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Abstract

Air-sea interaction occurs through energy exchange between the atmosphere and the ocean. The tropical Pacific and Indian Oceans(IO) can affect changes in the East Asian Summer Monsoon(EASM) through different teleconnections. Therefore, it is important to understand how the air-sea interactions in each ocean basin affect the EASM. These air-sea interactions can be considered by utilizing the Atmospheric-Ocean coupled model system(AOGCM). However, the AOGCM requires more computing resources than the atmospheric model system with prescribed SST. In addition, the AOGCM results include the air-sea interaction and the ocean dynamics that interrupt understanding of the isolated impacts of the air-sea interaction. This study considers a simple 1-D ocean model(SOM) to represent the atmospheric bottom boundary conditions in more detail in the general circulation model(GCM). SOM is implemented in the GCM as a physical parameterization module called at every time step of the GCM. SOM computes 1-D temperature and salinity profiles in the upper ocean layers from the sea surface to about 200 m depth. SOM considers flux exchange at the sea surface and SST cooling by precipitation.Results of the SOM show enhanced precipitation over the tropical IO and Western Pacific warm pool(WP) regions, which enhances EASM by revised meridional circulation from the tropics to the mid-latitude area. However, there still exist overestimations of precipitation over the IO and WP. It is analyzed that the air-sea interaction over the western Pacific directly impacts the EASM through atmospheric circulation. In contrast, the tropical IO indirectly impacts the EASM by modulating the WP.