Extended Abstract (188K)6C.1
Topographic effect on a barotropic cyclone encountering a mountain: laboratory experiment and numerical simulation
PAPER WITHDRAWN
Hung-Cheng Chen, National Taiwan University, Taipei, Taiwan; and C. C. Chang and C. C. Chu
Motivated by the frequent disaster of typhoons encountering the island of Taiwan, the underlying fluid dynamical aspects were investigated by a joint laboratory experiment and numerical simulation of the near-topography motion of a vortex generated in a rotating tank with a sloping bottom. On the experimental side, the parameters of the rotating tank experiment were carefully determined according to similarity laws derived from the conservation of potential vorticity. On the numerical side, the flows under same conditions were also studied numerically; a modified shallow water model was numerically integrated by a multidimensional, positive-definite advection transport algorithm (MPDATA). The prominent feature of the cyclone motion driven by the background beta was the overall northwestward translating tendency. During the interaction of the cyclone with the topography, the trajectory of the vortex was deflected cyclonically or anti-cyclonically depending upon its impinging location. The fundamental dynamics associated with this interaction can be explained by the influence of the local topographic slope. A cyclone/ridge experiment was also performed to identify this topographic effect qualitatively. In addition, the effect of the lateral size of the topography was addressed in this study.
Session 6C, Tropical Cyclone Simulation: Dynamics I (Parallel with Sessions 6A, 6B, and 6D)
Tuesday, 30 April 2002, 2:00 PM-3:30 PM
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