A Climatology of the Super-Greenhouse Effect in the Indo-Pacific: Links to MJO, Deep Convection, and Cloud Radiative Feedbacks

The super-greenhouse effect (SGE) is a radiative phenomenon in the tropics characterized by enhanced water-vapour feedback in the troposphere that exceeds surface emissions, so that top-of-atmosphere outgoing long-wave radiation (OLR) decreases with increasing surface temperature. This process is a major contributor to the heating of the tropical atmosphere and ocean surface. Here we develop a climatology of the SGE in the Indo-Pacific region, using a collocated data-set of observations from multiple instruments in the A-train satellite constellation and the MERRA-2 reanalysis data-set. We show that the SGE is a persistent phenomenon in both clear and cloudy conditions, covering up to 50% of the tropics at any given time, and has spatio-temporal variability strongly linked to the MJO. We show that the radiative feedbacks and dynamic processes associated with clouds and deep convection generally enhance the clear-sky SGE. We also investigate how the strength and spatial extent of the SGE has changed in this region over the satellite era using reanalysis products. These results have implications for understanding the response of this region to a warming world.