ARCUS Student Award | 3rd Annual Award
3rd Annual ARCUS Award for Arctic Research Excellence
|Submitted by:||Gilles Arfeuille|
|Author:||Gilles Arfeuille and Lawrence A. Mysak|
|Title:||imulation of the interannual variability of the wind driven Arctic sea ice cover during 1958-1998|
|Affiliation:||Centre for Cimate and Global Change Research, Department of Atmospheric and Oceanic Sciences, McGill University, Montreal, Quebec, Canada|
A thermodynamic-dynamic sea ice model based on a granular material rheology (Tremblay and Mysak) is used to study the interannual variability of the Arctic sea ice cover during the 41-year period 1958-1998. Monthly wind stress forcing derived from the National Centers for Environmental Prediction (NCEP) Reanalysis data for this period is used to determine the year-to-year variations in the sea ice circulation and thickness. Special attention is given to analyzing the interannual variability of the sea ice volume in the Arctic Basin and the subsequent changes in the export of sea ice from this region into the Greenland Sea via Fram Strait. The contribution of the Fram Strait sea ice thickness and velocity anomalies to the sea ice export anomalies are first investigated, and the former is shown to be particularly important during several large export periods. The sea ice export anomalies are next related to the prior sea ice volume anomalies in the Arctic Basin. The origin and evolution of those sea ice volume anomalies are then related to the sea ice circulation and atmospheric forcing patterns in the Arctic. It is shown that the large sea ice export anomalies are generally preceded by large volume anomalies formed along the East Siberian Coast due to anomalous winds. Such ice anomalies develop when the Beaufort High is centered closer than usual to this coastal area. When the Beaufort High relocates near the Beaufort Sea and the Icelandic Low extends far into the Arctic Basin, the ice volume anomalies are transported to the Fram Strait region via the Transpolar Drift Stream. Finally, the link between the sea ice export through Fram Strait and the North Atlantic Oscillation (NAO) index is discussed. Although for some years there is a high correlation between the export and the index, there is not necessarily a causal relation between the wind (associated with the NAO) and the export. Therefore, these primarily results show that the Arctic Basin and its ice volume anomalies must be considered in order to fully understand the export through Fram Strait.