North Atlantic Warming Hole Modulates Interhemispheric Asymmetry of Future Temperature and Precipitation

The observed cooling in the subpolar North Atlantic, known as the warming hole, is receiving much attention because of its relationship with the climate sensitivity in the Earth System Models (ESMs). However, the impact of its future projection on the global climate remains unclear due to large uncertainties. Here, we show that the future warming hole changes will affect the interhemispheric asymmetry of temperature and precipitation by modulating the Northern Hemisphere (NH) warming. Models with a weaker warming hole in the future project stronger NH warming by injecting more non-radiative fluxes to the atmosphere. This leads to an asymmetric warming contrast between the two hemispheres, resulting in a meridional shift of the Inter-Tropical Convergence Zone and more precipitation increases in the NH. Our study implies that the future warming hole controls the interhemispheric heat exchanges and associated changes in the global temperature and precipitation, suggesting that its improved simulation is essential.