Wind Information for Marine Weather Forecasting from RADARSAT-1 Synthetic Aperture Radar Data: Initial Results from the "Marine Winds from SAR" Demonstration Project

The Canadian Ice Service (CIS), part of the Meteorological Service of Canada (MSC), is the federal government agency that is responsible for the operational delivery of ice information services to marine users operating in Canadian ice covered waters. RADARSAT-1 Synthetic Aperture Radar (SAR) imagery is the primary satellite data source that the CIS uses to monitor the vast, seasonally varying waters for which it is responsible. Although the CIS mission is primarily focused on ice monitoring, recently the role of the CIS has been expanded to include a marine service component.

The CIS receives about 4000 RADARSAT-1 scenes annually, including coverage of the Great Lakes and the eastern coast of Canada. Besides imaging the ice conditions, many of the images, for these two regions in particular, capture dramatic snapshots of atmospheric boundary layer phenomena imprinted on the ocean surface roughness. During the stormy winter period in these regions, particularly for the Great Lakes, there is a paucity of buoy observations to provide meteorological data for marine weather forecasting. It has already been demonstrated and proven that SAR imagery from RADARSAT-1 can be used to derive information of potential interest to meteorologists, such as the surface wind speed and direction. This type of information could fill an information gap during the winter for these specific areas.

In an effort to expand the use of RADARSAT-1 SAR imagery within the Meteorological Service, the CIS has initiated a demonstration project to process RADARSAT-1 imagery from its operational data stream for two winter periods (Jan-April, 2001 and 2002) and to deliver image data and wind information products to two regional weather centres. The RADARSAT-1 imagery for the two areas of interest are automatically extracted and reduced-resolution imagery (~ 1MB products) are generated and delivered automatically. In addition, graphical and text wind speed and direction products are generated using Satlantic's Ocean Monitoring Workstation and are delivered manually to the centres. This paper reports on the initial results from this demonstration project with a look towards the potential for the routine use of SAR data for coastal marine meteorology.