锡林郭勒盟大雪、暴雪天气气候特征及分型

利用1971—2010年内蒙古锡林郭勒盟15个地面气象观测站基本资料和常规观测资料,综合分析出了大雪天气的主要特征。结果表明:(1)40a大雪、暴雪日数由东南向西北逐渐减少。(2)10a大雪、暴雪平均日数呈波动变化的特点,纯雪的大雪、暴雪日数20世纪80年代和21世纪10年代整体偏少于20世纪70和90年代,且近20a出现降雪集中出现和不出现大雪的年份;含雨夹雪的大雪日数则是20世纪70年代和21世纪10年代整体多于20世纪八九十年代,暴雪日数则随年代逐渐减少。(3)大雪、暴雪(纯雪)出现在9月至次年5月,3月最多,全年在3月和10月存在两个峰值。而含雨夹雪的大雪、暴雪10月份出现最多,其次是4月。(4)综合分析2000年以来的24次大雪、暴雪(纯雪)过程,可把锡盟的降雪天气系统分为5类。

Analysis on Climate Characteristics and Types of Heavy Snow and Snowstorm in Xilin Gol League in Inner Mongolia

The main characteristics of heavy snow and snowstorm were comprehensively analyzed , using basic data at 15 meteorological stations and conventional observations data from 1971 to 2010. The results showed that： （1）The days of the heavy snow and snowstorm were decreased from southeast to northwest in the past 40 years.（2）The days of the pure heavy snow and snowstorm were fluctuated each decade, and it was less than the normal in the 80＇s and the recent ten years of the 21st century. But also , the days of the heavy snow were con- centrated emerged in some years and did not occur in the others between the past 20 years. And the sleet days were more in the 70＇s and the recent ten years of the 21st century. Blizzard days were gradually reduced with years. （3）The pure heavy snow and snowstorm occurred from September to May of the following year, most in March, and there were two peaks in March and October. The sleet occurred mostly in October, next in April. （4） Base on the comprehensive analysis of the 24 weather processes, the weather systems of snowfall could be divided into 5 categories in Xilin Gol league.