1960—2015年吉林省积雪初、终日期变化特征及其与气温和降水的关系

Spatial and Temporal Variation Characteristics of the Onset and Melting Dates of Snow Cover and Its Relationship with Air Temperature and Precipitation in Jilin Province During 1960-2015

利用吉林省45个气象站1960—2015年逐日积雪深度、气温和降水观测资料,分析该省积雪初、终日的变化特征及其对气候变化的响应。结果表明:(1)吉林省积雪初、终日的空间差异显著,东南山区积雪开始早且结束晚,可积雪期长;西北平原区积雪开始晚且结束早,可积雪期短。(2)吉林省积雪平均始于11月9日,止于次年4月1日,可积雪期达144 d。(3)近56 a积雪初、终日总体变化趋势不明显,但阶段性特征显著。其中,1980年代之前,积雪初日偏早、终日偏晚,1990年代后积雪初日偏晚、终日偏早,可积雪期缩短;积雪初、终日分别在1983年和1991年前后发生显著性突变。(4)积雪初、终日期对气温变化较为敏感。8—11月月平均气温与积雪初日呈显著正相关,而3月、4月平均气温与积雪终日呈显著负相关;积雪初、终日分别受0℃开始日期、10℃终止日期的影响。积雪初日与10月降水量呈显著负相关,而积雪终日与4月降水量呈显著正相关。

Based on the observations of snow cover onset date（SCOD） and melting date（SCMD） and daily average air temperature,precipitation from 45 meteorological stations in Jilin Province during 1960-2015,the temporal and spatial variation characteristics of SCOD,SCMD and its response to climate change were investigated. Results are as follows：（1） The spatial distributions of SCOD and SCMD were significantly different. SCOD was earlier and SCMD was later in the southeast mountain area of Jinlin Province,which resulted in longer possible snow cover duration（SCD）. On the contrary,SCOD was later and SCMD was earlier in the northwest plains,which caused a relatively short possible SCD.（2） The average SCOD and SCMD were November 9 and April 1,respectively,and the mean SCD was 144 days in Jilin Province.（3） In the past 56 years,the change trends of SCOD and SCMD weren＇t obvious on the whole,but the stage characteristic was significant. SCOD was earlier and SCMD was later before the 1980 s,but it was the opposite after the 1990 s,which indicated that the possible SCD shortened. The significant mutations of SCOD and SCMD occurred in 1983 and1991,respectively.（4） SCOD and SCMD were quite sensitive to the temperature change during 1960-2015. SCOD was positively correlated with monthly average air temperature from August to November,while SCOD was negatively correlated with average temperature in March and April. SCOD and SCMD were separately controlled by the starting date of 0 ℃ temperature and the ending date of 10℃ temperature. In addition,the correlation between SCOD and precipitation in October was negative and very significant,while that between SCMD and precipitation in April was positive and remarkable.