Abstract

The ocean is currently sequestering about 25% of the excess CO₂ produced by burning of fossil fuel. This long-term estimate is determined from a global mass balance of CO₂ based on estimates of fossil fuel production, and changes in atmospheric CO₂ mixing and isotopic ratios. To quantify regional fluxes on seasonal timescales we resort to methods based on concentration differences of CO₂ between air and surface ocean, and estimates of gas transfer from wind speeds over the ocean. This presentation focuses on the methodology, and advances in determining air-sea CO₂ fluxes using ships of opportunity and remotely sensed data. Results suggest good correspondence between these estimates and those based on global mass balances. Estimates of interannual variability in air-sea fluxes are relatively small at about 10% of the mean uptake while regional changes such as in the Equatorial Pacific can be significant, suggesting compensating effects in different parts of the ocean.

Light refreshments are served in the Interaction Area (4th floor of the Oceanography/Physics Building) at 4:00 p.m.

All seminars begin at 3:00 p.m. and are held in room 200 of the Oceanography/Physics building.