Cloud-free coverage - DMSP-OLS Nighttime Lights

Percent frequency of light detections (pct_lights) in cloud-free observations. The number of light detections is not provided but can be calculated by multiplying pct_lights by the number of cloud-free observations (cf_cvg). Data values range from 0-100. This composite set is a component of the DMSP-OLS nighttime lights imagery for the years 1992-2013. The individual images are cloud-free composites made using all the available archived DMSP-OLS (Defense Meteorological Satellite Program - Operational Linescan System) smooth resolution data for calendar years. In cases where two satellites were collecting data - two composites were produced. The products are 30 arc second grids, spanning -180 to 180 degrees longitude and -65 to 75 degrees latitude. Each composite set is named with the satellite and the year (F121995 is from DMSP satellite number F12 for the year 1995). Five ArcGIS image services are available, each containing images from 1992-2013. **Data creation:** 2016-01-01 **Contact points:** Metadata Contact: [National Geophysical Data Center](mailto:ncei.info@noaa.gov) Resource Contact: NOAA's National Geophysical Data Center NOAA Resource Contact: NOAA National Centers for Environmental Information (NCEI) **Data lineage:** The products are 30 arc second grids, spanning -180 to 180 degrees longitude and -65 to 75 degrees latitude. A number of constraints are used to select the highest quality data for entry into the composites: * Data are from the center half of the 3000 km wide OLS swaths. Lights in the center half have better geolocation, are smaller, and have more consistent radiometry. * Sunlit data are excluded based on the solar elevation angle. * Glare is excluded based on solar elevation angle. * Moonlit data are excluded based on a calculation of lunar illuminance. * Observations with clouds are excluded based on clouds identified with the OLS thermal band data and NCEP surface temperature grids. * Lighting features from the aurora have been excluded in the northern hemisphere on an orbit-by-orbit manner using visual inspection. More information on the attached file (gcv4_readme.txt) in the Distribution info section of this metadata. **Resource constraints:** Terms of Use: Whenever using or distributing DMSP data or derived images, please credit NOAA's National Centers for Environmental Information (NCEI). In details: Image and data processing by NOAA's National Geophysical Data Center. DMSP data collected by US Air Force Weather Agency. **Online resources:** NOAA National Centers for Environmental Information (NCEI) DMSP Data Download

The Stable lights image is the cleaned up version of the avg_vis image containing the lights from cities, towns, and other sites with persistent lighting, including gas flares. Ephemeral events, such as fires have been discarded. Then the background noise was identified and replaced with values of zero. Data values range from 1-63. This composite set is a component of the DMSP-OLS nighttime lights imagery for the years 1992-2013. The individual images are cloud-free composites made using all the available archived DMSP-OLS (Defense Meteorological Satellite Program - Operational Linescan System) smooth resolution data for calendar years. In cases where two satellites were collecting data - two composites were produced. The products are 30 arc second grids, spanning -180 to 180 degrees longitude and -65 to 75 degrees latitude. Each composite set is named with the satellite and the year (F121995 is from DMSP satellite number F12 for the year 1995). Five ArcGIS image services are available, each containing images from 1992-2013. **Data creation:** 2016-01-01 **Contact points:** Metadata Contact: [National Geophysical Data Center](mailto:ncei.info@noaa.gov) Resource Contact: NOAA's National Geophysical Data Center NOAA Resource Contact: NOAA National Centers for Environmental Information (NCEI) **Data lineage:** The products are 30 arc second grids, spanning -180 to 180 degrees longitude and -65 to 75 degrees latitude. A number of constraints are used to select the highest quality data for entry into the composites: * Data are from the center half of the 3000 km wide OLS swaths. Lights in the center half have better geolocation, are smaller, and have more consistent radiometry. * Sunlit data are excluded based on the solar elevation angle. * Glare is excluded based on solar elevation angle. * Moonlit data are excluded based on a calculation of lunar illuminance. * Observations with clouds are excluded based on clouds identified with the OLS thermal band data and NCEP surface temperature grids. * Lighting features from the aurora have been excluded in the northern hemisphere on an orbit-by-orbit manner using visual inspection. More information on the attached file (gcv4_readme.txt) in the Distribution info section of this metadata. **Resource constraints:** Terms of Use: Whenever using or distributing DMSP data or derived images, please credit NOAA's National Centers for Environmental Information (NCEI). In details: Image and data processing by NOAA's National Geophysical Data Center. DMSP data collected by US Air Force Weather Agency. **Online resources:** NOAA National Centers for Environmental Information (NCEI) DMSP Data Download

The row image (avg_vis) contains the average of the visible band digital number values with no further filtering. Data values range from 0-63. This composite set is a component of the DMSP-OLS nighttime lights imagery for the years 1992-2013. The individual images are cloud-free composites made using all the available archived DMSP-OLS (Defense Meteorological Satellite Program - Operational Linescan System) smooth resolution data for calendar years. In cases where two satellites were collecting data - two composites were produced. The products are 30 arc second grids, spanning -180 to 180 degrees longitude and -65 to 75 degrees latitude. Each composite set is named with the satellite and the year (F121995 is from DMSP satellite number F12 for the year 1995). Five ArcGIS image services are available, each containing images from 1992-2013. **Data creation:** 2016-01-01 **Contact points:** Metadata Contact: [National Geophysical Data Center](mailto:ncei.info@noaa.gov) Resource Contact: NOAA's National Geophysical Data Center NOAA Resource Contact: NOAA National Centers for Environmental Information (NCEI) **Data lineage:** The products are 30 arc second grids, spanning -180 to 180 degrees longitude and -65 to 75 degrees latitude. A number of constraints are used to select the highest quality data for entry into the composites: * Data are from the center half of the 3000 km wide OLS swaths. Lights in the center half have better geolocation, are smaller, and have more consistent radiometry. * Sunlit data are excluded based on the solar elevation angle. * Glare is excluded based on solar elevation angle. * Moonlit data are excluded based on a calculation of lunar illuminance. * Observations with clouds are excluded based on clouds identified with the OLS thermal band data and NCEP surface temperature grids. * Lighting features from the aurora have been excluded in the northern hemisphere on an orbit-by-orbit manner using visual inspection. More information on the attached file (gcv4_readme.txt) in the Distribution info section of this metadata. **Resource constraints:** Terms of Use: Whenever using or distributing DMSP data or derived images, please credit NOAA's National Centers for Environmental Information (NCEI). In details: Image and data processing by NOAA's National Geophysical Data Center. DMSP data collected by US Air Force Weather Agency. **Online resources:** NOAA National Centers for Environmental Information (NCEI) DMSP Data Download

Overview This layer is an image of nighttime lights of North America, including the Caribbean and Mexico, produced through a collaborative effort between the national atlas programs of Canada, Mexico, and the United States, in partnership with the Commission for Environmental Cooperation (CEC). The data were collected in 1996 and 1997 as part of the Defense Meteorological Satellite Program (DMSP) of the United States. DMSP satellites collect visible and infrared cloud imagery, as well as monitoring atmospheric, oceanographic, hydrologic, cryospheric, and near-Earth space environments. The program maintains a constellation of two sun-synchronous, near-polar orbiting satellites, with an orbital period of 101 minutes and an inclination of 99 degrees. This image was created during the periods 16–21 March 1996, 5–14 January 1997, and 3–12 February 1997, when the gain on the OLS sensor was turned down to 24 from the normal 64 decibels so that urban centers did not saturate the signal.  This is a revised version made in May 2002 map layer, with a corrected shoreline for Greenland. Geographic Coverage The coverage spans the North American continent, including Canada, Mexico, and the United States, as well as the Caribbean. Data Sources and Licensing Commission for Environmental Cooperation (CEC), based on data from the National Oceanic and Atmospheric Administration (NOAA) - National Geophysical Data Center (NGDC). The data is licensed under a Creative Commons Attribution 4.0 International License (CC BY 4.0), allowing redistribution and adaptation, including for commercial purposes, with appropriate attribution. Update frequency: As needed Limitations of use: None. Acknowledgment of the Commission for Environmental Cooperation and/or the National Oceanic and Atmospheric Administration (NOAA) - National Geophysical Data Center (NGDC) would be appreciated in products derived from these data. Vintage: 1996–1997 Applications (Intended Use) Visualizing urbanization and human settlement patterns across North America. Research on population distribution and land use as inferred from artificial lighting. Basemap and reference layer for continental-scale environmental analysis. Integration with other thematic layers in the North American Environmental Atlas for comprehensive continental analysis. Files Download

Layer Overview and Intended Use The Tropospheric Emissions: Monitoring of Pollution (TEMPO) Nitrogen Dioxide Vertical Column Troposphere layer provides information on the amount of nitrogen dioxide in the troposphere. This is provided as the total number of nitrogen dioxide molecules in the tropospheric column of air above one square centimeter on the Earth’s surface (units: molecules/cm^2). Nitrogen dioxide 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 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 updated daily with the previous day's data. 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 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 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 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 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 tropospheric column density (molecules per unit area in the lower atmosphere), not a concentration. Atmospheric concentration refers to the fractional amount of trace gas (e.g., nitrogen dioxide) relative to total air at a specific point, and changes with altitude. Conversion from 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 nitrogen dioxide is discouraged for the non-specialist. 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 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. 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 Nitrogen Dioxide (NO2) Tropospheric Vertical Column 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 and Intended Use The Tropospheric Emissions: Monitoring of Pollution (TEMPO) Nitrogen Dioxide Vertical Column Troposphere layer provides information on the amount of nitrogen dioxide in the troposphere. This is provided as the total number of nitrogen dioxide molecules in the tropospheric column of air above one square centimeter on the Earth’s surface (units: molecules/cm^2). Nitrogen dioxide 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 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 updated daily with the previous day's data. 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 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 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 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 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 tropospheric column density (molecules per unit area in the lower atmosphere), not a concentration. Atmospheric concentration refers to the fractional amount of trace gas (e.g., nitrogen dioxide) relative to total air at a specific point, and changes with altitude. Conversion from 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 nitrogen dioxide is discouraged for the non-specialist. 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 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. Contact For inquiries about this service, please contact larc-dl-asdc-tempo@mail.nasa.gov or post/view questions on the Earthdata Forum.