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AVHRR Cloud Properties - PATMOS-x

Sample image of NOAA CDR AVHRR Cloud Properties PATMOS-X product; it depicts cloud emissitivity across the globe.

This dataset provides scientific researchers a high quality Climate Data Record (CDR) of multiple cloud properties along with Advanced Very High Resolution Radiometer (AVHRR) brightness temperatures.

The AVHRR PATHFINDER Atmospheres Extended (PATMOS-x) provides an AVHRR climate data record that uses the Advanced Very High Resolution Radiometer (AVHRR) on the POES and METOP platforms. Due to its length, the AVHRR data record offers a unique resource for multi-decadal climate studies. PATMOS-x improved the quality of the dataset by recalibrating and renavigating the data. The resulting CDR provides confidence to climate variability studies over the last 30 years.

Data Variables

-Cloud Top Height
-Cloud Fraction
-Cloud Emissivity
-Cloud Top Pressure
-Cloud Top Temperature

Principal Investigator: Andy Heidinger, NOAA STAR

Cite dataset when used as a source. See the dataset's DOI landing page for citation details at doi:10.7289/V5348HCK.

The AVHRR instrument does not have an onboard calibration system for the 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 the calibration for a file is unlikely to change the 'preliminary' is removed and it is determined to be in its final version. The 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 such time that the final version is available. However, the Climate Data Portal at the University of Wisconsin - Madison serves the 'preliminary' version of the data with the most recent calibration available. While the differences tend to be quite small, we include this note for the purposes of tracking the specific data used for an application or in case a user feels even minor differences in calibration may affect their results.