| 高原横切变线与高原低涡关系的初步研究 |
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| 引用本文： | 杜梅,李国平,李山山.高原横切变线与高原低涡关系的初步研究[J].大气科学,2020,44(2):269-281. |
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| 作者姓名： | 杜梅 李国平 李山山 |
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| 作者单位： | 1.成都信息工程大学大气科学学院, 成都 610225 |
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| 基金项目： | 国家重点研发计划项目 2018YFC1507200，国家自然科学基金项目 41675057、41765003、41675042 |
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| 摘 要： | 基于大气运动方程组及散度方程,对高原横切变线上扰动稳定性问题以及切变线诱发高原低涡的动力学机制进行了理论分析并用欧洲中心(ECMWF)ERA-interim再分析资料对其进行验证。得出高原横切变线是高原低涡产生的重要背景场,切变线以南的水汽输送与辐合对于低涡的诱发作用是大气处于不平衡状态而引起散度场调整的结果,辐合增强区有利于高原低涡生成,低涡中心对应非平衡正值中心,低涡外围为非平衡项负值区。非平衡项负值大值与水汽辐合带的重叠区对降水落区有较好的指示意义。当高原南部的西南风带向东或东北方向移动或当低涡下游出现非平衡项负值中心时,低涡亦同向移动。若高原出现气旋式环流并且环流中心与非平衡项正值中心对应时,有利于低涡生成;进一步,当低涡中心与非平衡项正值中心对应且正值中心数值不断增大时,低涡趋于发展加强。
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| 关 键 词： | 高原切变线 扰动不稳定 高原低涡 水汽辐合 非平衡项 |
| 收稿时间： | 2018/8/9 0:00:00 |
| 修稿时间： | 2019/9/29 0:00:00 |
A Preliminary Study of the Relationship between the Plateau Transverse Shear Line and Plateau Vortex |
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| DU Mei,LI Guoping and LI Shanshan.A Preliminary Study of the Relationship between the Plateau Transverse Shear Line and Plateau Vortex[J].Chinese Journal of Atmospheric Sciences,2020,44(2):269-281. |
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| Authors: | DU Mei LI Guoping and LI Shanshan |
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| Institution: | 1.School of Atmospheric Sciences, Chengdu University of Information Technology, Chengdu 6102252.School of Atmospheric Sciences, Chengdu University of Information Technology, Chengdu 610225;Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters, Nanjing 2100443.Institute of Heavy Rain, Wuhan, China Meteorological Administration, Wuhan 430205 |
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| Abstract: | Based on atmospheric motion equations and a divergence equation, in this paper, we analyze and discuss the stability of the disturbance in the dynamic mechanism of the Tibetan Plateau vortex (TPV) induced by the transverse shear line (TSL) over the Tibetan Plateau (TP), which we then verify using ERA-interim reanalysis data. Based on our results, we conclude that the TSL is an important background field of the TPV. The TPV is induced by the transport of water vapor located south of the TSL and is associated with the adjustment of the divergence field caused by an imbalance in the atmosphere. This is favorable for the formation of a TPV in which the convergence is enhanced, with the center of the TPV corresponding to the positive center of the unbalanced aspects and the periphery of the TPV with the negative area of the imbalanced aspects. The area with a large negative value of unbalanced aspects coincides with vapor convergence, which can indicate the location of precipitation. When the southwest winds increase and move toward the east or northeast, or when there is a negative center area of unbalanced aspects downstream of the TPV, the vortex moves in the same direction. If there is a cyclonic circulation in the TP and the center of the cyclonic circulation corresponds to the positive center of the unbalanced aspects, this is conducive to the formation of the TPV. Furthermore, when the center of the vortex corresponds to the positive center of the unbalanced aspects, and this value continuously increases, this is also favorable for the development of the TPV. |
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| Keywords: | Plateau shear line Unstable perturbation Plateau vortex Vapor convergence Unbalanced aspects |
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