Climate System Physics and Dynamics:

The main focus of my research involves a theoretical approach to understanding global climate change. In particular, I have been investigating climate dynamical phenomena that have occurred in the recent geologic past. This research has focused on rapid climate shifts and climate instabilities that have occurred in nature. By studying past climate I hope to gain insight into the anthropogenic influence on climate change. I have been actively studying past climate through the use of computer simulation involving state of the art global climate models. These models are based on dynamical equations of hydrodynamics and the physics of the atmosphere, ocean, land surface and cryosphere. My past research areas have included such interesting topics as the greening of the Sahara during the Holocene maximum (9000-6000 years before present), the dynamics of the atmosphere and oceans during the last glacial maximum (21 000 years before present) and the onset of the last glacial inception (116 000 years before present). Thus, much of my research has involved understanding the cyclical behaviour of the climate in the past million years. During this part of the Pleistocene, the Earth has undergone large climate oscillations in which the northern hemisphere was covered by massive continental scale glaciers that waxed and waned with periods synchronous with those natural periodicities present in the Earth’s orbital dynamics. However, there are a number of open questions as to the exact nature of the response of the climate system to this external forcing and other internal forcing mechanisms.

Currently, my research has turned to understanding rapid climate shifts, which have occurred during the recent past. This type of climate change has involved massive changes to the ocean overturning circulation and the subsequent coupling with the rest of the Earth system. One such period of interest is the Younger Dryas (11 500 years ago). This current area of research is trying to understand the impact of fresh water input to the surface of various ocean basins, as might occur with future anthropogenic induced warming of the planet and melting of continental land ice.

The figure below shows some of the component that make up the energy cycle of the atmosphere.