2008年雪灾同平流层环流异常的关系

Relationship between stratospheric circulation anomalies and extended snow storm

为了探讨2008年我国南方罕见的低温、雨雪和冰冻灾害与平流层环流异常的关系,利用NCEP资料对2007年10月1日到2008年2月29日的平流层大气环流的逐日变化进行了分析.结果表明,这次低温、雨雪和冰冻灾害之前,平流层北极涡旋异常加强和变形,同时在中低纬地区平流层的环流也发生明显的变化.这些变化从平流层向下传,进而影响对流层.由此可见这次我国历史罕见的低温、雨雪和冰冻灾害不但与对流层大气环流的变化有关,也与平流层环流的变化有关.更有意义的是,平流层环流的变化超前了一个多月.因此利用平流层的信息作为天气预报的参考,对提高中长期天气预报(特别是重大灾害的预报)的准确率会起到积极的作用.

In order to investigate the relationship between the stratospheric circulation anomaly and the exceptionally serious snow storms which occurred in the southern part of China in 2008, the variation of the atmospheric circulation in the stratosphere from October, 2007 to February, 2008 was analyzed using NCEP data. The results show that before the occurrence of the snow storms the stratospheric north polar vortex abnormally strengthened and deformed, and the stratospheric circulation in the middle-lower latitudes changed significantly. These anomalies propagated downward and affected the troposphere. This means that the snow storms were connected not only with the changes of the tropospheric circulation, but also with the changes of the stratospheric circulation. Meaningfully, the changes of the stratospheric circulation were more than a month ahead of the snow storms. Therefore information of the stratospheric circulation is very conducive to improving the middle and long term weather forecast, especially the forecast of serious meteorological calamities.