Title: Meridional Shift of the Oyashio Extension front in the Past 36 years.

Journal: Geophysical Research Letters, 45(17): 9042-9048, doi: 10.1029/2018GL078433

Authors: WU B. -L., X. -P. Lin*, and B. Qiu

Abstract: The meridional shift of Oyashio Extension (OE) front in the past 36 years was analyzed by using the high-resolution Optimum Interpolation SST data. The annual mean OE front has moved northward in its eastern part (between 157°E and 172°E) by 0.018°/year but no obvious poleward shift in the western OE front (between 145°E and 157°E). It is shown that the trade wind became stronger and broader, and the whole wind field moved northward in the past 36 years, shifting the zero wind stress curl line (or the zero Sverdrup streamline) and the eastern OE front northward. The above mechanism is confirmed by a 1.5-layer reduced-gravity model simulation as well as the altimetry data. Meanwhile, the local Ekman heat transport anomaly due to the wind field changes is found to be one of the contributors to the northward shift of the eastern OE front. However, both wind stress curl and local Ekman heat transport anomalies do not favor northward shift of the western OE front.