Role of Mesoscale Convective Systems Developed around the Eastern Tibetan Plateau in the Eastward Expansion of an Upper Tropospheric High during the Monsoon Season

Abstract Dynamical models of organized mesoscale convective systems have identified the important features that help maintain their overarching structure and longevity. The standard model is the trailing stratiform archetype, featuring a front-to-rear ascending circulation, a mesoscale downdraft circulation, and a cold pool/density current that affects the propagation speed and the maintenance of the system. However, this model does not represent all types of mesoscale convective systems, especially in moist environments where the evaporation-driven cold pools are weak and the convective inhibition is small. Moreover, questions remain about the role of gravity waves in creating and maintaining organized systems and affecting their propagation speed. This study presents simulations and dynamical models of self-organizing convection in a moist, low–convective inhibition environment and examines the long-lived convective regimes that emerge spontaneously. This paper, which is Part I of this study, specifically examines the structure, kinematics, and maintenance of long-lived, upshear-propagating convective systems that differ in important respects from the standard model of long-lived convective systems. Linear theory demonstrates the role of ducted gravity waves in maintaining the long-lived, upshear-propagating systems. A steady nonlinear model approximates the dynamics of upshear-propagating density currents that are key to the maintenance of the mesoscale convective system.

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Analysis of mesoscale convective systems over Tibetan Plateau in summer

Chinese Geographical Science ◽

10.1007/s11769-006-0004-7 ◽

2006 ◽

Vol 16 (2) ◽

pp. 116-121

Author(s):

Zhong-yang Guo ◽

Xiao-yan Dai ◽

Jian-ping Wu ◽

Hui Lin

Keyword(s):

Tibetan Plateau ◽

Mesoscale Convective Systems ◽

Convective Systems ◽

Mesoscale Convective

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Statistical Characteristics of Mesoscale Convective Systems Initiated over the Tibetan Plateau in Summer by Fengyun Satellite and Precipitation Estimates

Remote Sensing ◽

10.3390/rs13091652 ◽

2021 ◽

Vol 13 (9) ◽

pp. 1652

Author(s):

Xidi Zhang ◽

Wenqiang Shen ◽

Xiaoyong Zhuge ◽

Shunan Yang ◽

Yun Chen ◽

...

Keyword(s):

Tibetan Plateau ◽

Rapid Development ◽

Mesoscale Convective Systems ◽

Statistical Characteristics ◽

The Tibetan Plateau ◽

Convective Systems ◽

Lower Cloud ◽

Mesoscale Convective ◽

Precipitation Estimates ◽

High Level

In order to investigate the key characteristics of mesoscale convective systems (MCSs) initiated over the Tibetan Plateau (TP) in recent years and the main differences in circulation and environmental factors between different types of MCSs, an automatic MCS identification and tracking method was applied based on the data from China’s Fengyun satellite and precipitation estimates. In total, 8820 MCSs were found to have been initiated over the TP during the summers from 2013 to 2019, and a total of 9.3% of them were able to move eastward out of the TP (EO). The number of MCSs showed a monthly variation, with a maximum in July and a minimum in June, while most EOs occurred in June. Compared with other types of MCSs, EOs usually had a lower cloud-top temperature, a greater rainfall intensity, a longer life duration, more rapid development, larger areas of rainfall and convective clouds, longer tracks and a wider influence range, indicating that EOs are more vigorous than the other types of MCSs. The movement of MCSs is mainly due to the mid- to high-level dynamic conditions, and moisture is an essential factor in their development and maintenance.

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