ISSN 1000-0526
CN 11-2282/P
CN 11-2282/P
Archive > Volume 46 Issue 10 > 2020,46(10):1362-1374. DOI:10.7519/j.issn.1000-0526.2020.10.010 Prev Next
Radar Echo Characteristics of an MesoAnticyclonic Supercell of Sichuan in August 2016
- Article
- Figures
- Metrics
- Preview PDF
- Reference
- Related
- Cited by
- Materials
Abstract:
The formation and evolution of the supercell that happened in Chengdu on 7 August 2016 were discussed. Based on Chengdu Doppler Weather Radar， windprofiling radar， and densely laidout automatic station observation， the contributing factors of the mesoanticyclone were studied in this paper. The results are as follows. The mesoanticyclonic supercell was formed under the northerly airflow in the west of the upper cold vortex, with strong cold advection in middle and upper levels. The convective instability energy (CAPE) reached 5 〖KG-*5〗029.7 J·kg-1, the temperature difference between 500 hPa and 850 hPa was 29℃, and the wind shear vector difference between 500 hPa and 925 hPa was about 16 m·s-1. The sounding as a whole took on the shape of a bell mouth, in which the upper level was dry and cold while the lower level was warm and wet. The existence of lowerlevel inversion was conducive to energy accumulation. Thunderstorms were triggered by westward winds under the forced uplift of Longquan Mountains, while downward flow produced cold outflow and triggered new cells continuously on the north side.Thunderstorms and new cells merged into supercell. The mesoanticyclonic supercell storm was accompanied by the echo characteristics such as lowlevel strong convergence, mesoanticyclone, rear inflow, rear inflow gap, vortex couple, etc. The formation of mesoanticyclone in S1 supercell storm was formed via merging the lower and middle levels. For lowlevel mesoanticyclones, small eddies were generated when thunderstorm and cells merged. The baroclinic vorticity was caused by the intrusion of dry cold air and warm wet updraft, which caused convergence to rotate. Thunderstorm developed strongly under strong convergence, and strong upward motion caused vertical vorticity to stretch, increasing rotation. For midlevel mesoanticyclones, the horizontal vorticity in the height range of 3-4 km was about 1.2×10-2 s-1, which was beneficial to the formation of horizontal vortex tubes. Vortex couples were generated under the strong updraft and downward airflow. The anticyclones were developed by counterclockwise rotation of midlevel and highlevel winds.
Keywords:
Project Supported:
Clc Number:
Mobile website
