Impact of the GeoMIP G1 sunshade geoengineering experiment on the Atlantic meridional overturning circulation

All models simulate warming of the northern North Atlantic relative to no geoengineering, despite geoengineering substantially offsetting the increases in mean global ocean temperatures.

Increases in the temperature of the North Atlantic Ocean at the surface (similar to 0.25 K) and at a depth of 500 m (similar to 0.10 K) are mainly due to a 10 Wm(-2) reduction of total heat flux from ocean to atmosphere. Although the AMOC is slightly reduced under the solar dimming scenario, G1, relative to piControl, it is about 37% stronger than under abrupt4 x CO2. The reduction of the AMOC under G1 is mainly a response to the heat flux change at the northern North Atlantic rather than to changes in the water flux and the wind stress.