用地面加密自动观测资料对北京地区一次飑线过程的分析  

Analysis on a Typical Squall Line Case with Surface Automatic Weather Observations

作　　者：王国荣[1] 卞素芬[1] 王令[1] 李青春[2] 

机构地区：[1]北京市气象台,北京100089 [2]北京城市气象研究所,北京100089

出　　处：《气象》2010年第6期59-65,共7页Meteorological Monthly

基　　金：气象新技术推广项目(CMATG2008Z08);公益性行业(气象)科研专项(GYHY200906039);中央公益性科研院所科研业务基金项目(iumky200904)

摘　　要：利用北京地区S波段Doppler雷达和地面5分钟加密自动站资料对发生在北京地区的一次典型飑线过程进行分析。结果表明:(1)飑线影响时自动站气象要素出现风向突变、风速骤增、温度下降、气压陡升等突变;(2)降水和雷暴大风与地面涡度有很好的对应。降水发生的位置及其与正涡度区的距离的变化能预示对流单体未来的发展趋势;(3)地面水汽通量(P)能直观地反映雷暴单体的地面出流,地形辐合线以及低层水汽输送等中小尺度特征。雷暴单体地面出流造成的正水汽通量与地形引起的正水汽通量的合并以及低层的东风配合加强了山前的辐合和抬升作用,是此次过程中雷暴在山前地区得到发展并造成局地强降水以及雷暴大风的主要原因。利用地面水汽通量制作雷暴发展潜势预报有意义。A typical squall line taking place in Beijing area is analyzed with the S-band Doppler weather radar data and intensive surface AWS observations in Beijing.The results indicate that：（1） meteorological elements show abrupt changes during the influence of the squall line,such as mutation in the wind direction, surge in wind speed,drop of temperature and steep rising of pressure;（2） there is a good relationship among surface vorticity,precipitation and thunderstorm winds.The position of precipitation and the variation of the distance between precipitation and positive vorticity can be used to indicate the future trend of convective cells;（3） surface water vapor flux shows some small scale characteristics,such as suface outflow of thunderstorm,terrain convergence and low-level water vapor transport.The combination of positive water vapor flux from thunderstorm＇s outflow and terrain convergence has strengthened the convergence and lift in the front of the mountain,this is the main reason for the quickly development of thunderstorm in the front of mountain and subsequently local heavy rain and thunderstorm winds.The surface water vapor flux can be used as an indicator of the future trend for the thunderstorms.

关 键 词：加密自动站 雷暴大风 地面涡度 地面水汽通量 

分 类 号：P458[天文地球—大气科学及气象学]