Projected Changes of the Low-latitude North-western Pacific Wind-driven Circulation under Global Warming
Title: Projected Changes of the Low-latitude North-western Pacific Wind-driven Circulation under Global Warming
Journal: Geophysical Research Letters, 44:4976-4984, doi:10.1002/2017GL073355
Authors: DUAN J., Z. -H. Chen*, and L. -X. Wu
Abstract: Based on the outputs of 25 models participating in the Coupled Model Inter-comparison Project Phase 5 (CMIP5), 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 (MC) and Kuroshio Current (KC) in the east of 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 Nino-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.