Severe Disaster of Blizzard,Freezing Rain and Low Temperature in January 2008 in China and Its Association with the Anomalies of East Asian Monsoon System
Severe Disaster of Blizzard,Freezing Rain and Low Temperature in January 2008 in China and Its Association with the Anomalies of East Asian Monsoon System
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发表时间：
2008
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通讯作者：
Wei Ke
中科院分区：
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作者：
Wei Ke
由于二零零八年一月中国发生的暴雪，冻雨，低温造成的经济损失严重，利用NCEP/本文利用NCAR再分析资料和中国各站观测资料，分析了与东亚季风系统各分量有关的异常，结果表明：乌拉尔阻塞的发展和维持，对东亚季风系统的发展和维持起着重要的作用中高纬度乌拉尔地区长时间高压使东亚大槽处于稳定状态，导致冷空气沿蒙古高原沿着向华中、华东、华南地区持续南下，同时西太平洋副热带高压进一步北移、向西移，这种环流结构导致大量的湿空气沿着副热带高压西缘从孟加拉湾向北输送，并与长江流域的冷空气汇合，从而导致了强降水的持续发生分析结果进一步表明，拉尼娜事件对我国冬季气候异常的影响不能很好地解释此次灾害的发生，热带西太平洋和西北大西洋海温异常对乌拉尔阻塞高压和西太平洋副热带高压位置的影响是重要的，此外，还讨论了准定常行星波活动的影响，即在北方半球低纬地区中高纬向对流层上层传播的加强，以及平流层极涡向下传播所表现出的平流层环流的影响也可能增加东亚地区的环流异常。
Due to the severity of the economic losses caused by the blizzard,freezing rain and low temperature occurred in China in January 2008,the causes and mechanism of this disaster are studied using the NCEP/NCAR reanalysis and station observational datasets in China.The authors analyzed the anomalies which are associated to the components of the East Asian monsoon system.The results show that the development and maintenance of the Ural Blocking High over the Ural area in mid and high latitudes for anomalously long time caused the East Asian trough to stay in a stable state,which led to the continuous southward intrusion of cold air along the Mongolian Plateau to Central China,East China and South China.Meanwhile,the western Pacific Subtropical High shifted further northward and westward,which led to the northward transports of a large amount of wet air along the west edge of the Subtropical High from the Bay of Bengal and the convergence with cold air in the Yangtze River valley.The above circulation configuration led to the prolonged occurrence of heavy snowfall and low temperature.Moreover,the results further show that the occurrence of this disaster can not be explained well by the influence of the La Nia event on wintertime climate anomalies in China.The sea surface temperature anomalies(SSTA) in the tropical western Pacific and Northwest Atlantic Ocean are important because of their influences on the Ural Blocking High and the position of western Pacific Subtropical High,respectively.Besides,we discussed the influence of quasi-stationary planetary wave activities,which shows intensification of propagation from mid and high latitudes toward the upper troposphere over low latitudes of the Northern Hemisphere.The influence from the stratospheric circulation,which is presented by downward propagation of strong stratospheric polar vortex,may also add to the circulation anomalies in East Asia.