Using SAR Remote Sensing, Field Observations, and Models to Better Understand Coastal Flows in the Gulf of Alaska

T he mesoscale atmospheric flow near coastlines with rugged, steep terrain is often very complex and can be quite intense (Young and Winstead 2005). During the cool season, extratropical cyclones over the Pacific Ocean frequently make landfall along the southeast coast of Alaska. Interaction of these synoptic-scale disturbances with the steeply rising coastal terrain (see Fig. 1) can produce strong coastal pressure gradients and winds to near hurricane force throughout coastal Alaska (Overland and Bond 1993). Specific phenomena that produce these winds include barrier jets, gap flows, downslope winds, and the interactions between them (Young and Winstead 2005). Winds can vary from nearly calm to storm force over a distance of as little as a few kilometers. There are, however, few in situ surface observations in the coastal zone to monitor such winds, exacerbating the hazard posed to marine and general aviation interests in coastal Alaska. The terrain-forced winds oriented in the alongcoast direction are classically referred to as barrier jets (Parish 1982; Doyle 1997). Examples in the literature include the cold air damming along the east slopes Using SAR Remote Sensing, Field Observations, and Models to Better Understand Coastal Flows in the Gulf of Alaska