Research Of The Interannual Interaction Between The Tropical Indian Ocean And The Tropical Pacific

The Indian Ocean Dipole (IOD) event and ENSO event have been analyzed by means of multiple data and LMDZ AGCM. This article mainly concentrates on the correlation between double air-sea interaction events as well as the respective evolution characteristic of both phenomenon. Moreover, the instability of the ocean (atmosphere) with the special background and corresponding basic current is also considered and the analytical solution is got. The prominent content include such five parts, the coherence analysis of air-sea interaction during ENSO event, the coherence analysis of air-sea interaction during IOD event, cross correlation between interannual IOD event and ENSO event, the wave instability considering the special background and corresponding basic current, research about climatology of SST and sea surface wind field in the tropical Pacific and tropical Indian Ocean. The conclusion of this article contains:(1) The climatology symmetric index and antisymmetric index which represent the uniform system of ocean and atmosphere is defined according to the unique kinetic character of the large-scale fluid. The symmetric mode, a state mode, and antisymmetric mode, a propagate westward mode, of ocean and atmosphere are distinguished clearly from each other. Also, the primary part which determines the symmetric mode emerges from non-divergenct wind and the dominant part which contributes to the antisymmetric mode mostly is irrotational wind. The article also compares the disparity of the climatology distribution of SST and sea surface wind field between 1948-1975 and 1976-2005. The SST of both the tropical Indian Ocean and the tropical Pacific after 80's is warm than before 80's . The location of the max increasing temperature lies in the central Indian Ocean and the south-east Pacific area.(2) Based on the analysis of the lower mode truncated shallow water model, it is shown that the meridional variation of the thermocline or the height field, together with its corresponding geostrophic current field, has significant influence on behavior of the equatorial low frequency wave. The eastward equator background current will change the speed of the classic Rossby wave, and even make it turn to eastward. Also this wave can interact with the topograhic Rossby wave to produce the instable wave, which propagates eastward. This type of barotropic instability is different with that in middle latitude. It comes from the coupling between the topograhic Rossby wave and the Rossby wave.The coupled instable wave propagates eastward and its phase speed is much lower than the classic Kelvin wave. Then initial sea temperature anomaly propagating...