Abstract. Precipitation over Antarctica is the main term in the surface mass
balance of the Antarctic ice sheet, which is crucial for the future evolution
of the sea level worldwide. Precipitation, however, remains poorly documented
and understood mainly because of a lack of observations in this extreme
environment. Two observatories dedicated to precipitation have been set up at
the Belgian station Princess Elisabeth (PE) and at the French station Dumont
d'Urville (DDU) in East Antarctica. Among other instruments, both sites
have a vertically pointing micro rain radar (MRR) working at the K band.
Measurements have been continuously collected at DDU since the austral summer
of
2015–2016, while they have been collected mostly during summer seasons at PE
since 2010, with a full year of observation during 2012. In this study, the
statistics of the vertical profiles of reflectivity, vertical velocity, and
spectral width are analyzed for all seasons. Vertical profiles were separated
into surface precipitation and virga to evaluate the impact of virga on the
structure of the vertical profiles. The climatology of the study area plays
an important role in the structure of the precipitation: warmer and moister
atmospheric conditions at DDU favor the occurrence of more intense
precipitation compared with PE, with a difference of 8 dBZ between both
stations. The strong katabatic winds blowing at DDU induce a decrease in
reflectivity close to the ground due to the sublimation of the snowfall
particles. The vertical profiles of precipitation velocity show significant
differences between the two stations. In general, at DDU the vertical
velocity increases as the height decreases, while at PE the vertical velocity
decreases as the height decreases. These features of the vertical profiles of
reflectivity and vertical velocity could be explained by the more frequent
occurrence of aggregation and riming at DDU compared to PE because of the
lower temperature and relative humidity at the latter, located further in the
interior. Robust and reliable statistics about the vertical profile of
precipitation in Antarctica, as derived from MRRs for instance,
are necessary and valuable for the evaluation of precipitation estimates
derived from satellite measurements and from numerical atmospheric models.