辽宁春季稳定通过界限温度日期的变化特征

为了掌握辽宁春季稳定通过界限温度日期的变化特征，从而为预报做准备。采用1961—2010年辽宁省53站逐日气温资料，计算辽宁春季稳定通过5℃和8℃的日期，并采用多种统计方法分析了稳定通过界限温度日期的时空变化特征。结果表明：1961—2010年53站辽宁春季气温稳定通过5℃和8℃日期的EOF第一模态表现为一致的偏早或偏晚特征；二者随时间有提前出现的趋势；二者的均方差在全省分布比较均匀；辽宁春季气温稳定通过5℃和8℃日期的突变点分别为1981和1993年，主要周期分别为4年和2年；辽宁春季气温稳定通过5℃和8℃日期有明显的区域特征。

Variation Characteristics of the Date Spring Temperature Above Critical Temperature Stably

In order to grasp the variation characteristics of the date spring temperature above critical temperature stably,to make preparation for the forecast.Based on the daily mean temperature data of 53 observational stations in Liaoning during 1961 to 2010,we calculated the dates on which Liaoning spring temperatures above 5℃ and 8℃ stably.Then the spatial and temporal features of the dates on which Liaoning spring temperatures above 5℃ and 8℃ stably were analyzed.Results showed that： the first pattern of EOF showed that the abnormal of the dates are consistent;the dates of the temperature above 5℃ and 8℃ stably in spring in Liaoning Province appeared earlier and earlier during 1961 to 2010;the standard deviation of the dates are uniform;the mutation points of the dates on which Liaoning spring temperatures above 5℃ and 8℃ stably are 1981 and 1993;the cyclic characteristics of the dates on which Liaoning spring temperatures above 5℃ and 8℃ stably are 4 a and 2 a;the dates on which Liaoning spring temperatures above 5℃ and 8℃ stably showed obvious area feature.