Seasonal and interannual variations of the North Equatorial Current bifurcation in a high-resolution OGCM SCIE SCOPUS

Cited 159 time in WEB OF SCIENCE Cited 173 time in Scopus
Title
Seasonal and interannual variations of the North Equatorial Current bifurcation in a high-resolution OGCM
Author(s)
Kim, YY; Qu, TD; Jensen, T; Miyama, T; Mitsudera, H; Kang, HW; Ishida, A
KIOST Author(s)
Kang, Hyoun-Woo(강현우)
Publication Year
2004-03
Abstract
The variation of the North Equatorial Current (NEC) bifurcation is investigated using results from a high-resolution ocean general circulation model (OGCM). The bifurcation occurs at about 15.5degreesN for the annual average and is easily identifiable in the upper 500 m, but it varies with time and depth. In agreement with recent observations, during the summer season the NEC bifurcation moves equatorward with a weak poleward shift with depth, while a large poleward movement with a poleward shift with depth is found during the winter season. Vertical mode decomposition indicates that the seasonal variation of the NEC bifurcation is dominated by the first two baroclinic modes. On the interannual timescale, the meridional migration of the NEC bifurcation is strongly influenced by El Nino/Southern Oscillation (ENSO); its correlation with the Southern Oscillation Index exceeds 0.8 in magnitude at depths around the thermocline. The NEC bifurcation occurs at its northernmost position during El Nino years and at its southernmost position during La Nina years. This variation is mainly accounted for by westward propagation of upwelling (downwelling) Rossby waves generated by winds in the central equatorial Pacific and by an anomalous anticyclone (cyclone) located in the western North Pacific when a warm (cold) event matures. The interannual variability of the NEC transport is highly correlated with that of the Mindanao Current (MC) and the Kuroshio transports. It is also found that the interannual variability of the NEC bifurcation latitude is highly correlated with the variations of transports in the NEC and the Kuroshio, but is less correlated with transport variations in the MC.
ISSN
0148-0227
URI
https://sciwatch.kiost.ac.kr/handle/2020.kiost/5270
DOI
10.1029/2003JC002013
Bibliographic Citation
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS, v.109, no.C3, 2004
Publisher
AMER GEOPHYSICAL UNION
Keywords
bifurcation; seasonal; interannual
Type
Article
Language
English
Document Type
Article
Publisher
AMER GEOPHYSICAL UNION
Related Researcher
Research Interests

Marine System Modeling,Ocean Climate,Ocean Circulation,해양시스템모델링,해양 기후,해양 순환

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