中亚低涡背景下中天山地区一次短时强降水过程中尺度特征  

Mesoscale characteristics of a short-time heavy rainfall under the background of the Central Asian Vortex in the middle Tianshan area

作　　者：万瑜 曹兴[3] 杨莲梅[1,4] WAN Yu1,2, CAO Xing3, YANG Lian-mei1,4(1. Xinjiang Meteorological Observatory, Urumqi 830002, China; 2. Institute of Desert Meteorology, China Meteorological Administration, Urumqi 830002, China; 3. Urumqi Meteorological Administration, Urumqi 830002, China; 4. Central Asia Research Center of Atmosphere Science, Urumqi 830002, China)

机构地区：[1]新疆气象台,新疆乌鲁木齐830002 [2]中国气象局乌鲁木齐沙漠气象研究所,新疆乌鲁木齐830002 [3]乌鲁木齐市气象局,新疆乌鲁木齐830002 [4]中亚大气科学研究中心,新疆乌鲁木齐830002

出　　处：《气象与环境学报》2018年第4期1-10,共10页Journal of Meteorology and Environment

基　　金：中国沙漠气象科学基金项目(Sqj2014010);新疆气象科研课题面上项目(MS201701);国家自然科学基金地区项目(41565003)共同资助

摘　　要：利用常规气象观测资料、区域自动气象站观测资料及卫星、多普勒天气雷达、风廓线等非常规探测资料和美国气象环境预报中心(National Centers for Environmental Prediction,NCEP)逐日4次的1°×1°再分析资料,对2015年6月27—28日中天山地区一次短时强降水过程的中尺度对流条件和对流系统特征进行分析。结果表明:此次中天山地区强降水天气过程是中亚低涡前部的东北—西南向气旋式切变和深厚的西南暖湿气流共同作用引发的,低层切变和气旋式辐合的动力抬升、地面中尺度辐合线是此次强对流天气的直接触发因子。里海和咸海南侧的水汽沿着中亚低涡底部的偏西气流和前部的西南气流输送至强降水区,为此次短时强降水过程提供了充沛的水汽条件。大气可降水量的跃变和风廓线产品的垂直变化特征与短时强降水的开始、加强及减弱具有较好的对应关系;红外云图反映了中天山地区短时强降水发生在对流云团云顶亮温(Temperature of Black Body,TBB)梯度最大处;短时强降水由低质心和高效率的降水回波造成的,降水强度与回波顶高度存在较好的正相关关系。Using the data from conventional and automatic weather stations,Doppler radar, satellite and wind-profiler radar as well as the associated NCEP（ National Centers for Environmental Prediction） reanalysis,we analyzed the convective conditions and mesoscale characteristics of a short-time heavy rainfall in the middle Tianshan area on June 27-28,2015. The results indicate that this strong convective weather process is caused by the interaction of the northeast to southwest anticyclonic shear in front of the central Asian vortex and the deep warm-wet flow coming from southwest. The direct impact systems to this process are convective instability, including the dynamic lifting condition, shear line in the lower troposphere, surface mesoscale convergence line and the cyclone type convergence center. The convergence of water vapor at the bottom of the central Asian vortex along west and that in front of the central Asian vortex along southwest attributes a favorable vapor condition to this process. Analysis shows that the abrupt variation of GPS-PWV（ Global Position System,Precipitable Water Vapor） and vertical variation of wind from wind-profiler radar have a good correspondence to the beginning, strengthening and ending of the precipitation. Satellite IR imagery shows that the short-time strong rainfall occurs at the maximum gradient area of the brightness temperature of convective clouds and is identified by the low centroid and the high-efficiency precipitation echoes. The precipitation intensity is positively correlated with the height of echo top.

关 键 词：中亚低涡 短时强降水 大气可降水量 风廓线 云顶亮温 

分 类 号：P458.2[天文地球—大气科学及气象学]