Projected changes of the low‐latitude north‐western Pacific wind‐driven circulation under global warming

Abstract

AbstractBased on the outputs of 25 models participating in the Coupled Model Intercomparison Project Phase 5, the projected changes of the wind‐driven circulation in the low‐latitude north‐western Pacific are evaluated. Results demonstrate that there will be a decrease in the mean transport of the North Equatorial Current (NEC), Mindanao Current, and Kuroshio Current in the east of the Philippines, accompanied by a northward shift of the NEC bifurcation Latitude (NBL) off the Philippine coast with over 30% increase in its seasonal south‐north migration amplitude. Numerical simulations using a 1.5‐layer nonlinear reduced‐gravity ocean model show that the projected changes of the upper ocean circulation are predominantly determined by the robust weakening of the north‐easterly trade winds and the associated wind stress curl under the El Niño‐like warming pattern. The changes in the wind forcing and intensified upper ocean stratification are found equally important in amplifying the seasonal migration of the NBL.