Polar Pathfinder Sampler (PPSM): AVHRR Polar Pathfinder 1.25 km data (1978-1996)

The AVHRR Polar Pathfinder 1.25 km data set provides information about polar climate and geophysical processes at the highest practical spatial and temporal resolution. For the first time, daily composites of AVHRR-collected cryospheric variables are compiled at a resolution suitable for regional and local monitoring, and process studies, of changing surface conditions such as sea ice formation, sea ice motion and ice sheet extent. The higher resolution provides the closest link between field data and the greater perspective afforded by a satellite view. Products include daily sea-ice motion vector fields and twice-daily composited images of albedo, skin surface temperature, and the calibrated and geolocated AVHRR channel data used to generate them. Products are mapped to the NSIDC Equal-Area Scalable Earth-Grid (EASE-Grid, Armstrong and Brodzik 1995). Spatial coverage includes both hemispheres, extending poleward of 50 degrees N and 53 degrees S latitudes. Temporal coverage begins September 1993 and extends through the present (1998). Plans are to continue acquisition and processing for 18 months after the Moderate Resolution Imaging Spectrometer (MODIS) becomes operational. For this AVHRR Pathfinder demonstration, three regions have been selected from 1997 Northern Hemisphere composites to correspond to areas of active field programs and ongoing research. These areas, the Surface Heat Budget of the Arctic Ocean (SHEBA) study region in the Beaufort Sea, the ETH/CU Camp in western Greenland, and Point Barrow, Alaska, cover the main polar surface types: sea ice cover, permanent ice sheets, and polar lands. Time-series visualizations are provided rather than a sample of the data product, to conserve space on the CD-ROM.