Analysis of L-band brightness temperature time series at DOME C — Antarctica

Antarctica is a very unique continent, completely covered by thousands of meter of ice and firn. Therefore its microwave signature is different from any other place on Earth. Although the emission at low microwave frequency of the East Antarctic plateau is temporally stable for long periods, especially at V polarization and for incidence angles close to the Brewster one, a detailed analysis of satellite and ground based L-band measurements revealed that changes in the characteristics of snow surface can have an appreciable effect on the emission at H polarization. This work is focused on analyzing the temporal variations of the brightness temperature and on linking it to their primary causes. Ground measurements and model simulations indicate that, when strong wind event take place, they could swipe away the first weak layers of snow, exposing the more dense ones. This superficial change can cause a variation of the overall snowpack emission which causes the brightness temperature at H pol to decrease appreciably. On the contrary, the accumulation and densification processes make the Tb to increase.