Diagnostic study of a morning convection event over southwestern coast of Taiwan during MeiYu season under weak synoptic condition / 梅雨季弱綜觀強迫下臺灣西南部沿海清晨對流發展之個案診斷分析研究

碩士 / 國立臺灣大學 / 大氣科學研究所 / 103 / In the morning of 8 June, 2012, convection approached and produced rainfall along the southwestern coast of Taiwan. During its approach, the system gradually organized into a linear structure and became more intense. After its landfall, new cells were
triggered at its nearside near the coastline, and the rainfall was mainly over the coastal region.
The case under study occurred during the Mei-Yu season under weak synoptic condition. Based on mesoscale analysis, the initial trigger of the convective system was mainly due to the convergence provided by the enhancing southwesterly winds to its rear. After the convective system made landfall, new cells were triggered by local convergence caused by the cold pool associated with convective downdrafts, and the system as a whole was maintained. Later, the convective system moved inland and
dissipated because of a decrease in CAPE(Convective Available Potential Energy)and an increase in CIN(Convective Inhibition). It was also found that the convective line strengthened near the coast over an area of local convergence between the environmental southwesterly winds and the land breeze.
The CReSS(Cloud Resolving Storm Simulator, CReSS) model was utilized to investigate this case. The run using a grid size of 500 m revealed that a favorable condition for convection development was produced in an area between the convergence lines at the leading edge ahead of low-level southwesterly winds and land
breeze. The simulated convection system exhibited a strong development in this area.
In this case, the land breeze enhanced the eastward-moving convective system embedded in the environmental southwesterly winds. The outflow associated with convective rainfall on the coastal region produced local convergence and initiated new cells to the rear of old convection. Obviously, the land breeze was important to initiate and enhance morning convection over southwestern coast of Taiwan.

Identiferoai:union.ndltd.org:TW/103NTU05022030
Date January 2015
CreatorsChi-Hong Ngai, 魏智航
ContributorsGeorge Tai-Jen Chen, 陳泰然
Source SetsNational Digital Library of Theses and Dissertations in Taiwan
Languagezh-TW
Detected LanguageEnglish
Type學位論文 ; thesis
Format91

Page generated in 0.0016 seconds