Modeling sea ice in Hudson Bay from a polar bear ( Ursus maritimus) perspective.

摘要

Sea ice concentration (SIC), the length of the ice-free period, and the break-up date are correlated with the survival and reproduction success of polar bears (Ursus maritimus) in Western Hudson Bay (WH). I use a high-resolution sea ice-ocean model to predict these parameters through the 21st century and to assess the threat on polar bears in WH. The model was validated and calibrated with GPS-data from polar bears in WH. Predictions are based on the IPCC greenhouse gas-emission scenarios: B1, A1B and A2. The model predicted significant changes in WH spring SIC in A1B and A2, and in the seasonal ice cycle in B1, A1B and A2. From 2061-2100, the mean break-up date advances 15.7 days (B1), 31.5 days (A1B), and 46 days (A2), and the mean ice-free period lengthens by 4.5 weeks (B1), 8.4 weeks (A1B), and 12.5 weeks (A2). Should the model projections be realized, a viable population of polar bears will not likely persist in WH until the end of this century.