Dramatic changes of global temperature, the atmospheric carbon dioxide content and ocean circulation between glacial and interglacial periods demonstrate the presence of such interactions. The diverse projects carried out by our group address questions related to the physical and the biological controls of biogeochemical cycles. Dedicated tracers are applied to study oceanic circulation, frequently in the context of the marine cycles of carbon and nutrients. Ongoing work using tracers concentrates on mixing across the thermocline, thermohaline circulation in the Greenland Sea and the effect of iron supply on the carbon cycle in the Southern Ocean.
Accurate measurements are essential to our work.
An instrument is being developed for the high quality analysis of the atmospheric oxygen to nitrogen ratio, which will allow us to better constrain the carbon cycle. Techniques for the accurate, automatic measurement of pH and total dissolved inorganic carbon in seawater have been developed and have been added to existing autonomous instruments. Modelling studies may provide insight into the regulation of biogeochemical cycles. A fully dynamic model of the global carbon cycle has been constructed to study its glacial to interglacial perturbations. Remarkable interactions between ocean nutrients and atmospheric oxygen have been demonstrated in a geophysiological model.