摘要
The relationship of the interannual variability of the transport and bifurcation latitude of the North Equatorial Current (NEC) to the El Ni o-Southern Oscillation (ENSO) is investigated. This is done through composite analysis of sea surface height (SSH) observed by satellite altimeter during October 1992-July 2009, and correspondingly derived sea surface geostrophic currents. During El Nio/La Ni a years, the SSH in the tropical North Pacific Ocean falls/rises, with maximum changes in the region 0-15°N, 130°E-160°E. The decrease/increase in SSH induces a cyclonic/anticyclonic anomaly in the western tropical gyre. The cyclonic/anticyclonic anomaly in the gyre results in an increase/decrease of NEC transport, and a northward/southward shift of the NEC bifurcation latitude near the Philippine coast. The variations are mainly in response to anomalous wind forcing in the west-central tropical North Pacific Ocean, related to ENSO events.
The relationship of the interannual variability of the transport and bifurcation latitude of the North Equatorial Current (NEC) to the E1 Nifio-Southern Oscillation (ENSO) is investigated. This is done through composite analysis of sea surface height (SSH) observed by satellite altimeter during October 1992-July 2009, and correspondingly derived sea surface geostrophic currents. During E1 Nifio/La Nifia years, the SSH in the tropical North Pacific Ocean falls/rises, with maximum changes in the region 0-15~N, 130~E-160~E. The decrease/increase in SSH induces a cyclonic/anticyclonic anomaly in the western tropical gyre. The cyclonic/anticyclonic anomaly in the gyre results in an increase/decrease of NEC transport, and a northward/southward shift of the NEC bifurcation latitude near the Philippine coast. The variations are mainly in response to anomalous wind forcing in the west-central tropical North Pacific Ocean, related to ENSO events.
作者
翟方国
胡敦欣
ZHAI Fangguo;HU Dunxin(Key Laboratory of Ocean Circulation and Waves,Chinese Academy of Sciences,Qingdao 266071,China;Institute of Oceanology,Chinese Academy of Sciences,Qingdao 266071,China;Graduate University of Chinese Academy of Sciences,Beijing 100049,China)
基金
Supported by the National Natural Science Foundation of China Major Project (No. 40890151)
the National Basic Research Program of China (973 Program) (No. 2007CB411802)