WMS: TEMPO Formaldehyde (HCHO) Vertical Column August 2023-September 2025 (Hourly During Daylight)

Formaldehyde Overview and Intended Use Multiple sources contribute to ambient formaldehyde including but not limited to wildfire emissions, industrial activities, and secondary production resulting from the oxidation of other compounds emitted by industries and vegetations. Formaldehyde is a carcinogenic, hazardous air pollutant. While ambient formaldehyde concentrations are usually below U.S. federal recommendations, ambient exposure can cause health issues in people. In addition to measuring formaldehyde for its impacts on human health, satellite formaldehyde observations are also extremely valuable in understanding atmospheric chemistry and production of ground-level ozone.   Layer Overview The Tropospheric Emissions: Monitoring of Pollution (TEMPO) Formaldehyde Vertical Column layer provides information on the amount of formaldehyde in the atmosphere as a vertical column density, calculated in molecules per square centimeter (molecules/cm^2). In other words, the total number of formaldehyde molecules present in the atmosphere from the Earth’s surface to the top of the atmosphere over an area of one square centimeter. Typical values range from 0 to 6e16 molecules/cm^2, though certain events like wildfires may cause these limits to be exceeded. Formaldehyde Level 3 files provide trace gas information on a regular grid consisting of 0.02° x 0.02° grid points across the TEMPO field of regard covering the continental United States (CONUS), much of Mexico, Canada, and the Caribbean. Level 3 files are derived by combining information from all Level 2 files constituting a TEMPO East-West scan cycle, using an area-weighted re-gridding approach. The data have been converted from their native file format (netCDF4) to Cloud Raster Format (CRF). TEMPO V04 algorithms address known issues in the V03, improving data quality. As a result, there are differences between the TEMPO V03 and V04 data. While qualitative analyses and general trends may remain similar between both versions, merging versions for quantitative analysis is discouraged. For details on the changes in the data, please see the User Guide on the TEMPO site.  Temporal CoverageThe temporal resolution of a nominal scan is approximately one hour during daylight hours, with more frequent scans in the morning over the eastern portion of the field of regard and in the evenings over the western portion of the field of regard. Each image is presented with the starting timestamp of the corresponding TEMPO scan. Due to the nature of the TEMPO instrument’s east to west scanning pattern, each image is a composite of measurements taken over a period of 40-60 minutes, depending on the spatial coverage of the scan.  This service was created using TEMPO data version (V03), which was released publicly on May 24, 2024, and cover the time period from August 2, 2023 to September 16, 2025. TEMPO Version 04 (V04) Level 1, 2, and 3 standard data products began production on September 17, 2025. All observations since the beginning of the mission are being reprocessed with V04 algorithms, with V04 products becoming publicly available as they are reprocessed. The TEMPO V04 data are accessible via this service. Once the V03 data reprocessing is completed, this V03 service will be deprecated.  Geographic CoverageImagery is available for the TEMPO field of regard covering the continental United States (CONUS), much of Mexico, Canada, and the Caribbean. The imagery in this image service is regridded onto a 0.02º longitude x 0.02º latitude grid and presented in the geographic coordinate system WGS 1984. The sensor’s native spatial resolution is ~2 km x 4.75 km at the center of TEMPO’s field of regard (33.5°N, 89.2°W) in WGS 1984. Data FilteringThe layer is filtered to remove low-quality pixels using the main data quality flag (removing low confidence measurements), solar zenith angle (removing data retrieved at high solar zenith angles), and effective cloud fraction (removing where clouds obscure the column) variables. The filters applied are set to remove pixels based on the following: main_data_quality_flag > 1, eff_cloud_fraction > 0.5, and solar_zenith_angle > 80.  Data Validation and Limitations of UseThese data should be considered as provisional products per the Provisional Product Maturity level defined in the TEMPO validation plan. These data are at provisional maturity, which means that product performance has been demonstrated through a large, but still (seasonally or otherwise) limited number of independent measurements. The analysis is sufficient for limited qualitative determinations of product fitness-for-purpose, and the product is potentially ready for testing by operational users and may be suitable for scientific publication. Users may consult the TEMPO User Guide for descriptions of the data and associated known issues.  The information shown here is total column density (molecules per unit area for the whole vertical column of the atmosphere), not a concentration. Atmospheric concentration refers to the amount of trace gas (e.g., formaldehyde) in a specific point (in this case altitude). Conversion from total column density to atmospheric concentration requires additional information, such as the state of the atmosphere and the vertical distribution of the column, which are not provided in this layer. The use of this layer to derive atmospheric concentrations of formaldehyde is discouraged for the non-specialist. Recommended Usage NotesWhen viewing the image service in the Esri online map viewer, it is recommended to use the multidimensional slider rather than the default time slider. The multidimensional slider can be accessed via the “multidimensional” icon in the right-hand menu.  TEMPO Mission Overview The 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). This allows TEMPO to maintain a continuous view of North America so that the instrument's light-collecting mirror can make a complete east-to-west scan of the field of regard hourly during daylight hours. By measuring sunlight reflected and scattered from the Earth's surface and atmosphere back to the instrument's detectors, TEMPO's ultraviolet and visible light sensors provide measurements of ozone, nitrogen dioxide, formaldehyde, and other constituents involved in the chemical dynamics of Earth’s atmosphere. The primary mission objective of TEMPO is to improve our understanding of air quality and its impacts. By providing near real-time data and comprehensive atmospheric composition measurements, TEMPO helps advance knowledge of the Earth system and improve air quality forecasting. These data also aid in quantifying how air quality affects vegetation, agriculture, and human health. ContactFor inquiries about this service, please contact larc-dl-asdc-tempo@mail.nasa.gov or post/view questions on the  Earthdata Forum.

This item provides the Open Geospatial Consortium (OGC) Web Map Service (WMS) access the TEMPO Formaldehyde (HCHO) Vertical Column Near Real-Time (NRT) service. The source service should be used when access to the actual data is required. The WMS service allows for quick access to the map imagery for consuming and serving dynamic maps.  Formaldehyde Overview and Intended UseMultiple sources contribute to ambient formaldehyde including but not limited to wildfire emissions, industrial activities, and secondary production resulting from the oxidation of other compounds emitted by industries and vegetations. Formaldehyde is a carcinogenic, hazardous air pollutant. While ambient formaldehyde concentrations are usually below U.S. federal recommendations, ambient exposure can cause health issues in people. In addition to measuring formaldehyde for its impacts on human health, satellite formaldehyde observations are also extremely valuable in understanding atmospheric chemistry and production of ground-level ozone.  Layer OverviewThe Tropospheric Emissions: Monitoring of Pollution (TEMPO) Formaldehyde Vertical Column Near Real-Time (NRT) layer provides information on the amount of formaldehyde in the atmosphere as a vertical column density, calculated in molecules per square centimeter (molecules/cm^2). In other words, the total number of formaldehyde molecules present in the atmosphere from the Earth’s surface to the top of the atmosphere over an area of one square centimeter. Typical values range from 0 to 6e16 molecules/cm^2, though certain events like wildfires may cause these limits to be exceeded. The TEMPO NRT formaldehyde files are produced using a fast version of the TEMPO baseline retrieval processor. TEMPO NRT formaldehyde Level 3 files provide trace gas information on a regular grid. Level 3 files are derived by combining information from all Level 2 files constituting a TEMPO East-West scan cycle, using an area-weighted re-gridding approach. The NRT processing optimizes radiance calibration, image navigation and registration, and cloud and trace gas retrievals for rapid processing, while ensuring that product quality is sufficient for most NRT applications. The data have been converted from their native file format (netCDF4) to Cloud Raster Format (CRF). Temporal CoverageThe temporal resolution of a nominal scan is approximately one hour during daylight hours, with more frequent scans in the morning over the eastern portion of the field of regard and in the evenings over the western portion of the field of regard. Each image is presented with the starting timestamp of the corresponding TEMPO scan. Due to the nature of the TEMPO instrument’s east to west scanning pattern, each image is a composite of measurements taken over a period of 40-60 minutes, depending on the spatial coverage of the scan. Data are updated hourly with any new scans that have been received. Data older than two days (48 hours) are removed from the service. On the rare occasion that the TEMPO instrument is not collecting data for an extended period of time, this service will retain only the latest scan until operations resume. The TEMPO operations log may be found on the TEMPO site.  Geographic CoverageImagery is available for the TEMPO field of regard covering the continental United States (CONUS), and much of Mexico, Canada, and the Caribbean. The imagery in this image service is regridded onto a 0.02º longitude x 0.02º latitude grid and presented in the geographic coordinate system WGS 1984. The sensor’s native spatial resolution is ~2 km x 4.75 km at the center of TEMPO’s field of regard (33.5°N, 89.2°W) in WGS 1984. Data FilteringThe layer is filtered to remove low-quality pixels using the main data quality flag (removing low confidence measurements), solar zenith angle (removing data retrieved at high solar zenith angles), and effective cloud fraction (removing data where clouds obscure the tropospheric column) variables. The filters applied are set to remove pixels based on the following: main_data_quality_flag > 1, eff_cloud_fraction > 0.5, or solar_zenith_angle > 80.  Data Validation and Limitations of UseThese data should be considered as provisional products per the Provisional Product Maturity level defined in the TEMPO validation plan.  These data are at provisional maturity, which means that product performance has been demonstrated through a large, but still (seasonally or otherwise) limited number of independent measurements. The analysis is sufficient for limited qualitative determinations of product fitness-for-purpose, and the product is potentially ready for testing by operational users and may be suitable for scientific publication.  Users may consult the TEMPO User Guide for descriptions of the data and associated known issues.  The information shown here is total column density (molecules per unit area for the whole vertical column of the atmosphere), not a concentration. Atmospheric concentration refers to the fractional amount of trace gas (e.g., formaldehyde) relative to total air at a specific point, and changes with altitude. Conversion from total column density to atmospheric concentration requires additional information, such as the state of the atmosphere and the vertical distribution of the column, which are not provided in this layer. The use of this layer to derive atmospheric concentrations of formaldehyde is discouraged for the non-specialist. Recommended Usage NotesWhen viewing the image service in the Esri online map viewer, it is recommended to use the multidimensional slider rather than the default time slider. The multidimensional slider can be accessed via the “multidimensional” icon in the right-hand menu.  While qualitative analyses and general trends may remain similar between the TEMPO standard and NRT versions, merging versions for quantitative analysis is discouraged. Standard and NRT formaldehyde retrievals differ due to differences in the differential formaldehyde slant column densities derived through spectral fitting due to (1) the use of a different radiance reference and (2) the omission of the radiance wavelength calibration in the L1 NRT processing. For details on the changes in the data, please see the TEMPO User Guide and the TEMPO NRT Data Products User Guide and ATBD Supplement on the TEMPO site.  The TEMPO NRT ArcGIS service provides access to TEMPO formaldehyde NRT data earlier than the TEMPO standard formaldehyde data are available in the standard formaldehyde ArcGIS service. The TEMPO NRT products are useful for applications with low-latency requirements; however, it is recommended to switch to the TEMPO Formaldehyde Standard Version 04 (V04) service, once the data becomes available in that service. TEMPO V04 data are available from September 17, 2025 to present and the service is updated daily with the previous day’s data. TEMPO Mission OverviewThe 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). This allows TEMPO to maintain a continuous view of North America so that the instrument's light-collecting mirror can make a complete east-to-west scan of the field of regard hourly during daylight hours. By measuring sunlight reflected and scattered from the Earth's surface and atmosphere back to the instrument's detectors, TEMPO's ultraviolet and visible light sensors provide measurements of ozone, nitrogen dioxide, formaldehyde, and other constituents involved in the chemical dynamics of Earth’s atmosphere. The primary mission objective of TEMPO is to improve our understanding of air quality and its impacts. By providing near real-time data and comprehensive atmospheric composition measurements, TEMPO helps advance knowledge of the Earth system and improve air quality forecasting. These data also aid in quantifying how air quality affects vegetation, agriculture, and human health. ContactFor inquiries about this service, please contact larc-dl-asdc-tempo@mail.nasa.gov or post/view questions on the Earthdata Forum.

Formaldehyde Overview and Intended Use Multiple sources contribute to ambient formaldehyde including but not limited to wildfire emissions, industrial activities, and secondary production resulting from the oxidation of other compounds emitted by industries and vegetations. Formaldehyde is a carcinogenic, hazardous air pollutant. While ambient formaldehyde concentrations are usually below U.S. federal recommendations, ambient exposure can cause health issues in people. In addition to measuring formaldehyde for its impacts on human health, satellite formaldehyde observations are also extremely valuable in understanding atmospheric chemistry and production of ground-level ozone.   Layer Overview The Tropospheric Emissions: Monitoring of Pollution (TEMPO) Formaldehyde Vertical Column layer provides information on the amount of formaldehyde in the atmosphere as a vertical column density, calculated in molecules per square centimeter (molecules/cm^2). In other words, the total number of formaldehyde molecules present in the atmosphere from the Earth’s surface to the top of the atmosphere over an area of one square centimeter. Typical values range from 0 to 6e16 molecules/cm^2, though certain events like wildfires may cause these limits to be exceeded. Formaldehyde Level 3 files provide trace gas information on a regular grid consisting of 0.02° x 0.02° grid points across the TEMPO field of regard covering the continental United States (CONUS), much of Mexico, Canada, and the Caribbean. Level 3 files are derived by combining information from all Level 2 files constituting a TEMPO East-West scan cycle, using an area-weighted re-gridding approach. The data have been converted from their native file format (netCDF4) to Cloud Raster Format (CRF). Temporal CoverageThe temporal resolution of a nominal scan is approximately one hour during daylight hours, with more frequent scans in the morning over the eastern portion of the field of regard and in the evenings over the western portion of the field of regard. Each image is presented with the starting timestamp of the corresponding TEMPO scan. Due to the nature of the TEMPO instrument’s east to west scanning pattern, each image is a composite of measurements taken over a period of 40-60 minutes, depending on the spatial coverage of the scan. Data are available from September 17, 2025 to present and updated daily with the previous day’s data.The previous TEMPO data version (V03) was released publicly on May 24, 2024, and cover the time period from August 2, 2023 to September 16, 2025. All observations since the beginning of the mission are being reprocessed with V04 algorithms, with V04 products becoming publicly available in this service as they are reprocessed. The TEMPO V03 data are accessible via this service. Once the V03 data reprocessing is completed, the V03 service will be deprecated.   Geographic CoverageImagery is available for the TEMPO field of regard covering the continental United States (CONUS), much of Mexico, Canada, and the Caribbean. The imagery in this image service is regridded onto a 0.02º longitude x 0.02º latitude grid and presented in the geographic coordinate system WGS 1984. The sensor’s native spatial resolution is ~2 km x 4.75 km at the center of TEMPO’s field of regard (33.5°N, 89.2°W) in WGS 1984. Data FilteringThe layer is filtered to remove low-quality pixels using the main data quality flag (removing low confidence measurements), solar zenith angle (removing data retrieved at high solar zenith angles), and effective cloud fraction (removing where clouds obscure the column) variables. The filters applied are set to remove pixels based on the following: main_data_quality_flag > 1, eff_cloud_fraction > 0.5, or solar_zenith_angle > 80.  Data Validation and Limitations of UseThese data should be considered as provisional products per the Provisional Product Maturity level defined in the TEMPO validation plan. These data are at provisional maturity, which means that product performance has been demonstrated through a large, but still (seasonally or otherwise) limited number of independent measurements. The analysis is sufficient for limited qualitative determinations of product fitness-for-purpose, and the product is potentially ready for testing by operational users and may be suitable for scientific publication. Users may consult the TEMPO User Guide for descriptions of the data and associated known issues.  TEMPO V04 algorithms address known issues in the V03, improving data quality. As a result, there are differences between the TEMPO V03 and V04 data. While qualitative analyses and general trends may remain similar between both versions, merging versions for quantitative analysis is discouraged. For details on the changes in the data, please see the User Guide on the TEMPO site.  Note: The information shown here is total column density (molecules per unit area for the whole vertical column of the atmosphere), not a concentration. Atmospheric concentration refers to the amount of trace gas (e.g., formaldehyde) in a specific point (in this case altitude). Conversion from total column density to atmospheric concentration requires additional information, such as the state of the atmosphere and the vertical distribution of the column, which are not provided in this layer. The use of this layer to derive atmospheric concentrations of formaldehyde is discouraged for the non-specialist. Recommended Usage NotesWhen viewing the image service in the Esri online map viewer, it is recommended to use the multidimensional slider rather than the default time slider. The multidimensional slider can be accessed via the “multidimensional” icon in the right-hand menu.  TEMPO Mission Overview The 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). This allows TEMPO to maintain a continuous view of North America so that the instrument's light-collecting mirror can make a complete east-to-west scan of the field of regard hourly during daylight hours. By measuring sunlight reflected and scattered from the Earth's surface and atmosphere back to the instrument's detectors, TEMPO's ultraviolet and visible light sensors provide measurements of ozone, nitrogen dioxide, formaldehyde, and other constituents involved in the chemical dynamics of Earth’s atmosphere. The primary mission objective of TEMPO is to improve our understanding of air quality and its impacts. By providing near real-time data and comprehensive atmospheric composition measurements, TEMPO helps advance knowledge of the Earth system and improve air quality forecasting. These data also aid in quantifying how air quality affects vegetation, agriculture, and human health. ContactFor inquiries about this service, please contact larc-dl-asdc-tempo@mail.nasa.gov or post/view questions on the  Earthdata Forum.

Formaldehyde Overview and Intended UseMultiple sources contribute to ambient formaldehyde including but not limited to wildfire emissions, industrial activities, and secondary production resulting from the oxidation of other compounds emitted by industries and vegetations. Formaldehyde is a carcinogenic, hazardous air pollutant. While ambient formaldehyde concentrations are usually below U.S. federal recommendations, ambient exposure can cause health issues in people. In addition to measuring formaldehyde for its impacts on human health, satellite formaldehyde observations are also extremely valuable in understanding atmospheric chemistry and production of ground-level ozone.  Layer OverviewThe Tropospheric Emissions: Monitoring of Pollution (TEMPO) Formaldehyde Vertical Column Near Real-Time (NRT) layer provides information on the amount of formaldehyde in the atmosphere as a vertical column density, calculated in molecules per square centimeter (molecules/cm^2). In other words, the total number of formaldehyde molecules present in the atmosphere from the Earth’s surface to the top of the atmosphere over an area of one square centimeter. Typical values range from 0 to 6e16 molecules/cm^2, though certain events like wildfires may cause these limits to be exceeded. The TEMPO NRT formaldehyde files are produced using a fast version of the TEMPO baseline retrieval processor. TEMPO NRT formaldehyde Level 3 files provide trace gas information on a regular grid. Level 3 files are derived by combining information from all Level 2 files constituting a TEMPO East-West scan cycle, using an area-weighted re-gridding approach. The NRT processing optimizes radiance calibration, image navigation and registration, and cloud and trace gas retrievals for rapid processing, while ensuring that product quality is sufficient for most NRT applications. The data have been converted from their native file format (netCDF4) to Cloud Raster Format (CRF). Temporal CoverageThe temporal resolution of a nominal scan is approximately one hour during daylight hours, with more frequent scans in the morning over the eastern portion of the field of regard and in the evenings over the western portion of the field of regard. Each image is presented with the starting timestamp of the corresponding TEMPO scan. Due to the nature of the TEMPO instrument’s east to west scanning pattern, each image is a composite of measurements taken over a period of 40-60 minutes, depending on the spatial coverage of the scan. Data are updated hourly with any new scans that have been received. Data older than two days (48 hours) are removed from the service. On the rare occasion that the TEMPO instrument is not collecting data for an extended period of time, this service will retain only the latest scan until operations resume. The TEMPO operations log may be found on the TEMPO site.  Geographic CoverageImagery is available for the TEMPO field of regard covering the continental United States (CONUS), and much of Mexico, Canada, and the Caribbean. The imagery in this image service is regridded onto a 0.02º longitude x 0.02º latitude grid and presented in the geographic coordinate system WGS 1984. The sensor’s native spatial resolution is ~2 km x 4.75 km at the center of TEMPO’s field of regard (33.5°N, 89.2°W) in WGS 1984. Data FilteringThe layer is filtered to remove low-quality pixels using the main data quality flag (removing low confidence measurements), solar zenith angle (removing data retrieved at high solar zenith angles), and effective cloud fraction (removing data where clouds obscure the tropospheric column) variables. The filters applied are set to remove pixels based on the following: main_data_quality_flag > 1, eff_cloud_fraction > 0.5, or solar_zenith_angle > 80.  Data Validation and Limitations of UseThese data should be considered as provisional products per the Provisional Product Maturity level defined in the TEMPO validation plan.  These data are at provisional maturity, which means that product performance has been demonstrated through a large, but still (seasonally or otherwise) limited number of independent measurements. The analysis is sufficient for limited qualitative determinations of product fitness-for-purpose, and the product is potentially ready for testing by operational users and may be suitable for scientific publication.  Users may consult the TEMPO User Guide for descriptions of the data and associated known issues.  The information shown here is total column density (molecules per unit area for the whole vertical column of the atmosphere), not a concentration. Atmospheric concentration refers to the fractional amount of trace gas (e.g., formaldehyde) relative to total air at a specific point, and changes with altitude. Conversion from total column density to atmospheric concentration requires additional information, such as the state of the atmosphere and the vertical distribution of the column, which are not provided in this layer. The use of this layer to derive atmospheric concentrations of formaldehyde is discouraged for the non-specialist. Recommended Usage NotesWhen viewing the image service in the Esri online map viewer, it is recommended to use the multidimensional slider rather than the default time slider. The multidimensional slider can be accessed via the “multidimensional” icon in the right-hand menu.  While qualitative analyses and general trends may remain similar between the TEMPO standard and NRT versions, merging versions for quantitative analysis is discouraged. Standard and NRT formaldehyde retrievals differ due to differences in the differential formaldehyde slant column densities derived through spectral fitting due to (1) the use of a different radiance reference and (2) the omission of the radiance wavelength calibration in the L1 NRT processing. For details on the changes in the data, please see the TEMPO User Guide and the TEMPO NRT Data Products User Guide and ATBD Supplement on the TEMPO site.  The TEMPO NRT ArcGIS service provides access to TEMPO formaldehyde NRT data earlier than the TEMPO standard formaldehyde data are available in the standard formaldehyde ArcGIS service. The TEMPO NRT products are useful for applications with low-latency requirements; however, it is recommended to switch to the TEMPO Formaldehyde Standard Version 04 (V04) service, once the data becomes available in that service. TEMPO V04 data are available from September 17, 2025 to present and the service is updated daily with the previous day’s data. TEMPO Mission OverviewThe 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). This allows TEMPO to maintain a continuous view of North America so that the instrument's light-collecting mirror can make a complete east-to-west scan of the field of regard hourly during daylight hours. By measuring sunlight reflected and scattered from the Earth's surface and atmosphere back to the instrument's detectors, TEMPO's ultraviolet and visible light sensors provide measurements of ozone, nitrogen dioxide, formaldehyde, and other constituents involved in the chemical dynamics of Earth’s atmosphere. The primary mission objective of TEMPO is to improve our understanding of air quality and its impacts. By providing near real-time data and comprehensive atmospheric composition measurements, TEMPO helps advance knowledge of the Earth system and improve air quality forecasting. These data also aid in quantifying how air quality affects vegetation, agriculture, and human health. ContactFor inquiries about this service, please contact larc-dl-asdc-tempo@mail.nasa.gov or post/view questions on the Earthdata Forum.

This item provides the Open Geospatial Consortium (OGC) Web Map Service (WMS) access the TEMPO cloud fraction service. The source service should be used when access to the actual data is required.  The WMS service allows for quick access to the map imagery for consuming and serving dynamic maps.  Layer Overview  The Tropospheric Emissions: Monitoring of Pollution (TEMPO) Cloud Fraction layer provides information on the effective cloud fraction at 466 nm derived from the O2-O2 cloud retrieval algorithm used in TEMPO data processing. The effective cloud fraction is provided on a scale of zero (0) to one (1), with higher values indicating cloudier pixels and is a unitless quantity. The TEMPO cloud product is used to derive vertical columns of TEMPO trace gases (e.g., nitrogen dioxide, formaldehyde). Thus, this cloud fraction layer can be used to identify cloud coverage as observed by the TEMPO instrument, as well as used in conjunction with the TEMPO nitrogen dioxide and formaldehyde image services to provide context and additional information for those data. TEMPO cloud fraction Level 3 files provide cloud fraction information on a regular grid. Level 3 files are derived by combining information from all Level 2 files constituting a TEMPO East-West scan cycle, using an area-weighted re-gridding approach. The data have been converted from their native file format (netCDF4) to Cloud Raster Format (CRF). Temporal Coverage The temporal resolution of a nominal scan is approximately one hour during daylight hours, with more frequent scans in the morning over the eastern portion of the field of regard and in the evenings over the western portion of the field of regard. Each image is presented with the starting timestamp of the corresponding TEMPO scan. Due to the nature of the TEMPO instrument’s east to west scanning pattern, each image is a composite of measurements taken over a period of 40-60 minutes, depending on the spatial coverage of the scan. Data are available from September 17, 2025 to the present and updated daily with the previous day’s data. These data correspond to the Version 04 (V04) product operationally generated by the TEMPO science data processing center. All the observations since the beginning of the TEMPO mission (August 2023) are being reprocessed with to V04, and data will be added to this service upon their generation.   Geographic Coverage Imagery is available for the TEMPO field of regard covering the continental United States (CONUS), and much of Mexico, Canada, and the Caribbean. The imagery in this image service is regridded onto a 0.02º longitude x 0.02º latitude grid and presented in the geographic coordinate system WGS 1984. The sensor’s native spatial resolution is about 2 km x 4.75 km at the center of TEMPO’s field of regard (33.5°N, 89.2°W) in WGS 1984. Data Filtering The layer is filtered to remove pixels at high solar zenith angles, which typically have low quality. The applied filter is set to remove pixels based on the following criterion: solar_zenith_angle > 80°. Cloud fractions outside the range between 0.0 and 1.0 represent missing values. Data Validation These data should be considered as provisional products per the Provisional Product Maturity level defined in the TEMPO validation plan. The provisional maturity level means that product performance has been demonstrated through a large, but still (seasonally or otherwise) limited number of independent measurements. The analysis is sufficient for limited qualitative determinations of product fitness-for-purpose, and the product is potentially ready for testing by operational users and may be suitable for scientific publication. Users may consult the TEMPO User Guide for descriptions of the data and associated known issues.  Recommended Usage Notes When viewing the image service in the Esri online map viewer, it is recommended to use the multidimensional slider rather than the default time slider. The multidimensional slider can be accessed via the “multidimensional” icon in the right-hand menu.  TEMPO Mission Overview The Tropospheric Emissions: Monitoring of Pollution (TEMPO) instrument is a grating spectrometer, sensitive to the visible (VIS) and ultraviolet (UV) wavelengths of light in the spectral range of 290-490 nm and 540-740 nm with about 0.6 nm spectral resolution. The TEMPO instrument is attached to the Earth-facing side of a commercial telecommunications satellite (Intelsat 40e) in a geostationary orbit over 91° W longitude (about 22,000 miles above Earth’s equator). This allows TEMPO to maintain a continuous view of North America so that the instrument's light-collecting mirror can make a complete east-to-west scan of the field of regard hourly during daylight hours. By measuring sunlight reflected and scattered from the Earth's surface and atmosphere back to the instrument's detectors, TEMPO's ultraviolet and visible light sensors provide measurements of ozone, nitrogen dioxide, formaldehyde, and other constituents of Earth’s atmosphere. The primary mission objective of TEMPO is to improve our understanding of air quality and its impacts. By providing near real-time data and comprehensive atmospheric composition measurements, TEMPO helps advance knowledge of the Earth system and improve air quality forecasting. These data also aid in quantifying how air quality affects vegetation, agriculture, and human health, among others. Contact For inquiries about this service, please contact larc-dl-asdc-tempo@mail.nasa.gov or post/view questions on the Earthdata Forum.

This item provides the Open Geospatial Consortium (OGC) Web Map Service (WMS) access the TEMPO Total Column Ozone service. The source service should be used when access to the actual data is required. The WMS service allows for quick access to the map imagery for consuming and serving dynamic maps.  Ozone Overview and Intended Use Ozone (O₃) is a gas composed of three oxygen atoms and is naturally present in our atmosphere. It has a profound influence on life on Earth and the atmosphere. It exists in different layers of the atmosphere, with the largest abundance in the stratosphere, where it forms the ozone layer. This layer absorbs harmful ultraviolet (UV) radiation from the Sun, preventing it from reaching the surface and reducing the risk of skin cancer, cataracts, and other health issues, while also protecting ecosystems. However, ozone near the ground is a major pollutant that can cause respiratory problems and environmental damage. In addition, ozone plays a critical role in the oxidizing capacity of the troposphere and acts as an important greenhouse gas in the upper troposphere and lower stratosphere. Therefore, we monitor total column ozone and its vertical distribution using various instruments such as satellites and ground-based observations.   These observations usually provide the ozone columns as Dobson Units (DU), which is a unit of measurement of the amount of a trace gas in a vertical column through the Earth’s atmosphere. Per the definition of Dobson units, 1 Dobson Unit corresponds to a 0.01 mm thick ozone layer at standard atmospheric conditions (0°C (or 273.15 K), 1 atm (or 1013.25 hPa)). Understanding and tracking ozone levels is crucial for assessing environmental changes, monitoring ozone depletion, and ensuring the continued protection of life on Earth.   Layer Overview The Tropospheric Emissions: Monitoring of Pollution (TEMPO) Gridded Total Column Ozone layer provides information on the amount of ozone in the atmosphere as a total column, expressed in Dobson Units (DU). In other words, it represents the total amount of ozone molecules present in the atmosphere from the Earth’s surface to the top of the atmosphere. Ozone Level 3 files provide trace gas information on a regular grid consisting of 0.02° x 0.02° grid points across the field of regard. Level 3 files are derived by combining information from all Level 2 files constituting a TEMPO East-West scan cycle, using an area-weighted re-gridding approach. The data have been converted from their native file format (netCDF4) to Cloud Raster Format (CRF).   Temporal Coverage The temporal resolution of a nominal scan is approximately one hour during daylight hours, with more frequent scans in the morning over the eastern portion of the field of regard and in the evenings over the western portion of the field of regard. Each image is presented with the starting timestamp of the corresponding TEMPO scan. Due to the nature of the TEMPO instrument’s east to west scanning pattern, each image is a composite of measurements taken over a period of 40-60 minutes, depending on the spatial coverage of the scan. Data are available from September 17, 2025 to present and updated daily with the previous day’s data.   The previous TEMPO data version (V03) was released publicly on May 24, 2024, and cover the time period from August 2, 2023 to September 16, 2025. All observations since the beginning of the mission are being reprocessed with V04 algorithms, with V04 products becoming publicly available in this service as they are reprocessed. The TEMPO V03 data are accessible via this service. Once the V03 data reprocessing is completed, the V03 service will be deprecated.     Geographic Coverage Imagery is available for the TEMPO field of regard covering the continental United States (CONUS), much of Mexico, Canada, and the Caribbean. The imagery in this image service is regridded onto a 0.02º longitude x 0.02º latitude grid and presented in the geographic coordinate system WGS 1984. The sensor’s native spatial resolution is ~2 km x 4.75 km at the center of TEMPO’s field of regard (33.5°N, 89.2°W) in WGS 1984.   Data Filtering The layer is filtered to remove low-quality pixels based using the solar zenith angle (removing data retrieved at high solar zenith angles) and viewing zenith angle (removing data retrieved at high viewing zenith angles). The applied filters remove pixels based on the following: solar_zenith_angle > 80 or viewing_zenith_angle > 80. The filtering using the quality flag is pre-applied during the Level 3 data generation process to remove pixels based on quality_flag is not 0, 1, 2, or 5.   Data Validation and Limitations of Use These data should be considered as provisional products per the Provisional Product Maturity level defined in the TEMPO validation plan. These data are at provisional maturity, which means that product performance has been demonstrated through a large, but still (seasonally or otherwise) limited number of independent measurements. The analysis is sufficient for limited qualitative determinations of product fitness-for-purpose, and the product is potentially ready for testing by operational users and may be suitable for scientific publication. Users may consult the user guide for descriptions of the data and associated known issues.  TEMPO V04 algorithms address known issues in the V03, improving data quality. As a result, there are differences between the TEMPO V03 and V04 data. While qualitative analyses and general trends may remain similar between both versions, merging versions for quantitative analysis is discouraged. For details on the changes in the data, please see the User Guide on the TEMPO site.  Recommended Usage Notes When viewing the image service in the ESRI online map viewer, it is recommended to use the multidimensional slider rather than the default time slider. The multidimensional slider can be accessed via the “multidimensional” icon in the right-hand menu.  TEMPO Mission Overview  The 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). This allows TEMPO to maintain a continuous view of North America so that the instrument's light-collecting mirror can make a complete east-to-west scan of the field of regard hourly during daylight hours. By measuring sunlight reflected and scattered from the Earth's surface and atmosphere back to the instrument's detectors, TEMPO's UV and VIS light sensors provide measurements of ozone, nitrogen dioxide, formaldehyde, and other constituents involved in the chemical dynamics of Earth’s atmosphere.   The primary mission objective of TEMPO is to improve our understanding of air quality and its impacts. By providing near real-time data and comprehensive atmospheric composition measurements, TEMPO helps advance knowledge of the Earth system and improve air quality forecasting. These data also aid in quantifying how air quality affects vegetation, agriculture, and human health.   Contact For inquiries about this service, please contact larc-dl-asdc-tempo@mail.nasa.gov or post/view questions on the  Earthdata Forum.