A coupled sea ice-mixed layer-isopycnal model (OPYC, alias PIPE) was applied to simulate the circulation in the Southern Ocean. The model domain covered the Southern Ocean south of 24°S. The model was first spun ...A coupled sea ice-mixed layer-isopycnal model (OPYC, alias PIPE) was applied to simulate the circulation in the Southern Ocean. The model domain covered the Southern Ocean south of 24°S. The model was first spun up in a coarse resolution grid (2° longitude×1°latitude) for 40 years running; then was shifted into a fine resolution grid (1°longitude×0.5°latitude with a focus in the Indian Sector and the Antarctic Marginal Sea) for additional 5 years running in order to creat the detailed circulation pattern in the area of interest. The simulated annual averaged volume transport through Drake Passage was 145.3×106m 3/s and more similar to the observed result (134×106m 3/s) than FRAM’s result (about 200×106m 3/s). The simulated results of circulation and sea ice also agreed with those of previous results. The meridional streamfuction and meridional transport obtained from the simulated results were used to study the meridional characteristics of the Antarctic Circumpolar Current(ACC). The ACC is traditionally considered to be a zonal current. However, the modeled result showed the ACC’s significant non-zonal feature in some regions, such as the Kerguelen Plateau in the Indian Sector. Arranged in a staggered way, the northward and southward transport areas occur in the ACC region. The isopycnals go up in the northward transport areas and go down in the southward transport areas, which implied a spiral motion of fluid particles in the ACC. This spiral motion is caused by the non-zonal feature of the ACC and is constructed by the ACC’s north and south shifts in several regions of the Southern Ocean not only the Drake Passage. Though most meridional motions are limited in the ACC region, some meridional exchange channels across the ACC might exist in some areas, for example, in the Southeast Australian Basin near 150°E. The meridional streamfuction shows the Subtropical Cell, the Deacon Cell, the Subpolar Cell and the Polar Cell, but misses the Deep Cell. All the cells change with seasons. The Deacon Cell展开更多
文摘A coupled sea ice-mixed layer-isopycnal model (OPYC, alias PIPE) was applied to simulate the circulation in the Southern Ocean. The model domain covered the Southern Ocean south of 24°S. The model was first spun up in a coarse resolution grid (2° longitude×1°latitude) for 40 years running; then was shifted into a fine resolution grid (1°longitude×0.5°latitude with a focus in the Indian Sector and the Antarctic Marginal Sea) for additional 5 years running in order to creat the detailed circulation pattern in the area of interest. The simulated annual averaged volume transport through Drake Passage was 145.3×106m 3/s and more similar to the observed result (134×106m 3/s) than FRAM’s result (about 200×106m 3/s). The simulated results of circulation and sea ice also agreed with those of previous results. The meridional streamfuction and meridional transport obtained from the simulated results were used to study the meridional characteristics of the Antarctic Circumpolar Current(ACC). The ACC is traditionally considered to be a zonal current. However, the modeled result showed the ACC’s significant non-zonal feature in some regions, such as the Kerguelen Plateau in the Indian Sector. Arranged in a staggered way, the northward and southward transport areas occur in the ACC region. The isopycnals go up in the northward transport areas and go down in the southward transport areas, which implied a spiral motion of fluid particles in the ACC. This spiral motion is caused by the non-zonal feature of the ACC and is constructed by the ACC’s north and south shifts in several regions of the Southern Ocean not only the Drake Passage. Though most meridional motions are limited in the ACC region, some meridional exchange channels across the ACC might exist in some areas, for example, in the Southeast Australian Basin near 150°E. The meridional streamfuction shows the Subtropical Cell, the Deacon Cell, the Subpolar Cell and the Polar Cell, but misses the Deep Cell. All the cells change with seasons. The Deacon Cell
