Improving predictions of coastal air-sea CO2 fluxes

HALES, B., D. FEELY, C. SABINE, R. LETELIER, P. STRUTTON, M. SARACENO, AND T. TAKAHASHI

San Francisco, USA

Conferencia; AGU Fall Meeting; 2007

AGU

Coastal ocean air-sea CO2 fluxes are regionally and seasonally intense, and may significantly impact estimates of net continental fluxes or bias estimates of terrestrial carbon fluxes in regions where there is cross-shore airflow. Unfortunately the large natural variability of the coastal oceans means that the coastal oceans are observationally undersampled, and significant uncertainties regarding net carbon cycling in coastal margins limit the application of mass-balance approaches, placing significant limits on our ability to constrain net coastal fluxes. The Pacific coast of North America epitomizes these issues, with extreme variability in air-sea pCO2 differences and cross-coastal airflow patterns. We present new measurements of surface-water pCO2 in previously undersampled regions of the Pacific coast, based on mooring- and ship-of-opportunity sampling programs, which have signifcantly increased the coverage of observations in Pacific coastal waters. To this new data combined with historical observations we apply our previously- developed empirical algorithms based on remote-sensing observations to fill spatial and temporal observational gaps. From these we create seasonal and annual maps of CO2 flux distributions, and net air-sea flux estimates. We compare our predictions with observations to determine where, when and why the algorithms perform poorly or well.