Evidence of a Coastally Trapped Disturbance along the Beaufort Sea coastline

Christopher J. Kubu
Peter L. Jackson


in preparation

Abstract

A search for Coastally Trapped Disturbances (CTDs) along the Beaufort Sea coastline was conducted using a specially deployed surface station network between July 1994 and August 1995. CTDs occur along the coastlines of South Africa, western North and South America, and Australia, but have not been previously described along the Beaufort Sea coastline. CTDs are meso-scale weather phenomena that are vertically trapped by thermal stratification and laterally trapped by the Coriolis force and coastal orography. The Beaufort Sea coastline has a mountainous topography and exhibits frequent periods of stable stratification which is similar to cases documented in other locations. Analysis of surface pressure and other parameters revealed a coastally trapped event along the Beaufort Sea coastline. The event was initiated on the synoptic scale by the movement westward along the coast of a low pressure system both aloft and near the surface. It was found that the propagation speed, surface pressure structure and across-shore decay characteristics are consistent with an interpretation of the event as a solitary Kelvin wave. This case represents the first description of a CTD along the Beaufort Sea coastline.