Globally gridded satellite (GriSat) observations for climate studies

Geostationary earth orbit (GEO) satellites have provided routine, high temporal resolution Earth observations since the 1970s. Despite the long period of record, use of these data in climate studies has been limited for numerous reasons, among them: there is no central archive of GEO data for all international satellites, full temporal and spatial resolution data are voluminous, and diverse calibration and navigation formats encumber multi-satellite climate studies. These issues are, however, overcome using GEO data archived by the International Satellite Cloud Climatology Project (ISCCP). ISCCP has archived a subset of the full resolution GEO data at ~10 km resolution at 3 hourly intervals since 1983. Recent efforts at NOAA's National Climatic Data Center to make the data available include remapping the data to standard map projection, recalibrating the data to ensure temporal homogeneity, extending the record of observations back to 1978 and reformatting the data for distribution. The gridded dataset includes observations from the visible, infrared window and infrared water vapor channels. Data are stored in the netCDF format using standards that permit a wide variety of tools and libraries to quickly and easily process the data. A novel data layering approach, together with sufficient satellite and file metadata allows users to access the data at varying levels of complexity based on their needs. The result is a fundamental climate data record already in use by the meteorological community. Examples include reanalysis of tropical cyclones, studies of global precipitation and detection of the inter-tropical convergence zone.