Influence of anomalous low-level circulation on the Kuroshio in the Luzon Strait during ENSO
Journal
Ocean Modelling
Journal Volume
159
Date Issued
2021
Author(s)
Kuo Y.-C
Abstract
Basin-scale wind curl anomalies in the North Pacific associated with El Ni?o increase westward Kuroshio transport in the Luzon Strait, whereas those associated with La Ni?a reduce it. However, the Kuroshio current in the Luzon Strait is further affected by mesoscale eddies and local wind stress. Numerical experiments are conducted to demonstrate that the anomalous low-level circulation over the Philippine sea during El Ni?o weakens the northeasterly monsoon and favors the development of mesoscale eddies at the same time. This is caused by the increased baroclinic instability in the Subtropical Countercurrent (STCC)/North Equatorial Current region. Our results are supported by the long-term observational data. Consequently, the Kuroshio pattern in the Luzon Strait during El Ni?o tends to be more unsteady. During La Ni?a, the Kuroshio loop is enhanced in response to strengthened northeasterly winds. Furthermore, vorticity stretching, caused by local wind stress and associated curl anomalies during La Ni?a, contributes to the formation of a cyclonic eddy off the southeastern Taiwan. ? 2021 Elsevier Ltd
Subjects
Wind stress; Baroclinic instability; Cyclonic eddy; Kuroshio current; Mesoscale eddy; Numerical experiments; Observational data; Philippine seas; Subtropical countercurrent; Ocean currents; air-sea interaction; computer simulation; countercurrent; El Nino; El Nino-Southern Oscillation; La Nina; mesoscale eddy; monsoon; numerical model; oceanic circulation; wind field; wind stress; Kuroshio Region; Luzon Strait; Pacific Ocean; Pacific Ocean (North)
Type
journal article