Air-sea CO2 Exchange in the Arctic Marine Environment

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At a global scale, the Earth's oceans absorb a significant quantity of CO2, presently offsetting ~30% of human emissions. The Arctic Ocean is particularly effective at removing this important greenhouse gas from the atmosphere, but its ability to do so in the future may change as a result of climate warming. My research program is focused on better understanding the current and future role of the Arctic Ocean in the global carbon cycle. I will pursue three avenues of investigation: (1) identifying and quantifying the processes that control gas exchange rates in ice-affected seas; (2) identifying and quantifying the processes in sea ice and seawater that determine CO2 concentrations and set the potential for exchange with the atmosphere; and (3) the use of models and remote sensing to estimate CO2 exchange budgets over large scales.***The first research area deals with the physical and chemical processes that allow gases to transfer between a water surface (or an ice surface) and the atmosphere. In lower-latitude oceans these processes are fairly well known, but the presence of sea ice complicates matters significantly. In the short term, my research program will study air-ice CO2 exchange during the winter-to-spring transition using eddy covariance - a meteorological technique that can directly measure gas exchange. Another short-term goal will be to apply this technique to different platforms (ships and islands) to measure CO2 exchanges with seawater.***The second research area will focus on the biological, geological, and chemical (biogeochemical) processes that determine CO2 concentrations (pCO2) in surface seawater, and in water trapped within or on top of sea ice. An initial goal of the program will be to observe processes controlling seawater pCO2 from winter through spring break-up by using consecutive ice-camp and ship-based field studies. Ice-camp studies will also allow investigation of processes controlling pCO2 in sea ice brine and melt ponds. ***The third research area will combine results from the first two areas to estimate CO2 exchange budgets over larger space and time scales. Remote sensing will be used to extrapolate measurements of sea surface (and possibly sea ice) pCO2, and to estimate gas exchange rates. Numerical modeling will similarly be used to extrapolate field measurements over larger areas, and also to predict the future impacts of climate change. ***The overarching impact of this research program will be the identification and quantification of the processes that control CO2 exchange in the Arctic Ocean. Maximum impact will be achieved as the data and knowledge generated by the program are incorporated into global climate change models. The program will also have an important impact by training numerous highly qualified personnel, who will become important components of the global knowledge economy.**