A coupled single-layer/two-layer model is employed to study the South China Sea (SCS) upper circulation and its response before and after the onset of summer monsoon. It is found that, in summer, due to the β effect ...A coupled single-layer/two-layer model is employed to study the South China Sea (SCS) upper circulation and its response before and after the onset of summer monsoon. It is found that, in summer, due to the β effect and the first baroclinic mode of the wind-driven current, a northward western boundary jet current is formed along the Indo-China Peninsula coast, and it leaves the coast at about 13° N and diffuses towards northeast; next to the Indo-China Peninsula, a large anticyclonic gyre in the southern SCS and a cyclonic eddy to the north of this gyre are induced. There are two possible mechanisms for the generation of this anticyclonic gyre: first, it is induced by the summer wind stress curl; second, it is associated with the westward moving of two anticyclonic eddies, which are originally generated to the west of Palawan Island and over the Nansha Trough respectively, in winter. The cyclonic eddy north of this anti-cyclonic gyre may be induced by the summer wind stress curl or related to the southwestward moving of the cyclonic eddy/gyre induced by the Kuroshio branch in the northern SCS.展开更多
In order to explore the interaction be- tween the sea and monsoon in the South China Sea, the heat exchanges at air-sea interface during mon- soon periods in 1986 were calculated using observa- tional data. It shows t...In order to explore the interaction be- tween the sea and monsoon in the South China Sea, the heat exchanges at air-sea interface during mon- soon periods in 1986 were calculated using observa- tional data. It shows that when the summer monsoon bursts and prevails over the South China Sea, the air-sea interface heat exchange is strong and the latent heat rises rapidly in the intertropical conver- gence zone and the tropic cyclone system near 20.49°N, 114.14°E. On May 24, 1986, the sensible heat became positive in the typhoon system. The heating exchange indicates that heat is transported from ocean to atmosphere, with major contribution of latent heat. When the summer monsoon prevails over the South China Sea and the weather is fine, even SST (sea surface temperature) is high, but sensible heat appears to be negative. The heat exchange indicates that heat is transported from atmosphere to ocean, with major contribution of short-wave radiation absorbed by sea surface and sensible heat. When summer monsoon is over and the northeast monsoon prevails over the South China Sea, the heat ex- change at air-sea interface is very strong. The heat- ing exchange shows that the ocean heats the at- mosphere, with major contribution of latent heat when cold air arrives at the sea surface and the sensible heat rises to positive rapidly. Therefore it can be concluded that the heat exchange at air-sea interface is different from the SST in South China Sea. Whenthe summer monsoon prevails over the South China Sea, the main trend is the ocean responding to the atmosphere.展开更多
基金of South China Sea Institute of Oceanology,Chinese Academy of Sciences under contract No.LYQY200310the National Nantural Science Foundation of China under contract No.40376003 the National Special Key Project of China under contract No.2001DIA 50041.
文摘A coupled single-layer/two-layer model is employed to study the South China Sea (SCS) upper circulation and its response before and after the onset of summer monsoon. It is found that, in summer, due to the β effect and the first baroclinic mode of the wind-driven current, a northward western boundary jet current is formed along the Indo-China Peninsula coast, and it leaves the coast at about 13° N and diffuses towards northeast; next to the Indo-China Peninsula, a large anticyclonic gyre in the southern SCS and a cyclonic eddy to the north of this gyre are induced. There are two possible mechanisms for the generation of this anticyclonic gyre: first, it is induced by the summer wind stress curl; second, it is associated with the westward moving of two anticyclonic eddies, which are originally generated to the west of Palawan Island and over the Nansha Trough respectively, in winter. The cyclonic eddy north of this anti-cyclonic gyre may be induced by the summer wind stress curl or related to the southwestward moving of the cyclonic eddy/gyre induced by the Kuroshio branch in the northern SCS.
基金This work was supported by Natural Science Foundation of Guangdong Province(Grant Nos.04102749&04009790)President Foundation of 0ceanological Science and Technology,South China Sea Branch,State 0ceanic Administration of China(Grant Nos.0104&0311)+1 种基金Research Foundation of Tropical 0ceanological and Meteorological Science(Grant No.200414)the Air-Sea Interface Heat Exchange of the Typhoon Project of Shanghai Typhoon Institute Foundation.
文摘In order to explore the interaction be- tween the sea and monsoon in the South China Sea, the heat exchanges at air-sea interface during mon- soon periods in 1986 were calculated using observa- tional data. It shows that when the summer monsoon bursts and prevails over the South China Sea, the air-sea interface heat exchange is strong and the latent heat rises rapidly in the intertropical conver- gence zone and the tropic cyclone system near 20.49°N, 114.14°E. On May 24, 1986, the sensible heat became positive in the typhoon system. The heating exchange indicates that heat is transported from ocean to atmosphere, with major contribution of latent heat. When the summer monsoon prevails over the South China Sea and the weather is fine, even SST (sea surface temperature) is high, but sensible heat appears to be negative. The heat exchange indicates that heat is transported from atmosphere to ocean, with major contribution of short-wave radiation absorbed by sea surface and sensible heat. When summer monsoon is over and the northeast monsoon prevails over the South China Sea, the heat ex- change at air-sea interface is very strong. The heat- ing exchange shows that the ocean heats the at- mosphere, with major contribution of latent heat when cold air arrives at the sea surface and the sensible heat rises to positive rapidly. Therefore it can be concluded that the heat exchange at air-sea interface is different from the SST in South China Sea. Whenthe summer monsoon prevails over the South China Sea, the main trend is the ocean responding to the atmosphere.
