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Aerosol optical depth (AOD) is an assessment of the amount of visible and infrared light aerosols scatter or absorb in a column of the atmosphere, and is sometimes referred to as aerosol optical thickness (AOT). AOD is a unitless measure. From an observer on the ground, an AOD of less than 0.1 is characteristic of a clear sky, bright Sun, and maximum visibility. As AOD increases to 0.5, 1.0, and greater than 3.0, aerosols become so dense that the Sun is obscured.
Descriptions of these measurements will be reviewed in more detail later in this Data Pathfinder. The following sections will help guide you to topic-specific data and resources for accessing, visualizing, preparing/manipulating (e.g. subsetting), and analyzing data. Each observation, model, and reanalysis data has unique characteristics that should be considered when evaluating its use.
An asterisk (*) next to an entry indicates that near real-time (NRT) data products are available through NASA's Land, Atmosphere Near real-time Capability for EOS (LANCE). While not intended for scientific research, NRT data are good resources for monitoring ongoing or time-critical events. To learn more about the difference between NRT and Standard Science Products, see Near Real Time versus Standard Products.
Spatial Resolution | Spatial Coverage | Temporal Resolution | Temporal Coverage | Spectral Resolution | Satellite/ Platform | Name (Sensor, Model, etc.) | Observation, Model, or Reanalysis | File Format |
---|---|---|---|---|---|---|---|---|
250 m, 500 m, 1 km, 10 km, 3 km | Global | Daily, 8-day, 16-day, monthly, quarterly, yearly | 2000 (Terra)/2002 (Aqua)-present | 36 spectral bands ranging in wavelength from 0.4 µm to 14.4 µm | Terra/Aqua | *Moderate Resolution Imaging Spectroradiometer (MODIS) | Observation | HDF-EOS |
6 km, 1° | Global | *6-minute, Daily, Monthly |
2012-present | 0.600-0.680 µm, 3.55-3.93 µm, 10.5-12.4 µm | NASA/NOAA Suomi National Polar-orbiting Partnership (Suomi NPP) and NOAA-20 | Visible Infrared Imaging Radiometer Suite (VIIRS): Deep Blue | Observation | HDF5, HDF-EOS5 |
6 km | Global | <-minute | 2012-present | 0.600-0.680 µm, 3.55-3.93 µm, 10.5-12.4 µm | NASA/NOAA Suomi NPP Dark Target | *Visible Infrared Imaging Radiometer Suite (VIIRS): Dark Target | Observation | netCDF4 |
0.25°, 13 km x 24 km | Global | *~98 minutes, Daily |
2004-present | 1.0-0.45 nm Full Width and Half Maximum (FWHM) | Aura | *Ozone Monitoring Instrument (OMI) | Observation | HDF-EOS5 |
10 km | Global | 12-24 per day | 2017-present | 10 channels from 317-779 nm | Deep Space Climate Observatory (DSCOVR) | EPIC | Observation | HDF5 |
0.5° x 0.625° | Global | 1-hourly, monthly | 1980-near present | N/A | N/A | MERRA -2 | Reanalysis | netCDF |
N/A | Varies | Sub-hourly | Varies by site | N/A | Ground-based | AERONET | Observation | ASCII |
Point measurements | Global | Periodic flights occurred during each deployment | 2016-2018 | varies | Airborne Field Campaign | Atmospheric Tomography Mission (ATom) campaign with varying instruments | Observation | netCDF |
Moderate Resolution Imaging Spectroradiometer (MODIS) instruments are aboard NASA’s Terra (launched 1999) and Aqua (launched 2002) satellites and provide estimates about AOD. Terra's orbit is timed so that it passes from north to south across the equator in the morning, while Aqua passes south to north over the equator in the afternoon.
MODIS daily data can be visualized and interactively explored using NASA Worldview:
The non-aerosol signal of surface reflectance needs to be separated from the aerosol signal to accurately obtain AOD. Scientists have developed two algorithms for MODIS data to account for these effects: Dark Target and Deep Blue. In the latest dataset collection, these two algorithms have been merged, using the highest quality for each. For more information about the differences between these, see What is the difference between dark target and deep blue?
Dark Target and Deep Blue data can be interactively visualized using NASA Worldview:
Using an online interactive tool called Giovanni, map visualizations of MODIS AOD data products can be downloaded as PNG images, or as GeoTIFF or KMZ files; time-series data are available as CSV data files, and animations are in either webm video format or animated GIF images:
Research quality MODIS data products can be accessed directly from Earthdata Search:
Near real-time (NRT) MODIS Surface Reflectance data are available through NASA’s Land, Atmosphere Near real-time Capability for EOS (LANCE) within 60 to 125 minutes after a satellite observation.
MODIS/Terra and MODIS/Aqua NRT data in Earthdata Search:
MODIS/Terra and MODIS/Aqua Combined NRT data in Earthdata Search:
The Ozone Monitoring Instrument (OMI) aboard NASA's Aura satellite has a coarser spatial resolution than MODIS and VIIRS, but provides data at individual wavelengths from the ultraviolet (UV) to the visible. This is important because pollutants have different spectral signatures. For example, a wavelength range around 400 nm can be used to detect elevated layers of absorbing aerosols such as biomass burning and desert dust plumes.
Daily data can be accessed and interactively explored using NASA Worldview:
Using an online interactive tool called Giovanni, map visualizations of OMI AOD data products can be downloaded as PNG images, or as GeoTIFF or KMZ files; time-series data are available as CSV data files, and animations are in either webm video format or animated GIF images:
The Earth Polychromatic Imaging Camera (EPIC) is a 10-channel spectroradiometer (317 to 780 nm) aboard NOAA’s Deep Space Climate Observatory (DSCOVR) spacecraft (which is a partnership between NASA, NOAA, and the U.S. Air Force). EPIC provides color images of the entire sunlit face of Earth at least once every two hours from 1 million miles away. DSCOVR’s location gives it a unique angular perspective that is used to measure ozone, aerosols, cloud reflectivity, cloud height, vegetation properties, and UV radiation estimates.
Research quality data can be accessed using Earthdata Search:
The Visible Infrared Imaging Radiometer Suite (VIIRS) instruments aboard the NASA/NOAA Suomi National Polar-orbiting Partnership (Suomi NPP) and NOAA-20 satellites collect AOD data at a finer spatial resolution than MODIS. VIIRS uses the Deep Blue algorithm over land and the Satellite Ocean Aerosol Retrieval (SOAR) algorithm over water to determine atmospheric aerosol loading for daytime cloud-free, snow-free scenes. Downloading a VIIRS data file provides the data with just the land algorithm, just the ocean algorithm, and the merged algorithm.
Daily data can be accessed and interactively explored using NASA Worldview:
Research quality data products can be accessed using Earthdata Search:
The Modern-Era Retrospective analysis for Research and Applications version 2 (MERRA-2) offers a data assimilation of AOD analysis available every three hours from 1980 to present with a latency of about three weeks after the end of a month.
Monthly data can be accessed and explored interactively using NASA Worldview:
NASA's Global Modeling and Assimilation Office’s (GMAO) offers visualizations of MERRA-2 AOT data:
Using an online interactive tool called Giovanni, map visualizations of MERRA-2-analyzed AOD data products can be downloaded as PNG images, or as GeoTIFF or KMZ files; time-series data are available as CSV data files, and animations are in either webm video format or animated GIF images:
Research quality data products can be accessed using Earthdata Search and Google Earth Engine:
Thirty years of ground-based AOD measurements are available through NASA’s Aerosol Robotic Network (AERONET). AERONET is a global network of ground-based Sun photometers. These photometers calculate AOD and the amount of water vapor in the atmosphere by comparing the amount of light they detect with the amount of solar radiation that would be observed in an aerosol-free atmosphere. AERONET also takes sky brightness measurements that can be used to infer aerosol size distribution, refractive index, and single scattering albedo.
The Atmospheric Tomography Mission (ATom) is a NASA Earth Venture Suborbital-2 mission to study the impact of human-produced air pollution on greenhouse gases and on chemically reactive gases in the atmosphere. ATom deployed an extensive gas and aerosol payload on the NASA DC-8 aircraft for systematic, global-scale sampling of the atmosphere, profiling continuously from 0.2 to 12 km altitude. Around-the-world flights were conducted in each of four seasons between 2016 and 2018.
Aerosol Index (AI) is a measurement related to AOD and indicates the presence of an increased amount of tiny suspended particles called aerosols in the atmosphere. In general, a lower AI value indicates more clear skies due to a lower concentration of aerosols. The calculation of the Aerosol Index is based on wavelength-dependent changes in Rayleigh scattering in the ultraviolet (UV) spectral range where ozone absorption is very small. The aerosol index is derived from normalized radiances using 2 wavelength pairs at 340 and 378.5 nm. UVAI can be calculated in the presence of clouds so that daily global coverage is possible. This is ideal for tracking the evolution of episodic aerosol plumes from dust outbreaks, volcanic ash, significant fire events, and biomass burning.
Descriptions of these measurements will be reviewed in more detail later in this Data Pathfinder. The following sections will help guide you to topic-specific data and resources for accessing, visualizing, preparing/manipulating (e.g. subsetting), and analyzing data. Each observation, model, and reanalysis data has unique characteristics that should be considered when evaluating its use.
An asterisk (*) next to an entry indicates that near real-time (NRT) data products are available through NASA's Land, Atmosphere Near real-time Capability for EOS (LANCE). While not intended for scientific research, NRT data are good resources for monitoring ongoing or time-critical events. For more information about the differences between NRT and Standard Science Products, please see Near Real-Time versus Standard Products.
Spatial Resolution | Spatial Coverage | Temporal Resolution | Temporal Coverage | Spectral Resolution | Satellite/ Platform |
Name (Sensor, Model, etc.) |
Observation, Model, or Reanalysis |
File Format |
---|---|---|---|---|---|---|---|---|
13 km x 24 km, 13 x 12 km 0.25°, 1° |
Global | 98 minutes, 32 days |
2004-present | 1.0-0.45 nm Full Width and Half Maximum (FWHM) | Aura | Ozone Monitoring Instrument (OMI) | Observation | HDF-EOS5 |
50 km* | Global | 101 minutes, Daily | 2018-present | 250-420 nm *NRT:wavelength pairs at 340 and 378.5 nm |
NASA/NOAA Suomi National Polar-orbiting Partnership (Suomi NPP) | *Ozone Mapping and Profiler Suite (OMPS) | Observation | HDF5 |
7 km x 3.5 km, 5.5 km x 3.5 km |
Global | 101.5 minutes, Daily | 2017-present | 270 nm–2.3 µm, 0.55 nm | Sentinel-5P | TROPOMI | Observation | netCDF |
0.5º x 0.625° | Global | Monthly | 1980-present | N/A | N/A | MERRA-2 | Reanalysis | netCDF |
The NASA Earthdata Cloud Cookbook has tutorials to help access Earth science data in the cloud
The Ozone Monitoring Instrument (OMI) aboard NASA's Aura satellite has a coarser spatial resolution than MODIS and VIIRS, but provides data at individual wavelengths from the ultraviolet (UV) to the visible. This is important because pollutants have different spectral signatures. For example, a wavelength range around 400 nm can be used to detect elevated layers of absorbing aerosols such as biomass burning and desert dust plumes.
Daily data can be accessed and interactively explored using NASA Worldview:
Using an online interactive tool called Giovanni, map visualizations of OMI AI data products can be downloaded as PNG images, or as GeoTIFF or KMZ files; time-series data are available as CSV data files, and animations are in either webm video format or animated GIF images:
Level 2 data are available
OMPS Aerosol Index layer indicates the presence of UV-absorbing particles in the air.
Daily data can be accessed and interactively explored using NASA Worldview:
Level 2 data are available in Earthdata Search:
The Tropospheric Monitoring Instrument (TROPOMI) was co-funded by ESA (European Space Agency) and the Netherlands and is the single payload aboard ESA's Sentinel-5P spacecraft. TROPOMI measures solar radiation reflected by and radiated from Earth.
Research quality data from Earthdata Search:
The Modern-Era Retrospective analysis for Research and Applications, Version 2 (MERRA-2) is the latest version of global atmospheric reanalysis for the satellite era produced by NASA's Global Modeling and Assimilation Office (GMAO) using the Goddard Earth Observing System Model (GEOS) version 5.12.4. The dataset covers the period of 1980 to present with the latency of about 3 weeks after the end of a month.
Using an online interactive tool called Giovanni, map visualizations of MERRA-2 Aerosol Index data products can be downloaded as PNG images, or as GeoTIFF or KMZ files; time-series data are available as CSV data files, and animations are in either webm video format or animated GIF images:
Atmospheric particulate matter (PM) refers to microscopic particles of solid or liquid matter suspended in the air. These inhalable particles range in size from coarse particles like PM10 that have a diameter of 10 micrometers (μm) or less to finer particles, designated PM2.5 or PM1.0, that have a diameter of 2.5 μm, 1.0 μm, or less. While microscopic in size, PM can have a big effect on climate, precipitation, and air quality that may in turn impact human health.
It's important to be aware of the differences between Aerosol Optical Depth (AOD) and PM2.5. AOD is an optical measurement averaged over an area in a column of air from the top of the atmosphere to the surface and is a unitless measure. PM2.5 is a measure of the mass of particles in a specific size range within a given volume of air near the surface taken at a specific point in time. The overall differences between AOD and PM2.5:
Because the two measurements are so different, it may seem that they are not relatable. However, there are several different techniques to estimate surface concentrations of PM2.5 from AOD measurements. While there is a relationship between AOD and PM2.5, there are other factors that can affect AOD, like humidity, the vertical distribution of aerosols, and the shape of the particles. For example, an increase in humidity will increase the size of particles and therefore increase the AOD even though the PM2.5 level will be the same.
Descriptions of these measurements will be reviewed in more detail later in this Data Pathfinder. The following sections will help guide you to topic-specific data and resources for accessing, visualizing, preparing/manipulating (e.g. subsetting), and analyzing data. Each observation, model, and reanalysis data has unique characteristics that should be considered when evaluating its use.
Spatial Resolution | Spatial Coverage | Temporal Resolution | Temporal Coverage | Spectral Resolution | Satellite/ Platform | Name (Sensor, Model, etc.) | Observation, Model, or Reanalysis | File Format |
---|---|---|---|---|---|---|---|---|
12 km x 12 km |
N. America |
3-hourly |
2022-present |
N/A |
N/A |
Model |
netCDF, ASCII | |
0.5º x 0.625° | Global | Monthly | 1980-present | N/A | N/A | MERRA-2 | Reanalysis | netCDF |
0.25º x 0.312° |
Global | 3-hourly | Near-real time assimilation (DAS), 10-day forecast at 00z, and 5-day forecast at 12z |
N/A | N/A | GEOS FP | Analysis | netCDF |
0.25º x 0.25° | Global | 15 min, Hourly | Daily 5-day forecast | N/A | N/A | GEOS-CF | Model | netCDF |
Using the Hazardous Air Quality Ensemble System (HAQES), the Air Quality Laboratory at George Mason University developed real-time surface PM2.5 composition products as one project of the NASA Health Air Quality Applied Science Team (HAQAST). HAQES is a real-time ensemble forecast of hazardous air quality events, such as wildfires, dust storms, and volcanic eruptions. Regional and global models from multiple agencies have been used to create the ensemble, including NASA's Goddard Earth Observing System (GEOS); the Navy Aerosol Analysis and Prediction System (NAAPS) from the Naval Research Laboratory; the Global Ensemble Forecast System Aerosols (GEFS), High-Resolution Rapid Refresh (HRRR); and the NOAA-EPA Atmosphere-Chemistry Coupler-Community Multiscale Air Quality model (NACC-CMAQ).
The GEOS Forward Processing (GEOS FP) model and data assimilation system is the NASA Global Modeling and Assimilation Office's (GMAO) state-of-the-science numerical weather prediction (NWP) model that assimilates conventional and satellite-based weather observations, aerosol optical depth, and ozone in near real-time (NRT) in order to have the best initial conditions for the forecasts: 10-day at 00 UTC and 5-day at 12 UTC. GEOS FP forecasts are used to support a wide range of NASA missions and campaigns. Note that forecasts using the GEOS FP are experimental.
Goddard Earth Observing System (GEOS) GEOS-Composition Forecast (CF) system forecasts trace gas and aerosol fields using constrained meteorology from GEOS and the GEOS-Chem chemical mechanism. This community-developed, global 3D model of atmospheric chemistry is publicly available and offers five-day forecasts. Forecasts from the GEOS-CF system are experimental.
MERRA-2 is the latest version of global atmospheric reanalysis for the satellite era produced by NASA's Global Modeling and Assimilation Office (GMAO) using the Goddard Earth Observing System Model (GEOS) version 5.12.4. The dataset covers 1980 to present with the latency of about 3 weeks after the end of a month.
Monthly Dust Surface Mass Concentration (PM2.5) from MERRA-2 can be accessed and interactively explored using NASA Worldview:
Using an online interactive tool called Giovanni, data products can be visualized as a time-averaged map, an animation, seasonal maps, scatter plots, or a time series, as well as downloaded in .CSV format:
MERRA-2 PM2.5 in GMAO’s visualization and data access website, FLUID:
Earthdata GIS Products:
MERRA-2 PM2.5 in Earthdata Search and Google Earth Engine:
Very large dust storms lasting hours or days can be observed and tracked using satellite imagery. The most common source of dust globally is the Sahara Desert. Giant dust storms periodically sweep off the coast of West Africa and can be transported as far as Florida and the Caribbean.The amount of dust transported by these storms can be quantified using the Dust Score, which is calculated from data acquired by the Atmospheric Infrared Sounder (AIRS) instrument aboard NASA’s Aqua satellite. The AIRS Dust Score indicates the level of atmospheric aerosols in Earth’s atmosphere over the ocean. Dust is probable when the score is above 380, and higher scores indicate more certainty that dust is present. The numerical scale is a qualitative representation of the presence of dust in the atmosphere, an indication of where large dust storms may form, and the areas that may be affected.
Descriptions of these measurements will be reviewed in more detail later in this Data Pathfinder. The following sections will help guide you to topic-specific data and resources for accessing, visualizing, preparing/manipulating (e.g. subsetting), and analyzing data. Each observation, model, and reanalysis data has unique characteristics that should be considered when evaluating its use.
An asterisk (*) next to an entry indicates that near real-time (NRT) data products are available through NASA's Land, Atmosphere Near real-time Capability for EOS (LANCE). While not intended for scientific research, NRT data are good resources for monitoring ongoing or time-critical events. For more information about the differences between NRT and Standard Science Products, please see Near Real-Time versus Standard Products.
Spatial Resolution | Spatial Coverage | Temporal Resolution | Temporal Coverage | Spectral Resolution | Satellite/ Platform |
Name (Sensor, Model, etc.) |
Observation, Model, or Reanalysis |
File Format |
---|---|---|---|---|---|---|---|---|
50 km |
Global |
6 min, hourly, 3-hourly, 6-hourly |
2016-present for NRT, 2002 for other | 2,378 infrared channels in the 3.74 to 15.4 micron spectral range | Aqua | *AIRS | Observation | HDF-EOS |
The AIRS Dust Score can be visualized using NASA Worldview:
Create and share layered maps with AIRS data using the AIRS Browse Tool.
Research quality data products can be accessed using Earthdata Search:
Near real-time (NRT) MODIS Surface Reflectance data are available through NASA’s Land, Atmosphere Near real-time Capability for EOS (LANCE) within 60 to 125 minutes after a satellite observation:
Nitrogen dioxide (NO2) is a pollutant, the primary sources of which are automobile exhaust, smoke from industry, and the burning of fossil fuels. If breathed in, NO2 can aggravate respiratory conditions such as asthma. Long-term exposure can lead to the development of asthma and potentially increase susceptibility to respiratory infections. NO2 reacts with other chemicals in the atmosphere, forming particulate matter and ozone, producing haze and acid rain, and contributing to nitrogen pollution in coastal waters.
Descriptions of these measurements will be reviewed in more detail later in this Data Pathfinder. The following sections will help guide you to topic-specific data and resources for accessing, visualizing, preparing/manipulating (e.g. subsetting), and analyzing data. Each observation, model, and reanalysis data has unique characteristics that should be considered when evaluating its use.
An asterisk (*) next to an entry indicates that near real-time (NRT) data products are available through NASA's Land, Atmosphere Near real-time Capability for EOS (LANCE). While not intended for scientific research, NRT data are good resources for monitoring ongoing or time-critical events. To learn more about the difference between NRT and Standard Science Products, see Near Real Time versus Standard Products.
Spatial Resolution | Spatial Coverage | Temporal Resolution | Temporal Coverage | Spectral Resolution | Satellite/ Platform | Name (Sensor, Model, etc.) | Observation, Model, or Reanalysis | File Format |
---|---|---|---|---|---|---|---|---|
0.25°, 13 km x 24 km |
Global | 98 min, Daily | 2004-near present | 1.0-0.45 nm Full Width and Half Maximum (FWHM) | Aura | Ozone Monitoring Instrument (OMI) | Observation | HDF-EOS5 |
5.5 km x 3.5 km | Global | 101.5 minutes | 2021-present | 270 nm-2.3 µm, 0.55 nm | ESA Sentinel-5P | TROPOspheric Monitoring Instrument (TROPOMI) | Observation | netCDF |
2.0 km x 4.75 km | North America | Hourly | 08/2023 - present | 0.6 nm | Intelsat 40e | Tropospheric Emissions: Monitoring Pollution (TEMPO) | Observation | netCDF |
0.25º x 0.25° | Global | 15 min, Hourly | Daily 5-day forecast | N/A | N/A | GEOS-CF | Model | netCDF |
0.0083° x 0.0083° |
Near-global |
Yearly |
1990-2020 |
N/A |
N/A |
Model |
netCDF | |
Point measurements | Global | Periodic flights occurred during each deployment | 2016-2018 | Varies | Airborne Field Campaign | Atmospheric Tomography Mission (ATom) campaign with varying instruments | Observation | netCDF |
Data Visualizations
The Ozone Monitoring Instrument (OMI) aboard NASA’s Aura satellite uses an imaging spectrometer to distinguish between aerosol types, such as smoke, dust, and sulfates. It measures cloud pressure and coverage, which provides data to derive tropospheric ozone. OMI provides a record of total ozone and other atmospheric parameters related to ozone chemistry and climate. OMI also measures pollutants such as ozone, nitrogen dioxide, sulfur dioxide, and aerosols, which the U.S. Environmental Protection Agency (EPA) has designated as posing serious threats to human health and agricultural productivity.
Daily OMI NO2 data can be accessed and interactively explored using NASA Worldview:
NASA's Air Quality site provides more information on NO2, as well as trend maps and pre-made images of NO2 over cities and power plants.
Using an online interactive tool called Giovanni, map visualizations of OMI NO2 data products can be downloaded as PNG images, or as GeoTIFF or KMZ files; time-series data are available as CSV data files, and animations are in either webm video format or animated GIF images:
Research quality data products can be accessed using Earthdata Search:
The Tropospheric Monitoring Instrument (TROPOMI) was co-funded by ESA (European Space Agency) and the Netherlands. It is the single payload aboard ESA's Sentinel-5P spacecraft and measures the solar radiation reflected by and radiated from Earth.
Research quality data:
The Tropospheric Emissions: Monitoring of Pollution (TEMPO) instrument is a grating spectrometer, sensitive to visible (VIS) and ultraviolet (UV) wavelengths of light with a spectral range of 290-490 + 540-740 nm and 0.6 nm spectral resolution. The TEMPO instrument is attached to the Earth-facing side of a commercial telecommunications satellite (Intelsat 40e) in geostationary orbit over 91˚ W longitude (about 22,000 miles above Earth’s equator).
Research quality data:
These data are at beta maturity, which means that the product is minimally validated but may still contain significant errors; it is based on product quick looks using the initial calibration parameters. Because the products at this stage have minimal validation, users should refrain from making conclusive public statements regarding science and applications of the data products until a product is designated at the provisional validation status. For inquiries about this or other TEMPO data releases, please contact larc-dl-asdc-tempo@mail.nasa.gov or post/view questions on the Earthdata Forum.
Goddard Earth Observing System (GEOS) GEOS-Composition Forecast (CF) system forecasts trace gas and aerosol fields using constrained meteorology from GEOS and the GEOS-Chem chemical mechanism. This community-developed, global 3D model of atmospheric chemistry is publicly available and offers five-day forecasts. Forecasts using the GEOS system are experimental and the use of these forecasts for purposes other than research is not recommended.
The Nitrogen Dioxide Surface-Level Annual Average Concentrations Product contains estimated global NO2 surface values derived using a Land Use Regression (LUR) model (based on 5,220 NO2 monitors in 58 countries and land use variables) for the years 2010-2012. NO2 column densities from the Ozone Monitoring Instrument and MERRA-2 scale the concentrations to other years between 1990 and 2020. This product is part of NASA's Health and Air Quality Applied Sciences Team (HAQAST) effort.
Research quality data products can be accessed using Earthdata Search:
The Atmospheric Tomography Mission (ATom) is a NASA Earth Venture Suborbital-2 mission to study the impact of human-produced air pollution on greenhouse gases and on chemically reactive gases in the atmosphere. ATom deployed an extensive gas and aerosol payload on the NASA DC-8 aircraft for systematic, global-scale sampling of the atmosphere, profiling continuously from 0.2 to 12 km altitude. Around-the-world flights were conducted in each of four seasons between 2016 and 2018.
The primary sources of sulfur dioxide (SO2) are the burning of fossil fuels by power plants and industry. Volcanic emissions also contribute SO2, but in relatively smaller quantities. As with NO2, SO2 can aggravate respiratory conditions, especially asthma. In areas with high levels of SO2, sulfur oxides can react with other components to create small particles that contribute to overall particulate matter. This small particulate matter can contribute to low visibility in areas where SO2 is high. SO2 also can lead to acid rain.
Descriptions of these measurements will be reviewed in more detail later in this Data Pathfinder. The following sections will help guide you to topic-specific data and resources for accessing, visualizing, preparing/manipulating (e.g. subsetting), and analyzing data. Each observation, model, and reanalysis data has unique characteristics that should be considered when evaluating its use.
An asterisk (*) next to an entry indicates that near real-time (NRT) data products are available through NASA's Land, Atmosphere Near real-time Capability for EOS (LANCE). While not intended for scientific research, NRT data are good resources for monitoring ongoing or time-critical events. To learn more about the difference between NRT and Standard Science Products, see Near Real Time versus Standard Products.
Spatial Resolution | Spatial Coverage | Temporal Resolution | Temporal Coverage | Spectral Resolution | Satellite/ Platform | Name (Sensor, Model, etc.) | Observation, Model, or Reanalysis | File Format |
---|---|---|---|---|---|---|---|---|
50 km x 50 km | Global | 6 minutes | 2002-2023 | 2,378 infrared channels in the 3.74-15.4 micron spectral range | Aqua | *AIRS | Observation | HDF-EOS |
13 km x 24 km, 0.25°, 1° | Global | 98 minutes, Daily | 2004-present | 1.0-0.45 nm Full Width and Half Maximum (FWHM) | Aura | Ozone Monitoring Instrument (OMI) | Observation | HDF-EOS5 |
7.5 km x 3 km | Global | 101 minutes, Daily | 2018 | 250-420 nm | NASA/NOAA Suomi National Polar-orbiting Partnership (Suomi NPP) | Ozone Mapping and Profiler Suite (OMPS) | Observation | netCDF-4 |
7 x 3.5 km for all spectral bands, with the exception of the UV1 band (7 x 28 km2) and SWIR bands (7 x 7 km2) | Global | Daily | 2017-present | 270 nm-2.3 µm, 0.55 nm | ESA Sentinel-5P | TROPOspheric Monitoring Instrument (TROPOMI) | Observation | netCDF |
165 km x 3 km | Near-global (-82º to +82º latitude) | 15 minutes, Twice daily [day, night] |
2021-present | 190 and 240 GHz | Aura | *MLS | Observation | HDF-EOS5 |
0.5° x 0.625° | Global | Hourly, 3 hourly, Monthly |
1980-present | N/A | N/A | MERRA-2 | Reanalysis | netCDF |
0.25º x 0.25° |
Global | 15 min, Hourly | Daily 5-day forecast | N/A | N/A | GEOS-CF | Model | netCDF |
0.25º x 0.312° |
Global | 3-hourly | Near-real time assimilation (DAS), 10-day forecast at 00z, and 5-day forecast at 12z | N/A | N/A | GEOS FP |
Analysis |
netCDF |
Point measurements | Global | Periodic flights occurred during each deployment | 2016-2018 | varies | Airborne Field Campaign | Atmospheric Tomography Mission (ATom) campaign with varying instruments | Observation | netCDF |
Data Visualizations
The Atmospheric Infrared Sounder (AIRS) is a hyperspectral sounder that collects daily global measurements of water vapor and temperature profiles as one of four instruments comprising the AIRS Project Instrument Suite. When launched in 2002, the AIRS Project Instrument Suite was the most advanced atmospheric sounding system ever deployed in space. AIRS data are combined with data from the Advanced Microwave Sounding Unit (AMSU-A1 and AMSU-A2) and the Humidity Sounder for Brazil (HBS) to provide 3D measurements of temperature and water vapor through the atmospheric column along with measurements of atmospheric trace gases and surface and cloud properties. These data are used by weather prediction centers to improve forecasts and to validate climate models. They also are used in applications ranging from volcanic plume detection to drought forecasting.
NRT AIRS SO2 data can be accessed and interactively explored using NASA Worldview:
Create and share layered maps with AIRS data using the AIRS Browse Tool.
Research quality data products can be accessed using Earthdata Search:
The Ozone Monitoring Instrument (OMI) aboard NASA's Aura satellite uses an imaging spectrometer to distinguish between aerosol types, such as smoke, dust, and sulfates. It measures cloud pressure and coverage, which provides data to derive tropospheric ozone. OMI provides a record of total ozone and other atmospheric parameters related to ozone chemistry and climate. OMI also measures criteria pollutants such as ozone, nitrogen dioxide, sulfur dioxide, and aerosols, which the U.S. Environmental Protection Agency (EPA) has designated as posing serious threats to human health and agricultural productivity.
NRT data can be accessed and interactively explored using NASA Worldview:
NASA Global Sulfur Dioxide Monitoring program that provides imagery of daily SO2 from OMI, OMPS, and TROPOMI. The site also provides information on the source of emissions.
In addition, the Historical Anthropogenic Sulfur Dioxide Emissions dataset, available through NASA's Socioeconomic Data and Applications Center (SEDAC), offers annual estimates of anthropogenic global and regional SO2 emissions spanning the period 1850-2005.
Using an online interactive tool called Giovanni, map visualizations of OMI SO2 data products can be downloaded as PNG images, or as GeoTIFF or KMZ files; time-series data are available as CSV data files, and animations are in either webm video format or animated GIF images:
Research quality data products can be accessed using Earthdata Search:
The Ozone Mapping and Profiler Suite (OMPS) aboard the joint NASA/NOAA Suomi National Polar-orbiting Partnership (Suomi NPP) satellite tracks the health of Earth's ozone layer and measures the concentration of atmospheric ozone.
Daily data can be accessed and interactively explored using NASA Worldview:
Research quality data products can be accessed using Earthdata Search:
The Tropospheric Monitoring Instrument (TROPOMI) was co-funded by ESA (European Space Agency) and the Netherlands, and is a space-borne, nadir-viewing, imaging spectrometer covering wavelength bands between the ultraviolet and the shortwave infrared. TROPOMI is the single payload aboard ESA's Sentinel-5P spacecraft and measures the solar radiation reflected by and radiated from Earth.
Research quality data products can be accessed using Earthdata Search:
The Microwave Limb Sounder (MLS) is a passive microwave radiometer/spectrometer that measures microwave thermal emission from the limb (edge) of Earth’s atmosphere to sense vertical profiles of atmospheric gases, temperature, pressure, and cloud ice. MLS measurements are acquired globally day and night and can be obtained in the presence of ice clouds and aerosols that prevent measurements by shorter-wavelength infrared, visible, and ultraviolet sensing techniques. MLS data support investigations in three general scientific areas: stratospheric ozone layer stability, climate change, and air quality.
MLS NRT data are typically available within three hours of observation and are broken into files containing about 15 minutes of data. The most recent seven days of data are available online.
Research quality data products can be accessed using Earthdata Search:
The GEOS Forward Processing (GEOS FP) model and data assimilation system is GMAO’s state-of-the-science numerical weather prediction (NWP) model that assimilates conventional and satellite-based weather observations, aerosol optical depth, and ozone in near real-time (NRT) in order to have the best initial conditions for the forecasts: 10-day at 00 UTC and 5-day at 12 UTC. GEOS FP forecasts are used to support a wide range of NASA missions and campaigns.
Goddard Earth Observing System (GEOS) GEOS-Composition Forecast (CF) system forecasts trace gas and aerosol fields using constrained meteorology from GEOS and the GEOS-Chem chemical mechanism. This community-developed, global 3D model of atmospheric chemistry is publicly available and offers five-day forecasts. Forecasts using the GEOS system are experimental and use of these forecasts for purposes other than research is not recommended.
Modern-Era Retrospective analysis for Research and Applications, Version 2 (MERRA-2) is the latest version of global atmospheric reanalysis for the satellite era produced by NASA's Global Modeling and Assimilation Office (GMAO) using the Goddard Earth Observing System Model (GEOS) version 5.12.4. The dataset covers the period of 1980-present with the latency of about 3 weeks after the end of a month.
Monthly modeled data from MERRA-2 can be accessed and interactively explored using NASA Worldview:
Global Modeling and Assimilation Office’s offers visualizations of MERRA-2 SO2 data:
Using an online interactive tool called Giovanni, map visualizations of MERRA-2 SO2 data products can be downloaded as PNG images, or as GeoTIFF or KMZ files; time-series data are available as CSV data files, and animations are in either webm video format or animated GIF images:
The Atmospheric Tomography Mission (ATom) is a NASA Earth Venture Suborbital-2 mission to study the impact of human-produced air pollution on greenhouse gases and on chemically reactive gases in the atmosphere. ATom deployed an extensive gas and aerosol payload on the NASA DC-8 aircraft for systematic, global-scale sampling of the atmosphere, profiling continuously from 0.2 to 12 km altitude. Around-the-world flights were conducted in each of four seasons between 2016 and 2018.
Carbon monoxide (CO) is released when something is burned, such as in the combustion of fossil fuels or biomass. Outdoor levels are rarely high enough to cause issues; when they do reach dangerous levels, however, they can affect people with certain types of heart disease. CO is an excellent tracer of pollution transport since it is a long-lived in the atmosphere. It is also helpful for identifying the source of air masses.
Descriptions of these measurements will be reviewed in more detail later in this Data Pathfinder. The following sections will help guide you to topic-specific data and resources for accessing, visualizing, preparing/manipulating (e.g. subsetting), and analyzing data. Each observation, model, and reanalysis data has unique characteristics that should be considered when evaluating its use.
An asterisk (*) next to an entry indicates that near real-time (NRT) data products are available through NASA's Land, Atmosphere Near real-time Capability for EOS (LANCE). While not intended for scientific research, NRT data are good resources for monitoring ongoing or time-critical events. To learn more about the difference between NRT and Standard Science Products, see Near Real Time versus Standard Products.
Spatial Resolution | Spatial Coverage | Temporal Resolution | Temporal Coverage | Spectral Resolution | Satellite/ Platform | Name (Sensor, Model, etc.) | Observation, Model, or Reanalysis | File Format |
---|---|---|---|---|---|---|---|---|
50 km x 50 km | Global | 6 minutes | 2002-present | 2,378 infrared channels in the 3.74-15.4 micron spectral range | Aqua | *AIRS | Observation | HDF-EOS |
165 km x 3 km | Near-global | Twice daily [day, night] | 2004-present | At millimeter and submillimeter wavelengths | Aqua | *MLS |
Observation |
HDF-EOS5 |
~22 km | Global | Daily, Monthly | 2000-present | near-infrared radiation at 2.3 µm and thermal-infrared radiation at 4.7 µm | Terra | *MOPITT | Observation | HDF-EOS5 |
5.5 km x 7 km | Global | 101.5 minutes | 2018-present | 270 nm-2.3 µm, 0.55 nm | Sentinel-5P | TROPOMI | Observation | netCDF |
0.25º x 0.25° | Global | 15 min, Hourly | Daily 5-day forecast | N/A | N/A | Model | netCDF | |
0.25º x 0.312° | Global | 3-hourly | Near-real time assimilation (DAS), 10-day forecast at 00z and 5-day forecast at 12z | N/A | N/A | GEOS FP | Analysis | netCDF |
Point measurements | Global | Periodic flights occurred during each deployment | 2016-2018 | varies | Airborne Field Campaign | Atmospheric Tomography Mission (ATom) campaign with varying instruments | Observation | netCDF |
Data Visualizations
NASA’s Atmospheric Infrared Sounder (AIRS), in conjunction with the Advanced Microwave Sounding Unit (AMSU), senses emitted infrared and microwave radiation from Earth to provide a 3D look at Earth's weather and climate. Working in tandem, the two instruments make simultaneous observations of Earth's surface. With more than 2,000 channels sensing different regions of the atmosphere, the system creates a global, 3D map of atmospheric temperature and humidity, cloud amounts and heights, greenhouse gas concentrations and many other atmospheric phenomena. Launched into Earth orbit in 2002, the AIRS and AMSU instruments are aboard NASA's Aqua spacecraft and are managed by NASA's Jet Propulsion Laboratory in Southern California.
NRT and daily data can be accessed and interactively explored using NASA Worldview:
Create and share layered maps with AIRS data using the AIRS Browse Tool.
Research quality data products can be accessed using Earthdata Search:
The Microwave Limb Sounder (MLS) instrument aboard NASA's Aura satellite collects Carbon Monoxide (CO) Mixing Ratio layer at 215 hectopascals (hPa). This indicates carbon monoxide levels at the vertical atmospheric pressure level of 215 hPa and is measured in parts per billion by volume (ppbv).
Daily data can be accessed and interactively explored using NASA Worldview:
Near real-time (NRT) data are typically available within 3 hours of observation and are broken into files containing about 15 minutes of data. The most recent 7 days of data are available online. Spatial coverage is near-global (-82º to +82º latitude) with each profile spaced 1.5º or ~165 km along the orbit track (roughly 15 orbits per day). The vertical coverage is from 215 to 0.1 hPa.
Research quality (Level 2) data are available through Earthdata Search:
The Measurement of Pollution in the Troposphere (MOPITT) instrument aboard NASA's Terra satellite is designed to enhance our knowledge of the lower atmosphere and to observe how it interacts with the land and ocean biospheres. MOPITT’s specific focus is on the distribution, transport, sources, and sinks of carbon monoxide in the troposphere.
Daily and monthly data can be accessed using NASA Worldview:
Using an online interactive tool called Giovanni, data products can be visualized as a time-averaged map, an animation, seasonal maps, scatter plots, or a time series, as well as downloaded in .CSV format:
Research quality data products can be accessed using Earthdata Search:
The Tropospheric Monitoring Instrument (TROPOMI) was co-funded by ESA (European Space Agency) and the Netherlands, and is a space-borne, nadir-viewing, imaging spectrometer covering wavelength bands between the ultraviolet and the shortwave infrared. TROPOMI is the single payload aboard ESA's Sentinel-5P spacecraft and measures the solar radiation reflected by and radiated from Earth.
Research quality data products can be accessed using Earthdata Search:
The GEOS Forward Processing (GEOS FP) model and data assimilation system is GMAO’s state-of-the-science numerical weather prediction (NWP) model that assimilates conventional and satellite-based weather observations, aerosol optical depth, and ozone in near real-time (NRT) in order to have the best initial conditions for the forecasts: 10-day at 00 UTC and 5-day at 12 UTC. GEOS FP forecasts are used to support a wide range of NASA missions and campaigns. There is no data assimilation of CO observations in GEOS FP.
GEOS-Composition Forecast (CF) system forecasts trace gas and aerosol fields using constrained meteorology from GEOS and the GEOS-Chem chemical mechanism. This community-developed, global 3D model of atmospheric chemistry is publicly available and offers 5-day forecasts. Forecasts using the GEOS system are experimental and are produced for research purposes only. There is no data assimilation of CO observations in GEOS-CF.
The Atmospheric Tomography Mission (ATom) is a NASA Earth Venture Suborbital-2 mission to study the impact of human-produced air pollution on greenhouse gases and on chemically reactive gases in the atmosphere. ATom deployed an extensive gas and aerosol payload on the NASA DC-8 aircraft for systematic, global-scale sampling of the atmosphere, profiling continuously from 0.2 to 12 km altitude. Around-the-world flights were conducted in each of four seasons between 2016 and 2018.
Ozone (O3) is a trace gas that can be either beneficial or harmful depending on where it is found in the atmosphere. Beneficial O3 is found naturally in trace amounts in the upper atmosphere (the stratosphere) where it protects life on Earth from the Sun’s ultraviolet (UV) radiation. Harmful O3 is found in the troposphere, the lowest layer of the atmosphere, where it serves as a potent greenhouse gas and can aggravate existing health problems in humans, especially those with respiratory conditions. O3 is not emitted directly into the atmosphere, but instead forms from the chemical reaction between nitrogen oxides and volatile organic compounds that are emitted from power plants, industrial facilities, and cars powered by internal combustion engines (there are also natural emissions of nitrogen oxides and volatile organic compounds from lightning, soil, and vegetation). Reactions to create O3 take place in the presence of sunlight. Because of the need for sunlight, unhealthy levels of O3 are often reached on very sunny days and in urban environments.
Descriptions of these measurements will be reviewed in more detail later in this Data Pathfinder. The following sections will help guide you to topic-specific data and resources for accessing, visualizing, preparing/manipulating (e.g. subsetting), and analyzing data. Each observation, model, and reanalysis data has unique characteristics that should be considered when evaluating its use.
An asterisk (*) next to an entry indicates that near real-time (NRT) data products are available through NASA's Land, Atmosphere Near real-time Capability for EOS (LANCE). While not intended for scientific research, NRT data are good resources for monitoring ongoing or time-critical events. To learn more about the difference between NRT and Standard Science Products, see Near Real Time versus Standard Products.
Spatial Resolution | Spatial Coverage | Temporal Resolution | Temporal Coverage | Spectral Resolution | Satellite/ Platform |
Name (Sensor, Model, etc.) |
Observation, Model, or Reanalysis |
File Format |
---|---|---|---|---|---|---|---|---|
13 km x 24 km, 13 x 12 km |
Global |
98 min |
2004-present |
0.63 nm, 0.42 nm, 0.63 nm |
Aura |
Observation |
HDF-EOS5 | |
50 km |
Global |
6 min, hourly, 3-hourly, 6-hourly |
2016-present for NRT, 2002 for non-NRT |
2,378 infrared channels in the 3.74 to 15.4 micron spectral range |
Aqua |
*AIRS |
Observation |
HDF-EOS |
50 km |
Near-global |
101 minutes, daily |
2011-present |
250-420 nm |
Suomi NPP |
*OMPS |
Observation |
HDF-5 |
0.5° x 1.0° |
Global |
daily |
2018-present |
270nm-495nm, 675nm-775nm, 2305nm-2385nm |
ESA Sentinel-5P |
Observation |
netCDF | |
165 km x 3 km |
Near-global (-82º to +82º latitude) |
15 minutes |
Most recent 7 days |
190 and 240 GHz |
Aura |
*MLS |
Observation |
HDF-EOS5 |
0.5° x 0.625° |
Global |
Monthly |
1980-present |
N/A | N/A |
Reanalysis |
netCDF | |
0.25º x 0.25° |
Global | 15 minutes, Hourly | Daily 5-day forecast | N/A | N/A | GEOS-CF | Model | netCDF |
0.25º x 0.312° | Global | 3-hourly | Near-real time assimilation (DAS), 10-day forecast at 00z, and 5-day forecast at 12z |
N/A |
N/A |
Analysis |
netCDF | |
Point measurements | Global | Periodic flights occurred during each deployment | 2016-2018 | Varies | Airborne Field Campaign | Atmospheric Tomography Mission (ATom) campaign with varying instruments | Observation | netCDF |
Surface-based point and profile measurements | North America | 5 minutes - daily | Periodic, 2012-present | DIAL technique, 266-300nm | Ground-based | Tropospheric Ozone Lidar Network (TOLNet) | Observation | HDF4-GEOMS, ASCII |
Data Visualizations
The Atmospheric Infrared Sounder (AIRS) is a hyperspectral sounder that collects daily global measurements of water vapor and temperature profiles as one of four instruments comprising the AIRS Project Instrument Suite.
Using an online interactive tool called Giovanni, map visualizations of AIRS Ozone data products can be downloaded as PNG images, or as GeoTIFF or KMZ files; time-series data are available as CSV data files, and animations are in either webm video format or animated GIF images:
Research quality data products can be accessed using Earthdata Search:
The Ozone Monitoring Instrument (OMI) aboard NASA's Aura satellite has a coarser spatial resolution than MODIS and VIIRS, but provides data at individual wavelengths from the ultraviolet (UV) to the visible. This is important because pollutants have different spectral signatures. For example, a wavelength range around 400 nm can be used to detect elevated layers of absorbing aerosols such as biomass burning and desert dust plumes.
Daily data can be accessed using NASA Worldview:
Using an online interactive tool called Giovanni, data products can be visualized as a time-averaged map, an animation, seasonal maps, scatter plots, or a time series, as well as downloaded in .CSV format:
Research quality data products can be accessed using Earthdata Search:
Ozone (O3) in the lower stratosphere and upper troposphere as measured by the Microwave Limb Sounder (MLS) instrument aboard NASA's Aura satellite. The O3 Mixing Ratio layer at 46 hectopascals (hPa) indicates ozone levels at the vertical atmospheric pressure level of 46 hPa, and is measured in parts per billion by volume (ppbv). It is derived from the MLS Ozone product (ML2O3_NRT) available from the MLS. The sensor resolution is 5 km and imagery resolution is 2 km.
Daily data can be accessed and interactively explored using NASA Worldview:
Near real-time (NRT) data are typically available within 3 hours of observation and are broken into files containing about 15 minutes of data. The most recent 7 days of data are available online. Spatial coverage is near-global (82º north and south latitude), with each profile spaced 1.5º or ~165 km along the orbit track (roughly 15 orbits per day). The vertical coverage is from 261 to 0.1 hPa.
Research quality (Level 2) data are available through Earthdata Search:
The European Space Agency (ESA) and the Copernicus Sentinel Project make available the Sentinel-5P TROPOspheric Monitoring Instrument (TROPOMI) atmospheric composition data to NASA for access and distribution. Sentinel-5P is the first of the Atmospheric Composition Sentinels and provides measurements of O3, NO2, SO2, CH4, CO, formaldehyde, aerosols, and cloud at high spatial, temporal, and spectral resolutions.
The OMPS instrumental suite aboard the joint NASA/NOAA Suomi National Polar-orbiting Partnership (Suomi NPP), NOAA-20, and NOAA-21 satellites are now the operational instruments for the NASA and NOAA ozone monitoring program. OMPS consists of three ozone measuring sensors that operate in UV and VIS spectral ranges and sample the same air-masses within a few minutes. The OMPS Nadir Mapper (OMPS-NM) was designed to measure atmospheric total column ozone with configurable nadir temporal (along-track) and spatial (across-track) resolutions. The OMPS-NM aboard Suomi NPP collects data at a larger 50 x 50 km pixel size, while NOAA-20 and NOAA-21 OMPS-NM observations are collected at a smaller pixel size. OMPS-NM also offers SO2 and other trace gas measurements but lacks spectral coverage in the violet-blue wavelength typically used for NO2 retrievals. (Note: NO2 observations are possible from OMPS, but they are less optimal as compared with OMI.) OMPS Limb Profilers (OMPS-LP) aboard the Suomi NPP and NOAA-21 satellites provide measurements of vertical ozone profiles in the stratosphere. Tropospheric ozone column is estimated by combining these measurements with total columns from OMPS-NM and meteorological data. The OMPS tropospheric column record extends tropospheric measurements from the Aura OMI/MLS.
Daily data can be accessed using NASA Worldview:
Research quality (Level 2) data are available through Earthdata Search:
The GEOS Forward Processing (GEOS FP) model and data assimilation system is GMAO’s state-of-the-science numerical weather prediction (NWP) model that assimilates conventional and satellite-based weather observations, aerosol optical depth, and ozone in near real-time (NRT) in order to have the best initial conditions for the forecasts: 10-day at 00 UTC and 5-day at 12 UTC. GEOS FP forecasts are used to support a wide range of NASA missions and campaigns.
GEOS-Composition Forecast (CF) system forecasts trace gas and aerosol fields using constrained meteorology from GEOS and the GEOS-Chem chemical mechanism. This community-developed, global 3D model of atmospheric chemistry is publicly available and offers 5-day forecasts. Forecasts using the GEOS system are experimental.
The Ozone Mixing Ratio data product is the MERRA-2 analyzed ozone at 42 pressure levels, along with important meteorological fields such as temperature, wind components, specific humidity, and geopotential height, which are useful for analysis of ozone.
Monthly data can be accessed and interactively explored using NASA Worldview:
Using an online interactive tool called Giovanni or through the GMAO FLUID webpage, map visualizations of MERRA-2 Ozone data products can be downloaded as PNG images, or as GeoTIFF or KMZ files; time-series data are available as CSV data files, and animations are in either webm video format or animated GIF images:
MERRA-2 Ozone data are available through Earthdata Search and in Google Earth Engine Data Catalog:
ATom is a NASA Earth Venture Suborbital-2 mission to study the impact of human-produced air pollution on greenhouse gases and on chemically reactive gases in the atmosphere. ATom deployed an extensive gas and aerosol payload on the NASA DC-8 aircraft for systematic, global-scale sampling of the atmosphere, profiling continuously from 0.2 to 12 km altitude. Around-the-world flights were conducted in each of four seasons between 2016 and 2018.
The Tropospheric Ozone Lidar Network (TOLNet) was established in 2012 to provide high spatio-temporal observations of tropospheric ozone to (1) better understand physical processes driving the ozone budget in various meteorological and environmental conditions, and (2) validate the tropospheric ozone measurements of spaceborne missions. Datasets include profiles of tropospheric ozone number density and mixing ratio at a variety of vertical and temporal resolutions as well as collocated surface measurements.
Other links:
Formaldehyde (CH2O or HCHO) is a volatile hydrocarbon and a known carcinogenic air pollutant common in smoke. Large concentrations of formaldehyde are found in the presence of biomass burning and industrial sites where it is a byproduct of combustion (there also are biogenic emissions of formaldehyde). Formaldehyde affects human health and also has significant—but little understood—effects on Earth’s atmosphere where it contributes to ozone formation.
Descriptions of these measurements will be reviewed in more detail later in this Data Pathfinder. The following sections will help guide you to topic-specific data and resources for accessing, visualizing, preparing/manipulating (e.g. subsetting), and analyzing data. Each observation, model, and reanalysis data has unique characteristics that should be considered when evaluating its use.
An asterisk (*) next to an entry indicates that near real-time (NRT) data products are available through NASA's Land, Atmosphere Near real-time Capability for EOS (LANCE). While not intended for scientific research, NRT data are good resources for monitoring ongoing or time-critical events. To learn more about the difference between NRT and Standard Science Products, see Near Real Time versus Standard Products.
Spatial Resolution | Spatial Coverage | Temporal Resolution | Temporal Coverage | Spectral Resolution | Satellite/ Platform |
Name (Sensor, Model, etc.) |
Observation, Model, or Reanalysis |
File Format |
---|---|---|---|---|---|---|---|---|
0.1°, 13 km x 24 km |
Global |
Daily |
2004-present |
1.0-0.45 nm Full Width and Half Maximum (FWHM) |
Aura |
Observation |
HDF-EOS5 | |
50 km |
Global |
101 minutes |
2012-2020 |
328.5 nm-356.5 nm |
Suomi NPP |
OMPS | Observation | netCDF |
5.5 km x 3.5 km, 7.5 km x 3.5 km |
Global |
101.5 minutes |
2018-present |
270 nm-2.3 µm, 0.55 nm |
ESA Sentinel-5P |
Observation |
netCDF | |
0.25º x 0.25° | Global | Hourly | Daily 5-day forecast | N/A | N/A | GEOS-CF | Model | netCDF |
NASA’s Health and Air Quality Applied Sciences Team (HAQAST) Guide:
Data Visualizations
The Ozone Monitoring Instrument (OMI) aboard NASA's Aura satellite measures the amount of formaldehyde (CH2O), among other constituents in the atmosphere.
Using an online interactive tool called Giovanni, map visualizations of OMI Formaldehyde data products can be downloaded as PNG images, or as GeoTIFF or KMZ files; time-series data are available as CSV data files, and animations are in either webm video format or animated GIF images:
Research quality (Level 2) data are available from Earthdata Search:
The OMPS-NPP L2 NM Formaldehyde (HCHO) Total Column swath orbital product provides formaldehyde measurements from the Ozone Mapping and Profiling Suite (OMPS) Nadir-Mapper (NM) instrument on the Suomi-NPP satellite.
Research quality (Level 2) data are available through Earthdata Search:
The European Space Agency (ESA) and the Copernicus Sentinel Project make available the Sentinel-5P TROPOspheric Monitoring Instrument (TROPOMI) atmospheric sulfur dioxide and formaldehyde data to NASA for access and distribution. Sentinel-5P is the first of the Atmospheric Composition Sentinels and is expected to provide measurements of ozone, NO2, SO2, CH4, CO, formaldehyde, aerosols and cloud at high spatial, temporal and spectral resolutions.
TROPOMI HCHO data are available in Earthdata Search
The Goddard Earth Observing System (GEOS) Composition Forecast (CF) system forecasts trace gas and aerosol fields using constrained meteorology from GEOS and the GEOS-Chem chemical mechanism. This global 3D model of atmospheric chemistry is publicly available and offers five-day forecasts with chemical and meteorological diagnostics on the same temporal and spatial resolution. Forecasts using the GEOS system are experimental.
Ammonia (NH3) is a colorless gas with a pungent smell. It reacts with other common substances in the atmosphere, such as sulfuric acid and nitric acid, to form two classes of particles: ammonium sulfate and ammonium nitrate.
Descriptions of these measurements will be reviewed in more detail later in this Data Pathfinder. The following sections will help guide you to topic-specific data and resources for accessing, visualizing, preparing/manipulating (e.g. subsetting), and analyzing data. Each observation, model, and reanalysis data has unique characteristics that should be considered when evaluating its use.
An asterisk (*) next to an entry indicates that near real-time (NRT) data products are available through NASA's Land, Atmosphere Near real-time Capability for EOS (LANCE). While not intended for scientific research, NRT data are good resources for monitoring ongoing or time-critical events. To learn more about the difference between NRT and Standard Science Products, see Near Real Time versus Standard Products.
Spatial Resolution | Spatial Coverage | Temporal Resolution | Temporal Coverage | Spectral Resolution | Satellite/ Platform |
Name (Sensor, Model, etc.) |
Observation, Model, or Reanalysis |
File Format |
---|---|---|---|---|---|---|---|---|
13.5 km | Global | Daily | 2021-present | 2,378 infrared channels in the 3.74 to 15.4 micron spectral range | Aqua |
Observation |
netCDF | |
0.25º x 0.25° |
Global |
Hourly |
Daily 5-day forecast |
N/A |
N/A | GEOS-CF | Model | netCDF |
NASA’s Health and Air Quality Applied Sciences Team (HAQAST) Guide:
Data Visualizations
The NASA Earthdata Cloud Cookbook has tutorials to help access Earthdata in the cloud
Standard and Summary TROPESS AIRS products are available through Earthdata Search:
The Goddard Earth Observing System (GEOS) Composition Forecast (CF) system forecasts trace gas and aerosol fields using constrained meteorology from GEOS and the GEOS-Chem chemical mechanism. This global 3D model of atmospheric chemistry is publicly available and offers five-day forecasts with chemical and meteorological diagnostics on the same temporal and spatial resolution. Forecasts using the GEOS system are experimental and are produced for research purposes only.
Clouds form when suspended aerosols and water vapor get caught up in rising air motions. Natural aerosols such as mineral dust from deserts and sea salt have always served as nuclei on which water vapor condenses to form clouds. The amount of aerosols in the air is one of the most important factors for cloud formation. High amounts of human-made aerosols in the atmosphere can lead to heavier rainfall, while clouds with high levels of human-made aerosols can lead to delayed rainfall, which makes clouds grow larger, taller, and longer-lived. When they finally shed their water, storms may be stronger.
Descriptions of these measurements will be reviewed in more detail later in this Data Pathfinder. The following sections will help guide you to topic-specific data and resources for accessing, visualizing, preparing/manipulating (e.g. subsetting), and analyzing data. Each observation, model, and reanalysis data has unique characteristics that should be considered when evaluating its use.
An asterisk (*) next to an entry indicates that near real-time (NRT) data products are available through NASA's Land, Atmosphere Near real-time Capability for EOS (LANCE). While not intended for scientific research, NRT data are good resources for monitoring ongoing or time-critical events. To learn more about the difference between NRT and Standard Science Products, see Near Real Time versus Standard Products.
Spatial Resolution | Spatial Coverage | Temporal Resolution | Temporal Coverage | Spectral Resolution | Satellite/ Platform |
Name (Sensor, Model, etc.) | Observation, Model, or Reanalysis | File Format |
---|---|---|---|---|---|---|---|---|
10 km: 6.9-36.5 GHz; 5 km: 89.0 GHz | Global | Hours | 2020-present | 6 Bands: 6.9, 10.65, 18.7, 23.8, 36.5, 89.0 GHz | GCOM-W1 | *AMSR2 | Observation | netCDF-4 HDF-EOS5 |
50 km | Global | 6 minutes | 2002-present (standard) | 2,378 infrared channels in the 3.74 to 15.4 micron spectral range | Aqua | *AIRS | Observation | HDF-EOS |
275 meters at all off-nadir angles | Global | Hours |
2000-present; 2016-present (NRT) |
Four spectral bands: blue, green, red, and near-infrared; center wavelength of each of these bands is 446, 558, 672, and 867 nanometers respectively | Terra | *Multi-angle Imaging SpectroRadiometer (MISR) | Observation | HDF-EOS2 |
1 km, 5 km |
Global |
Daily |
1999-present |
36 spectral bands ranging in wavelength from 0.4 µm to 14.4 µm |
Terra |
Observation |
HDF-EOS | |
250 m, 500 m, 1000 m, 5600 m |
Global |
Daily |
2002-present |
36 spectral bands ranging in wavelength from 0.4 µm to 14.4 µm |
Aqua |
Observation |
HDF-EOS | |
0.5° x 0.625° |
Global |
Monthly |
1980-present | N/A | N/A | MERRA-2 |
Reanalysis |
netCDF |
NASA’s Health and Air Quality Applied Sciences Team (HAQAST) Guide:
Data Visualizations
AIRS, in conjunction with the Advanced Microwave Sounding Unit (AMSU), senses emitted infrared and microwave radiation from Earth to provide a 3D look at Earth's weather and climate. Working in tandem, the two instruments make simultaneous observations down to Earth's surface. With more than 2,000 channels sensing different regions of the atmosphere, the system creates a global 3D map of atmospheric temperature and humidity, cloud amounts and heights, greenhouse gas concentrations and many other atmospheric phenomena. Launched in 2002, the AIRS and AMSU instruments fly aboard NASA's Aqua spacecraft.
Cloud top altitude is the pressure altitude calculated from the retrieved AIRS cloud top pressure assuming a surface pressure of 1000 hPa and a scale height of 6 kilometers. These are the approximate altitudes where clouds have infrared optical depths of unity. AIRS can sense up to two cloud decks in a column of atmosphere.
AIRS data can be accessed and interactively explored using NASA Worldview:
Total Cloud Fraction is the product of cloud fractional coverage and cloud infrared emissivity. Low fraction can indicate either small, highly emissive clouds or more extensive but less emissive clouds.
AIRS data can be accessed and interactively explored using NASA Worldview:
Using an online interactive tool called Giovanni, map visualizations of AIRS Cloud data products can be downloaded as PNG images, or as GeoTIFF or KMZ files; time-series data are available as CSV data files, and animations are in either webm video format or animated GIF images:
Research-quality data products can be accessed using Earthdata Search. Key Geophysical parameters including Fractional Cloud Cover, Cloud Top Height, Cloud Top Temperature:
The AMSR2 instrument aboard the Japan Aerospace Exploration Agency Global Change Observation Mission-Water 1 (GCOM-W1) satellite is a conically scanning passive microwave radiometer. This instrument senses microwave radiation for 12 channels and 6 frequencies ranging from 6.9 GHz to 89 GHz.
Near real-time (NRT) products are generated within 3 hours of the last observations in the file, by the Land, Atmosphere Near real-time Capability for EOS (LANCE). NRT products are generated in HDF-EOS-5 augmented with netCDF-4/CF metadata and are available from the LANCE. If data latency is not a primary concern, please consider using science quality products rather than NRT products.
The Columnar Cloud Liquid Water parameter is a measure of the liquid water in a column of atmosphere in units of grams per square meter.
AMSR2 data can be accessed and interactively explored using NASA Worldview:
Research-quality data products can be accessed using Earthdata Search. Key Geophysical parameters within this product include: cloud liquid water over ocean
MISR aboard NASA's Terra satellite views Earth with cameras pointed at nine different angles. As the instrument flies overhead, each region of Earth's surface is successively imaged by all cameras in each of four wavelengths (blue, green, red, and near-infrared). MISR monitors monthly, seasonal, and long-term trends in three areas: 1) amount and type of atmospheric particles (aerosols), including those formed by natural sources and by human activities; 2) amounts, types, and heights of clouds, and 3) distribution of land surface cover, including vegetation canopy structure.
The MISR Cloud Stereo Height product displays the fraction of global cloud stereo heights between 1.5 and 2.0 km calculated from MISR radiances averaged on a monthly basis. MISR stereo cloud heights are geometric calculations of the height of cloud tops based on the angular displacement (parallax) of clouds across the nine angles captured by MISR’s cameras.
MISR data can be accessed and interactively explored using NASA Worldview:
The Moderate Resolution Imaging Spectroradiometer (MODIS) continually collects data in 36 spectral channels with global coverage every 1 to 2 days. Its exceptionally broad spectral range enables MODIS data to be used in studies across numerous disciplines, including vegetative health, changes in land cover and land use, oceans and ocean biology, sea surface temperature, and cloud analysis. It also is used extensively for monitoring fires and natural hazards along with oil spills. An important attribute of MODIS data is the availability of MODIS data products in real-time and near real-time. Direct broadcast stations around the world download raw MODIS data in real-time directly from the satellite, while NASA’s Land, Atmosphere Near Real-time Capability for EOS (LANCE) provides several MODIS products within three hours of satellite observation.
Aqua/MODIS and MODIS/Terra cloud data can be accessed and interactively explored using NASA Worldview:
Using an online interactive tool called Giovanni, map visualizations of MODIS Cloud data products can be downloaded as PNG images, or as GeoTIFF or KMZ files; time-series data are available as CSV data files, and animations are in either webm video format or animated GIF images:
Research-quality data products can be accessed using Earthdata Search. Key Geophysical parameters within this product include: Cloud Optical Thickness, Fraction, Water Path, Cloud Top Temperature, Cloud Height and more:
The Modern-Era Retrospective analysis for Research and Applications, Version 2 (MERRA-2) is the latest version of global atmospheric reanalysis for the satellite era produced by NASA’s Global Modeling and Assimilation Office (GMAO) using the Goddard Earth Observing System Model (GEOS) version 5.12.4. The dataset covers the period of 1980 to present with the latency of about 3 weeks after the end of a month.
The ISCCP Cloud Albedo (Monthly) layer is created from a time-averaged two-dimensional monthly mean data collection. This data collection consists of parameters from the Cloud Feedback Model Intercomparison Project (CFMIP) Observations Simulator Package (COSP), such as International Satellite Cloud Climatology Project (ISCCP) total cloud area fraction, MODIS cloud fraction water (ice) mean, MODIS cloud fraction low (mid,high) mean, MODIS cloud particle size water (ice) mean.
MERRA-2 Cloud Albedo (Monthly) data can be accessed and interactively explored using NASA Worldview:
Using an online interactive tool called Giovanni, map visualizations of MERRA-2 Cloud data products can be downloaded as PNG images, or as GeoTIFF or KMZ files; time-series data are available as CSV data files, and animations are in either webm video format or animated GIF images:
Precipitation, particularly rain, affects air quality as it can remove precursors of air pollution, as well as particulate matter. Rain can also suppress certain emissions, such as dust. Higher precipitation amounts generally result in lower aerosol optical depth (AOD) values.
Descriptions of these measurements will be reviewed in more detail later in this Data Pathfinder. The following sections will help guide you to topic-specific data and resources for accessing, visualizing, preparing/manipulating (e.g. subsetting), and analyzing data. Each observation, model, and reanalysis data has unique characteristics that should be considered when evaluating its use.
An asterisk (*) next to an entry indicates that near real-time (NRT) data products are available through NASA's Land, Atmosphere Near real-time Capability for EOS (LANCE). While not intended for scientific research, NRT data are good resources for monitoring ongoing or time-critical events. To learn more about the difference between NRT and Standard Science Products, see Near Real Time versus Standard Products.
Spatial Resolution | Spatial Coverage | Temporal Resolution | Temporal Coverage | Spectral Resolution | Satellite/ Platform |
Name (Sensor, Model, etc.) | Observation, Model, or Reanalysis | File Format |
---|---|---|---|---|---|---|---|---|
15 km |
Global |
2 days |
2012-near present |
16 channels ranging in frequency from 6.925 GHz to 89 GHz |
SHIZUKU (GCOM-W1) |
*Advanced Microwave Scanning Radiometer 2 (AMSR2) |
Observation |
HDF5 |
25 km |
Global |
12 hours |
2002-present |
2,378 infrared channels in the 3.74 to 15.4 micron spectral range |
Aqua |
*AIRS |
Observation |
HDF-EOS |
0.5° |
Global |
Daily, Monthly |
1983-2022 |
Varies |
Global Precipitation Climatology Project (GPCP) (multiple satellites) |
Varies |
Model |
netCDF |
0.1° |
Global |
30-minute, Daily, Monthly |
2000-present |
Varies |
GPM IMERG (multiple satellites) |
Varies |
Observation |
HDF, NetCDF, or GeoTIFF |
5 km |
50° N to 50° S, 180° W to 180° E |
5-day, 10-day, 15-day |
2000-present |
N/A |
N/A |
CHIRPS- Global Ensemble Forecast System (GEFS) |
Model |
GeoTIFF |
1 km |
Over continental North America and Hawaii and Puerto Rico |
Daily |
Over continental North America and Hawaii from 1980 and over Puerto Rico from 1950 through the end of the most recent full calendar year |
N/A |
N/A |
Model |
netCDF, Cloud Optimized GeoTIFF (COG) | |
0.01°, 0.1°, 0.125°, 0.25°, 1° |
Global | Hourly, 3-hourly,Daily, Monthly | 2000-2022 | N/A | N/A | Land Data Assimilation Systems (LDAS) | Model | netCDF |
0.5° x 0.625° | Global | Hourly, Daily, Monthly | 1980-present | N/A | N/A | MERRA-2 | Reanalysis | netCDF |
Data Visualizations
The Atmospheric Infrared Sounder (AIRS) is a grating spectrometer aboard NASA's Aqua satellite. In combination with the Advanced Microwave Sounding Unit (AMSU) and the Humidity Sounder for Brazil (HSB), AIRS constitutes an innovative atmospheric sounding group of visible, infrared, and microwave sensors.
The AIRS Precipitation Estimate is an estimate of daily precipitation measured in millimeters using cloud-related parameters of cloud-top pressure, fractional cloud cover, and cloud-layer relative humidity. The precipitation algorithm is a regression between these parameters and observed precipitation data. It is an estimate from AIRS using a TOVS-like algorithm and is intended for merging into the precipitation product of the Global Precipitation Climatology Project (GPCP).
Create and share layered maps with AIRS data using the AIRS Browse Tool.
Research-quality data products can be accessed using Earthdata Search:
The Advanced Microwave Scanning Radiometer 2 (AMSR2) instrument collects data that indicate the rate at which precipitation is falling on the ocean surface in millimeters per hour (mm/hr).
Data can be accessed and interactively explored using NASA Worldview:
Create and share layered maps with AMSR2 data using the AIRS Browse Tool.
Research-quality data products can be accessed using Earthdata Search:
Near real-time (NRT) Surface Precipitation products are generated within 3 hours by the Land, Atmosphere Near real-time Capability for EOS (LANCE). The NRT products are generated in HDF-EOS-5 augmented with netCDF-4/CF metadata and are available via HTTPS from LANCE. If data latency is not a primary concern, please use science quality products. Science quality products are an internally consistent, well-calibrated record of Earth's geophysical properties to support science.
NASA's Precipitation Measurement Missions (PMM) provide a continuous record of precipitation data through the Tropical Rainfall Measuring Mission (TRMM; operational 1997 to 2015) and the Global Precipitation Measurement mission (GPM; launched in 2014). GPM, the TRMM successor mission, provides more accurate measurements, improved detection of light rain and snow, and extended spatial coverage.
Data products from TRMM and GPM are available individually and have been integrated with data from a global constellation of satellites to yield precipitation estimates with improved spatial coverage and temporal resolution. The first integrated product was the TRMM Multi-satellite Precipitation Analysis (TMPA), which has been superseded by the Integrated Multi-satellitE Retrievals for GPM (IMERG). IMERG's multiple runs accommodate different user requirements for accuracy and latency (Early = 4 hours, e.g., for flash flood events; Late = 12 hours, e.g., for crop forecasting; and Final = 3 months, with the incorporation of rain gauge data, for research).
GPM data can be visualized using NASA Worldview:
The Short-term Prediction Research and Transition (SPoRT) project at NASA's Marshall Space Flight Center in Huntsville, AL, is a NASA- and NOAA-funded activity to transition experimental/ quasi-operational satellite observations and research capabilities to the operational weather community to improve short-term weather forecasts on a regional and local scale. SPoRT offers a Near Real-Time Viewer for IMERG data:
Users may access and visualize these data directly through ClimateSERV. Additional datasets include IMERG, Evaporative Stress Index, SMAP Soil Moisture, Rainfall, and NDVI.
Using an online interactive tool called Giovanni, map visualizations of IMERG data products can be downloaded as PNG images, or as GeoTIFF or KMZ files; time-series data are available as CSV data files, and animations are in either webm video format or animated GIF images:
NASA Earthdata GIS Products:
Near-real time (NRT) data:
Research-quality data products can be accessed using Earthdata Search:
SERVIR (a joint initiative of NASA, USAID, and geospatial organizations in Asia, Africa, and Latin America) and the Climate Hazards Group (CHG) at University of California at Santa Barbara have developed an improved rainfall forecast dataset that merges two highly recognized datasets: Climate Hazards Group InfraRed Precipitation with Station (CHIRPS) and the NCEP’s Global Ensemble Forecasting System (GEFS). GEFS is a weather forecast system that provides daily forecasts out to 16 days at 1º X 1º resolution at 6-hour intervals.The combined CHIRPS-GEFS dataset uses the higher spatial resolution of CHIRPS and the advanced forecasting ability of GEFS to provide up to a 16-day forecast updated every five days at a global spatial resolution of 5 km. CHIRPS-GEFS model data are available for analysis and download through the SERVIR Product Catalog. Users may access and visualize these data directly through ClimateSERV.
Another NASA source for precipitation data is Daymet, which can be accessed through NASA's Oak Ridge National Laboratory Distributed Active Archive Center (ORNL DAAC). Daymet is a collection of gridded estimates of daily weather parameters including minimum and maximum temperature, precipitation, vapor pressure, radiation, snow water equivalent, and day length at 1 km resolution over North America, Puerto Rico, and Hawaii. Daymet data are available from 1980 to present (North America and Hawaii) and from 1950 to present (Puerto Rico) and can be retrieved in a variety of ways, including: Earthdata Search; an API available through ORNL DAAC; ORNL DAAC tools; and through the Application for Extracting and Exploring Analysis Ready Samples (AppEEARS) application. Along with daily data, annual Daymet climatologies also are available.
The Global Precipitation Climatology Project (GPCP) is the precipitation component of an internationally coordinated set that combines observations and satellite precipitation data.
Using an online interactive tool called Giovanni, map visualizations of GPCP Precipitation data products can be downloaded as PNG images, or as GeoTIFF or KMZ files; time-series data are available as CSV data files, and animations are in either webm video format or animated GIF images:
The Land Data Assimilation System (LDAS) includes a global collection (GLDAS), a North American collection (NLDAS), National Climate Assessment-Land Data Assimilation System (NCA-LDAS), and a Famine Early Warning Systems Network (FEWS NET) Land Data Assimilation System (FLDAS). LDAS uses measurements including air temperature, precipitation, soil texture, and topography. GLDAS modeled data are available from January 1948 to present. NLDAS modeled datasets are available from January 1979 to present. FLDAS modeled datasets are available from January 1982 to present.
Data can be accessed and interactively explored using NASA Worldview:
Using an online interactive tool called Giovanni, data products can be visualized as a time-averaged map, an animation, seasonal maps, scatter plots, or a time series, as well as downloaded in .CSV format:
The Modern-Era Retrospective analysis for Research and Applications, Version 2 (MERRA-2) provides data beginning in 1980. Due to the amount of historical data available, MERRA-2 data can be used to look for trends and patterns as well as anomalies. There are several options available: 1-hourly, 3-hourly, 6-hourly, daily, and monthly. These options provide information on precipitation.
Data can be accessed and interactively explored using NASA Worldview:
Using an online interactive tool called Giovanni, map visualizations of MERRA-2 Precipitation data products can be downloaded as PNG images, or as GeoTIFF or KMZ files; time-series data are available as CSV data files, and animations are in either webm video format or animated GIF images:
GIS Product using MERRA-2 reanalysis data:
Research-quality air surface temperature data products can be accessed using Earthdata Search:
The NASA Prediction Of Worldwide Energy Resources (POWER) Data Access Viewer provides MERRA-2 meteorological parameters through a web mapping application with the capability for data subsetting, charting, and visualizing. The data are also available via API as well as via OPeNDAP.
Humidity is a measure of the amount of water vapor present in the atmosphere, which can impact air quality. For example, humidity levels affect the chemical reactions that control the formation of certain pollutants, like ozone. Additionally, in urban areas, humid air can trap pollutants close to the ground keeping them from moving and dissipating.
Descriptions of these measurements will be reviewed in more detail later in this Data Pathfinder. The following sections will help guide you to topic-specific data and resources for accessing, visualizing, preparing/manipulating (e.g. subsetting), and analyzing data. Each observation, model, and reanalysis data has unique characteristics that should be considered when evaluating its use.
An asterisk (*) next to an entry indicates that near real-time (NRT) data products are available through NASA's Land, Atmosphere Near real-time Capability for EOS (LANCE). While not intended for scientific research, NRT data are good resources for monitoring ongoing or time-critical events. To learn more about the difference between NRT and Standard Science Products, see Near Real Time versus Standard Products.
Spatial Resolution | Spatial Coverage | Temporal Resolution | Temporal Coverage | Spectral Resolution | Satellite/ Platform |
Name (Sensor, Model, etc.) | Observation, Model, or Reanalysis | File Format |
---|---|---|---|---|---|---|---|---|
1° |
Global |
Daily, Weekly, Monthly |
2002-present |
2,378 infrared channels in the 3.74 to 15.4 micron spectral range |
Aqua |
Observation |
HDF-EOS | |
0.5° x 0.625° |
Global |
Hourly, Daily, Monthly |
1980-current |
N/A |
N/A |
Reanalysis |
netCDF |
Data Visualizations
The NASA Earthdata Cloud Cookbook has tutorials to help access Earthdata in the cloud
The Atmospheric Infrared Sounder (AIRS) is a hyperspectral sounder that collects daily global measurements of water vapor and temperature profiles as one of four instruments comprising the AIRS Project Instrument Suite.
Data can be accessed and interactively explored using NASA Worldview:
Create and share layered maps with AIRS data using the AIRS Browse Tool.
Using an online interactive tool called Giovanni, map visualizations of AIRS Relative Humidity data products can be downloaded as PNG images, or as GeoTIFF or KMZ files; time-series data are available as CSV data files, and animations are in either webm video format or animated GIF images:
Research-quality data products can be accessed using Earthdata Search:
The Modern-Era Retrospective analysis for Research and Applications, Version 2 (MERRA-2) provides data beginning in 1980. Due to the amount of historical data available, MERRA-2 data can be used to look for trends and patterns as well as anomalies. There are several options available: 1-hourly, 3-hourly, 6-hourly, daily, and monthly. These options provide information on precipitation.
Monthly data can be accessed and interactively explored using NASA Worldview:
MERRA-2 Weather Maps
Using an online interactive tool called Giovanni, map visualizations of MERRA-2 Humidity data products can be downloaded as PNG images, or as GeoTIFF or KMZ files; time-series data are available as CSV data files, and animations are in either webm video format or animated GIF images:
GIS Product using MERRA-2 reanalysis data:
Research-quality data products can be accessed using Earthdata Search:
The NASA Prediction Of Worldwide Energy Resources (POWER) Data Access Viewer provides MERRA-2 meteorological parameters through a web mapping application with the capability for data subsetting, charting, and visualizing. The data are also available via API, GIS enabled, as well as via OPeNDAP.
The POWER Meteorological Data Overview provides additional information.
Currents of air carry pollutants from region to region, country to country, and even continent to continent. As these air currents move, they affect atmospheric chemistry by dispersing pollution, diluting concentrations, and creating less favorable conditions for secondary pollutants to form. Strong air currents help disperse pollution, leading to lower concentrations, while weak air currents can help increase the accumulation of pollution in certain locations. Additionally, wind transports pollutants at a given location depending on wind direction and location of source, leading to an increase or decrease in that pollutant. Aerosols are transported by wind, so higher aerosol concentrations are generally measured downwind from source regions.
Descriptions of these measurements will be reviewed in more detail later in this Data Pathfinder. The following sections will help guide you to topic-specific data and resources for accessing, visualizing, preparing/manipulating (e.g. subsetting), and analyzing data. Each observation, model, and reanalysis data has unique characteristics that should be considered when evaluating its use.
An asterisk (*) next to an entry indicates that near real-time (NRT) data products are available through NASA's Land, Atmosphere Near real-time Capability for EOS (LANCE). While not intended for scientific research, NRT data are good resources for monitoring ongoing or time-critical events. To learn more about the difference between NRT and Standard Science Products, see Near Real Time versus Standard Products.
Spatial Resolution | Spatial Coverage | Temporal Resolution | Temporal Coverage | Spectral Resolution | Satellite/ Platform |
Name (Sensor, Model, etc.) | Observation, Model, or Reanalysis | File Format |
---|---|---|---|---|---|---|---|---|
5 km, 10 km |
Global |
Hourly, Daily |
2012-present |
10 km: 6.9-36.5 GHz; 5 km: 89.0 GHz |
SHIZUKU (GCOM-W1) |
*Advanced Microwave Scanning Radiometer 2 (AMSR2) |
Observation |
HDF-EOS5 |
25 km |
Near-global |
Hourly, Near-daily |
2017-present |
Microwave: 1.575 GHz; L-Band (2-1 GHz) |
Cyclone Global Navigation Satellite System (CYGNSS) |
Delay Doppler Mapping Instrument (DDMI) |
Observation |
netCDF-4 |
0.5° x 0.625° |
Global |
Monthly |
1980-present |
N/A |
N/A |
Reanalysis |
netCDF |
NASA’s Health and Air Quality Applied Sciences Team (HAQAST) Guide:
Data Visualizations
Data, often in near real-time (NRT), can be accessed and interactively explored using NASA Worldview:
Create and share layered maps with AMSR2 data using the AIRS Browse Tool.
Research-quality AMSR2 Wind, Level 2 NRT data are available in Earthdata Search from NASA’s Land, Atmosphere Near real-time Capability for EOS (LANCE) 75 to 140 minutes after a satellite observation.
The Delay Doppler Mapping Instrument (DDMI) is the single instrument aboard the eight individual satellites comprising NASA’s Cyclone Global Navigation Satellite System (CYGNSS) constellation. Each DDMI contains both a traditional Global Positioning System (GPS) navigation receiver integrated with a reflections processor. The DDMI aboard each of the eight CYGNSS micro-satellites receives signals broadcast from four orbiting GPS satellites along with the return of the same GPS satellite’s signal reflected from Earth. These signals are used to provide measurements of wind speed over the ocean to better understand and predict tropical cyclones.
Data can be accessed and interactively explored using NASA Worldview:
Research-quality data products can be accessed using Earthdata Search:
The Modern-Era Retrospective analysis for Research and Applications, Version 2 (MERRA-2) provides data beginning in 1980. Due to the amount of historical data available, MERRA-2 data can be used to look for trends and patterns as well as anomalies. There are several options available: 1-hourly, 3-hourly, 6-hourly, daily, and monthly. These options provide information on precipitation.
Monthly data can be accessed and interactively explored using NASA Worldview:
MERRA-2 Weather Analyses Maps
Using an online interactive tool called Giovanni, map visualizations of MERRA-2 Wind data products can be downloaded as PNG images, or as GeoTIFF or KMZ files; time-series data are available as CSV data files, and animations are in either webm video format or animated GIF images:
GIS Product using MERRA-2 reanalysis data:
Research-quality data products can be accessed using Earthdata Search:
The NASA Prediction Of Worldwide Energy Resources (POWER) Data Access Viewer provides MERRA-2 meteorological parameters through a web mapping application with the capability for data subsetting, charting, and visualizing. The data are also available via API, GIS enabled, as well as via OPeNDAP.
Surface Air Temperature (SAT) refers to the air temperature generally measured at approximately 6.5 feet (about 2 meters) above the ground or ocean surface. Surface air temperature provides a key indicator of climate change, contributing to the “global surface temperature record”.
Descriptions of these measurements will be reviewed in more detail later in this Data Pathfinder. The following sections will help guide you to topic-specific data and resources for accessing, visualizing, preparing/manipulating (e.g. subsetting), and analyzing data. Each observation, model, and reanalysis data has unique characteristics that should be considered when evaluating its use.
An asterisk (*) next to an entry indicates that near real-time (NRT) data products are available through NASA's Land, Atmosphere Near real-time Capability for EOS (LANCE). While not intended for scientific research, NRT data are good resources for monitoring ongoing or time-critical events. To learn more about the difference between NRT and Standard Science Products, see Near Real Time versus Standard Products.
Spatial Resolution | Spatial Coverage | Temporal Resolution | Temporal Coverage | Spectral Resolution | Satellite/ Platform | Name (Sensor, Model, etc.) |
Observation, Model, or Reanalysis |
File Format |
---|---|---|---|---|---|---|---|---|
1° |
Global |
3 hours, 12 hours, Daily, Monthly |
2002-present |
2,378 infrared channels in the 3.74 to 15.4 micron spectral range |
Aqua |
Observation |
HDF-EOS | |
1 km |
Over continental North America and Hawaii and Puerto Rico | Daily | Over continental North America and Hawaii from 1980 and over Puerto Rico from 1950 through the end of the most recent full calendar year | N/A | N/A | Daymet |
Model |
netCDF, Cloud Optimized GeoTIFF (COG) |
Varies: 0.01°, 0.1°, 0.125°, 0.25°, 1° |
Global | Varies: Hourly, 3-hourly,Daily, Monthly | Varies: 1948-present |
N/A | N/A | Land Data Assimilation Systems (LDAS) | Model | netCDF |
0.5° x 0.625° |
Global |
Monthly |
1980-present |
N/A | N/A |
Reanalysis |
netCDF |
NASA’s Health and Air Quality Applied Sciences Team (HAQAST) Guide:
Data Visualizations
The Atmospheric Infrared Sounder (AIRS) is a hyperspectral sounder that collects daily global measurements of water vapor and temperature profiles as one of four instruments comprising the AIRS Project Instrument Suite.
Data can be accessed and interactively explored using NASA Worldview:
Create and share layered maps with AIRS data using the AIRS Browse Tool.
Using an online interactive tool called Giovanni, data products can be visualized as a time-averaged map, an animation, seasonal maps, scatter plots, or a time series, as well as downloaded in .CSV format:
Research-quality air surface temperature data products can be accessed using Earthdata Search:
AIRS NRT data are available from NASA’s Land, Atmosphere Near real-time Capability for EOS (LANCE) 75 to 140 minutes after a satellite observation.
A NASA source for air temperature modeled data is Daymet. Daymet is a collection of gridded estimates of daily weather parameters including minimum and maximum temperature, precipitation, vapor pressure, radiation, snow water equivalent, and day length at 1 km resolution over North America, Puerto Rico, and Hawaii. Daymet data are available from 1980 to present (North America and Hawaii) and from 1950 to present (Puerto Rico).
Research-quality air surface temperature data products can be accessed using Earthdata Search:
The Land Data Assimilation System (LDAS) includes a global collection (GLDAS), a North American collection (NLDAS), National Climate Assessment - Land Data Assimilation System (NCA-LDAS), and a Famine Early Warning Systems Network (FEWS NET) Land Data Assimilation System (FLDAS). LDAS uses measurements including air temperature, precipitation, soil texture, and topography. GLDAS modeled data are available from January 1948 to present. NLDAS modeled datasets are available from January 1979 to present. FLDAS modeled datasets are available from January 1982 to present.
Monthly data can be visualized using NASA Worldview:
Using an online interactive tool called Giovanni, map visualizations of LDAS data products can be downloaded as PNG images, or as GeoTIFF or KMZ files; time-series data are available as CSV data files, and animations are in either webm video format or animated GIF images:
The Modern-Era Retrospective analysis for Research and Applications, Version 2 (MERRA-2) provides data beginning in 1980. Due to the amount of historical data available, MERRA-2 data can be used to look for trends and patterns as well as anomalies. There are several options available: 1-hourly, 3-hourly, 6-hourly. These options provide information on surface skin temperature, air temperature at 2 m, and air temperature at 10 m.
Data can be accessed and interactively explored using NASA Worldview:
MERRA-2 Weather Maps
Using an online interactive tool called Giovanni, map visualizations of MERRA-2 Temperature data products can be downloaded as PNG images, or as GeoTIFF or KMZ files; time-series data are available as CSV data files, and animations are in either webm video format or animated GIF images:
GIS Product using MERRA-2 reanalysis data:
Research-quality air surface temperature data products can be accessed using Earthdata Search:
Land surface reflectance is a measure of the fraction of incoming solar radiation reflected from Earth's surface to a satellite-borne or aircraft-borne sensor. These data provide an estimate of the surface spectral reflectance as it would be measured at ground level in the absence of atmospheric scattering or absorption, which is referred to as atmospheric correction.
Changes can be detected and characterized using surface reflectance data when comparing multiple images for the same region of Earth’s surface. For example, as pollutants or aerosols like dust spread over an area, they can affect surface reflectance values and this can be detected by sensors aboard orbiting satellites. This allows land cover to be observed and analyzed over time using sustained land imaging and multi-spectral high-resolution imagery. Surface reflectance data are not only used for visualizing the surface, but also for computing metrics and creating models that are useful for specific analysis.
Descriptions of these measurements will be reviewed in more detail later in this Data Pathfinder. The following sections will help guide you to topic-specific data and resources for accessing, visualizing, preparing/manipulating (e.g. subsetting), and analyzing data. Each observation, model, and reanalysis data has unique characteristics that should be considered when evaluating its use.
An asterisk (*) next to an entry indicates that near real-time (NRT) data products are available through NASA's Land, Atmosphere Near real-time Capability for EOS (LANCE). While not intended for scientific research, NRT data are good resources for monitoring ongoing or time-critical events. To learn more about the difference between NRT and Standard Science Products, see Near Real Time versus Standard Products.
Spatial Resolution | Spatial Coverage | Temporal Resolution | Temporal Coverage | Spectral Resolution | Satellite/ Platform |
Name (Sensor, Model, etc.) |
Observation, Model, or Reanalysis |
File Format |
---|---|---|---|---|---|---|---|---|
15 m, 30 m |
Global |
Varies |
2000-present |
14 bands ranging from 0.52 µm to 11.65 µm |
Terra |
Observation |
HDF-EOS, GeoTIFF | |
500 m, 1 km, 0.05° |
Global |
1-2 days |
2000-present |
36 bands ranging from 0.4 µm to 14.4 µm |
Terra, Aqua |
Observation |
HDF-EOS5 | |
375 m, 500 m, 750 m, 1 km, |
Global |
1-2 days, 8-day |
2017-present |
22 bands ranging from 0.41 µm to 12.01 μm |
Suomi NPP |
Observation |
HDF5, HDF-EOS5, netCDF4 | |
15 m, 30 m, 60 m |
Global |
16 days |
1982-present (various missions) |
OLI/OLI-2: 9 bands ranging in wavelength from 0.43 µm to 1.38 µm ETM+: 8 bands ranging in wavelength from 0.45 µm to 12.5 µm TM: 7 bands ranging in wavelength from 0.45 µm to 2.35 µm |
Landsat 4, 5, 7, 8, 9 |
Observation |
GeoTIFF | |
30 m |
Near-global (no Antarctic) |
2-3 days |
2013-present |
OLI/OLI-2: 9 bands ranging in wavelength from 0.43 µm to 1.38 µm MSI: 12 bands ranging in wavelength from 0.443 µm to 2.190 µm |
Harmonized Landsat Sentinel-2 (HLS: Landsat 8, 9 + Sentinel-2A/B) |
Observation |
Cloud Optimized GeoTIFF (COG) |
The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) instrument is a cooperative effort between NASA and Japan's Ministry of Economy, Trade and Industry (METI).
ASTER Surface Reflectance data can be visualized and interactively explored using NASA Worldview:
Research quality ASTER data products are available through Earthdata Search:
ASTER surface reflectance products are processed on-demand and can be requested through Earthdata Search:
The Enhanced Thematic Mapper (ETM+), the Operational Land Imager (OLI), and the Thermal Infrared Sensor-2 (TIRS-2) are aboard the joint NASA/USGS Landsat series of satellites.
OLI data can be visualized and interactively explored using NASA Worldview:
Research quality Landsat 7, 8, and 9 ETM+, OLI, and OLI-2 land surface reflectance data products can be accessed directly using Earthdata Search.
Harmonized Landsat Sentinel-2 (HLS) data provide consistent global observation of Earth’s surface reflectance and top-of-atmosphere (TOA) brightness data from the Landsat OLI and the ESA (European Space Agency) Multi-Spectral Instrument (MSI) every 2 to 3 days with 30-meter spatial resolution.
HLS Surface Reflectance data can be visualized and interactively explored using NASA Worldview:
Research quality HLS data products can be accessed directly from Earthdata Search
The Application for Extracting and Exploring Analysis Ready Samples (AppEEARS) tool offers a simple and efficient way to access, transform, and visualize geospatial data from a variety of federal data archives, including USGS Landsat Analysis Ready Data (ARD) surface reflectance products.
Moderate Resolution Imaging Spectroradiometer (MODIS) Surface Reflectance products provide an estimate of the surface spectral reflectance as it would be measured at ground level in the absence of atmospheric scattering or absorption.
MODIS Surface Reflectance data can be visualized and interactively explored using NASA Worldview:
Multiple Geographic Information Systems (GIS) MODIS Surface Reflectance data layers with different band combinations are available through Esri’s ArcGIS OnLine (AGOL). NASA GIS data may be used with open-source GIS software:
Research quality MODIS data products can be accessed directly from Earthdata Search:
Near real-time (NRT) MODIS Surface Reflectance data are available through NASA’s Land, Atmosphere Near real-time Capability for EOS (LANCE) within 60 to 125 minutes after a satellite observation:
Earthdata GIS Products:
The Visible Infrared Imaging Radiometer Suite (VIIRS) instrument is aboard the NASA/NOAA Suomi National Polar-orbiting Partnership (Suomi NPP) and NOAA-20 satellites.
VIIRS Surface Reflectance data can be visualized and interactively explored using NASA Worldview:
Research quality VIIRS data products can be accessed directly from Earthdata Search:
Near real-time (NRT) VIIRS Surface Reflectance data are available through LANCE within 60 to 125 minutes after a satellite observation:
Topography is the general configuration of the land surface, including its relief and the position of its natural features. Factors including regional topography, prevailing wind speed and direction, amount of natural and human-created aerosols, increased industrial growth and urbanization, and high population density can result in unhealthy levels of air pollution that can affect a region for days and weeks. Topographic data are often in the form of Digital Elevation Models (DEMs) or grids with values representing the height of a cell.
Descriptions of these measurements will be reviewed in more detail later in this Data Pathfinder. The following sections will help guide you to topic-specific data and resources for accessing, visualizing, preparing/manipulating (e.g. subsetting), and analyzing data. Each observation, model, and reanalysis data has unique characteristics that should be considered when evaluating its use.
Spatial Resolution | Spatial Coverage | Temporal Resolution | Temporal Coverage | Spectral Resolution | Satellite/ Platform |
Sensor(s)/ Model Name |
Observation or Model | File Format |
---|---|---|---|---|---|---|---|---|
30 m for U.S., 60 m, 90 m, 1 km for global | Global | One-time estimate | 2000 | N/A | SRTM | N/A | Observation | HGT, netCDF4 |
30 m | Global | Multi-year | 2000-2013 | 14 bands ranging from 0.52 µm to 11.65 µm | Terra | ASTER | Observation |
HDF-EOS or GeoTIFF |
25 m diameter |
51.6° N to 51.6° S |
One-time estimate | 2019-2022 | Laser wavelength: 1.064 µm | International Space Station |
Global Ecosystem Dynamics Investigation (GEDI) mission |
Observation and Model | HDF5 |
30 m |
All land between 60° N and 56° S latitude. |
Multi-day |
2000 |
N/A |
NASA Making Earth System Data Records for Use in Research Environments (MEaSUREs) Digital Elevation Model (NASADEM) |
Inputs from multiple sensors including SRTM, ASTER, ICESat GLAS and PRISM |
Model |
HGT or netCDF4 |
The Terra Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) Digital Elevation Model provides a global digital elevation model (DEM) of land areas on Earth at a spatial resolution of 1 arc second (approximately 30 meter horizontal posting at the equator).
DEM data accuracy is typically very sensitive to vegetation cover; however, data from the ASTER instrument tend to perform better over specific landcover types. DEM data can be accessed and interactively explored using NASA Worldview:
Research quality topography data products are available from Earthdata Search:
In addition to Earthdata Search, SRTM and ASTER data can be accessed through AppEEARS.
The Global Ecosystem Dynamics Investigation (GEDI) Level 3 Land Surface Metrics dataset provides gridded mean canopy height, standard deviation of canopy height, mean ground elevation, standard deviation of ground elevation, and counts of laser footprints per 1 km x 1 km grid cells within 52° north and south latitude. Data are available from April 2019 through 2022. Level 3 gridded products can be used to create digital elevation models, characterize important carbon and water cycling processes, and more.
Users may download customized subsets (Level 3 and Level 4) of GEDI data using the Spatial Data Access Tool through NASA’s Oak Ridge National Laboratory Distributed Active Archive Center (ORNL DAAC).
GEDI L3 Gridded Land Surface Metrics data can be visualized and interactively explored using NASA Worldview:
Research quality data can be accessed using Earthdata Search:
One of the most common topography data sources is the Shuttle Radar Topography Mission (SRTM). SRTM provides a DEM of all land between 60° north and 56° south latitude, which encompasses about 80% of Earth's landmass.
DEM data can be accessed and interactively explored using NASA Worldview:
Research quality topography data products are available from Earthdata Search:
In addition to Earthdata Search, SRTM can be accessed through AppEEARS.
The NASA Making Earth System Data Records for Use in Research Environments (MEaSUREs) Digital Elevation Model (DEM) version 1 (NASADEM_HGT) dataset provides global elevation data at 1 arc second spacing. NASADEM extends the legacy of the SRTM by improving the DEM height accuracy and data coverage as well as providing additional SRTM radar-related data products. NASADEM are distributed in 1 degree latitude by 1 degree longitude tiles and consist of all land between 60° N and 56° S latitude. This accounts for about 80% of Earth’s total landmass.
Research quality topography data products are available from Earthdata Search:
Descriptions of these measurements will be reviewed in more detail later in this Data Pathfinder. The following sections will help guide you to topic-specific data and resources for accessing, visualizing, preparing/manipulating (e.g. subsetting), and analyzing data. Each observation, model, and reanalysis data has unique characteristics that should be considered when evaluating its use.
An asterisk (*) next to an entry indicates that near real-time (NRT) data products are available through NASA's Land, Atmosphere Near real-time Capability for EOS (LANCE). While not intended for scientific research, NRT data are good resources for monitoring ongoing or time-critical events. To learn more about the difference between NRT and Standard Science Products, see Near Real Time versus Standard Products.
Spatial Resolution | Spatial Coverage | Temporal Resolution | Temporal Coverage | Spectral Resolution | Satellite/ Platform |
Sensor(s)/ Model Name | Observation or Model | File Format |
---|---|---|---|---|---|---|---|---|
9 km to 40 km |
Near global |
Daily, 3 days |
2015- present |
1.41 GHz (Radiometer frequency) |
Soil Moisture Active Passive (SMAP) |
*Radar (active; no longer functional) Microwave radiometer (passive) |
Observation and Model |
HDF5 |
25 km |
Global |
50 min |
2012-near present |
16 channels ranging in frequency from 6.925 GHz to 89 GHz |
SHIZUKU (GCOM-W1) |
*Advanced Microwave Scanning Radiometer 2 (AMSR2) |
Observation |
HDF-EOS5 |
0.01°, 0.1°, 0.125°, 0.25°, 1° |
Global |
Hourly, 3-hourly,Daily, monthly |
1948-present |
N/A |
N/A |
Land Data Assimilation Systems (LDAS) |
Model |
netCDF |
3 km |
Continental U.S., Alaska, Puerto Rico |
Daily |
2003-2021 |
N/A |
N/A |
Short-term Prediction Research and Transition-Land Information System (SPoRT-LiS) |
Model |
netCDF |
9 km |
Global |
3 hour |
2015-present |
N/A |
N/A |
Model |
HDF5 | |
0.5° x 0.625° |
Global |
Hourly, daily, monthly |
1980-present |
N/A |
N/A |
Reanalysis |
netCDF | |
0.125° |
North America |
7 days |
2002-present |
N/A |
N/A |
Model |
netCDF |
Data Visualizations
The Advanced Microwave Scanning Radiometer (AMSR) for EOS (AMSR-E) instrument and the AMSR-2 instrument provide volumetric soil moisture data. The Advanced Microwave Scanning Radiometer 2 (AMSR2) instrument provides global passive microwave measurements of surface soil moisture. Near real-time (NRT) products available through the Land, Atmosphere Near real-time Capability for EOS (LANCE) are generated within 3 hours of the last observations in the file.
Data can be visualized using NASA Worldview:
Using an online interactive tool called Giovanni, map visualizations of AMSR-2 data can be downloaded as PNG images, or as GeoTIFF or KMZ files; time-series data are available as CSV data files, and animations are in either webm video format or animated GIF images:
Near-real time data:
Research-quality data products can be accessed using Earthdata Search:
NASA's Soil Moisture Active Passive satellite (SMAP, launched in 2015) measures the moisture in the top 5 cm of soil globally daily and every 2-3 days at a resolution of 9-36 km.
Near real-time SMAP imagery can be accessed and interactively explored using NASA Worldview:
Research quality data products can be accessed using Earthdata Search:
Near real-time (NRT) SMAP data are available through NASA’s Land, Atmosphere Near real-time Capability for EOS (LANCE) within 60 to 125 minutes after a satellite observation:
Weekly soil moisture and groundwater drought indicators are available each week based on terrestrial water storage observations derived from Gravity Recovery and Climate Experiment (GRACE) satellite data and integrated with other observations, using a sophisticated numerical model of land surface water and energy processes, referred to as GRACE Data Assimilation for Drought Monitoring (GRACE-DA-DM).
NASA’S Global Modeling And Assimilation Office (GMAO), in collaboration with the University of Montana and NASA’s Jet Propulsion Laboratory, provides value-added Level 4 data products. These Level 4 datasets merge SMAP observations into physically-based numerical models of the land surface water, energy, and carbon cycles. Available Level 4 data include global, 9-km, 3-hourly estimates of surface and root zone soil moisture, surface and soil temperature, and land surface fluxes, along with algorithm diagnostics from the ensemble-based data assimilation system. Level 4 data also include global, 9-km, daily estimates of net ecosystem CO2 exchange, component carbon stocks and fluxes, and sub-grid information broken down by plant functional types.
Near real-time SMAP imagery can be accessed and interactively explored using NASA Worldview:
These data products are available from Earthdata Search:
NASA, in collaboration with other agencies, has developed models of soil moisture content that incorporate satellite information with ground-based data (when ground-based data are available). The Land Data Assimilation System (LDAS) includes a global collection (GLDAS), a North American collection (NLDAS), National Climate Assessment - Land Data Assimilation System (NCA-LDAS), and a Famine Early Warning Systems Network (FEWS NET) Land Data Assimilation System (FLDAS). LDAS uses measurements including air temperature, precipitation, soil texture, and topography. GLDAS modeled data are available from January 1948 to present. NLDAS modeled datasets are available from January 1979 to present. FLDAS modeled datasets are available from January 1982 to present.
The NLDAS experimental drought monitor is derived from near real-time soil moisture output model data:
Soil MERGE (SMERGE) is a root-zone soil moisture product developed by merging NLDAS land surface model output with surface satellite retrievals from the ESA (European Space Agency) Climate Change Initiative. This data product contains root-zone soil moisture of 0-40 cm layer, Climate Change Initiative (CCI)-derived soil moisture anomalies of 0-40 cm layer, and a soil moisture data estimation flag.
Using an online interactive tool called Giovanni, map visualizations of LDAS and SMERGE data products can be downloaded as PNG images, or as GeoTIFF or KMZ files; time-series data are available as CSV data files, and animations are in either webm video format or animated GIF images:
LDAS Soil Moisture data from GLDAS, NLDAS and FLDAS are available in Earthdata Search:
The Short-term Prediction Research and Transition (SPoRT) project at NASA's Marshall Space Flight Center in Huntsville, AL, is a NASA- and NOAA-funded activity to transition experimental/quasi-operational satellite observations and research capabilities to the operational weather community to improve short-term weather forecasts on a regional and local scale.SPoRT-Land Information System (SPoRT-LiS) provides real-time 3km Land Information System data on the following parameters: Volumetric Soil Moisture, Relative Soil Moisture, Column-Integrated Relative Soil Moisture, and Green Vegetation Fraction.
SPoRT offers a Near Real-Time Viewer that includes SMAP datasets for the following regions:
The Modern-Era Retrospective analysis for Research and Applications, Version 2 (MERRA-2) provides data beginning in 1980. Due to the amount of historical data available, MERRA-2 data can be used to look for trends and patterns, as well as anomalies. There are several options available: hourly and monthly from 1980.
Using an online interactive tool called Giovanni, map visualizations of MERRA-2 Soil Moisture data products can be downloaded as PNG images, or as GeoTIFF or KMZ files; time-series data are available as CSV data files, and animations are in either webm video format or animated GIF images:
MERRA-2 Soil Moisture data in Earthdata Search
Air quality-related deaths and diseases that are exacerbated by air pollution are preventable, but prevention requires a knowledge of where vulnerable populations exist and what interventions are needed in these communities. Poor air quality tends to be elevated in low to middle-income countries, where 98% of urban centers with populations greater than 100,000 do not meet World Health Organization (WHO) guidelines.
Integrating socioeconomic data with air quality data can provide a more accurate analysis of populations facing greater exposure and vulnerability from pollutants. A number of socioeconomic factors need to be considered when analyzing air quality, including:
NASA’s Socioeconomic Data and Applications Center (SEDAC) is the home for socioeconomic data in NASA’s Earth Observing System Data and Information System (EOSDIS) collection. Hosted at Columbia University’s Center for International Earth Science Information Network (CIESIN), SEDAC synthesizes Earth science and socioeconomic data and information in ways useful to a wide range of decision makers and other applied users and serves as an “Information Gateway” between the socioeconomic and Earth science data and information domains.
SEDAC’s Air Quality Data for Health-Related Applications data collection provides air quality data for health-related research and applications. This collection consists of the Daily and Annual PM2.5 Concentrations for the Contiguous United States, 1-km Grids, v1 (2000-2016) and Daily 8-Hour Maximum and Annual O3 Concentrations for the Contiguous United States, 1-km Grids, v1 (2000-2016) datasets. A similar NO2 dataset is in development. Additional SEDAC datasets on population exposure and vulnerability (Note: An Earthdata Login is required for data access):
Combining regional or community-level socioeconomic data (such as life expectancy, prevalence of asthma, or prevalence of health insurance coverage) with Earth science data (such as NO2 and SO2 concentrations) provides a way of examining environmental justice aspects of air quality and exploring how certain communities are impacted to a greater degree by pollution. For more information about how NASA is applying Earth science data to environmental justice, please see the Environmental Justice at NASA Backgrounder. The following open access articles provide additional information about research using Earth science data to explore environmental justice:
Panoply: NASA’s Panoply visualization tool plots geo-referenced and other arrays from netCDF, HDF, GRIB, and other datasets. It can be used to help plot data on global or regional maps, allow users to select from multiple map projections, and overlay continent outlines or masks