Earth System Feedbacks in Past Climates
I am a second year PhD student in Dr Alex Archibald's group. I am investigating how changes in the levels of trace gases and particles in past atmospheres affected the climate. I use a range of tools from a 1D photolysis model to state-of-the-art Earth system models.
Phanerozoic Oxygen Variability
Atmospheric oxygen has varied from as little as 15% to as much as 30% over the last ~500 million years. The resulting changes in atmospheric pressure have profound implications for past climates. However, the production of ozone is likely to be substantially altered in atmospheres with different oxygen levels. I am using HadGEM3-AO, an atmosphere-ocean general circulation model with interactive atmospheric chemistry to investigate how ozone changes affect the sensitivity of the climate to changes in oxygen levels.
Earth System Feedbacks in the Pliocene
The Pliocene is often used as a proxy for future climate change, as CO2 levels were around those of the present day but the climate was much warmer and sea levels considerably higher. However, most simulations of the Pliocene neglect potentially important Earth system feedbacks such as aerosol and atmospheric chemistry changes. I am investigating the impacts that including these processes have on climate simulations of the Pliocene, using HadGEM3-A, a general circulation model with interactive tropospheric and stratospheric chemistry and a microphysical aerosol scheme.