cloud/snow differentiation), surface type, albedo

M11

2.25

0.05

Aerosols (optimal aerosol optical thickness over land), cloud optical properties, surface type, active fires, net heat flux

MWIR (Mid-Wave Infrared) spectral region, use of PV (Photovoltaic) HgCdTe detectors

I4

3.74

0.38

Imagery (identification of low and dark stratus), active fires

M12

3.70

0.18

SST (Sea Surface Temperature), cloud mask/cover, cloud EDRs, surface type, land/ice surface temperature, aerosols

M13

4.05

0.155

SST (essential for skin SST in tropics and during daytime), land surface temperature, active fires, precipitable water

TIR (Thermal Infrared) spectral region, use of PV (Photovoltaic) HgCdTe detectors

M14

8.55

0.3

Cloud mask/cover (pivotal for cloud phase detection at night, cloud optical properties

M15

10.763

1.00

SST, cloud EDRs and SDRs (Science Data Records), land/ice surface temperature, surface type

I5

11.450

1.9

Imagery (nighttime imagery band)

M16

12.013

0.95

SST, cloud mask/cover, land/ice surface temperature, surface type

Table 11: Definition of VIIRS spectral bands

DNB (Day-Night Band) FPA

VNIR FPA

SWIR/MWIR FPA

TIR FPA

One broadband

9 bands

8 bands

4 bands, 1 with TDI

CCD detector

Si PIN diodes

PV HgCdTe detector

PV HgCdTe detector

FPIE (Focal Plane Interface Electronics)

ROIC (Readout Integrated Circuit)

ROIC

ROIC

Filter/Bezel

Filter/Bezel

Si micro-lens array

Ge micro-lens array

Tops = 253 K

Tops = ambient

Filter/Bezel

Filter/Bezel

 

 

Tops = 80 K

Tops = 80 K

Table 12: Overview of the FPA design of VIIRS

Some key EDRs of VIIRS: 121)

• SST (Sea Surface Temperature). VIIRS is capable to provide a nadir resolution of 750 m (by aggregating detectors 3:l in-track near nadir, 2:l in-track aggregation out to a 2,000 swath, and 1:1 out to 3,000 km) to simultaneously optimize spatial resolution and noise performance. - The SST solution combines the traditional long-wave infrared (LWIR) split window with a second split window in the mid-wave infrared (MWIR) for a globally robust SST algorithm. The MWIR split window has a higher transmissivity than the traditional LWIR split window for improved atmospheric correction. The low-noise design is operable day and night with 0.25 K precision, and 0.35 K total measurement uncertainty (rms error).

• Imagery and cloud detection/typing. The imagery solution provided on VIIRS includes six high-resolution bands and an additional 16 moderate-resolution bands. One of these, a reflective panchromatic band (DNB), is operable in low-light conditions down to a quarter moon. A swath with of 3000 km is provided.

• Soil moisture. A VIIRS/CMIS data fusion solution was derived. The approach combines the fine spatial resolution of VIIRS with traditional coarser-resolution microwave-derived soil moisture retrievals to achieve excellent results over both open and partially vegetated scenes. The estimation procedure involves two steps: 1) CMIS estimates soil moisture at coarse spatial resolution. This involves inversion of dual-polarized microwave brightness temperatures. 2) CMIS-derived low-resolution soil moisture is linked to the scene optical parameters, such as NDVI (Normalized Difference Vegetation Index), surface albedo, and LST (Land Surface Temperature). The linkage of the microwave-derived soil moisture to NDVI, surface albedo and LST is based on the “Universal Triangle” approach of relating land surface parameters. The three high-resolution optical parameters are aggregated to microwave resolution for the purpose of building the linkage model. The linkage model, in conjunction with high-resolution NDVI, surface albedo, and LST, is then used to disaggregate microwave soil moisture into high-resolution soil moisture.

VIIRS will collect radiometric and imagery data in 22 spectral bands within the visible and infrared region ranging from 0.4 to 12.5 µm. These data are calibrated and geolocated in ground processing to generate SDRs (Sensor Data Records) that are equivalent to NASA Level 1B products. The VIIRS SDRs in turn will be used to generate 22 EDRs (Environmental Data Records) including two KPPs (Key Performance Parameters): SST (Sea Surface Temperature) and Imagery. Since the quality of these EDRs depends upon the quality of the underlying SDRs, adequate SDR quality is crucial to JPSS mission success. 122) 123)

DNB (Day Night Band) overview in VIIRS

The DNB will measure VIS radiances from the Earth and atmosphere (solar/lunar reflection and both natural and anthropogenic nighttime light emissions) during both day and night portions of the orbit. In comparison to the OLS (Operational Linescan System) of the DMSP series, some of the DNB channel improvements include 1) reduced instances of pixel saturation, 2) a smaller IFOV, leading to reduced spatial blurring, 3) superior calibration and radiometric resolution, 4) collocation with multispectral measurements on VIIRS and other NPOESS sensors, 5) and generally increased spatial resolution and elimination of cross-track pixel size variation. 124)

The DNB is implemented as a dedicated focal plane assembly (FPA) that shares the optics and scan mechanism of the other VIIRS spectral bands. This integral design approach offers lower overall system complexity, cost, mass, and volume compared to a separate DNB sensor. Unlike the OLS, the DNB will feature radiometric calibration, with accuracy comparable to the other VIIRS spectral bands.

To achieve satisfactory radiometric resolution across the large dynamic range (seven orders of magnitude) of day/night radiances encountered over a single orbit, the DNB selects its amplification gain dynamically from three simultaneously collecting stages (groups of detectors residing upon the same FPA). The stages detect low-, medium-, and high-radiance scenes with relative radiometric gains of 119,000:477:1 (high:medium:low gain). Each of the three stages covers a radiance range of more than 500:1, so that the three together cover the entire required radiance range with generous overlap. Two identical copies of the high-gain stage are provided, which improves the SNR at very low signal levels and allows for the correction of pixels impacted by high-energy subatomic particles. The scene is scanned sequentially such that each scene is imaged by all three gains virtually simultaneously.

The signals from all gain stages are always digitized, using 14 bits for the high-gain stage and 13 bits for the medium- and low-gain stages. This fine digitization assures the DNB will have a sufficiently fine radiometric resolution across the entire dynamic range. Logic in the VIIRS Electronics Module (EM) then selects, on a pixel-by-pixel basis, the most appropriate of the three stages to be transmitted to Earth. In general, the VIIRS EM logic chooses the most sensitive stage in which the pixel is not saturated. This imaging strategy produces nonsaturated calibrated radiances in bright areas, and data with a lower dynamic range in the darkest areas with less SNR and radiometric accuracy.

In summary, the VIIRS DNB feature will bring significant advances to operational and research applications at night (over OLS operations) due to the increased sensitivity of the instrument.

 

RSB (Reflective Solar Band) radiometric calibration: 125) 126)

VIIRS features 15 reflective solar bands (RSB) in the range of 0.4-2.25 µm. The reflective bands use sunlight reflected from a SD (Solar Diffuser) after passing through an attenuating SDS (Solar Diffuser Screen) as a reference illumination source. The RSB calibration is currently performed by offline trending of calibration scale factors derived from the SD and SV (Space View) observations. These calibration scale factors are used to periodically update LUT (Look-Up Tables) used by the ground processing to generate the calibrated earth radiance and reflectance in the Sensor Data Records (SDR).

RSB calibration data is acquired once per orbit when sunlight incident on the SD uniformly illuminates the VIIRS detectors, providing a large and calculable reference radiance level. The calibration scale factor is the ratio of the calculated SD radiance at the entrance aperture to the SD radiance measured by the instrument using calibration coefficients derived from the pre-launch calibration. The calibration scale factor in effect measures the change in instrument “gain” as the instrument ages on orbit relative to the gain measured during pre-launch instrument response characterization.

TED (Thermal Emissive Band) calibration: 127)

VIIRS has 7 thermal emissive bands use an OBC-BB (On-Board Calibrator Blackbody) maintained at a constant elevated temperature as a reference illumination source. The 7 emissive bands are centered at 3.74, 11.45, 3.75, 4.05, 8.55, 10.76, and 12.01 µm. The two emissive image bands are mainly for cloud imagery and precise geolocation. The 5 moderate-resolution emissive bands are used to determine surface temperature and cloud top pressure. The only dual gain band TEB M13 is used for determining surface temperature at low radiance, and fire detection at high radiance.

The VIIRS emissive band calibration concept is a common two-point calibration by viewing onboard blackbody and cold space. However, the VIIRS emissive band calibration algorithm is more complicated than other sensors such as AVHRR and MODIS, because of the instrument response verses the scan angle. The TEBs (Thermal Emissive Bands) are calibrated using OBC-BB that has been carefully characterized in prelaunch activities. The OBC-BB emissivity is estimated to be 0.99609-0.99763 for the TEB bands based on prelaunch testing in the thermal vacuum chamber. The OBC-BB temperature is carefully controlled using heater elements and thermistors. The calibration algorithm, based on measured BB temperature and emissivity, computes radiances and compares it with counts to determine gain adjustments.

VIIRS significantly outperforms the legacy AVHRR in spatial, spectral, and radiometric accuracy. Early assessment of the VIIRS TEB calibration shows the sensor is stable and exceeds the specification. The onboard calibration accuracy for NEdT compares very favorably with pre-launch thermal vacuum tests. Consistency tests among VIIRS, MODIS, AVHRR, and CrIS further confirm the stability and accuracy of the VIIRS TEB.

 

 


 

Ground Segment

In September 2010, the Raytheon Company was awarded a contract by NASA on behalf of NOAA for the development of JPSS-1 (Joint Polar Satellite System-1). The award of the JPSS Common Ground System enables uninterrupted support to meet both civilian and defense weather needs. It allows Raytheon to continue the development and evolution of the ground system into an exceptional operational program for JPSS and DMSP (Defense Meteorological Satellite Program). 128) 129) 130)

The main elements of the JPSS common ground system for NOAA and DoD – currently comprises:

• C3S (Command, Control and Communications Segment)

- Includes mission planning, enterprise management, antenna resource scheduling, satellite operations, data relay and spacecraft and instrument engineering. A key feature of the C3S is the 15 unmanned global ground stations that receive JPSS and DWSS mission data, termed the DRN (Distributed Receptor Network). The receptors, linked with high-bandwidth commercial fiber, can quickly transport the data to four U.S. data processing centers. Most data will ultimately be completely processed and delivered to the Weather Centrals in less than 30 minutes from the time of collection.

- The MMC (Mission Management Center) provides accurate, high-performance tools that precisely manage JPSS and DWSS missions. The C3S tools give crews keen insight, comprehensive operational oversight, detailed mission planning capability, full control of space and ground assets, continuous monitoring and assessment of overall system performance.

• IDPS (Interface Data Processing Segment). The IDPS features high-speed, symmetric, multi-processing computers that will rapidly convert large streams of JPSS and DWSS sensor data that are 100 times the volume of legacy data, providing numerous EDRs (Environmental Data Records) at four weather Centrals in the United States. These vital EDRs range from atmospheric to land and ocean surface products. The EDRs detail cloud coverage, temperature, humidity and ozone distribution, as well as snow cover, vegetation, sea surface temperatures, aerosols, space environment and earth radiation budget information. This wealth of information enables numerous users to monitor and predict changes in weather, climate, and ocean conditions. JPSS and DWSS products will also be available to the scientific community to expand our knowledge of the environment.

• FTS (Field Terminal Segment). The FTS, equipped with specially configured IDPS software, will permit worldwide fixed and mobile field terminals deployed aboard ships, at military bases, in theaters of operation, and at educational and scientific institutions to receive and process the continuous broadcasts of JPSS and DWSS sensed data as the satellites pass overhead.

Figure 67: JPSS operations overview (NASA, NOAA, Ref. 1)
Figure 67: JPSS operations overview (NASA, NOAA, Ref. 1)
Figure 68: JPSS high level operational concept (Ref. 129)
Figure 68: JPSS high level operational concept (Ref. 129)

Satellite owner

Satellite

JPSS service

NOAA

Suomi-NPP (launch on October 28, 2011)
JPSS-1 (launch in 2017)
JPSS-2 (launch in 2022)

Full Service: commanding and data processing

DoD (Department of Defense)

DMSP
Coriolis (launch January 6, 2003)

Data acquisition and routing

JAXA (Japan Aerospace Exploration Agency)

GCOM-W1 (launch May 17, 2012)
GCOM-W2
GCOM-W3
GCOM-C1 (launch in 2014)

Data processing

EUMETSAT (European Organization for the Exploitation of Meteorological Satellites)

MetOp-A (launch October 19, 2006)
MetOp-B (launch September 17, 2012)

Data routing

Table 13: JPSS satellite fleet (Ref. 129)

On January 17, 2014, Raytheon successfully completed the Block 2 CDR (Critical Design Review), confirming readiness to support the JPSS-1 satellite. Block 2 represents a complete architectural and technological refresh of JPSS CGS and a significant step in supporting the next generation of the program. 131)

 

US Partnerships in JPSS Program

• EUMETSAT

- EUMETSAT provides mid-morning orbit

- Both support planning and operations (e.g., Antarctic Data Acquisition)

• JAXA (Japan Aerospace Exploration Agency)

- GCOM-W1 (Global Change Observation Mission – Water) provides AMSR-2 data – continuity for NASA’s Aqua satellite

- NOAA provides ground system services in exchange for data from AMSR-2

• NSC (Norwegian Space Center), Norway

- Provision of satellite tracking and environmental data acquisition services

• Canada (DND) and France (CNES) for SARSAT Program

• France (CNES) – Argos Program

Since being deployed for NOAA's Suomi-NPP (National Polar-orbiting Partnership) in 2011, JPSS CGS, one of the few multi-mission ground solutions, is now providing unprecedented global observation capability. Leveraging a common ground system across national and international agencies is the most efficient and cost effective way to improve global environmental observational capabilities. 132)

By leveraging a flexible architecture and integrating new and legacy technologies, the JPSS CGS reduces development and sustainment costs and has proven it can be quickly adapted to a variety of mission needs spanning civil, military and scientific communities.

In addition to supporting NOAA's Suomi-NPP and the GCOM-W1 mission of JAXA, other JPSS CGS support includes the MetOp series of EUMETSAT (European Organization for the Exploitation of Meteorological Satellites) and DoD's DMSP (Defense Meteorological Satellite Program) series.

Figure 69: JPSS ground system high-level architecture as of July 2012 (image credit: NASA, NOAA, Ref. 1)
Figure 69: JPSS ground system high-level architecture as of July 2012 (image credit: NASA, NOAA, Ref. 1)

 

JPSS GS Architecture with DoDAF 2 

DoDAF 2 = Department of Defense Architecture Framework version 2.0.

1) Introduction – Modeling the JPSS GS Architecture with DoDAF 2. 133)

• The JPSS Ground System (GS) is a complex, globally operated environmental satellite control, data retrieval, data processing, and environmental data product distribution system. Items of complexity include a large number of:

- takeholders

- project processes

- relationships with development contractors, and

- architectural modernization.

• The JPSS Ground Project (GP) uses the DoDAF 2.0 (Department of Defense Architecture Framework version 2.0) to manage and coordinate the GS development by identifying:

- JPSS GS organizational structure and performers;

- actions performed by the organizational entities;

- information that must flow among the entities; the systems, functions, and actions that enable realization of the JPSS capabilities; and,

- information and data exchanged among performers and systems.

• This focus on is on the processes for providing the SDRs (Sensor Data Records) and EDRs (Environmental Data Records) that are reduced from the satellite data and distributed to the program customers.

- A global view of the JPSS GS architecture is given in the following reference. 134)

2) Using DoDAF 2 with UPDM 2 to Describe JPSS Data Reduction Processes.

• A satellite’s data is arriving at the IDPS (Integrated Data Processing System) in the NSOF (NOAA Satellite Operations Facility) in Suitland, MD.

• The systems views needed to describe how the IDPS processes the data are those prescribed by the DoDAF 2 Systems Viewpoint (SV) SV-4 diagrams and SV-6 tables.

- There are 2 types of SV-4 diagrams: the System Functionality Description describes the hierarchy of systems and system Functions

- while the System Functionality Flow Description shows how the data flows through each system function action that processes the data.

- Each SV-6 System Resource Flow Matrix line item is a tabular description of each data element exchange between two system function actions in the companion SV-4 flow diagram.

• The DoDAF 2 views are presented using the UPDM 2 (Unified Profile for DoDAF and MODAF version 2.0).

- The modeling tool used is MagicDraw UML version 17.0.3 with UPDM 2 version 17.0.3.

- DoDAF 2 was selected when JPSS was initiated to take over for the NPOESS program.

3) SV-4 System Functionality Description Diagrams (see Ref. 133).

• Provide hierarchical views of the systems with their included functions.

• Documentation of the systems and functions are captured in the properties of those systems and functions.

• Show the lower level system and software functions used to process the data captured by the JPSS Project.

• Identify the system and software functional process flows that generate each deliverable data product.

• Assist in Systems Engineering requirements tracking.

• Identify the lower level specifications and verification plans defined in the SRS (Software Requirements Specification) that govern the JPSS data products.

• Identify the software algorithms contained in the lower level specifications.

4) Summary:

• The JPSS GS weather data processing architecture is indeed very complex

• Identifying and managing all levels of product dependencies to ensure product performance has been a challenge.

- Previous attempts to capture have quickly fallen out of date as the massive data flow and algorithm architecture evolved.

- Flight system Cal/Val is scheduled to span months of data capture, reduction, analysis and adjustment.

• The application of DoDAF 2/UPDM 2 has provided a mechanism to capture and manage this complex data processing architecture. Traces algorithm and data back to L1/L2 weather/climate performance metrics.

• The tool automatically manages dependencies which used to be managed by engineering/scientific analysis.

• The application of DoDAF 2/UPDM 2 will lead to a more structured process at significantly reduced resource costs, enabling more efficient and faster evolution and progress.

 


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95) http://ceres.larc.nasa.gov/

96) Susan Thomas, Kory J. Priestley, Mohan Shankar, Nathaniel P. Smith, Mark G. Timcoe, “Pre-launch Characterization of the Clouds and the Earth's Radiant Energy System (CERES) Flight Model 5 (FM5) Instrument on NPP,” Proceedings of IGARSS (International Geoscience and Remote Sensing Symposium), Vancouver, Canada, July 24-29, 2011

97) Eric Gillard, ”Keeping an Eye on Earth’s Energy Budget,” NASA, 24 Oct. 2017, URL: https://www.nasa.gov/feature/langley/keeping-an-eye-on-earth-s-energy-budget

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99) R. S. Wilson, R. B. Lee, et al., “On-orbit solar calibrations using the Aqua Clouds and Earth's Radiant Energy System (CERES) in-flight calibration system,” Proceedings of SPIE, Vol. 5151, 2003, pp. 288-299

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110) T. Scalione, F. De Luccia, J. Cymerman, E. Johnson, J. K. McCarthy, D. Olejniczak, “VIIRS Initial Performance Verification Subassembly, Early Integration and Ambient Phase I Testing of EDU,” Proceedings of IGARSS 2005, Seoul, Korea, July 25-29, 2005

111) C. P. Welsch, H. Swenson, S. A. Cota, F. DeLuccia, J. M. Haas, C. Schueler, R. M. Durham, J. E. Clement, P. E. Ardanuy, “VIIRS (Visible Infrared Imager Radiometer Suite): A Next-Generation Operational Environmental Sensor for NPOESS, IGARSS/IEEE 2001, Sydney, Australia, July 9-13, 2001

112) Carl Schueler , J. Ed Clement, Lane Darnton, Frank De Luccia, Tanya Scalione, Hilmer Swenson, “VIIRS Sensor Performance,” Proceedings of IGARSS 2003, Toulouse, France, July 21-25, 2003

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118) B. Guenther, “A Calibration Algorithm Design and Analysis for VIIRS Thermal Emissive Bands Based on the EOS MODIS Approach,” Proceedings of IGARSS 2003, Toulouse, France, July 21-25, 2003

119) X. Xiong, R. Murphy, “The Impact of Solar Diffuser Screen on the Radiometric Calibration of Remote Sensing Systems,” Proceedings of IGARSS 2003, Toulouse, France, July 21-25, 2003

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122) Frank De Luccia, Bruce Guenther, Chris Moeller, Xiaoxiong Xiong, Robert Wolfe, “NPP VIIRS Pre-launch Performance and SDR Validation,” Proceedings of IGARSS (International Geoscience and Remote Sensing Symposium), Vancouver, Canada, July 24-29, 2011

123) Mitchell D. Goldberg, “SUOMI National Polar-orbiting Partnership Status and Instrument Performance,” Proceedings of the 11th Annual JACIE (Joint Agency Commercial Imagery Evaluation ) Workshop, Fairfax, Va, USA, April 17-19, 2012, URL: http://calval.cr.usgs.gov/wordpress/wp-content/uploads/Goldberg_JACIE_2012_Goldberg1.pdf

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125) Kameron Rausch, Frank De Luccia, David Moyer, Jason Cardema, Ning Lei, Jon Fulbright, Chengbo Sun, Vincent Chiang, “Suomi NPP VIIRS Reflective Solar Band Radiometric Calibration,” Proceedings of IGARSS (International Geoscience and Remote Sensing Symposium), Munich, Germany, July 22-27, 2012

126) Slawomir Blonski, Changyong Cao, Sirish Uprety, Xi Shao, “Using Antarctic Dome C Site and simultaneous nadir overpass observations for monitoring radiometric performance of NPP VIIRS instrument,” Proceedings of IGARSS (International Geoscience and Remote Sensing Symposium), Munich, Germany, July 22-27, 2012

127) Quanhua Liu, Changyong Cao, Fuzhong Weng, “Suomi NPP VIIRS emissive band radiance calibration and Analysis,” Proceedings of IGARSS (International Geoscience and Remote Sensing Symposium), Munich, Germany, July 22-27, 2012

128) “Raytheon Awarded Joint Polar Satellite System Contracts - NASA contracts replace and expand previous NPOESS commitment to Raytheon,” URL: http://www.globalsecurity.org/space/library/news/2010/space-100930-raytheon01.htm

129) Jeffrey L. Hayden, Alan Jeffries, “On Using SysML, DoDAF 2.0 and UPDM to Model the Architecture for the NOAA’s Joint Polar Satellite System (JPSS) Ground System (GS),” Proceedings of SpaceOps 2012, The 12th International Conference on Space Operations, Stockholm, Sweden, June 11-15, 2012, URL: http://www.spaceops2012.org/proceedings/documents/id1289592-Paper-001.pdf

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131) “Raytheon receives contract modification on JPSS Common Ground System,” Space Daily, March 6, 2014, URL: http://www.spacedaily.com/reports/Raytheon_receives_contract_modification_on_JPSS_Common_Ground_System_999.html

132) “Joint Polar Satellite System Common Ground System now serving newest mission,” Space Daily, January 10, 2013, URL: http://www.spacedaily.com/reports/Joint_Polar_Satellite_System_Common_Ground_System_now_serving_newest_mission_999.html

133) Robert Morgenstern, Jeff Hayden, Alan Jeffries, Laura Ellen Dafoe, “Application of DoDAF 2.0 for NOAA’s JPSS Ground System and Project,” GSAW (Ground System Architectures Workshop) 2013, March 18-21, 2013, Los Angeles, CA, USA, URL: http://sunset.usc.edu/GSAW/gsaw2013/s4/jeffries.pdf

134) Robert Morgenstern, Jeff Hayden, Alan Jeffries, “Defining the Complex JPSS Ground System in Pieces Using DoDAF 2.0 as Implemented with UPDM,” Proceedings of the AIAA Space Conference & Exposition, Sept. 11-13, 2012, Pasadena, CA, USA, paper: AIAA2012-5256, DOI: 10.2514/6.2012-5256
 


The information compiled and edited in this article was provided by Herbert J. Kramer from his documentation of: ”Observation of the Earth and Its Environment: Survey of Missions and Sensors” (Springer Verlag) as well as many other sources after the publication of the 4th edition in 2002. - Comments and corrections to this article are always welcome for further updates (eoportal@symbios.space).

 

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