CO2 flux measurements during SEASAW

The uncertainties in the parameterization of air-sea gas fluxes as a function of wind speed are at least a factor of two; significant improvements are required if climate models are to be able to properly account for the effects of the exchange of CO2 and other greenhouse gases between the atmosphere and oceans. The problem is greatest at high wind speeds where there have, to date, been few if any direct measurements of gas fluxes. During the SEASAW cruises, eddy correlation measurements of CO2 fluxes were made at mean wind speeds up to approximately 20 m/s; along with measurements of mean CO2 concentrations in both atmosphere and ocean. The whitecap fraction - a controlling factor in gas exchange via bubble mediated processes – was also assessed via a continuous photographic record. Here we present initial CO2 flux estimates from the SEASAW cruises, comparisons with existing parameterization, and some model estimates of the large scale variability forced by changing synoptic situation.