Impacts on the Southern Hemisphere Hadley Cell Edge in Climate Models

The Southern Hemisphere Hadley cell describes the circulation in the atmosphere from the equator to approximately 30°S. This edge of the Tropics has been observed to expand polewards over the satellite era. This thesis explores and utilises present climate model biases and their role in simulating the Hadley cell edge to address prevailing uncertainties. Using a range of climate model experiments, circulation features from outside of the tropics are found to have leading impacts on the Hadley cell edge. The research highlights the complex interaction of tropical-to-extratropical circulation and the impact of their errors on reliable climate model simulations.