2008年安徽雪深全国之最的成因探讨

Discussion on the Causation of Depth Snow in Anhui in 2008

基于大气探测资料和雪灾评估报告,分析2008年雪情分布状况,得出安徽雪深为全国最大的事实,并从天气学、数值模式模拟方面探讨安徽雪深之最的原因。结果表明:①2008年安徽雪深较大的区域集中在大别山和江淮之间,该区域为全国积雪深度之最。②西南暖湿气流北上,北方阻塞系统稳定存在,冷暖空气在长江中下游不断交汇,水汽凝结易形成雨雪天气。水汽输送和相对湿度很大,非常有利于在安徽形成较大降雪天气。③雪、冻雨的天气学分析说明,长江以北地区易形成降雪,江南地区则易形成冻雨。④短波槽长期稳定维持在安徽附近地区,成为安徽省积雪深度最大的理由之一。⑤MM5模式模拟结果验证淮河以南地区降水较大,江南地区的降水表现为冻雨,江北地区则表现为降雪。

Based on the atmospheric detection data and evaluation report about snow disaster, the snow distribution status was analyzed. The troth that snow depth of Anhui was maximal in our country was found. The causation was discussed with weather science and simulation of numerical model. The results were as follow： the Dabieshan mountain and Jianghuai area were centralized with snow in 2008, with maximum area of snow depth all over the country, Cool and warm air from western-southern in China moved to the north.Blocking high of the north existed stably.Cool and warm air exchange in mid-lower was reached in Changjiang River. Vapor coagulated rain and snow. Vapor transportation and big relative humidity made for big snow. Weather analysis of snow and ice rain explained that snow was formed easily in the north of Changjiang River and ice rain was formed easily in the south, Short wave trough maintained stably in Anhui vicinity. It was one cause of maximum snow depth.The simulation of MM5 model validated the precipitation in the south of Huaihe River.