1961-2009年宁夏大到暴雪气候特征和变化规律

Characteristics and Variation of Heavy Snow in Ningxia Region in 1961-2009

选取宁夏20个气象观测站的天气现象和降水量观测资料,运用合成、Le Page检测、Mexihat小波变换和最大熵谱法,分析了宁夏大到暴雪发生次数的气候特征和年际、年代际的变化规律及其突变和周期.结果表明:宁夏大到暴雪多发生在春季和秋季,南多北少地域特征明显,15mm以下大到暴雪出现频次高,年际、年代际的变化特征明显,连续偏少年持续时间长,多发期具有明显突变特征,具有多时间尺度显著周期.

Selecting the weather phenomenon and precipitation recorded in 20 stations in Ningxia Region and using the methods of composition,Le page test,Mexihat wavelet transform and maximum entropy spectrum,an analysis of climate characteristics,annual and decade variations,abrupt change and period of heavy snow frequency in Ningxia Region was conducted.The result shows that most heavy snow occurs in spring and autumn.It is obvious that the frequency of heavy snow in southern Ningxia Region is more than that in northern Ningxia Region.The heavy snow in Ningxia Region with the precipitation less than 15 mm has high frequency,together with visible features of annual and decade variations,longer duration of continuous little heavy snow years,abrupt change in the frequent occurring phase and multiple time scale cycles.