HR: 1330h
AN: A42B-0762    [PDF]
TI: Parallel Computation of Ocean-Atmosphere-Wave Coupled Storm Surge Model
AU: * Kim, K
EM: kokim@rcde.dpri.kyoto-u.ac.jp
AF: Kyoto University, Gokasho, Uji, Kyoto, 611-0011 Japan
AU: Yamashita, T
EM: yamashit@rcde.dpri.kyoto-u.ac.jp
AF: Disaster Prevention Research Institute, Gokasho, Uji, Kyoto, 611-0011 Japan
AB: Ocean-atmosphere interactions are very important in the formation and development of tropical storms. These interactions are dominant in exchanging heat, momentum, and moisture fluxes. Heat flux is usually computed using a bulk equation. In this equation air-sea interface supplies heat energy to the atmosphere and to the storm. Dynamical interaction is most often one way in which it is the atmosphere that drives the ocean. The winds transfer momentum to both ocean surface waves and ocean current. The wind wave makes an important role in the exchange of the quantities of motion, heat and a substance between the atmosphere and the ocean. Storm surges can be considered as the phenomena of mean sea-level changes, which are the result of the frictional stresses of strong winds blowing toward the land and causing the set level and the low atmospheric pressure at the centre of the cyclone can additionally raise the sea level. In addition to the rise in water level itself, another wave factor must be considered. A rise of mean sea level due to white-cap wave dissipation should be considered. In bounded bodies of water, such as small seas, wind driven sea level set up is much serious than inverted barometer effects, in which the effects of wind waves on wind-driven current play an important role. It is necessary to develop the coupled system of the full spectral third-generation wind-wave model (WAM or WAVEWATCH III), the meso-scale atmosphere model (MM5) and the coastal ocean model (POM) for simulating these physical interactions. As the component of coupled system is so heavy for personal usage, the parallel computing system should be developed. In this study, first, we developed the coupling system of the atmosphere model, ocean wave model and the coastal ocean model, in the Beowulf System, for the simulation of the storm surge. It was applied to the storm surge simulation caused by Typhoon Bart (T9918) in the Yatsushiro Sea. The atmosphere model and the ocean model have been made the parallel codes by SPMD methods. The wave-current interface model was developed by defining the wave breaking stresses. And we developed the coupling program to collect and distribute the exchanging data with the parallel system. Every models and coupler are executed at same time, and they calculate own jobs and pass data with organic system. MPMD method programming was performed to couple the models. The coupler and each models united by the separated group, and they calculated by the group unit. Also they passed message when exchanging data by global unit. The data are exchanged every 60-second model time that is the least common multiple time of the atmosphere model, the wave model and the ocean model. The model was applied to the storm surge simulation in the Yatsushiro Sea, in which we could not simulated the observed maximum surge height with the numerical model that did not include the wave breaking stress. It is confirmed that the simulation which includes the wave breaking stress effects can produce the observed maximum height, 450 cm, at Matsuai.
UR: http://rcde2.dpri.kyoto-u.ac.jp/~kokim/agu.htm
DE: 1255 Tides--ocean (4560)
DE: 3339 Ocean/atmosphere interactions (0312, 4504)
DE: 4504 Air/sea interactions (0312)
DE: 4560 Surface waves and tides (1255)
DE: 4564 Tsunamis and storm surges
SC: Atmospheric Sciences [A]
MN: 2003 Fall Meeting