1995 Fiscal Year Final Research Report Summary
A study of numerical modeling of tropical cyclones and formation
| Project/Area Number |
06640555
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
Meteorology/Physical oceanography/Hydrology
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| Research Institution | University of Tokyo |
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Principal Investigator |
YAMASAKI Masanori Tokyo University Graduate School of Science, Prof., 大学院・理学系研究科, 教授 (40242101)
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| Project Period (FY) |
1994 – 1995
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| Keywords | tropical cyclone / organization of cummulus convection / mesoscale / non-hydrostatic model |
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| Research Abstract |
In this study, based on two types of models such as a non-hydrostatic axi-symmetric model which can resolve cumulus-scale motion and a three-dimensional hydrostatic model with cumulus-scale parameterization which the author developed. many numerical experiments have been performed in order to understand the mechanism of tropical cyclone formation and mesoscale structure. As for model improvement. vertical distribution of heat released by parameterized convection in the hydrostatic model was improved to get better simulation of mesoscale structure of tropical cyclones.
Numerical experiments were performed to understand the formation process of tropical cyclones in intertropical convergence zone. Meso-scale organization of cumulus convection is found to be essential to formation of a vortex and its intensification. In this experiment mesoscale structure such as strong winds located at the southeastern portion of the vortex and cyclonic rotation of mesoscale organized convection were simulated well. The mesoscale structure of wind and temperature fields were analyzed in some detail. Numerical experiments were also performed to simulate and understand the process where Rossby mode is separated from Kelvin mode in the equatorial area. A vortex developed from a Rossby mode and it transformed into a tropical cyclone.
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