Sea Ice-Edge Enhancement Using Polar-Orbiting Environmental Satellite Data

Abstract

The authors develop and discuss satellite image enhancements of sea ice boundaries to the north and west of Alaska. Using data from the NOAA Advanced Very High Resolution Radiometer (AVHRR), the authors illustrate how a pixel-by-pixel difference image of the two AVHRR solar channels can suppress the effects of optically thin cloud cover, revealing underlying detail. These difference images are compared to satellite ice products derived from the DMSP Special Sensor Microwave Imager (SSM/I). AVHRR enhancements have improved daily operational support to fishing, crabbing, scientific research, and especially oil exploration in the coastal waters of Alaska. In particular, the AVHRR solar difference image has greatly facilitated the preparation of daily maps depicting the major ice edge. During a two-week period in 1991 characterized by frequent cloudiness, analysts were able to prepare information locating the major ice edge 90 percent of the time using this product. The potential of SSM/I ice products, new in nonmilitary ice edge mapping support, is also discussed.