This long-term satellite data record contains observations of atmospheric temperature and humidity at multiple pressure levels. The data set is produced primarily using input from infrared radiation (IR) sounder instruments such as High-Resolution Infrared Radiation Sounder (HIRS). Current data holdings span 1984-12-26 to 2021-12-31 with data derived from HIRS instruments onboard the NOAA and Metop polar-orbiting satellite series. Future holdings are planned to also include data derived from other IR sensors (e.g. CrIS and IASI).

The data product is global and at the native sensor spatial resolution (e.g. 10, 20 km at nadir) with observations up to twice daily. The temperature variable is available at the surface, 2 meter, 1000 hPa, 850 hPa, 700 hPa, 600 hPa, 500 hPa, 400 hPa, 300 hPa, 200 hPa, 100 hPa, and 50 hPa levels. The specific humidity variable is available at the 2 meter, 1000 hPa, 850 hPa, 700 hPa, 600 hPa, 500 hPa, 400 hPa, and 300 hPa levels. This data is most reliable under clear-sky conditions, and as such cloudy pixels have been removed and/or marked with quality flags.