1961-2015年我国鲁东南地区降雪的气候特征分析

利用鲁东南地区18个代表站1961-2015年的逐日降水量、逐日天气现象、积雪深度资料，对近55 a来降雪的气候特征进行了统计分析。结果表明：鲁东南地区年均降雪日数、强降雪日数、降雪量、强降雪量及年均雪深、年最大积雪深度的空间分布总体上山区多于平原和沿海，区域差异明显。21世纪00年代以前为多雪时期，以后为少雪时期。近55 a的年均降雪日数、强降雪日数、降雪量、强降雪量及年均雪深、年最大积雪深度皆呈减少趋势，降雪由多转少的转折年份均在1993年，年均雪深、年最大积雪深度的减少分别出现在1987年、1986年。鲁东南地区降雪主要集中在1-2月份，3月份强降雪量最大，平均雪深、最大积雪深度的最大月份分别出现在11月份、3月份。降雪时段为10月23日-次年4月28日，降雪的初终日西北部山区皆为最早。降雪日数、强降雪日数、降雪量、强降雪量、雪深均存在3 a的周期，最大积雪深度存在4～5 a的周期。

Analysis of the climate characteristics of snowfall in southeastern Shandong Province from 1961 to 2015

Based on the daily precipitation, daily weather phenomenon and snow cover depth data from 18 meteorological stations in southeastern Shandong Province from 1961 to 2015, the climatic characteristics of snowfall in the recent 55 years were analyzed. The results showed that the spatial distribution of annual snowfall days, heavy snowfall days, snowfall, extreme snowfall, snow cover depth and maximum depth of snow cover in mountain areas were more than that in plains and coastal areas in southeastern Shandong Province, with an obvious regional difference. Before the 2000s, there had been a snowy period, followed by a less snowy period. From 1961 through 2015, the average number of snowfall days, heavy snowfall days, extreme snowfall, snow cover depth and maximum depth of snow cover had been decreasing, the turning year from more to less of snowfall was in 1993 and snow depth, maximum depth of snow cover was in 1987, 1986. Snowfall in the southeastern Shandong Province had been mainly concentrated in January and February, with the maximum extreme snowfall in March. The month of maximum average snow depth and maximum depth of snow cover occurred in November and March, respectively. The snowfall period was from October 23 to April 28; the early beginning date and the ending date of snowfall always occurred in the northwest mountains. There was a period of 3 years in the variation cycle of snowfall days, heavy snowfall days, snowfall, extreme snowfall and snow depth, and there was a period of 4~5 years of maximum depth of snow cover.