A precise monitoring of snow surface height in the region of Lambert Glacier basin-Amery Ice Shelf, East Antarctica
The net surface snow accumulation on the Antarctic ice sheet is determined by a combination of precipitation, sublimation and wind redistribution. We present a one-year record of hourly snow-height measurements at LGB69 (70°50'S, 77°04(E,1850 m a.s.l.), east side of Lambert Glacier basin (LGB), and 4 year record at G3 (70°53'S, 69°52'E, 84 m a.s.l.), Amery Ice Shelf (AIS). The measurements were made with ultrasonic sensors mounted on automatic weather stations installed at two sites. The snow accumulation at LGB69 is approximately 70 cm. Throughout the winter, between April and September, there was little change in surface snow height (SSH) at the two sites. The negative SSH change is due to densification at LGB69, and is due to both ablation and densification at G3. The strongest accumulation at two sites occurred during the period between Octobers and March (accounting for 101.6% at LGB69), with four episodic increasing events occurring during 2002 for LGB69, and eight events during 1999-2002 for G3 (2 to 3 events per year). At LGB69, these episodic events coincided with obvious humidity "pulses" and decreases of incoming solar radiation as recorded by the AWS. Observations of the total cloud amount at Davis station, 160 km NNE of LGB69, showed good correlation with major accumulation events recorded at LGB69. There was an obvious anti-correlation between the lowest cloud height at Davis and the daily accumulation rate at LGB69. Although there was no correlation over the total year between wind speed and accumulation at LGB69, large individual accumulation events are associated with episodes of strong wind (>7 m/s), we estimate drift snow may contribute to total SSH up to 35%. Strong accumulation events at LGB69 are associated with major storms in the region and inland transport of moist air masses from the coast.
作 者： XIAO Cunde QIN Dahe BIAN Lingen ZHOU Xiuji I.Allison YAN Ming 作者单位： XIAO Cunde(Department of Atmospheric Science, Peking University, Beijing 100871, China;Chinese Academy of Meteorology Sciences, Beijing 100081, China;Laboratory of Ice Core and Cold Regions Environment, Cold and Arid Regions Environmental and Engineering Research In)QIN Dahe(Laboratory of Ice Core and Cold Regions Environment, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China)
BIAN Lingen(Chinese Academy of Meteorology Sciences, Beijing 100081, China)
ZHOU Xiuji(Department of Atmospheric Science, Peking University, Beijing 100871, China;Laboratory of Ice Core and Cold Regions Environment, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China)
I.Allison(Australian Antarctic Division and Antarctic Climate and Ecosystems CRC, Private Bag 80 Hobart, Tasmania, 7001, Australia)
YAN Ming(Polar Research Center of China, Shanghai 200129, China)
刊 名： 中国科学D辑（英文版） SCI 英文刊名： SCIENCE IN CHINA (EARTH SCIENCES) 年，卷(期)： 2005 48(1) 分类号： P9 关键词： Antarctica Lambert Glacier basin Amery Ice Shelf accumulation katabatic wind