Meteorological forcing of sea ice variability in the Southern Beaufort Sea

Arctic climate processes are, in general, poorly understood. One of the complexities in understanding how the arctic will respond to global scale climate variability and change is the role which snow and sea ice play in controlling energy and mass fluxes across the ocean-sea ice-atmosphere (OSA) interface. The snow/sea ice system is significant at a range of time and space scales on how the atmosphere and ocean are coupled throughout the annual cycle. Feedback mechanisms complicate these processes and the timing of particular events can have significant impacts in both the ecological and geophysical characteristics of the system.

The Canadian Arctic Shelf Exchange Study (CASES) is a Canadian led international research program which will examine the relationship between sea ice variability and carbon fluxes between the Mackenzie Shelf/Cape Bathurst Polynya and the Canada Basin. In this paper we provide an overview of the CASES experiment including plans for a 365 day ice breaker based sampling program to begin in September, 2003. We then present results from a historical analysis which was conducted to provide context to the field sampling program. We present results from ocean, sea ice and meteorological coupling over the period 1978 to 2001 within the CASES study region.

Results show that the sea ice average areal extent and spatial distribution have been decreasing at an alarming rate in the southern Beaufort Sea since 1978. The meteorological forcing of this reduction is evaluated through analysis of NCEP reanalysis data in periods where prolonged negative and positive anomalies in sea ice concentration persist. The results illustrate that sea ice dynamics and thermodynamics can be influenced by subtle atmospheric and pressure pattern differences between the North Pacific and the Southern Beaufort Sea. We conclude the paper with a discussion of the importance of sea ice mass balance and areal extent reduction relative to carbon fluxes on and across the Beaufort Shelf.