Taiwan Yushan Snowfall Activity and Its Association with Atmospheric Circulation from 1979 to 2009

作     者：蔡梨敏 刘广英 王自发 

作者机构：Graduate University of the Chinese Academy of Sciences Institute of Atmospheric PhysicsChinese Academy of Sciences Graduate Institute of Earth SciencesChinese Culture University 

出 版 物：《Advances in Atmospheric Sciences》 (大气科学进展（英文版）)

年 卷 期：2011年第28卷第6期

页      面：1423-1432页

核心收录：

学科分类：07[理学] 070601[理学-气象学] 0706[理学-大气科学] 

基　　金：sponsored jointly by the National 937 Project (2010CB951804) and the Chinese Culture University 

主　　题：Yushan snowfall activity atmospheric circulation 

摘      要：Yushan is the most famous location for snow in Taiwan Willie snowIali in the subtropical zone is rare. When it is snowing in Yushan, people are experiencing unusually cold and wet weather elsewhere in Taiwan. In this study, Yushan snowfall activity from 1979 to 2009 and the related atmosphere circulation were examined with the Taiwan Central Weather Bureau＇s Yushan weather station observations and the National Centers for Environmental Prediction/Department of Energy （NCEP/DOE） reanalysis atmospheric data. To provide a quantitative measure of snowfall events, a snowfall activity index （SAI） was defined in this study. The time series of yearly SAIs shows that Yushan snowfall activity for an active year, such as 1983 （SAI =39 153） was ~118 times larger than for an inactive year, such as 1999 （SAI=331）. Our analyses show that snowfall activity is closely related to the position of the East Asian Trough （EAT） and the strength of the West Pacific High （WPH）. In active years, when the EAT shifted eastward and the strength of WPH increased, an anomalous anticyclone occurred in the West Pacific. This anticyclone introduced anomalous southwesterly flows along the southeastern cost of China s Mainland and over Taiwan, resulting in a wetter-than-normal atmosphere that favored snowfall. Alternatively, in inactive years, a drierhan-normal atmosphere resulted in sluggish snowfall seasons.