| Autor: |
Huijun HUANG, Jianmeng ZHENG, Tao MA, Wancheng ZHANG, Yu HE, Li ZHU |
| Jazyk: |
čínština |
| Rok vydání: |
2023 |
| Předmět: |
|
| Zdroj: |
Gaoyuan qixiang, Vol 42, Iss 2, Pp 403-416 (2023) |
| Druh dokumentu: |
article |
| ISSN: |
1000-0534 |
| DOI: |
10.7522/j.issn.1000-0534.2021.00114 |
| Popis: |
Based on the historical weather map of MICAPS made by China Meteorological Administration， the daily meteorological observation data from 125 stations in Yunnan Province， and ERA-interim data， the climatic characteristics of heavy rainfall processes caused by Plateau vortex shear in summer from 1991 to 2018 in Yunnan province were statistically analyzed.The main results are as follows： （1） The Plateau vortex shear affects Yunnan in summer， and heavy rain occurs 12 times a year on average.The frequency of heavy rain decreases with obvious interannual variation.There were as many as 25 cases in 1998 and the least in 2010.The Plateau vortex shear affects Yunnan most frequently in June with an average of 5 times， followed by July.（2） The plateau vortex shear can cause consistent heavy rainfall in Yunnan.From the perspective of the affected area， it is mainly distributed in the northwest Yunnan， western Yunnan， central Yunnan and east Yunnan， and the eastern part of northwest of Yunnan is also a frequent area， most of which is located in the east of Lijiang to Kunming and the vicinity of Ailao Mountain.（3） The characteristics of atmospheric circulation causing heavy in Yunnan are mainly that the western Pacific subtropical high strength is weak， the weak ridge maintains between Burma area， the plateau low vortex shear easily effects the area from the northwestern margin of Sichuan to Yunnan， the water vapor is mainly from the Bay of Bengal and some from the plateau， and convergence in Yunnan for the heavy rainfall by providing sufficient moisture.（4） The weather system of heavy rain in early August 2014 was mainly caused by the Plateau vortex shear and 700 hPa shear line.The positive helicity of the middle and lower layers is much larger than the negative helicity of the upper layers， indicating that the positive vorticity convergence and upward movement in the middle and lower layers is higher than the negative vorticity divergence in the upper layers， which provides a powerful dynamic condition for the generation of heavy rainfall.The results show that the horizontal distribution of wet helicity at 700 hPa is indicative of the heavy precipitation area caused by low vortex shear over the plateau. |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
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