A polar low over The Labrador Sea: Interactions with topography and an upper-level potential vorticity anomaly, and an observation by RADARSAT-1 SAR

Polar lows, high latitude marine mesoscale cyclones, are an enigmatic atmospheric phenomenon. With their small spatial scales, their short life times, and their tendency to develop in remote data sparse regions; they remain difficult to observe and to model. In this paper we use a variety of data sets to discuss the development of a polar low over the Labrador Sea that is of interest for several reasons. First, it developed out of the remnants of a synoptic‐scale cyclone that underwent a bifurcation due to an interaction with the high topography of southern Greenland. Second, the transformation of the resulting circulation into a polar low was aided by an interaction with an upper‐tropospheric potential vorticity anomaly. Finally, the event was observed by the Synthetic Aperture Radar on the RADARSAT‐1 satellite. The resulting image of the ocean's surface provides a new and provocative view of a most interesting weather system.