辽宁省冬半年降雪初终日的气候变化特征

Climate Change Characteristic of the Beginning and Ending Dates of Snowfall in Winter Half Year of Liaoning Province

利用1961—2007年降雪初始日期、终止日期以及降雪初、终日间天数资料,详细地分析了降雪初始日期、终止日期以及降雪初、终日间天数的时空分布及变化情况、突变和周期性特征。辽宁省降雪的初始日期主要集中在10、11月,终止日期主要在3、4月。降雪初始日期在近47年有所推迟;降雪终止日期明显提前,平均每10年提前2.2天。降雪初、终日间天数明显缩短,平均每10年减少3天。降雪的初始日期、终止日期以及降雪初、终日间天数均存在突变现象。降雪的初始日期、终止日期以及降雪初、终日间天数均存在2～6年的周期。气温与降雪初始日期和终止日期存在着密切的联系。降雪的初始日期与同年10月和11月的平均最高气温相关关系最好,其次是10月和11月的平均气温。

Based on the data of the annual beginning,ending dates and their interval days of snowfall during 1961_2007,the temporal and spatial distributions,the long-term changes,the catastrophe features,the periodic characteristic of the annual beginning,ending dates and their interval days are analyzed.The beginning date of snowfall in Liaoning Province mostly appears in October and November and the ending date mainly occurs in March and April.The appearance of the beginning date is delayed in the past 47 years,but without passing the statistical test.The ending date is obvious negative trend,and be advanced by 2.2 days every decade.The interval days of snowfall are significantly shorter,reducing by 3 days every decade.The beginning date,ending date and their interval days of snowfall have a periodic variation with the period of 2～6 years.There is a significant correlation between temperature the beginning and ending dates of snowfall.The beginning date has the highest relation correlation coefficient with the mean maximum temperature in October and November,secondly the mean temperature.