Pearse Buchanan is a PhD candidate at the University of Tasmania. He is interested in defining how the ocean has responded to, and driven climate change in the past through exploring the complex interaction between ocean physics and biogeochemistry.
His Fulbright project will focus on the oceanic nitrogen cycle, which forms an essential component of the ocean’s weighty role in the climate system. Past variations in nitrogen are tell-tale signs of changes in ocean productivity, and therefore whether the ocean acted as a net contributor, or consumer of greenhouse gases. Pearse will work with researchers at the Sigman Lab at Princeton University to explore how past changes in the oceanic nitrogen cycle affected the air-sea exchange of two major greenhouse gases, carbon dioxide (CO2) and nitrous oxide (N2O). In this way, the ocean’s continued role in the changing climate system can be better defined and predicted.