Abstract
<jats:p>Abstract. We investigate how weather regimes influence surface precipitation and associated cloud microphysical processes at Dumont d’Urville (DDU; 66.7° S, 140.0° E) using data from the Antarctic Precipitation: Remote Sensing from Surface and Space (APRES3) project. Two precipitation-producing regimes, Summer Warm Air Advection (S-WAA) and Low-Pressure (Low-P), account for 94.2 % of total precipitation at DDU. Hydrometeor growth processes were analysed through comprehensive case studies of Low-P and S-WAA events. The polarimetric signatures during the Low-P event indicate riming and secondary ice production (SIP) within the −10 to −14 °C layer (2–3.5 km), which falls within the dendritic growth zone (DGZ; approximately −10 to −20 °C). Riming intensifies between 1 and 2 km (−7 to −10 °C), whereas below 1 km, downslope flow leads to pronounced hydrometeor sublimation and sublimation-induced SIP. Thus, the surface precipitation associated with this event displays an intermittent pattern, with a predominance of graupel. In contrast, the S-WAA regime is associated with a moist boundary layer, favouring persistent surface precipitation. The polarimetric signatures in the upper half of the DGZ (−14 to −20 °C, 2.5–3.5 km) suggest hydrometeor growth through vapour deposition, while signatures below down to 1 km (−8 to −14 °C) align with aggregation processes. Enhanced riming and SIP driven by the Hallett–Mossop process are observed below 1 km. Our findings emphasise that synoptic weather regimes primarily impact precipitation growth, while boundary-layer flow and moisture play a significant role in snowfall efficiency at DDU in East Antarctica.</jats:p>