Understanding the Response of Tropical Ascent to Warming Using an Energy Balance Framework

Abstract:

It is expected that the tropical mean circulation and convective mass flux will decrease with surface warming. This work explores this topic in more detail using a diagnostic rooted in energy and mass balance that links the fractional area covered by the region of upward motion to the strength of the mean circulation. Changes in tropical ascent area and of the strength of the mean circulation relate to changes in the ratio between the heating over convective regions and cooling over clear regions. Additionally, the convective mass flux over deeply convecting regions may increase despite a weakening of the global mean.