Carbonate Compensation Dynamics in the Past and Future

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My research program is undergoing a radical change of direction. From three decades of modelling processes in sediments, I have decided to focus on large scale ocean-related problems that impact our society. Specifically, I have chosen to start with predicting acidification of the oceans. The increased acidity is having and will have profound, largely negative, effects on the biology of the Oceans. The source of this acidity is the build-up of man-produced CO2 in the atmosphere and its subsequent adsorption by the Oceans. There is a natural neutralization process acting in the Oceans, called compensation, which involves dissolution of previously deposited calcium carbonate on the seafloor. However, the neutralization is out of synchronization with the input rate of acid. We need to understand better and more fully the mechanics of the neutralization and the time scales on which it will occur. It is the goal of my current research program to investigate and comprehend these mechanisms, including their time scales and their consequences to the earth's chemical environment. The prediction of the rate of neutralization currently comes from complex models of the oceans that are extremely difficult to solve. As a first step in building my new research program, I have succeeded in formulating a very simple model of CO2 neutralization, which appears to give predictions as robust as those from the complex models. Over the next 5 years I wish to test the utility, power and resilience of my new model by applying it to past acidification events in the Earth's history. One such event occurred 55.8 M years ago (the PETM). A great deal of data has been collected about oceanic environmental conditions at that time (via so-called paleoceanographic proxies). Working with a post-doctoral fellow(s) I will compare my model output with those data to test the hindcasting ability of my model. Success would mean that a simple and powerful tool would exist to model the Ocean's future.