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.