The dynamic climatology of the beaufort to Laptev sea sector of the polar basin for the summers of 1975 and 1976

Abstract

AbstractFor the summer months of 1975 and 1976, the total vertical velocity at 850 millibars is computed from a diagnostic atmospheric model as an index of synoptic activity in the Beaufort to Laptev Sea sector of the Polar Basin. The objective is to identify the major modes of synoptic activity in the region and to determine the major formative mechanisms for significant synoptic vortices. This will lead to an understanding of the dynamics involved in the evolution and maintenance of synoptic patterns in the Arctic.Cluster analysis is used to stratify the 850 mb geopotential height data into synoptic modes. The mean 850 mb total vertical velocity field for each cluster is calculated, and indices related to each of the formative mechanisms are related to these individual fields through regression analysis and pattern comparison. These mechanisms are: vorticity and thickness advection, diabatic effects of latent heat release and surface heating, and frictional and orographic influences at the surface. Explanations for the dynamics of the major regional vortices are discussed.