New Insight Into the Formation Mechanism of Wintertime Thermal Front West of Luzon Island

Abstract

AbstractWintertime thermal front west of Luzon Island (WTFWLI) plays a vital role in local marine biogeochemical environment, geostrophic thermal advection of Luzon cold eddy (LCE) was once recognized as the causation of WTFWLI. However, current investigation based on multi‐source data revealed poor spatial correspondence between WTFWL and LCE over an interannual scale during 1993–2022, highlighting the necessity of revisiting the mechanism of WTFWLI. Our analysis shows that formation of WTFWLI was mainly caused by a northward warm tongue caused by geostrophic thermal advection of a northward current west of Luzon Island. The northward warm tongue encounters cold water west of Luzon Island and forms the WTFWLI at the boundary of cold and warm water. Our study provides a new explanation for the formation mechanism of WTFWLI, which will help deepen people's understanding of thermal front dynamics.