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A semi-idealized modeling study on the long-lived eastward propagating mesoscale convective system over the Tibetan Plateau

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Science China Earth Sciences 2021年第11期64卷 1996-2014页

作者： Shenming FU Zi MAI Jianhua SUN Wanli LI Qi ZHONG Jiaren SUN Yuanchun ZHANG International Center for Climate and Environment Sciences Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China Heavy Rain and Drought-Flood Disasters in Plateau and Basin Key Laboratory of Sichuan Province Chengdu 610225China National Meteorological Center of China Meteorological Administration Beijing 100081China Key Laboratory of Cloud-Precipitation Physics and Severe Storms Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China China Meteorological Administration Training Center Beijing 100081China Key Laboratory of Urban Ecological Environmental Simulation and Protection of Ministry of Environmental Protection South China Institute of Environmental Sciencesthe Ministry of Environmental Protection of ChinaGuangzhou 501530China

Based on a 16-warm-season statistical study on the mesoscale convective systems(MCSs)that were generated over the Tibetan Plateau(TP),11 long-lived eastward propagating MCSs of the same type were selected for a composite semiidealized simulation and a corresponding no-latent-heating sensitivity run by using the Weather Research and Forecasting(WRF)*** evolutionary features and associated mechanisms of this type of long-lived eastward propagating MCS were *** results are as follows:(i)This type of MCS was generated in a favorable background environment which was characterized by a notable upper-tropospheric divergence south of an upper-level jet,a strong warm advection around a middle-level shortwave trough’s central area,and an instable convective stratification below the *** of the MCS featured rapid increase of cyclonic vorticity in the middle and lower *** convergence-related vertical stretching and tilting were key factors for the cyclonic-vorticity’s production,and convection-related upward cyclonic-vorticity transport contributed to the upward extending of the MCS.(ii)During the vacating stage of the MCS,it first coupled with a quasistationary Tibetan Plateau vortex(TPV)over the TP’s eastern section,and then decoupled from the *** the former stage,the MCS contributed to maintaining ascending motions and convergence associated with the TPV,which favored its persistence;whereas,in the latter stage,decoupling weakened the TPV-associated convection *** reduced the upward transport of cyclonic vorticity notably,which,together with the negative tilting effect,finally led to the vortex’s dissipation.(iii)After vacating TP,the MCS first weakened due to the disappearance of strong direct sensible heating from the TP on its bottom,and then,under the favorable conditions associated with the shortwave trough over the eastern section of the TP,the MCS redeveloped ***-related cyclonic-vor

关键词： Tibetan Plateau Mesoscale convective system Tibetan Plateau vortex Heavy rainfall vorticity budget Sensitivity simulation

A Study on a Heavy Rainfall Event Triggered by an Inverted Typhoon Trough in Shandong Province

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Acta meteorologica Sinica 2009年第4期23卷 468-484页

作者：赵宇崔晓鹏王建国 Nanjing University of Information Science & Technology Laboratory of Cloud-Precipitation Physics and Severe Storms Institute of Atmospheric Physics Chinese Academy of Sciences Henan Provincial Meteorological Bureau

A heavy rainfall event that occurred in Shandong Province in 26 28 August 2004 was caused mainly by Typhoon Acre and cold air activities related to a westerly trough. The event was triggered by an inverted typhoon trough, which was closely associated with the intensification of the low-level southeasterly flow and the northward transport of heat and momentum in the periphery of the typhoon low. A numerical simulation of this event is performed using the nonhydrostatic mesoscale model MM5 with two-way interactive and triply-nested grids, and the structure of the inverted typhoon trough is studied. Furthermore, the formation and development mechanism of the inverted typhoon trough and a mesoscale vortex are discussed through a vorticity budget analysis. The results show that the heavy rainfall was induced by the strong convergence between the strong and weak winds within the inverted typhoon trough. Dynamic effects of the low-level jet and the diabatic heating of precipitation played an important role in the development of the inverted typhoon trough and the formation of the mesoscale vortex. The vorticity budget analysis suggests that the divergence term in the low troposphere, the horizontal advection term, and the convection term in the middle troposphere were main contributors to positive vorticity. Nonetheless, at the same pressure level, the effect of the divergence term and that of the adveetion term were opposite to each other. In the middle troposphere, the vertical transport term made a positive contribution while the tilting term made a negative contribution, and the total vorticity tendency was the net result of their counteractions. It is found that the change tendency of the relative vorticity was not uniform horizontally. A strong positive vorticity tendency occurred in the southeast of the mesoscale vortex, which is why the heavy rainfall was concentrated there. The increase of positive vorticity in the low （upper） troposphere was caused by horizontal

关键词： heavy rainfall event landing typhoon inverted typhoon trough vorticity budget

A Numerical Study of the Evolution of a Mesoscale Convective Vortex on the Meiyu Front

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Acta meteorologica Sinica 2013年第6期27卷 889-909页

作者：王金鑫潘益农王石成 School of Atmospheric Sciences Nanjing UniversityKey Laboratory for Mesoscale Severe Weather/Ministry of Education Lianyungang Meteorological Bureau

The Advanced Research WRF（Weather Research and Forecasting） model is used to simulate the evolution of a mesoscale convective vortex（MCV） that formed on the Meiyu front and lasted for more than two days. The simulation is used to investigate the underlying reasons for the genesis, intensification, and vertical expansion of the MCV. This MCV is of a type of mid-level MCV that often develops in the stratiform regions of mesoscale convective systems. The vortex strengthened and reached its maximum intensity and vertical extent（from the surface to upper levels） when secondary organized convection developed within the mid-level circulation. The factors controling the evolution of the kinetic and thermal structure of the MCV are examined through an analysis of the budgets of vorticity, temperature, and energy. The evolution of the local Rossby radius of deformation reveals the interrelated nature of the MCV and its parent mesoscale convective system.

关键词： mesoscale convective vortex vorticity budget temperature budget energy budget Rossby deformation radius

Comparison of two types of persistent heavy rainfall events during sixteen warm seasons in the Sichuan Basin

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Atmospheric and Oceanic Science Letters 2021年第6期14卷 48-53页

作者： Yuanchun Zhang Jianhua Sun Luqi Zhu Huan Tang Shuanglong Jin Xiaolin Liu Key Laboratory of Cloud-Precipitation Physics and Severe Storms(LACS) Institute of Atmospheric PhysicsChinese Academy of SciencesBeijingChina College of Atmospheric Sciences Lanzhou UniversityLanzhouChina State Key Laboratory of Operation and Control of Renewable Energy&Storage Systems China Electric Power Research InstituteBeijingChina Electric Power Meteorology State Grid Corporation Joint Laboratory(CEPRI) BeijingChina

Based on hourly precipitation from national surface stations,persistent heavy rainfall events(PHREs)over the Sichuan Basin(SCB)are explored during the warm season(May to September)from 2000 to 2015 to compare synoptic circulations and maintenance mechanisms between different PHRE *** are two main types of PHREs:one is characterized by a rain belt west of 106°E over the SCB(WSB-PHREs),and the other features a rain belt east of 106°E over the SCB(ESB-PHREs).In total,there are 18 ESB-PHREs and 10 WSB-PHREs during the study ***,the rain belts of WSB-PHREs are along the terrain distribution east of the Tibetan Plateau,while the precipitation intensity of ESB-PHREs is *** the two types of PHREs,the shortwave trough over the SCB and the western Pacific subtropical high act as their favorable background environments,particularly for *** water vapor of WSB-PHREs is mainly transported from the South China Sea,whereas for ESB-PHREs the South China Sea and Bay of Bengal are their main moisture *** composite vorticity budgets of southwest vortices during their mature stage indicate that the convergence effect is a dominant factor for maintaining the two types of PHREs,and the strong vertical vorticity advection is also favorable,but the relative contribution of vertical advection is larger for WSB-PHREs.

关键词： Southwest vortex Persistent heavy rainfall event Large-scale circulation vorticity budget

Mechanisms accounting for the repeated occurrence of torrential rainfall over South Thailand in early January 2017

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Atmospheric and Oceanic Science Letters 2020年第2期13卷 155-162页

作者： JIN Shuanglong FU Shenming State Key Laboratory of Operation and Control of Renewable Energy&Storage Systems China Electric Power Research InstituteBeijingChina Electric Power Meteorology State Grid Corporation Joint Laboratory BeijingChina International Center for Climate and Environment Sciences Institute of Atmospheric PhysicsChinese Academy of SciencesBeijingChina

Based on CMORPH precipitation estimates and ERA5 reanalysis data,this study investigates the mechanisms accounting for the repeated occurrence of torrential rainfall over South Thailand in early January 2017,which induced the strongest floods over Ko Samui and Ko Phangan in the last almost 30 *** is found that the maintenance of a northeastward-moving mesoscale vortex that formed southwest of the Indochina Peninsula was the direct reason for the series of torrential rainfall *** of the vorticity budget illustrates that convergence-related horizontal shrinking was the most favorable factor for the maintenance of the *** was the second most favorable factor,whereas horizontal and vertical transport mainly caused a net export of cyclonic vorticity from the vortex’s three-dimensional range,which was detrimental for its *** analysis indicates that tilting and vertical vorticity transport were sensitive to the vortex’s displacement and the enhancement of cyclonic vorticity at lower levels around the vortex,respectively,as the two factors showed completely different effects on the persistence of the vortex during two different stages.

关键词： Heavy Rainfall Thailand vorticity budget Tilting