We compared circulations under the Filchner-Ronne Ice Shelf (FRIS) and the Ross Ice Shelf (RIS) using output from the Whole Antarctica Ocean Model driven by repeated year atmospheric forcing and processed by the particle-tracking Parcels model. Three Lagrangian characteristics were calculated: the visitation frequency, the mean age, and the representative particle trajectory. In both FRIS and RIS, the High Salinity Shelf Water (HSSW) entered through depressions off the western coast of ice shelves. We found that HSSW transformed into the Ice Shelf Water that departed both ice shelves at central ice front locations (approximately 58-57°W in Ronne Ice Shelf and 175°W in RIS). The outflow through the Ronne Ice Front we identified has not attracted attention until now, although it has been observed. Almost half of the particles departed FRIS through the Ronne Ice Front, whereas about 20% stayed under FRIS. The rest of the particles flow out through the Filchner Trough. In contrast, only 2% of the particles stayed under RIS. The mean age of water leaving FRIS through the Ronne Ice Front and the water leaving RIS was 7–8 years, whereas the water leaving FRIS through the Filchner Trough was about 10 years.

Studying precipitation at very high latitudes is a challenge, particularly during the polar winter. Direct monitoring of ice habit and size in high latitude precipitation is crucial for validating the algorithms used to derive precipitation from radar, and for improving the climatological modeling of polar areas. The high plateau lacks long-term direct observations of precipitation. In this work, carried out at Concordia Station (Dome-C (DC), -75°S, 123°E, 3233 m a.m.s.l), the use of a depolarization LIDAR, a flatbed scanner (ICECAMERA), a microwave profiler (HAMSTRAD) and meteorological instrumentation made possible the study, over the period 2014-2021, of shape, size, height and temperature of formation of precipitation. The precipitation sources were classified into four types: ice fogs, liquid fogs, mixed-phase clouds, and cirrus. Ten representative ice habits for Dome-C were chosen. The size distribution for every habit was calculated, allowing for the estimation of the corresponding radar reflectivity. The use of W-band radars, such as CLOUDSAT, with a sensitivity of -28dB, resulted in capturing all the crystals observed in Concordia. A positive trend was observed between grain size and height in ice habits that are typical of cloud precipitation. North West (NW) and North East (NE) winds at cloud height, blowing from coastal regions, caused the majority of precipitation from clouds. The study also examined the height trend of the ice habit composition of precipitation. The ice habit composition for each of the four types of precipitation source was analyzed, and the possibility of determining the source by simply observing the precipitation was explored. This work marks the first comprehensive investigation of precipitation on the eastern Antarctic plateau.