Strong ocean currents are found on the western side of the ocean basins, which flow from the tropics toward the poles in both hemispheres. These western boundary currents have shown strong changes in the last few decades, which have resulted in intensified ocean warming in the poleward extensions of these boundary currents; these changes are projected to amplify further in the future.
In the Southern Hemisphere, recent changes in the western boundary currents are thought to have been primarily driven by changes in the surface westerly winds that encircle Antarctica. These westerly winds are generally considered to be changing uniformly in all three ocean basins; however, recent studies have shown that there are strong regional variations both historically and in future projections. In this study, it is found that regional differences in wind projections can account for about 30% of the projected warming in the Tasman Sea and the southern Australia region as well as a sizeable fraction of warming in the Agulhas Current region. This amplified warming in the Indian and the Pacific Ocean basins is primarily driven by changes in ocean circulation.
- Paper: Goyal, R., England, M.H., Jucker, M., Sen Gupta, A., 2021. Response of Southern Hemisphere Western Boundary Current Regions to Future Zonally Symmetric and Asymmetric Atmospheric Changes. Journal of Geophysical Research: Oceans 126, e2021JC017858. https://doi.org/10.1029/2021JC017858