Contrary responses of the Gulf Stream and the Kuroshio to Arctic sea ice loss

Results show that the Gulf Stream (Kuroshio) weakens (strengthens) in response to Arctic sea ice loss via ocean (atmosphere) adjustments. More precisely, the Kuroshio acceleration is mainly due to the anomalous wind stress over the North Pacific, while the ocean gyre adjustments in the Atlantic are responsible for the weakened Gulf Stream.

As positive buoyancy fluxes induced by Arctic sea ice loss trigger a slowdown of the Atlantic Meridional Overturning Circulation (AMOC), the Gulf Stream decelerates evidently and the current speed decreases by about 5–8 cm/s in the upper ocean. Resulting from less advection and horizontal diffusion in the temperature budget, less poleward warm water leads to narrow sea surface cooling sandwiched between strong warming in the subpolar and subtropical Atlantic.