摘要
利用江苏盐城多普勒天气雷达资料结合自动气象站和常规观测资料对2007年7月25日苏北兴化等地的一次雷雨大风过程进行了分析。结果表明:风灾是由两种不同类型的雷暴大风产生的。一种是阵风锋,产生于风暴前沿,影响时地面产生7~9级大风。另一种是下击暴流,产生于多单体风暴中,其反射率因子核初始高度高于-20℃等温线高度,有中层径向辐合和反射率因子核下降的特征。影响时风暴内部下沉气流在地面强烈辐散,产生10级以上的大风。阵风锋上空有新生单体合并进原风暴,风暴发展加强;当下击暴流产生、风暴减弱后,阵风锋上又有新生单体补充进原风暴,导致下击暴流连续产生,阵风锋持续影响。
A strong rainstorm is analysis which occurred in Xinghua located the north of Jiangsu province on 25 July 2007. Results show that wind disaster originated from two kinds of rain- storm. One kind was the gust front which occurred at the front of the storm. Strong wind of grade 7- 9 was attained when it happened. Another kind was the downburst arose in the multi- cell storm. The original height of reflectivity core was higher than - 20℃ isotherm. It had the characteristics of convergence on the mid level and descending of reflectivity core. The strong wind above grade 10 was attained, when the descending airflow diverged strongly on the ground. A new cell was combined with the former storm, above the gust front, thus the storm enhanced.When the downburst happened, the storm weakened, and another new cell was combined with the former storm. The downburst happened continuously, and the impact of gust front persisted.
出处
《气象》
CSCD
北大核心
2009年第1期55-64,I0004-I0007,共14页
Meteorological Monthly