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A Modeling Study of an Atmospheric Bore Associated With a Nocturnal Convective System Over China
Author(s) -
Zhang Shushi,
Parsons David B.,
Xu Xin,
Wang Yuan,
Liu Jiufu,
Abulikemu Abuduwaili,
Shen Wenqiang,
Zhang Xidi,
Zhang Shengxi
Publication year - 2020
Publication title -
journal of geophysical research: atmospheres
Language(s) - English
Resource type - Journals
eISSN - 2169-8996
pISSN - 2169-897X
DOI - 10.1029/2019jd032279
Subject(s) - mesoscale meteorology , convection , geology , nocturnal , weather research and forecasting model , streak , meteorology , climatology , gravity wave , atmospheric sciences , geophysics , physics , astronomy , astrophysics , gravitational wave
Bores have been shown to play a role in the initiation and maintenance of mesoscale convective systems (MCSs), particularly during the night after the boundary layer stabilizes. To date, the generation, evolution, and structure of bores over China has received little attention. This study utilizes observations and simulations with the WRF‐ARW model to investigate the generation and evolution of an atmospheric bore observed over Yangtze‐Huai Plains of China. The bore was associated with a nocturnal MCS that first formed over elevated terrain. The bore was observed ahead of the MCS with a maximum lateral extension of ~100 km. The feature lasted for over 90 mins and propagated at a speed of ~13 m/s, slightly faster than the MCS. In the simulation, the bore evolved from the separating “head” of the convectively generated gravity current. The bore then continued to propagate ahead of the MCS, even after the dissipation of the feeder current, and took on the appearance of an undular bore. The bore lifted a layer of convectively unstable air above the nocturnal surface inversion, initiating new convection ahead of the MCS to help maintain the MCS. The Scorer parameter ahead of the bore revealed a low‐level wind profile with curvature of the vertical profile of horizontal wind, favoring the trapping of wave energy and the persistence of the bore. These results are generally consistent with the role of bores in the maintenance of nocturnal MCSs and emphasize the need for future studies into the relationship between bores and nocturnal MCSs over China.