摘要
根据1980—2006年500 hPa天气图及地面观测资料,对河西走廊中部降雹天气总结出了两种典型环流形势,并用2005—2006年多普勒雷达产品资料分析了这两种典型天气背景场下冰雹天气反射率因子、经向速度、垂直剖面、回波顶高度、垂直液态水含量、速度方位显示风廓线等物理量的变化特征,同时对冰雹指数产品在临近预报应用中的误差进行了分析。结果表明:河西走廊中部强降雹与具有强高悬垂结构的飑线和超级单体相联系,回波顶高度、垂直液态水含量对冰雹强度和持续时间指示性好;用强冰雹指数计算的冰雹尺寸偏大,主要是由于月份不同,0℃和-20℃层高度变化较大。
According to the data of 500 hPa circulation and the surface data from 1980 to 2006, there are two types of typical environmental background of hail weather in middle part of Hexi Corridor of Gansu. Using the Doppler radar products from 2005 to 2006, the features of the hail weather are analyzed, including the base reflectivity, mean radial velocity, cross-section of reflectivity and velocity, echo top （ET）, vertically integrated liquid（VIL） and vertical wind profile, etc. At the same time, the estimation er- ror of the hail index are analyzed in near forecasting. Results indicate that the severe hail weather is relative to the high overhang structure of squall line and suppercell, the ET and VIL are well corresponding to the intensities and the time of hail strengthening or disappearing. The hail size calculated by using the strong hail index is partial to greatly, it main is because the height of 0℃ layer and --20℃ layers will be changed with the various months.
出处
《高原气象》
CSCD
北大核心
2008年第6期1343-1349,共7页
Plateau Meteorology
基金
国家自然科学基金项目(40575008)资助
关键词
冰雹
雷达回波特征
垂直液态水含量
回波顶高度
冰雹指数
Hail
Echo characteristic of Doppler top
Hail index radar
Vertically integrated liquid
Height of echo
