Synthesis of passive microwave and radar altimeter data for estimating accumulation rates of dry polar snow

Abstract

In this paper, we compare dry-snow extinction coefficients derived from satellite radar altimeter data with brightness temperature data from passive microwave measurements over a portion of the East Antarctic plateau. The comparison between the extinction coefficients and the brightness temperatures shows a strong negative correlation, where the correlation coefficients ranged from –0·87 to –0·95. The large-scale trend shows that the extinction coefficient of the dry polar snow decreases with increasing surface elevation, while the average brightness temperature increases with surface elevation. Our analysis shows that the observed trends are related to geographical variations in scattering coefficient of snow, which, in turn, are controlled by variations in surface temperature and snow accumulation rate. By combining informa.tion present in the extinction coefficient and brightness temperature datasets, we develop a simple semi-empirical model that can be used to obtain accumulation rate estimates of dry polar snow.