Using Synthetic Aperture Radar In the Forecasting of Polar Mesoscale Cyclones

Polar mesoscale cyclones, or polar lows, are dangerous to ships and coastal communities in and around the Bering Sea. The ability to forecast these storms is hampered by the lack of in situ-data available in this region. The Canadian RADARSAT-1 Synthetic aperture radar (SAR) has been shown an effective tool at imaging polar lows, sometimes where other satellites cannot. SAR is an active sensor that has the ability to remotely sense the high-resolution surface wind variability over the oceans, independent of time and cloud conditions. In conjunction with the National Weather Service in Anchorage, Alaska, we are conducting an experiment to measure the possible usefulness of SAR to operational weather forecasters. As part of this study, forecasters are asked to produce a surface analysis of the Bering Sea using all of the data they normally would have available. Next, the same group of forecasters will be given SAR data and asked to make a new forecast. These two forecasts will then be compared to assess the potential utility of SAR data to operational forecast in the region. The results of this assessment will be presented in this paper. This effort should also serve as an important introduction of SAR data to the Anchorage National Weather Service since they will begin receiving daily SAR imagery and derived products as part of the NOAA NESDIS Alaska SAR demonstration starting in October 1999.