Coastal Winds and Sea ICE Detection from the NOAA Near Real-Time Advanced Scatterometer (ASCAT) Processor

The NOAA near real-time operational ASCAT ocean surface wind vectors are produced at 12.5 and 25 km swath grid resolutions. However, due to land contamination most coastal zones are left without any wind retrievals. In this paper, we show how combination of the enhanced resolution normalized radar backscattered cross section (sigma0) algorithm with an aggressive land contribution ratio rejection technique and a land contamination correction algorithm allows for accurate wind to be retrieved within 1-2.5 km of the coast. To achieve acceptable accuracy for operational applications, an additional calibration of the enhanced resolution sigma0 was also found necessary. This algorithm was tested within the Alaskan coastal waters. Variability in the sea ice along the Alaskan coasts also required implementation of a high-resolution ice detection algorithm, which yielded a combined wind and ice product from the ASCAT measurements. The results are presented and discussed.