大气和海洋科学快报（英文版）2021，Vol.14Issue(2)：13-20,8.
东北一次雪飑事件的触发机制研究
Trigger mechanism of a snow burst event in Northeast China
摘要
Abstract
A snow burst event characterized by brief heavy snowfall affected Northeast China and caused serious social im-pact on 26 January 2017,with the snowband generally aligned with a northeast-southwest-oriented cold front.ECMWF reanalysis data were used to diagnose the possible trigger mechanism.Results showed there were two stages:(a)an initial stage far away from the Changbai Mountains,and(b)an enhancement stage under the influ-ence of high terrain.During the initial stage,the coupling of low-level frontogenesis and a favorable convergence pattern caused strong upward motion,contributing to the release of instability.When the snowband approached the high terrain during the enhancement stage,the various instabilities were triggered by the low-level frontoge-nesis,terrain circulation,and strong wind shear associated with the low-level jet.Further,a modified Q-vector divergence including generalized potential temperature was calculated to diagnose the vertical motion.It showed that the frontogenesis terms contributed greatly to the negative Q-vector divergence along the moist isentropes,while the pseudo-vorticity terms played a role in the regions with strong wind shear associated with the low-level jet in the warm section,suggesting both were important in stimulating the ascending motion.The regions with negative Q-vector divergence had a close relationship with the vertical structure of convection,indicating the potential to track the development of the snowband in the next few hours.关键词
雪飑/锋生/Q矢量Key words
Snow burst/Frontogenesis/Q-vector引用本文复制引用
Baofeng Jiao,Lingkun Ran,Xinyong Shen,Yanbin Qi..东北一次雪飑事件的触发机制研究[J].大气和海洋科学快报（英文版）,2021,14(2):13-20,8.基金项目
This study was supported by the Strategic Priority Research Pro-gram of the Chinese Academy of Sciences[grant numbers XDA17010105 and XDA20100304],the National Key Research and Development Pro-gram[grant numbers 2018YFC1507104 and 2019YFC1510400],the Key Projects of Jilin Province Science and Technology Development Plan[grant numbers 20180201035SF],and the National Natural Sci-ence Foundation of China[grant numbers 41775140 and 41790471]. （）
