The Pathfinder Atmospheres Extended (PATMOS-x) Cloud Properties Climate Data Record (CDR) provides data for multiple cloud properties retrieved from the radiance and reflectance data collected by the following satellite instruments:
- Advanced Very High-Resolution Radiometer (AVHRR)
- Visible Infrared Imaging Radiometer Suite (VIIRS)
- High-resolution Infra-Red Sounder (HIRS)
- Cross-track Infrared Sounder (CrIS) Infrared
- Atmospheric Sounding Interferometer (IASI)
PATMOS-x improved the quality of the dataset by recalibrating and renavigating the data. The resulting CDR supports climate variability studies over the period of record providing a long-term resource for multi-decadal studies. The final record has global coverage at a 0.1°x0.1° equal angle grid and extends from 1979–present.
To help the project receive continued support, updates, and improvement, tell us how you use PATMOS-x Cloud Properties CDR data by completing our optional User Registration Form.
Technical Note
Data quality note: The 13.3 micron channel on the NOAA-18 HIRS instrument produced corrupt data for a period in 2023. The corruption began gradually January 12th and becomes severe by January 16th. The behavior subsides and the data looks normal by April 29th. Inconsistencies in cloud detection and height assignment can be seen in NOAA-18 PATMOS-x files for this period.
The AVHRR instrument does not have an onboard calibration system for solar reflectance channels (0.63-, 0.86- and 1.6-microns). As a result, the most recent data relies on an extrapolation of the existing calibration (Heidinger et al. 2010). The most recent data contain the word 'preliminary' in the file name to indicate that the values may change slightly as new calibration coefficients become available. Once a file is calibrated, 'preliminary' is removed. Calibration process is performed approximately once a year at the University of Wisconsin - Madison. As a result, there is often more than one version of 'preliminary' files for the most recent data. To avoid confusion NCEI archives only the first 'preliminary' version of data until the final version is available.