A preliminary investigation on causes of the catastrophic snowstorm in March,2007 in the northeastern parts of China
A preliminary investigation on causes of the catastrophic snowstorm in March,2007 in the northeastern parts of China
复制标题
作者：
Yuan Wei
2007年3月3-5日，一场暴雪给中国东北部地区带来了创纪录的降雪，造成了严重的灾害和巨大的损失。本文通过分析此次雪灾前后的大气环流异常，探讨了这次雪灾的可能机制。结果表明，雪灾发生前两周左右，出现了持续的北极强异常振荡、南极振荡、欧亚遥相关型和北太平洋振荡。这些异常的大气环流激发了中国东部沿海地区的强异常南风，持续地将暖湿空气输送到中国东北部，当3月上旬大气环流发生变化时，来自高纬度的强冷空气在中国东北部与暖空气相遇，导致该地区出现显著冷锋，并伴随着强降雪和低温天气。研究结果表明，应充分考虑预报区域前期大气环流异常和累积水汽状况，有助于改进降水预报，特别是强降水预报。
A snowstorm deposited record-breaking snowfall over the northeastern parts of China on March 3-5,2007,resulting in severe disasters and heavy losses.The objective of this study is to explore the possible mechanism responsible for this extreme event by analyzing the atmospheric circulation anomalies prior to and during the event.The results show that there had been persistent strong anomalous Arctic Oscillations,Antarctic Oscillations,Eurasian teleconnection pattern,and North Pacific Oscillations in about two weeks before the event.Those anomalous atmospheric circulations stimulated the strong anomalous southerlies along the east coastal regions of China,which persistently transferred the warm and wet air to the northeastern areas of China,thus raising the moisture content and air temperature there and providing proper warm and wet conditions for the occurrence of the extreme snowstorm event.When the atmospheric general circulation changed in early March,the strong cold air from the high latitudes met the warm air over the northeastern China,resulting in a remarkably cold front and associated strong snowfall and low temperature in that region.The results of this study imply that the anomalous atmospheric circulation and the cumulative moisture condition in the forecast region in the early stage should be fully considered,which is helpful to the improvement of rainfall forecast,especially the heavy rainfall forecast.