Evidence of sublimation in the vertical profiles of radar reflectivity and its impact on snowfall estimation at the ground at Mario Zucchelli Antarctic Station

Abstract

Snow is the main positive component of surface mass balance in Antarctica. Therefore, accurate snow measurements of snowfall play a crucial role in characterizing the Antarctic ice sheet's variability and its impact on the sea-level rise. The remote sensing of precipitation and in situ measurements are, in general, challenging tasks and even more difficult in an environment like Antarctica. Radar profilers are increasingly used in Antarctic research stations to highlight snowfall processes through vertical reflectivity profiles and improve the quantitative precipitation estimation, also exploiting the synergy with surface measurements. This work summarizes the field campaign experience at the Italian Antarctic station "Mario Zucchelli," analyzing the vertical profiles of reflectivity collected by a Micro Rain Radar (MRR), set with a vertical resolution of 35 m and a temporal resolution of 1 min. Such an MRR set up allowed us to use a trustworthy range gate just 105 m above the ground, thus avoiding contamination of clutter. Factors influencing the behavior of vertical profiles are analyzed, emphasizing the sublimation process and its implications on surface snowfall estimation at the ground.