Observation of the Atmospheric Surface Layer on Bare Ice in the Circumference of the Yamato Mountains, Antarctica

Abstract

The measurements of profiles of wind speed and air temperature in the atmospheric surface layer above bare ice surface in the circumference of the Yamato Mountains were carried out under neutral and unstable conditions in December, 1973. The results are summarized as follows: 1) The value of aerodynamic roughness parameter (Z_0) was constantly 0.085 cm independent on wind speed, and this value corresponded to the depth of spoon-cut features (2-3 cm) on the bare ice surface. 2) The relation between the friction velocity (U_*) and the wind speed at 1 m height (U_1) is expressed by U_*=0.057 U_1. 3) Atmosphere showed an unstable condition (negative Richardson number) with the decrease of wind speed, as the bare ice surface was heated by radiation. 4) Eddy diffusivity obtained on the bare ice surface in neutral condition was larger than that of sea ice around Syowa Station.