ISSN 1000-0526
CN 11-2282/P
CN 11-2282/P
Archive > Volume 47 Issue 4 > 2021,47(4):450-462. DOI:10.7519/j.issn.1000-0526.2021.04.006 Prev Next
Radar Echo Characteristics of Short-Time Severe Rainfall in the Periphery of Subtropical High in Yunnan Province
- Article
- Figures
- Metrics
- Preview PDF
- Reference
- Related
- Cited by
- Materials
Abstract:
Based on the data of effective short-time severe rainfall at 219 national stations and from 7 Doppler weather radars in Yunnan Province from May to October in 2014-2016, the short-time severe rainfall in the periphery of the subtropical high in Yunnan is further subdivided into three categories, including the Qinghai-Tibet high and western Pacific subtropical high convergence category, simple periphery of the subtropical high category and the west side of subtropical high with westerly trough category. The conclusions are as follows. August is the high incidence period of short-time severe rainfall in the periphery of the subtropical high in Yunnan Province, and the precipitation period is concentrated in the afternoon and the first half of the night. The Qinghai-Tibet high and western Pacific subtropical high convergence precipitation distributes along the convergence area, with high intensity and relatively concentrated falling area. The simple periphery of the subtropical high precipitation is mainly located in southern Yunnan, manifested as three large-value zones. The west side of subtropical high with westerly trough precipitation is mainly located at the edge of Yunnan with scattered falling areas. The average intensity of the three types of precipitation echoes is between 35 dBz and 45 dBz with average duration of 9 volume scans. Nearly a quarter of the echoes have inclination and strong echo gradients, and the precipitation is obviously heavier than the echo which does not appear. In a way that can be used as a basis for judging the intensity of precipitation. The occurrence time of the strongest ET and VIL of the three types of precipitation is basically at the same time as that of the strongest echo, or slightly lagged behind. Nearly half of the Qinghai-Tibet high and western Pacific subtropical high convergence VWPs have southwesterly or westerly airflows in the lower layer, which corresponds to the obvious characteristics of warm advection. With the development of precipitation, the disappearance of no-data area corresponding to the clear sky area around the subtropical high is the most obvious feature of VWPs of precipitation in the simple periphery of the subtropical high. For the west side of subtropical high with westerly trough category, whether precipitation begins or not, invasion of upper northwest airflow and middle-level wind shear both exist, corresponding to the cold advection brought by the rear of the low trough and the intersection of warm and cold air currents.
Keywords:
Project Supported:
Clc Number:
Mobile website
