Using satellite thermal infrared imagery to study boundary layer structure in an Antarctic katabatic wind region

Abstract

We use snow surface temperatures obtained from thermal infrared (TIR) satellite imagery, together with radiosonde profiles of free-air temperature and high-resolution topographic data to study the thermal structure of the atmospheric boundary layer in a coastal region ofEast Antarctica. Surface temperatures over a coastal ice shelf are shown to be significantly lower than those observed on the lower part of the adjoining coastal slopes as a result of the strong surface temperature inversion that forms over the ice shelf. Between 400 and 1500 m elevation the surface temperature lapse rate is close to the dry adiabatic value while the free-air temperature profile is significantly stable over this height range. We argue that this implies that the strength of the surface inversion increases with increasing elevation. Above 1500 m the surface temperature lapse rate becomes significantly superadiabatic and the coldest surface temperatures are found a few 10s of kilometres inland of the highest topography. The technique may prove useful for studying boundary layer structure in other regions of Antarctica where suitable high-resolution topographic data are available.