A mesoscale analysis of heavy rain caused by frontal and topographical heterogeneities on Taiwan Island
- 136 Downloads
The prevailing mesoscale model MM5 (V3) is used to simulate a heavy rain case caused by interaction between a move-in front and topographical heterogeneities on Taiwan Island. It is found that both thermodynamic and dynamic fields along the front are heterogeneous in time and space. The heterogeneity becomes more significant as the effect of topography is added on. The heterogeneous distribution of physical variables along the front is the main reason for the heterogeneous frontal rain band; the optimum cooperation of the low level and upper level jet is another reason for the development of the rain band. Topography can strengthen the rainfall and causes extremely heavy rain cells. Updraft induced by topography extends to a rather low level, while the uplifted air by frontal circulation can reach to higher levels. The quasi-steady topographic circulation overlaps the frontal circulation when the front moves over Taiwan Island; the advantageous cooperation of various mesoscale conditions causes the large upward velocity on the windward side of the island.
Key wordsfrontal heterogeneity heavy storm topographical circulation MM5 Taiwan Island
Unable to display preview. Download preview PDF.
- Chen, Yi-Leng, and Mei-Yu Cheng, 2000: Characteristics of rainfall distributions and surface wind fields over the Taiwan area during the 1996 and 1997 Meiyu season.Proc. Conf. on Weather Analysis and Forecasting, Taiwan University, 89.Google Scholar
- Climatology Data Office of Fujian Province, 1987:Taiwan’s Climate. Edited by editorial board ofTaiwan Chimate, China Ocean Press, Beijing, 1–5. (in Chinese)Google Scholar
- Cui Chunguang, Min Airong, and Hu Bowei, 2002: Dynamic effect of Mesoscale terrain on “98.7” extremely heavy rain in the east of Hubei Province.Acta Meteorologica Sinica,60(5), 602–612 (in Chinese).Google Scholar
- Hao Weifeng, Su Xiaobin, Wang Qinan, and Kou Zheng, 2001: The observational features and the cause analysis of hilly boundary-layer jet.Acta Meteorologica Sinica,59(1), 120–128. (in Chinese)Google Scholar
- Lai Xinzhi, 2002: Numerical simulation study on mesoscale convective system during Meiyu season of Taiwan—Case TAMEX IOP8. Institute of Atmospheric Physics, Center College of Taiwan, 1. (in Chinese)Google Scholar
- Lin, P. L., H. C. Lai, and Y. F. Sheng, 2000: A numerical study on a shallow front passage over Taiwan IslandIslandduring TAMEX IOP8.Proc. Conf. on Weather Analysis and Forecasting, Taiwan University, 264.Google Scholar
- Lou Xiaofeng, Hu Zhijin, Shi Yueqin, Wang Pengyun, and Zhou Xiuji, 2003: Numerical simulation of a heavy rainfall case in South China.Adv. Atmos. Sci.,20(1), 128–138.Google Scholar
- Lu Keli, and Zhao Deming, 1997: Effects of both the condensation process of moisture and upper and low-level jets on the cold-front circulation.Scientia Atmospherica Sinica,21(3), 317–323. (in Chinese)Google Scholar
- Song Weiguo, and Chen Tairan, 2001: On the Influence of water vapor on low-level jet in Meiyu season.Atmospheric Sciences (Taiwan),28(1), 1–13. (in Chinese)Google Scholar
- Sun Jian, Zhao Ping, and Zhou Xiuji, 2002: The mesoscale structure of a south China rainstorm and the influence of complex topography.Acta Meteorologica Sinica,60(3), 333–342. (in Chinese)Google Scholar
- Yue Caijun, Shou Shaowen, Lin Kaiping, and Yao Xiuping, 2003: Diagnosis of the heavy rain near a Meiyu front using the wetQ vector partitioning method.Adv. Atmos. Sci.,20(1), 37–44.Google Scholar