Near Real-Time Sea Ice Discrimination Using SeaWinds on QUIKSCAT

Within the frame provided by the Ocean and Sea Ice Satellite Application Facility (OSI SAF) created by European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT), the Royal Netherlands Meteorological Institute (KNMI) has developed sea ice screening routines for both the ERS and ASCAT radar sensors based on probabilistic distances to empirical C-Band models for sea ice and ocean backscatter. The Microwave Earth Remote Sensing group at Brigham Young University
(BYU) in the United States has also developed an ice screening method for the Ku-Band SeaWinds radar sensor, which KNMI adopted initially for its own processing. Prompted by its own analyses and user queries, the KNMI decided to use an additional Sea Surface Temperature (SST) filter to prevent occasional erratic winds over sea ice surfaces. Since wind information near the ice edge is quite relevant, this document reports on renovated efforts at KNMI to develop an improved sea ice detection algorithm for SeaWinds similar to the one used for ERS and ASCAT sensors, where computed residuals to geophysical Ku-Band ice and ocean model functions are interpreted as probabilities and then combined with prior information on the sea ice state using a Bayesian discrimination algorithm to produce Near Real-Time (NRT) sea ice maps.