Snow accumulation/ablation pattern in the Larsemann Hills area and Schirmacher Oasis region, East Antarctica

摘要

Schirmacher Oasis, central Dronning Maud Land (cDML) and Larsemann Hills of East Antarctica are exposed in two different physiographic settings. In Schirmacher Oasis, vast stretch of ice shelf is in the north and the polar ice sheet in the south, whereas, in Larsemann Hills area, landmass and ice sheet is directly in contact with the ocean. The Larsemann Hills area is characterized by a polar lowland cold climate with relatively lower amounts of precipitation, restricted period of snow melting, and low rates of ice melt as compared to Schirmacher Oasis. In Larsemann Hills area, snow ablation is dominant over accumulation, whereas in the Schirmacher region of central Dronning Maud Land, the snow accumulation is relatively dominant over ablation. In Larsemann Hills area, the average monthly snow ablation is dominant over snow accumulation and shows a continuous average annual ablation from 2013-17 with total weight of snow lost during 2013-15 is 15075000 cm3 and during 2016-17 is 66850000 cm3 respectively whereas during 2015-16, the total weight of snow gained is 189525000 cm~3 (W. Eq.). In Schirmacher Oasis, during 2011-12, 2012-13 and 2013-14 the Polar Ice Sheet shows continuous average annual accumulation of 84000000 cm~3, 48850000 cm~3 and 63269000 cm3 respectively whereas during the years 2015 and 2016 a continuous ablation of the order of 58314000 cm3 and 26264000 cm3 was recorded.The snow accumulation in Larsemann Hills area and Schirmacher Oasis, East Antarctica shows positive correlation with average annual wind speed with correlation coefficient (R) of 0.66 and 0.67 respectively indicating drift snow as an important component of total snow accumulation. In addition, relative humidity in Schirmacher Oasis with measure of reliability (R2 = 0.20) and wind direction in Larsemann Hills (R~2= 0.46) shows some degree of positive correlation in controlling the snow accumulation/ablation pattern. Therefore, suggesting that the rate of snow accumulation/ ablation is not uniform throughout the region and is affected by dominantly parameters like wind speed, relative humidity etc.