A case-study in tracking 1998 polynya ice dynamics in Smith Sound, North Water polynya region, Canadian Arctic, using RADARSAT-1 data

Abstract

AbstractMonitoring ice motion provides insight into the relative contributions of atmospheric and oceanic forcing to polynya dynamics In this study ice kinematics in the North Water (NOW) region, northern Baffin Bay Canadian Arctic are determined using time-sequential RADARSAT-1 ScanSARWide imagery (from the period January-December 1998), processed by the automated ice-tracking algorithm (Tracker) currently used at the Canadian Ice Service (CIS). A case-study is then carried out on the Smith Sound region from January till the end of june 1998 to monitor polynya formation, maintenance and disintegration. This has two objectives: (1) to evaluate satellite ice-motion products as a means of better understanding the relative contributions of latent- and sensible-heat mechanisms responsible for the formation and behaviour of the NOW polynya, and (2) to study the influence of winds on regional sea-ice motion. Derived ice-motion maps were validated using in situ ice beacons deployed onto floes in the NOW region during the 1998 ship-based science experiment. Tracker-derived displacement and directional regressions were 0.93 and 0.79, respectively, with a total standard error of 3.6 km in magnitude and 38.8° in direction. Analysis of monthly mean ice-motion maps shows that a significant export of ice occurs from the polynya. A comparison of weekly-averaged ice motion with the mean wind-field data suggests that ice export in Smith Sound is influenced by synoptic-scale atmospheric pressure systems.