A case study of old-ice import and export through Peary and Sverdrup Channels in the Canadian Arctic Archipelago:: 1998-2005

This case study attempts to quantify the amount and timing of the import, export and through-flow of old ice in the Peary Channel-Sverdrup Channel area of the northern Canadian Arctic Archipelago during the period 1998-2005. The study combines quantitative weekly area-averaged ice coverage evaluations from the Canadian Ice Service (CIS) Digital Archive with detailed analysis of RADARSAT imagery and ice-motion results from the CIS ice-motion algorithm. The results show that in 1998 more than 70% of the old ice in Peary-Sverdrup was lost, half by melt and export to the south and the other half by export north into the Arctic Ocean, and that no Arctic Ocean old ice was imported into Peary-Sverdrup. A net import of 10% old ice was seen in 1999, with some indication of through-flow into southern channels. In 2000, no net import of old ice occurred in Peary-Sverdrup, but there was significant through-flow, with evidence of old ice reaching the Northwest Passage by November. Full recovery of the old-ice regime was complete by the end of 2001. More than two-thirds of the recovery was due to the in situ formation of second-year ice. Conditions in the following 3 years were near normal.