Change of Low-level Jet in a Heavy Rainstorm Process of Xiangtan in July 2016

• 作者: Chen Si Dai Jin He Ning Lin Mingli
• 来源期刊: 气象与环境研究:英文版
• 学科: 地球科学
• 关键词: RAINSTORM Low-level JET index WIND PROFILE product Xiangtan
• 年，卷（期）: 2019,（2）
• 页码范围: 10-14
• 页数: 5页
• 分类号: P442

摘要

Based on the previous research on the model of rainstorm weather with low-level jet in Xiangtan,using the classification result of radar echo characteristics,the wind profile data provided by new generation of weather radar in Changsha and hourly rainfall data,a thorough study of the heavy rainfall from 2 to 5 July 2016 in Xiangtan was conducted. It was concluded that heavy precipitation had the characteristics of the WPSH pattern of rainstorm with low-level jet at early stage,and then it converted to cold shear jet pattern in latter stage. When low-level southwest jet began to have momentum download,that is to say,there was more than 12 m/s of southwest jet below 1 km,and it rapidly strengthened and expanded downward,it was conducive to the occurrence of short-term rainstorm. The low-level jet would not immediately cause a strong precipitation when it reached the station,with a certain lag. A positive correlation existed between the increase of low-level jet index and precipitation intensity,and low-level jet index could predict the occurrence of heavy rainfall and rain intensity.