MONSOON · Monsoons and climate change: roles of atmospheric and oceanic processes

Monsoons affect more than half the world’s population yet the dynamics of monsoons are poorly understood. Climate models struggle to accurately simulate monsoons and projections of how these circulations will respond to climate change are highly uncertain. A transformed understanding of monsoon dynamics has the potential to improve both climate models and predictions of how this key feature of the climate system will respond to global warming.This project will use idealised climate-model simulations to quantify the impacts of clouds, water vapour, carbon dioxide, and ocean heat transport on changes in monsoon dynamics. These atmospheric and oceanic processes have recently been shown to affect the Hadley circulation and midlatitude storm tracks, but their influences on monsoons are unknown. To isolate and quantify the effect of each process on the monsoon response to climate change, a novel set of simulations employing the radiation-locking technique and a simple dynamic representation of ocean heat transport will be performed. This reduced-complexity methodology will deliver a greatly improved mechanistic understanding of monsoons under climate change. The enhanced knowledge of monsoon dynamics that results from this project will ultimately lead to improvements in climate models and to better predictions of how monsoons will change in the future, with important benefits for societies around the world.