一次基于综合探测资料的山东半岛冷流暴雪特征分析  

Characteristics Analysis on a Snowstorm in Shandong Peninsula by Using Multiple Observation Data

作　　者：周淑玲 王科[2] 杨成芳[3] 周艺 ZHOU Shuling WANG Ke YANG Chengfang ZHOU Yi(Weihai Meteorological Office of Shandong, Weihai 264200 Nanjing University of Information Science and Technology, Nanjing 210044 Shandong Meteorological Observatory, Jinan 250031)

机构地区：[1]威海市气象局,威海264200 [2]南京信息工程大学,南京210044 [3]山东省气象台,济南250031

出　　处：《气象》2016年第10期1213-1222,共10页Meteorological Monthly

基　　金：中国气象局预报员专项(CMAYBY2015-041);国家自然科学基金项目(41175044和41475038);山东省气象局预报员专项(SDYBY2014-06)共同资助

摘　　要：利用多普勒天气雷达、风廓线雷达、加密自动站、浮标站、常规探空和地面等多种观测资料,对2014年12月山东半岛东部一次冷流暴雪的发生、演变特征进行了分析。结果表明:(1)此次冷流暴雪发生时渤海上空500 hPa气温在-36℃左右,850 hPa气温在-18^-16℃,海面西北风>12 m·s^(-1)。700 hPa以下为混合层,1000~700 hPa混合层内近乎饱和。浮标站资料显示海表面到850 hPa的较大海气温差和山东半岛较强海岸锋是产生暴雪的重要原因。(2)暴雪发生时雷达回波的PPI在30~45 dBz;每6 min雷达回波垂直剖面显示1个较强降雪回波单体持续时间可达到1h。雷达资料反演0.8 km以上风场表明:强降雪回波位于NE与NW风辐合区的东侧,冷流暴雪的水平风辐合主要在3 km以下。风廓线雷达资料表明:暴雪发生前在100m以下有弱西风存在,暴雪发生时1 50~700 m弱的西北风(<6 m·s^(-1))和低层切变线辐合的共同存在,有利于降雪对流的加强;当这种弱西北风层消失后,降雪即停止。Using multiple data of Doppler weather radar, wind-profiling radar, automatic station, buoy sta- tion, conventional sounding and surface observation, the characteristics of occurrence and evolution of one snowstorm event in the east of Shandong Peninsula in December 2014 are analyzed. The results show that firstly, over the Bohai Sea, the 500 hPa temperature is --36℃ or so, the 850 hPa temperature is in the range of --18-16℃, the direction of the Bohai Sea surface wind is northwest and its velocity is more than 12 m ·s^-1 when the snowstorm occurred. The conventional sounding data show that the mixing layer is below 700 hPa and the atmosphere in the 1000--700 hPa mixing layer is almost saturated. The buoy sta- tion shows that the larger air-sea temperature difference bewteen the Bohai Sea surface and 850 hPa, and the stronger coastal front in Shandong Peninsula are the critical causes for the snowstorm. Secondly, dur- ing the snowstorm, the radar reflectivity is between 30 and 45 dBz. The analysis on the radar echo vertical section of the re{lectivity every 6 min reveals that a strong snow echo cell can maintain for one hour. The velocity of Doppler data shows that the distribution of heavy snow cells occurs in the east area of the conve- rsence zone between NE and NW winds. The horizontal wind convergence of cold-flow snowstorm mainly exists below 3 km. The wind profile radar data show that there is a low-level western breeze under 100 m before the formation of the snowband. The existence of weak northwestern wind in 150--700 m height and the convergence of low-level shear line are beneficial to strengthening the convection of snowstorm. When such weak northwestern wind layer disappears, the snowstorm ends.

关 键 词：山东半岛冷流暴雪 中尺度特征 综合探测资料 多普勒雷达反演风场 

分 类 号：P458[天文地球—大气科学及气象学]