摘要
利用江西省2002—2007年局地强对流天气过程的多普勒天气雷达产品资料,通过统计分析多普勒天气雷达最大反射率因子、垂直积分液态含水量及其密度、三体散射和中气旋等产品特征,对江西省突发性局地强对流天气的临近预报预警进行研究。结果认为,江西突发性局地强对流天气主要出现在春季和夏季,夏季突发性局地强对流风暴的伸展高度普遍比春季高。最大反射率因子≥55dBz可以作为局地强对流天气预警的临界指标,≥60dBz可以作为局地冰雹预警的临界指标;VIL密度≥2.8g/m3可以作为局地强对流天气预警的临界指标,≥3.2g/m3可以作为局地冰雹预警的临界指标,≥4.0g/m3可以作为较大冰雹预警的临界指标。三体散射是大冰雹的有效判据。风暴内出现中气旋特征,应立即发布强对流天气预警。很多突发性局地强风暴不一定会出现中气旋特征报警,在这种情况下应通过分析径向速度产品来判断中气旋特征。
Based on the statistic analysis of maximum reflectivity （DBZM）, vertical integrated liquid （VIL） and VIL density, three body scatter spike （TBSS） and mesocyclone signature （M）, the Doppler weather radar products of the emergent local convections from 2002 to 2007 in Jiangxi province are used to study the emergent local convections in Jiangxi province. The results indicate that emergent local convections mostly occur in spring and summer and they have lower tops in spring than those in summer. DBZM ≥50 dBz can be used as the threshold of local convection and DBZM ≥60 dBz as that of local hail. VIL densities ≥2.8 g/m^3, 3.2 g/m^3 and 4.0 g/m^3 can respectively indicate local convection, local hail and heavy hail. TBSS is an effective indicator for heavy hail. Severe weather warning should be issued once mesocyclone appears in the storm. Since lots of emergent local convections do not present mesocyclone warning on radar products, forecasters should estimate mesocyclone signatures using radial velocity products.
出处
《气象与减灾研究》
2008年第2期48-52,共5页
Meteorology and Disaster Reduction Research
基金
中国气象局气象新技术推广项目(编号:CMATG2008M42)
关键词
局地强对流
多普勒天气雷达
产品
特征
Local convection, Doppler weather radar, Product, Characteristic.
