南方地区低温雨雪事件的时空分布和成因研究

Temporal and Spatial Distribution of Southern Snow Events and Causes Study

选用1961-2011 年中国南方地区降水、气温和ERA-Intemn再分析资料,采用旋转EOF 方法,对发生低温雨雪的台站进行分析,发现南方地区的低温雨雪天气可大致划分为4 个区域.筛选出1 月4 个典型低温多雨雪年和高温少雨雪年,将高度场进行滤波,滤出2. 5 -6 天的天气尺度瞬变波动部分来研究我国南方地区持续性低温雨雪天气与天气尺度瞬变扰动的关系.发现大西洋上空强天气尺度瞬变扰动在欧亚大陆以波列的形势向下游传播,在频发年,瞬变扰动的强度较少发年强,且较少发年有更多的扰动波列东传;波动能量的向东频散为下游的槽脊活动提供了源源不断的能量,有利南方地区大气斜压不稳定维持和持续低温雨雪天气的维持.

Based on the data of Precipitation and temperature in South China and the reanalysis data of ERA-Inrerim,we analyzed the stations which snow occurrence with the method of rotating EOF,and found that south China can be roughly divided into 4 areas. We selected 4 typical cold and rainy years and less snow years at high temperature of January and filtered the height field. Wefilterde out 2. 5 days of synoptic scale transient fluctuation part to study the relationship between the continued South China area of low temperature,rain,snow and weather and synoptic scale transient disturbance. And found that over the Atlantic strong transient eddies in Eurasia to wave the situation to the downstream transmission. In the year of frequent,less intensity of the transient disturbance of strong,and less hair years have more disturbance Boliedong. Wave energy to the east the frequency dispersion for downstream trough and ridge activity provides a steady stream of energy,favorable to the south area baroclinic instability maintain and continue to maintain low temperature,rain,snow and weather.