祁连山老虎沟12号冰川积累区微气象特征

Characteristics of Micrometeorological Elements in Accumulation Zone of Laohugou Glacier No.12 in Qilian Mountains

利用2008年10月1日-2009年9月30日祁连山老虎沟12号冰川积累区海拔5040m自动气象站观测资料,初步分析了该地区气温、冰川表面温度、降水、相对湿度、空气和冰川表面比湿、气压、风速、风向、感热和潜热通量等气象要素的平均日变化和季节变化特征。结果表明,气温年平均值为-11.8℃,全年正积温仅为16.5℃,具有日较差小、年较差大的气温特征;降水主要集中在5-9月,约占全年的85%,年降水量为424.2mm;气压冬季低、夏季高,属于典型的高山型;年平均风速为3.7m·s-1,冰川风显著;感热通量要强于潜热通量,大气与冰川表面的湍流交换中,大气以损失热量为主。

Based on the observed data from the automatic weather station set up at an altitude of 5040 m in accumulation zone of the Laohugou Glacier No.12 during the period from 1 October 2008 to 30 September 2009, mean diurnal and seasonal variations of air and glacial surface temperature, precipitation, relative humidity, air and glacial surface specific humidity, air pressure, wind speed and direction, sensible and latent heat fluxes were analyzed. The results show that annual mean and daily positive accumulated values of air temperature were -11.8℃ and 16.5℃ separately with a feature of small daily range and large annual range. Precipitation occurred mainly from May to September which was 85% of the annual total （424.2 mm）. Air pressure was low in winter and high in summer, which belonged to the mountain type. Annual mean values of wind speed was 3.7 m·s-1 and glacier wind was notable. The sensible heat flux was larger than the latent heat flux and the heat of atmosphere was loss in the turbulent fluxes exchange between air and glacial surface.