2008年初呼和浩特地区持续低温、降雪成因分析

The Cause Analysis and Characteristic of Sustaining Low Temperature Snowfall at the beginning of 2008 in Hohhot

利用常规气象观测资料、以及国家气候中心的海温监测资料等,对2008年初呼市地区出现低温降雪天气的强度、范围、持续时间和灾害影响作了初步分析,并与历史同期进行了比较。分析表明:此次低温降雪天气是在近年来最严重的一次"拉尼娜"事件背景下发生的,与欧亚地区持续大气环流异常密切相关,在"北脊南槽"和西太平洋副高偏北偏强的形势下,北方冷空气不断南下,同时印度洋和孟加拉湾暖湿气流源源不断地往北到东北方向输送,冷暖气流在我国中东部地区频繁交汇,造成了我市持续低温、降雪异常偏多。

Using the conventional meteorological observation data and the sea surface temperature data of national climate centre, the intensity, range, duration, damage influence of low temperature snowfall weather at the beginning of 2008 in Hohhot were prelimi- nary analyzed, and it was compared with the contemporaneous data in history. The results showed： the occurrence of low temperature snowfall weather under the background of the most serious ＂la nina＂ events in recent years, it closely related to abnormal and contin- uous atmospheric circulation in Eurasian region. In the situation that ＂north ridge south trough＂ and west pacific subtropical high pressure are northern and strong, northern cold air go southward continuously, the warm-wet air stream of Indian Ocean and the bay of Bengal was transported northeastward continuously, the cold and warm air streams converge frequently in mid-eastern china, it caused that sustaining low temperature snowfall is abnormal more in Hohhot.