Spatial and temporal patterns in snow accumulation, western Dronning Maud Land, Antarctica

Abstract

ABSTRACT. During the Swedish Antarctic Expedition to Dronning MaudLand, Antarctica, 1988-89 the net accumulation was estimated for an area from the coast to about 400 km inland. Stake measurements were used to obtain the spatial variability and firn cores were used for the temporal variability. The mean annual accumulation for the period 1976-88 is about 0.4 m w.e. for Riiser-Larsenisen and about 0.3 m w.e. for the area above the grounding line. The accumulation rate at higher altitudes, > 2500 m a.s.!., is about 0.1 m w.e. for 1955-88. One record from the ice shelf covers the period 1957-88, and suggests an increase in accumulation of about 12%. Between 1976 and, the accumulation has decreased by about 50%, most likely due to lower temperatures as suggested by the temperature record from Halley.

Spatial characteristics of snow accumulation in Dronning Maud Land, Antarctica

“…2). Similar results with coherence in the spatial pattern over time were obtained previously from other stakeline surveys (e.g., Isaksson and Karlén, 1994;Young et al, 1982). In the first part (165 -215 km), where the snow layer mapped by GPR is young (4 years), the difference in amplitudes between GPR data and stake data is not as pronounced as in the second part where the snow layer is relatively old (22 years).…”

“…In the coastal area, the oldest traced snow layers were deposited in 1972. Changes in accumulation rate over the period 1972-1997 have been documented by Isaksson and Karlén (1994) and Isaksson et al (1996Isaksson et al ( , 1999. The deviations or trends observed are not consistent within the study area, and, therefore, it is not possible to assess the extent to which temporal accumulation changes affect the indirect dating.…”

Subglacial Preservation of Valley Morphology at Amundsenisen, Western Dronning Maud Land, Antarctica

“…In areas without surface melting, the temperature at 10 m closely corresponds to the mean annual air temperature (Paterson, 1981). Accumulation measurements in the firn core showed a mean annual precipitation of 10·4 cm water equivalents at this site during the period 1955-1988 (Isaksson and Karlén, 1994).…”

“…The firn temperature at a depth of 10 m was −28.3°C (Isaksson and Karlén, 1994). In areas without surface melting, the temperature at 10 m closely corresponds to the mean annual air temperature (Paterson, 1981).…”

Influence of climatic teleconnections on the temporal isotopic variability as recorded in a firn core from the coastal Dronning Maud Land, East Antarctica

“…Annual δ 18 O values and mean annual temperature from 'Novo', show poor correlation suggesting that other factors do influence the δ 18 O and δD records in this region. Since isotopic content of snowfall in the coastal Antarctic sites is sensitive to factors such as poleward moving airmasses, variations in local moisture sources and sea ice extent (Isaksson and Karlén 1994;Noone and Simmonds 2004) in addition to the temperature, and since the precipitation is largely dependent on the cyclonic storm activity, direct interpretation of oxygen isotopes in terms of temperature is not realistic.…”