1960—2009年辽宁冬季风寒温度时空变化特征

Temporal and spatial characters of winter wind chill temperature from 1960 to 2009 in Liaoning province

基于1960—2009年辽宁省52个气象站气象资料,采用风寒温度计算公式和适合辽宁地区的分级标准并分类,得出近50 a历年各类别风寒温度日数。使用旋转经验正交分解法(REOF),分别针对各类别风寒温度日数进行区域划分,并分析其空间分布和变化趋势。结果表明:辽宁省可按4个风寒温度类别分别分区,凉爽至轻度风寒可分为4个区域,而轻度、中度及重度风寒可分为3个区域;辽东半岛5个地市所在地理区域为易患风寒日数最少的地域,辽宁北部、东北部5个地市为易患风寒日数最多的地域;辽宁地区各风寒类别所在划分区域的日数变化相位基本一致;年平均易患风寒日数总体变化趋势在1986年发生突变,在1960—1985年相对偏多,1986—2009年相对偏少。

Based on the meteorological data at 52 weather stations in Liaoning province from 1960 to 2009, the number of winter wind chill temperature days for the different levels was calculated using a winter wind chill tem- perature formula and its optimal classification standard for Liaoning province. Based on the winter wind chill tem- perature days ,the study area was divided by a rotated empirical orthogonal function（REOF） method, and its spa- tial distribution and trend were analyzed. The results show that it could be divided into four levels based on winter wind chill temperature in Liaoning province, and each level has different sub-regions. The study area could be di- vided into four regions for cold to slight wind chill level, while it is three regions for the other three levels, i. e. mild, moderate and severe levels. There is less number of winter wind chili temperature days in five cities around Liaodong peninsula, while there is more in five cities located in the north and northeast of Liaoning province. The variation trends of winter wind chili temperature days for four levels are similar. The number of annual mean win- ter wind chill temperature days is higher during 1960-1985, while it is less during 1986-2009. There is an abrupt change in 1986 for winter wind chill temperature days.