A century of accumulation and temperature changes in Dronning Maud Land, Antarctica

A mass balance program was initiated in the Vestfjella-Heimefrontfjella area of western Dronning Maud Land during the austral summer of 1988-1989. As a part of this program, spatial and temporal variations in snow accumulation and temperature / stable isotopes are measured using shallow firn cores. In this paper we present surface accumulation data and discuss the climatic implications of the stable isotope records from two shallow firn cores, One 30-m-deep core, obtained about 200 km from the coast at 700 m asl(73 degrees 36'S, 12 degrees 26'W), covers the period 1932-1991. The other core was drilled at about 500 km from the coast at 2900 m asl (75 degrees 00'S, 2 degrees 00'E) and covers the period 1865-1991. The recent accumulation increase that has been reported from several areas of the Antarctic continent is not present in either of these records. Instead, our coastal record suggests a significant decrease in accumulation, with the strongest trend from about 1975. There is a positive trend in the oxygen isotope signal in both cores, which in the coastal core corresponds to a temperature increase of about 1.8 degrees C since the early 1930s, and in the high-altitude core to about 0.8 degrees C since 1865. However, it is likely that part of this increase in delta(18)O is due to a change of moisture source.