Our research in marine biogeochemistry largely focuses on the contribution from marine systems, especially coastal ecosystems, to the global budgets of the greenhouse gases carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O). To this there are two main aspects. The first is a strong emphasis on evaluating the important geophysical controls of the rate of air-sea gas exchange, which is reflected in variability of the gas transfer velocity (kw) in space and time. Indeed, deriving kw values that are representative of large ocean areas presents the single largest challenge to accurately estimating the global marine sink for anthropogenic CO2. We have pursued this via large scale gas-exchange experiments at sea in conjunction with UK and international partners. Many of these we have led (e.g. DOGEE-SOLAS, funded by NERC, and ASGAMAGE, funded by the EU). During DOGEE-SOLAS we carried out the first ever open ocean release of an artificial surfactant combined with gaseous tracers, in order to evaluate the potential control of kw by biological surfactant, a process which is almost certainly globally important. We are also actively involved in smaller-scale mesocosm and laboratory based experiments (NERC and Leverhulme Trust funding) in which we are evaluating the modification of kw in biologically productive coastal waters by both biological surfactant and micro-organisms in the sea surface microlayer, the latter in conjunction with external partners. In a recently awarded project (NERC, 2013) we will extend these laboratory based studies to the open ocean in order to provide the first ever in-situ estimates of ocean basin scale variability in kw due to natural surfactant. These data will feed into models of Atlantic Ocean CO2 uptake that will be run by external collaborators within the wider project framework. The second aspect of our work concerns direct estimates of the exchange fluxes of CO2, CH4 and N2O between various marine compartments and the troposphere. Our focus is thus on the processes of production, consumption and subsequent air-sea exchange of these gases in temperate estuaries and shallow marginal seas, in mangrove ecosystems in conjunction with international partners, and in oceanic upwelling systems. All of these areas are strong source regions of these gases to the troposphere.
2013-2017: RAGNARoCC: Radiatively active gases from the North Atlantic Region and Climate Change (NERC £125,657 to Newcastle (although the total consortium gets £2 million.) Project Leader(s): Prof. R.C. Upstill-Goddard
2011-2013: Influence of offshore-onshore surfactant gradients on air-sea gas exchange: Deutsche Forschungsgemeinschaft (DFG) Research Fellowship to Dr Klaus Schneider-Zapp (salary only).