气象学报2016，Vol.74Issue(6)：902-918,17.
中国冷季高架对流个例初步分析
A preliminary case study of elevated convection in China
摘要
Abstract
The criteria for elevated convection in China are proposed first based on comprehensive reviews of international and domestic publications related to elevated convection.Three elevated convection cases are then analyzed using regular upper-air and surface observations,Doppler weather radar data and the NCEP reanalysis data.Major characteristics of the environmental background,radar echo structure,and genesis mechanisms for different types of elevated convection and their common features and differences are revealed.The common features of the three cases include strong baroclinicity and large vertical wind shears, and the convection area was located on the cold side several hundred kilometers away from the surface front in all the three ca-ses.Differences among them are that,the vertical convection in the first and second cases was triggered by conditional instabili-ty coordinated with abundant water vapor and lifting,while convection in the third case was related to the slantwise convection caused by conditional symmetric instability that acted in concert with water vapor and lifting.The first case occurred in south-ern China on 27 February 2012 with a weak MUCAPE (100 J/kg)and a strong vertical wind shear within 0-6 km.Convection in this case was weak with the maximum reflectivity of around 40 -45 dBz.This case produced lightning and graupels.The second case occurred in Shandong Peninsula on 30 March 2007 with a much higher MUCAPE (1400 J/kg)compared to that of the first case and a very strong vertical wind shear (wind vector difference between 0-6 km is 32 m/s)within 0-6 km.This case generated 2-3 supercell-like storms,several strong multi-cell cluster storms,and many weak multi-cell cluster storms. The maximum reflectivity of this case was about 65-70 dBz,and hails were observed at six weather stations with the maxi-mum hail diameter of 23 mm,while wind gust up to 21 m/s was observed at one weather station.The most possible triggering mechanism for the strong elevated convection on 30 March 2007 is the trapped large-amplitude mesoscale gravity wave excited by the upstream Taishan mountains under favorable environmental conditions,i.e.a deep layer of conditional instability and strong vertical wind shears above a thick layer of low-level frontal inversion (cold stable boundary layer).This trapped large-amplitude mesoscale gravity wave also played an important role in modulating the organization pattern of the convective storms after their genesis.The third and last case is a severe snowstorm occurred on 27 January 2008 in Anhui,Jiangsu and Zhejiang provinces.The analysis shows that one of the major mechanisms for this severe snowstorm is the slantwise convection triggered by conditional symmetric instability.Several key issues are briefly discussed as well.关键词
高架对流/条件不稳定/条件对称不稳定/俘获重力波/倾斜对流Key words
Elevated convection/Conditional instability/Conditional symmetric instability/Trapped gravity wave/Slantwise convection分类
天文与地球科学引用本文复制引用
俞小鼎,周小刚,王秀明..中国冷季高架对流个例初步分析[J].气象学报,2016,74(6):902-918,17.基金项目
资助课题国家自然科学基金项目（41475042）、国家973项目（2013CB430103）、公益性行业（气象）科研专项基金（GYHY201406002）。 （）
