阿尔山地区积雪变化特征

Variation Characteristics of Snow Cover in Aer Shan Region

选取阿尔山气象站1981—2015年冷季(10月—次年4月)气象资料,利用滑动平均、线性倾向估计和Mann-Kendall等方法,对年最大积雪深度、积雪日数、气温和降水量进行分析。结果表明,阿尔山地区年最大积雪深度主要发生在1月至3月,其中2月份概率最大,达50%;34 a内最大积雪深度呈上升趋势(2.77 cm/10a),年平均增加0.98%,且年最大积雪深度在1998年发生了突变,即在1998年之前增长缓慢,在2000年以后上升趋势显著。积雪日数的统计分析表明,初始积雪日数和有效积雪日数呈现略微减少趋势,而稳定积雪日数有微弱的增加趋势;通常初始积雪日数比有效积雪日数大30天左右。年最大积雪深度与稳定积雪时期的降水量、积雪日数、日照时数有显著的相关性,相关系数分别为0.647、0.515、0.584,但与稳定积雪时期的气温没有明显的相关性。在全球变暖的大环境下,积雪深度随着降水量和日照时数的增加而增加,且积雪深度受降水量的影响大于日照时数的影响。

Based on the daily data record from Aershan meteorological station in 1981—2015 cold seasons（ from October to next April）,the variation characteristics of the yearly maximum snow-cover depth,snow-cover days,air temperature and precipitation are investigated by using the methods of moving average,linear trend analysis and Mann-Kendall test. The results show that the yearly maximum snow-cover depth in Aershan mainly occurred in January to March,especially in February the highest probability was up to 50%. During the 34 years,the maximum snow-cover depth has an increasing trend with the rate of 2.77 cm /10 a and annually increased by 0. 98%. However the trend has mutated in 1998 that the maximum snow-cover depth increased slowly before 1998 but raised significantly after 2000. The statistics of snow-cover days show that the days of initial snow-cover period and the effective snow-cover period are tended to decrease,while the days of steady snow-cover period are tended to increase. The days of initial snow-cover period are around 30 days more than the days of effective snow-cover period. The annual maximum snow-cover depth was positively correlated to the precipitation,the snow-cover days and the sunshine duration in the steady snow-cover period with the correlation coefficients are 0.647,0.515 and 0.584,respectively,but less correlated to the corresponding air temperature. Under the background of global warming,the snow-cover depth increase with the increasing of precipitation and sunshine duration,and more influence coming from the former.