Research Group Interests
Our interest is in observing and understanding the global carbon cycle, both in the natural pre-industrial state and in its modern, heavily disturbed condition. Our special expertise is in making high precision measurements of carbon dioxide, other greenhouse gases and man-made compounds such as chlorofluorocarbons (CFCs) and other tracers, in the atmosphere and oceans. We are involved in many sub-disciplines of Earth system science, and we work with physical oceanographers, biogeochemists, and modellers of the present, past and future climate.
Ocean uptake and release of CO2
The oceans are presently taking up about a quarter of all the CO2 humans are emitting, and in the long run (several hundred years) we believe they will be the sink for most of the excess carbon dioxide that humans emit. The North Atlantic Ocean takes up substantial CO2 from the atmosphere, The uptake varies seasonally, year to year, and on longer time scales. We are studying it using surface observations, full-depth measurements, atmospheric measurements and models. We also measure ocean sources and sinks of other greenhouse gases (methane and nitrous oxide) and oxygen.
Circulation, mixing and CO2 exchange in the Southern Ocean
The Southern Ocean is the least studied and understood of the world’s oceans, with a unique circumpolar circulation. As the place where much of the deep ocean water first upwells to the surface, it dominates the natural concentration of CO2 in the atmosphere and is key to understanding how this has varied in the past. We are studying mixing and circulation in the region around Drake Passage (between South America and Antarctica) in an ambitious experiment, in which we contribute our ability to measure oceanic tracers at high precision and very low concentrations. Using models, we are exploring the ramifications for past atmospheric CO2, and for the uptake of anthropogenic, (human-emitted) CO2.
Here is a short film from 2014 about the DIMES project.