2008年贵州省持续性雨凇过程气候成因分析

Climatic Factor Analysis of the Continuous Glaze Process in Guizhou Province in 2008

2008年初中国南方低温雨雪冰冻过程中贵州出现长时间持续性雨凇。该文使用2008年1-2月逐日要素、环流、海温等资料对此次贵州省雨凇过程特征,大气环流、海温和海冰等气候因子及其影响进行分析,得到以下结论:(1)2008年初贵州的持续性雨凇过程主要分两个阶段:1月13日-2月2日东西向的省中部大范围强雨凇阶段及2月3日-2月15日南北向的省西部小范围强度相对较弱的雨凇阶段;(2)0℃日最高气温是雨凇出现与否的重要临界点;700 hPa与850 hPa温度差表征的逆温范围和强度可用于监测和预测强雨凇过程;(3)环流上,南掉到青藏高原西侧的切断低涡堆积的冷空气分南北两路绕过青藏高原东移,是此次持续性雨凇过程的直接原因;(4)秋季北极海冰密集度减少和减少幅度是冬季西伯利亚高压偏强、强冷空气堆积南下的前期主要信号,可作为贵州雨凇预测的早期信号之一;(5)2008年1月热带印度洋暖海温与赤道中东太平洋明显冷海温呈现非一致性变化,冬季热带印度洋暖海温通过二级热力适应对西太平洋副热带高压起到加强的作用,而拉尼娜冷海温对东亚冬季风起到偏强的影响,应当关注这两个区域冬季海温非协同性变化对贵州雨凇的影响和预测。

In early 2008,continuous glaze appeared in Guizhou during the freezing process of low temperature rain and snow in south China.In this paper,day-by-day elements,circulation,SST and other data from January to February 2008 were used to analyze the characteristics of glaze process,atmospheric circulation,SST,sea ice and other climate factors and their influences in Guizhou Province,and the following conclusions were drawn:①The daily maximum temperature of 0℃is a key point to freezing rain in Guizhou province.②The range and intensity of temperature inversion layer can be used as a circulation indicator of glaze disaster.③In the circulation,the cold air accumulated with the cut off low vortex flows around the Qinghai Tibet Plateau in two ways:North and south,which is the direct cause of the continuous glaze process.④The decrease and its extent of arctic sea ice density in autumn is one of the main early signals of the Siberian high and the strong cold air in winter.5)In January 2008,the warm SST of the tropical Indian Ocean and the cold SST of the equatorial Middle East Pacific Ocean presented inconsistent changes.In winter,the warm SST in the tropical Indian Ocean strengthened the subtropical high in the western Pacific through the secondary heat adaptation,while the cold SST in La Nina had a strong influence on the East Asian winter monsoon.We should pay attention to the influence and prediction of winter SST non-synergistic changes on glaze in Guizhou.