This dataset contains Commercial (Comm) Radio Occultation (RO) environmental data from UCAR using Spire Global Subsidiary data, which is an established method for remote sounding of the atmosphere. The technique uses an instrument in low-Earth orbit (LEO) to track radio signals from Global Navigation Satellite System (GNSS) transmitters as they rise or set through the atmosphere. The occulting atmosphere refracts or bends the radio signals, and given the precise positions of both satellites, the bending angle can be deduced from the time delay of the signal. Collecting these measurements for a full occultation through the atmosphere provides a vertical profile of bending angles, from which profiles of physical quantities such as temperature, humidity, and ionospheric electron density can be retrieved. These data primarily feed numerical weather prediction (NWP) models that support weather forecasts, and also support space weather analysis/prediction at NOAA.

This dataset contains Commercial (Comm) Radio Occultation (RO) Environmental Data Records (EDR) from PlanetiQ. It is from Radio Occultation Data Buy II (RODB-2) Indefinite Delivery/Indefinite Quantity (IDIQ), dated March 27, 2023 to March 26, 2028. For RODB-2 IDIQ, NOAA solicited commercial near-real-time satellite-based Global Navigation Satellite System (GNSS) Radio Occultation (RO) and ionospheric measurements that will be processed into neutral atmosphere and space weather products. These derived products will be fed into NOAA's operational data systems, including weather and space weather analysis and prediction systems, and used for weather, climate, and atmospheric research purposes. CommRO is an is an established method for remote sounding of the atmosphere. The technique uses an instrument in low-Earth orbit to track radio signals from Global Navigation Satellite System (GNSS) transmitters as they rise or set through the atmosphere. The occulting atmosphere refracts or bends the radio signals, and given the precise positions of both satellites, the bending angle can be deduced from the time delay of the signal. Collecting these measurements for a full occultation through the atmosphere provides a vertical profile of bending angles, from which profiles of physical quantities such as temperature, humidity, and ionospheric electron density can be retrieved. These data primarily feed numerical weather prediction (NWP) models that support weather forecasts, and also support space weather analysis/prediction at NOAA.

This dataset contains Commercial (Comm) Radio Occultation (RO) raw data from GeoOptics, which is an established method for remote sounding of the atmosphere. The technique uses an instrument in low-Earth orbit (LEO) to track radio signals from Global Navigation Satellite System (GNSS) transmitters as they rise or set through the atmosphere. The occulting atmosphere refracts or bends the radio signals, and given the precise positions of both satellites, the bending angle can be deduced from the time delay of the signal. Collecting these measurements for a full occultation through the atmosphere provides a vertical profile of bending angles, from which profiles of physical quantities such as temperature, humidity, and ionospheric electron density can be retrieved. These data primarily feed numerical weather prediction (NWP) models that support weather forecasts, and also support space weather analysis/prediction at NOAA.

This dataset contains Commercial (Comm) Radio Occultation (RO) Raw Data Records (RDR) from PlanetiQ. It is from Radio Occultation Data Buy II (RODB-2) Indefinite Delivery/Indefinite Quantity (IDIQ), dated March 27, 2023 to March 26, 2028. For RODB-2 IDIQ, NOAA solicited commercial near-real-time satellite-based Global Navigation Satellite System (GNSS) Radio Occultation (RO) and ionospheric measurements that will be processed into neutral atmosphere and space weather products. These derived products will be fed into NOAA's operational data systems, including weather and space weather analysis and prediction systems, and used for weather, climate, and atmospheric research purposes. CommRO is an is an established method for remote sounding of the atmosphere. The technique uses an instrument in low-Earth orbit to track radio signals from Global Navigation Satellite System (GNSS) transmitters as they rise or set through the atmosphere. The occulting atmosphere refracts or bends the radio signals, and given the precise positions of both satellites, the bending angle can be deduced from the time delay of the signal. Collecting these measurements for a full occultation through the atmosphere provides a vertical profile of bending angles, from which profiles of physical quantities such as temperature, humidity, and ionospheric electron density can be retrieved. These data primarily feed numerical weather prediction (NWP) models that support weather forecasts, and also support space weather analysis/prediction at NOAA.

This dataset contains Commercial (Comm) Radio Occultation (RO) Raw Data Records (RDR) from PlanetiQ. It is from Radio Occultation Data Buy II (RODB-2) Indefinite Delivery/Indefinite Quantity (IDIQ), dated March 27, 2023 to March 26, 2028. For RODB-2 IDIQ, NOAA solicited commercial near-real-time satellite-based Global Navigation Satellite System (GNSS) Radio Occultation (RO) and ionospheric measurements that will be processed into neutral atmosphere and space weather products. These derived products will be fed into NOAA's operational data systems, including weather and space weather analysis and prediction systems, and used for weather, climate, and atmospheric research purposes. CommRO is an is an established method for remote sounding of the atmosphere. The technique uses an instrument in low-Earth orbit to track radio signals from Global Navigation Satellite System (GNSS) transmitters as they rise or set through the atmosphere. The occulting atmosphere refracts or bends the radio signals, and given the precise positions of both satellites, the bending angle can be deduced from the time delay of the signal. Collecting these measurements for a full occultation through the atmosphere provides a vertical profile of bending angles, from which profiles of physical quantities such as temperature, humidity, and ionospheric electron density can be retrieved. These data primarily feed numerical weather prediction (NWP) models that support weather forecasts, and also support space weather analysis/prediction at NOAA.

This dataset contains Commercial (Comm) Radio Occultation (RO) raw data from Spire Global Subsidiary, which is an established method for remote sounding of the atmosphere. The technique uses an instrument in low-Earth orbit (LEO) to track radio signals from Global Navigation Satellite System (GNSS) transmitters as they rise or set through the atmosphere. The occulting atmosphere refracts or bends the radio signals, and given the precise positions of both satellites, the bending angle can be deduced from the time delay of the signal. Collecting these measurements for a full occultation through the atmosphere provides a vertical profile of bending angles, from which profiles of physical quantities such as temperature, humidity, and ionospheric electron density can be retrieved. These data primarily feed numerical weather prediction (NWP) models that support weather forecasts, and also support space weather analysis/prediction at NOAA.

**Please note, this dataset has been superseded by a newer version (see below). Users should not use this version except in rare cases (e.g., when reproducing previous studies that used this version).** Integrated Global Radiosonde Archive is a digital data set archived at the National Centers for Environmental Information (NCEI). This dataset contains monthly means of geopotential height, temperature, zonal wind, and meridional wind derived from the Integrated Global Radiosonde Archive (IGRA). IGRA consists of radiosonde and pilot balloon observations at over 1500 globally distributed stations, and monthly means are available for the surface and mandatory levels at many of these stations by contacting NCEI Customer Support. The period of record varies from station to station, with many extending from 1947 to 2016. Monthly means are computed separately for the nominal times of 0000 and 1200 UTC, considering data within two hours of each nominal time. A mean is provided, along with the number of values used to calculate it, whenever there are at least 10 values for a particular station, month, nominal time, and level.

**Please note, this dataset has been superseded by a newer version (see below). Users should not use this version except in rare cases (e.g., when reproducing previous studies that used this version).** Integrated Global Radiosonde Archive is a digital data set archived at the former National Climatic Data Center (NCDC), now National Centers for Environmental Information (NCEI). This dataset contains monthly means of geopotential height, temperature, zonal wind, and meridional wind derived from the Integrated Global Radiosonde Archive (IGRA). IGRA consists of radiosonde and pilot balloon observations at over 1500 globally distributed stations, and monthly means are available for the surface and mandatory levels at many of these stations. The period of record varies from station to station, with many extending from 1970 to 2016. Monthly means are computed separately for the nominal times of 0000 and 1200 UTC, considering data within two hours of each nominal time. A mean is provided, along with the number of values used to calculate it, whenever there are at least 10 values for a particular station, month, nominal time, and level.

The High-Resolution Infrared Radiation Sounder (HIRS) of intersatellite calibrated channel 12 brightness temperature product is a gridded global monthly time series product spanning from 1979 to the most current full month, updated monthly. Among the twenty channels in the HIRS instrument, channel 12 measures upper tropospheric water vapor. Multiple polar orbiting satellites in the NOAA Polar-orbiting Operational Environmental Satellite (POES) and MetOp series have carried HIRS instruments. Due to the independence in calibration of the individual HIRS instruments, biases exist between satellites. Examination of the intersatellite biases shows that the biases are scene brightness temperature dependent. These HIRS channel 12 measurements from the NOAA POES and MetOp series are calibrated to a baseline satellite based on intersatellite bias correction data. The dataset is provided as monthly mean 2.5x2.5 degree latitude/longitude in netcdf format. This CDR is key to understanding water vapor feedback climatology and has been used to study long-term water vapor variability, to evaluate climate models, and to study large-scale atmospheric circulations.

The High-Resolution Infrared Radiation Sounder (HIRS) of intersatellite calibrated channel 12 brightness temperature product is a gridded global monthly time series product spanning from 1979 to the most current full month, updated monthly. Among the twenty channels in the HIRS instrument, channel 12 measures upper tropospheric water vapor. Multiple polar orbiting satellites in the NOAA Polar-orbiting Operational Environmental Satellite (POES) and MetOp series have carried HIRS instruments. Due to the independence in calibration of the individual HIRS instruments, biases exist between satellites. Examination of the intersatellite biases shows that the biases are scene brightness temperature dependent. These HIRS channel 12 measurements from the NOAA POES and MetOp series are calibrated to a baseline satellite based on intersatellite bias correction data. The dataset is provided as monthly mean 2.5x2.5 degree latitude/longitude in netcdf format. This CDR is key to understanding water vapor feedback climatology and has been used to study long-term water vapor variability, to evaluate climate models, and to study large-scale atmospheric circulations.