一次罕见的山东半岛西部海效应暴雪过程的特征及机理研究  

Analysis on the Characteristics and Mechanism of a Rare Ocean-effect Snowstorm in the Western Shandong Peninsula

作　　者：郑怡[1] 杨成芳[1] 郭俊建[1] 张磊[1] 焦艳[2] ZHENG Yi;YANG Chengfang;GUO Junjian;ZHANG Lei;JIAO Yan(Shandong Meteorological Observatory,Ji'nan 250031,Shandong,China;North China Sea Marine Forecast Center of State Oceanic Administration,Qingdao 266061,Shandong,China)

机构地区：[1]山东省气象台,山东济南250031 [2]国家海洋局北海预报中心,山东青岛266061

出　　处：《高原气象》2019年第5期1017-1026,共10页Plateau Meteorology

基　　金：国家自然科学基金项目(41475038);环渤海区域科技协同创新基金项目(QYXM201708)

摘　　要：利用高时空分辨率MODIS和HIMAWARI-8卫星云图,多普勒天气雷达,风廓线雷达,加密自动站、浮标站及常规观测等多种观测资料,结合NCEP/NCAR逐日6 h再分析资料和ERA_Interim再分析资料,对2015年11月2526日山东半岛西部和北部海效应暴雪过程的降雪特征和形成机理进行了分析。结果表明:(1)此次过程中高空冷涡位置异常偏西偏南,对应地面等压线气旋式弯曲异常偏西,冷空气强盛,为半岛西部产生暴雪提供了有利的大尺度背景条件。(2)此次海效应暴雪过程存在多条降雪云带并有云带合并发展现象,每条云带内部可能存在多个云团(线),云带的位置和发展强度对降雪落区和降雪量具有良好的指示性。(3)对应强降雪时段,渤海海面海气温差为14℃左右,半岛西部存在不稳定层结,地面辐合线提供动力触发机制,前期水汽积累和后期强水汽辐合提供了充分的水汽条件,低层辐合区长期维持使降雪云带强烈发展并产生"列车效应",是导致此次半岛西部产生暴雪的主要原因。(4)此次暴雪过程中,山东半岛西部在能量和水汽方面优于半岛北部,且动力维持机制与半岛北部不同,其低层900 hPa以下存在西北风和偏北风的辐合。In this study,amount of available observational data were used,including satellites(MODIS and HIMAWARI-8),Doppler radar,profile radar,automatic stations,buoy stations,routine observation data,FNL atmospheric reanalysis data and ERA_Interim reanalysis data.The ocean-effect snowstorm occurring in the western and northern Shandong Peninsula during 25-26,November 2015 was diagnostically analyzed.The results are as follows:(1)In this case,the cold air was strong,the cold vortex was located westward and southward,corresponding to the surface isobaric cyclone bending anomaly,which provided a favorable large-scale background condition for the snowstorm in the western peninsula.(2)There were many snow cloud bands in the snow process,and there may be multiple cloud clusters in each cloud band.The location and development intensity of the cloud belt had a good indication for the snowfall area and amount.(3)Corresponding to the strong snowfall period,the Sea-air temperature difference was around 14℃,there were unstable stratification in the western Shandong Peninsula,the ground convergence line provided the dynamic trigger mechanism,the water vapor accumulated in the early stage and the strong water vapor convergence in the later stage provided sufficient water vapor conditions.The low level convergence area maintaining long time made the snowstorm cloud belts develop strongly and produced"train effect",which was the main cause of the blizzard in the western part of the peninsula.(4)In the course of the blizzard,the western part of the peninsula was superior to the northern part in terms of energy and water vapor,and the dynamic maintenance mechanism was different from the northern part.The convergence of the northwest wind and the northerly wind existed below 900 hPa,which can be used as a reference in the future weather forecast.

关 键 词：山东半岛西部 海效应暴雪 云带特征 动力机制 

分 类 号：P426.634[天文地球—大气科学及气象学]