Pan-oceanic response to increasing anthropogenic aerosols: Impacts on the Southern Hemisphere oceanic circulation

Examinations of the impact of anthropogenic aerosols on oceanic heat content have focused largely on the global average response. Given that aerosol-induced cooling is greater in the Northern Hemisphere (NH) than in the Southern Hemisphere (SH), do aerosols induce a greater impact on NH oceanic heat content? Sea level rise over the past 50 years has shown little hemispheric differentiation. Using a set of global climate model experiments forced with and without anthropogenic aerosols, we show that increasing aerosols in the 20th century induce a pan-oceanic heat redistribution. This leads to a reduction in the SH oceanic heat content comparable to that in the NH oceans. The process includes a strengthening of the northward cross-equatorial heat transport in the Atlantic and Pacific Oceans, with the majority taking place in the Atlantic Ocean via the most effective pathway: the globally interconnected ocean current system associated with the Atlantic overturning.