Estimating sea ice area flux across the Canadian Arctic Archipelago using enhanced AMSR-E

Abstract

Enhanced resolution Advanced Microwave Scanning Radiometer (AMSR-E) imagery is used to estimate daily sea ice area fluxes between the Canadian Arctic Archipelago and the Arctic Ocean and Baffin Bay for the period September 2002 to June 2007. Over the period, Amundsen Gulf and M'Clure Strait exported 54 × 103 km2 of sea ice area or roughly 77 km3 of sea ice volume each year into the Arctic Ocean. Export/import into the Arctic Ocean through the Queen Elizabeth Islands is small and uncertain since no estimates for July and August could be made due to atmospheric attenuation of the microwave signal. Lancaster Sound exported 68 × 103 km2 of sea ice area or roughly 102 km3 of ice volume into Baffin Bay. This produced a net loss of sea ice area of about 122 × 103 km2 or roughly 174 km3 a-1 which is presumed to be generated from within the Archipelago itself mainly through the stationary and transient polynyas and leads that form each winter. Daily ice area fluxes for Amundsen Gulf (AG) and Lancaster Sound (LS) were as high as ±2500 km2 d-1 and were event driven depending on synoptic scale atmospheric circulation and the mobility of the sea ice. Mean sea level pressure difference across each gate is moderately correlated with daily sea ice area fluxes despite the fact that free ice drift conditions are not always met in the region. Cross-gradient and daily sea ice area flux for Lancaster Sound show a large number of counter gradient ice flux occurrences suggesting that local mesoscale winds (nongeostrophic) and perhaps ocean currents play a role in transporting sea ice through this gate. Monthly ice fluxes for the AG and MS gate were positively correlated with the AO index indicating that a strong Beaufort Sea high pressure and gyre correspond to more export into the Beaufort Sea. Monthly fluxes for the LS gate were positively correlated with the NAO index indicating that strong southerly atmospheric circulation over Baffin Bay increases ice export into Baffin Bay from Lancaster Sound.