All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 41 17 1
PDF Downloads 13 8 2

THERMALLY AND FRICTIONALLY PRODUCED WIND SHEAR IN THE PLANETARY BOUNDARY LAYER AT LITTLE AMERICA, ANTARCTICA

BERNHARD LETTAUInstitute for Atmospheric Sciences, ESSA, Silver Spring, Md.

Search for other papers by BERNHARD LETTAU in
Current site
Google Scholar
PubMed
Close
Restricted access

Abstract

Pilot balloon wind profiles obtained by the first and second Byrd Antarctic Expeditions are analyzed to show that the mean observed wind shear between the surface and 1,000 m. can be resolved into a frictional component which produces a normal boundary layer wind spiral, and a thermal component resulting from the temperature gradient at the ice edge, which deforms the normal wind spiral. Values of surface stress, surface Rossby number, geostrophic drag coefficient, energy dissipation, and roughness length derived from the wind profiles are collectively sufficiently different from values obtained over land or water surfaces, to suggest that the ice surface produces its own characteristic wind distribution.

Abstract

Pilot balloon wind profiles obtained by the first and second Byrd Antarctic Expeditions are analyzed to show that the mean observed wind shear between the surface and 1,000 m. can be resolved into a frictional component which produces a normal boundary layer wind spiral, and a thermal component resulting from the temperature gradient at the ice edge, which deforms the normal wind spiral. Values of surface stress, surface Rossby number, geostrophic drag coefficient, energy dissipation, and roughness length derived from the wind profiles are collectively sufficiently different from values obtained over land or water surfaces, to suggest that the ice surface produces its own characteristic wind distribution.

Save