Drake Passage가 전지구 열염분 순환에 미치는 영향

Abstract

Global thermohaline circulation was simulated in an idealized ocean to verify its variability due to the Drake Passage in the Antarctic Ocean and its bottom topography. It was represented by NOAA/GFDL Modular Ocean Model, MOM, 3. Grids consist of latitudinal and longitudinal 2º and vertical 20 layers. We simplified the oceans as rectangular oceans linked together by the Antarctic Ocean. All of the bottom topography was ignored as a flat bottom except that of the Drake Passage. Wind over the surface layer has no zonal variation but only meridional one and restoring temperature and salinity were symmetric distribution across the equator. There were no zonal variations in all surface boundary conditions. Due to the variation of bottom topography in the Drake Passage, most changes of thermohaline circulation occurred in the North Atlantic but for the changes of the Antarctic Circumpolar Current directly affected by it. And especially in the cases with the shallow Drake Passage, the thermohaline circulations were strengthened in global ocean areas. In this study, we would explain how the effect of bottom topography in the Drake Passage on the thermohaline circulation propagated to the northern hemisphere and the reason why circulation changes were emphasized in specific areas.