열대 태평양 지역에서의 생물-물리 상호작용에 대한 모델링 연구

Abstract

Variability of marine phytoplankton associated with El Niño-Southern Oscillation (ENSO) and potential biological feedbacks on climate are investigated through coupled ocean model experiments forced by realistic surface wind from 1951 to 2010. The model used in this study is the MOM4p1 coupled to a biogeochemical model called TOPAZ (Tracers in the Ocean with Allometric Zooplankton). In general, MOM4p1-TOPAZ model simulates well the feature of phytoplankton variability associated with ENSO, which is consistent with our previous observation-bases study. That is, insufficient nutrient supply (suppressed equatorial upwelling) during El Niño reduces tropical phytoplankton. By analyzing different ocean hindcast experiments, the impact of phytoplankton on ENSO is evaluated. In the first one, the chlorophyll concentration is interactive with physical model, while in the second experiment, the chlorophyll is set to zero. The last experimental set consists of different amount of climatological chlorophyll derived from the first experiment. The main finding is that chlorophyll generally increases the mean SST by radiant heating to the ocean surface layer, while it decreases the equatorial Pacific SST through the upwelling of the cooled sub-surface water. The existence of chlorophyll generally intensifies the ENSO amplitude. On the other hand, interannually varying chlorophy