Mountain barrier baroclinity effects on surface winds along the Alaskan Arctic Coast

Abstract

The deployment of offshore pressure and position relaying buoys in February 1979 within the arctic ice pack has allowed for a more complete investigation of a wintertime mesoscale meteorological effect known as mountain barrier baroclinity (MBB). Total atmospheric boundary layer turning with height was estimated by comparing computed three hourly geostrophic winds (above the boundary layer) to simultaneous surface winds at Barter Island, Alaska. This total turning compared closely with wind velocity versus height data obtained through rawinsonde launches at Barter Island. Results indicate that the average turning of the wind from above the boundary layer to the surface was 140° during periods of MBB influence. In addition the average difference between simultaneously measured surface winds at Barter Island and Pt. Barrow, Alaska (during MBB periods) was 140°, which cannot be explained by existing synoptic (large‐scale) weather charts.The evidence explains the wintertime abundance of west to southwest winds seen on historical monthly wind direction histograms from Barter Island (64 km north of the Brooks Range) while Pt. Barrow (300 km north of the Brooks Range) histograms for similar months show an east to northeast bias. Finally, the occurrences of the MBB effect and a summertime sea breeze effect have been related to arctic tundra surface albedo.