Simulations of the 26 December 2004 Indian Ocean tsunami using amulti-purpose Ocean disaster simulation and prediction model

摘要

Under Advanced Ocean State Forecast activity at MOG/SAC, a comprehensive multi-model ensemble called TOAST comprising an ocean general circulation model, a coastal surge and tide prediction model coupled with a suitable cyclone prediction model is being tested. The model is designed specifically to simulate and predict ocean disasters like storm surge, etc. The model has flexible grids structure and apart from calculation of the surge height, it also provides the area of intense inundation in the coastal region. The ocean general circulation component of TOAST has a very clear separation of the barotropic and baroclinic modes of energy propagation. Due to this separation, it is possible to configure the model to retain very fast gravity waves, which are generally filtered away in studies connected with OGCM, and hence indicating a possibility to simulate tsunami. The 26 December 2004 Indian Ocean tsunami has been used as the case study to see the whole life cycle from generation to runaway using this model. The earthquake data has been converted into the model-required parameters using an elastic plate movement model employed for most of the earthquake studies. We have assumed the quake intensity at Richter scale 9.0 occurring at 0056 UTC and compared the simulation with Jason altimeter pass in the central Bay of Bengal at 0256 UTC. The results are very encouraging. The model simulations, even with the complication of a normal general circulation model, take about 180 min CPU time on a 4-CPU Itenium-2 machine at 9 km resolution, and therefore, has the potential of an operational mode system using faster computer systems.