Solar radiation enters the Earth's atmosphere with a portion being scattered by clouds and aerosols.

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Processing, archiving and distributing Earth science data
at the NASA Langley Research Center

Projects Supported

ASDC Projects Supported


Projects Definition/Description Spatial Coverage Temporal Coverage


The NASA MEaSUREs program began in 2008 and has the goal of creating stable, community accepted Earth System Data Records (ESDRs) for a variety of geophysical time series. A reanalysis and extension of the NASA Water Vapor Project (NVAP), called NVAP-M is being performed as part of this program. When processing is complete, NVAP-M will span 1987-2010. Read about changes in the new version.

Related Projects: SMMR

Global 1988- 2009


Polar Ozone and Aerosol Measurement (POAM) II instrument measures the vertical distribution of atmospheric ozone, nitrogen dioxide, and aerosol extinction. The instrument was developed by the Naval Research Laboratory (NRL). POAM II was launched aboard the French SPOT-3 satellite on September 26, 1993 into a Sun synchronous polar orbit.

Related Project: POAM III

Lat: -88.11 to -62.55 and 54.68 to 71.01 10/15/1993 - 11/13/1996


Polar Ozone and Aerosol Measurement (POAM) III instrument measures the vertical distribution of atmospheric ozone, water vapor, nitrogen dioxide, and aerosol extinction. The instrument was developed by the Naval Research Laboratory (NRL). POAM III was launched aboard the French SPOT-4 satellite in March 1998 into a Sun synchronous polar orbit.

Related Project: POAM II

Lat: -88.11 to -62.55 and 54.68 to 71.01 04/22/1998 - 12/05/2005

PolarWinds II

Beginning in the fall of 2014, NASA sponsored two airborne field campaigns, collectively called Polar Winds, designed to fly the Doppler Aerosol WiNd (DAWN) lidar and other instruments to take airborne wind measurements of the Arctic atmosphere, specifically over and off the coasts of Greenland during Oct-Nov 2014 and May 2015. In particular, Polar Winds conducted a series of science experiments focusing on the measurement and analyses of lower tropospheric winds and aerosols associated with coastal katabatic flows, barrier winds, the Greenland Tip Jet, boundary layer circulations such as rolls and OLEs (Organized Large Eddies), and near surface winds over open water, transitional ice zones and the Greenland Ice Cap.


Polar Winds I was based in Kangerlussuaq, Greenland and flew DAWN on board the NASA King Air UC-12B during Oct-Nov 2014 while Polar Winds II was based in Keflavik, Iceland and utilized the NASA DC-8 aircraft to fly DAWN and Dropsondes over the Arctic in May 2105. In total, twenty-four individual missions with over 80 hours of research flights were flown in the Arctic region near Greenland and Iceland during Polar Winds.


The focus instrument for the wind measurements taken over the Arctic during Polar Winds was the DAWN airborne wind lidar. At a wavelength of 2.05 microns and at 250 mj per pulse, DAWN is the most powerful airborne Doppler Wind Lidar available today for airborne missions. DAWN has previously been flown on the NASA DC-8 during the 2010 Genesis and Rapid Intensification Processes (GRIP) campaign and on the NASA C-12 for wind field characterization off the coast of Virginia. In addition to DAWN, Polar Winds utilized the High Definition Sounding System (HDSS) dropsonde delivery system developed by Yankee Environmental Services to drop almost 100 dropsondes during Polar Wind II to obtain additional high-resolution vertical wind profiles during most missions. These dropsondes also provided needed calibration/validation for the much newer DAWN measurements.

(53.5, 70.5)(-59, -6) 05/11/2015 -05/25/2015


The Prediction of Worldwide Energy Resource (POWER) project was initiated to improve upon the current SSE data set and to create new data sets from new satellite systems and forecast modeling data. The improved SSE data will continue to be focussed on the solar and wind Renewable Energy industry. New data sets will target Sustainable Buildings and Agroclimatology.

Global 30 year averages (1/1/1984 – 12/31/2013)


The Stratospheric Aerosol and Gas Experiment (SAGE) I instrument was launched February 18, 1979, aboard the Applications Explorer Mission-B (AEM-B) satellite (McCormick et al., 1979). The SAGE I instrument had four spectral channels centered at wavelengths of 1000, 600, 450, and 385 nanometers for nearly global measurement of aerosol extinction profiles and ozone and nitrogen dioxide concentration profiles. The AEM-B satellite was placed in an orbit of approximately 600 kilometers at an inclination of 56 degrees to extend the latitudinal coverage for the solar occultation measurements from 79 degrees South to 79 degrees North. The SAGE I instrument collected data for almost three years until the AEM-B satellite power subsystem failed.

The SAGE I instrument was a sun photometer that measured the attenuation of solar radiation through the Earth's atmosphere during spacecraft sunrise and sunset in the four spectral regions mentioned above. The solar radiance data were combined with spacecraft ephemeris and NOAA meteorological data and then numerically inverted to yield altitude profiles of aerosol extinction at wavelengths of 1000 and 450 nanometers and altitude profiles of ozone and nitrogen dioxide concentration.

The SAGE I aerosol data were validated by comparison with correlative lidar and dustsonde in situ measurements; the ozone data were validated by comparison with balloon ECC ozonesonde and rocket measurements; and the nitrogen dioxide measurements were compared with climatology.

Related Projects: SAM II, SAGE II, SAGE III

80N to 80S, 180E to 180W 02/18/1979 - 11/18/1981


The goals of the Stratospheric Aerosol and Gas Experiment (SAGE) II are to determine the spatial distributions of stratospheric aerosols, ozone, nitrogen dioxide, water vapor, and cloud occurrence by mapping vertical profiles and calculating monthly averages of each. The SAGE II sensor (a Sun Photometer) was launched into a 57-degree inclination orbit aboard the Earth Radiation Budget Satellite (ERBS) in October 1984. The Langley Data Center continues to receive and archive the SAGE II data that contain Aerosols, NO2, O3, and water vapor profiles.

Related Projects: SAM II, SAGE I, SAGE III

80N to 80S, 180E to 180W 10/24/1984 - 08/31/2005


The Stratospheric Aerosol and Gas Experiment (SAGE) III instrument utilizes the self-calibrating solar occultation technique to measure profiles of aerosols, clouds, ozone (O3), nitrogen dioxide (NO2), and water vapor (H2O), identified as critical in the U.S. National Plan for Stratospheric Monitoring, and utilizes lunar occultation observations to monitor the key nighttime species nitrogen trioxide (NO3) and chlorine dioxide (OClO).

SAGE III is a natural and improved extension of the very successful SAM II, SAGE I, and SAGE II experiments. The solar occultation (SOC), or Earth-limb extinction technique employed by these experiments is inherently a well-posed, well-behaved inversion problem, is self-calibrating, and has demonstrated high vertical resolution and high signal-to-noise and, therefore, possesses excellent accuracy.


50 to 80 degrees North, 30 - 50 degrees South 02/27/2002 - 12/31/2005


Launched on February 19, 2017 on a SpaceX Falcon 9 from Kennedy Space Center, the Stratospheric Aerosol and Gas Experiment III on the International Space Station (SAGE III-ISS) is the second instrument from the SAGE III project, externally mounted on the International Space Station (ISS). This ISS-based instrument uses a technique known as occultation, which involves looking at the light from the Sun or Moon as it passes through Earth’s atmosphere at the edge, or limb, of the planet to provide long-term monitoring of ozone vertical profiles of the stratosphere and mesosphere. The data provided by SAGE III-ISS includes key components of atmospheric composition and their long-term variability, focusing on the study of aerosols, chlorine dioxide, clouds, nitrogen dioxide, nitrogen trioxide, pressure and temperature, and water vapor. SAGE data has historically been used by the World Meteorological Organization to inform their periodic assessments of ozone depletion. These new observations from the International Space Station will continue the SAGE team's contributions to ongoing scientific understanding of the Earth's atmosphere.

Related Projects: SAGE I, SAGE II, SAGE III

Global 03/17/2017 - Present


The Stratospheric Aerosol Measurement (SAM) II experiment flew aboard the Nimbus-7 spacecraft and provided vertical profiles of aerosol extinction in both the Arctic and Antarctic polar regions. The SAM II data coverage began on October 29, 1978, and extended through December 18, 1993, until SAM II was no longer able to acquire the Sun. The data coverage for the Arctic region extends through January 7, 1991, and contains data gaps beginning in 1988 that increase in size each year. The data coverage for the Antarctic region is continuous through December 18, 1993, except for a time period from mid-January 1993 through October 1993. The data gaps for both the Arctic and Antarctic regions are due to an orbit degradation associated with the Nimbus-7 spacecraft.

Related Projects: SAGE I, SAGE II, SAGE III

Polar Regions 10/29/1978 - 12/18/1993