The Numerical Experiments of Southwesterly Formation over the Nansha Sea Area with the Effects of Terrain and Heat Perturbation

By using a five layer limited area primitive equations model, the terrain, heating perturbation over South Asia and a cooling perturbation over Australia are incorporated, respectively in the numerical model to discuss their effects on the southwesterly formation over the Nansha Sea area. The experiments of terrain show that the topographic effect is necessary on the southwesterly formation, but the topographic effect is not strong enough to make the southwest wind velocity reach 12 m/s. Furthermore, with the help of the effect of terrain, the experiment results including heating perturbation over the Philippines and the cooling perturbation over Australia, respectively, show that they can both make the southwesterly formation of above 12 m/s over the Nansha sea area. However, the heating perturbation over the Bay of Bengal has no effect on the formation of southwesterly over the Nansha Sea area