Tuesday, 13 January 2009: 11:30 AM
Evaluation and comparison of satellite-derived estimates of the gas transfer velocity with direct observations from research vessels
Room 128AB (Phoenix Convention Center)
Understanding and quantifying the exchange of gases, such as carbon dioxide, between the atmosphere and global oceans is of vital importance to climate community. While in situ observations from research vessels provide the most accurate observations of air-sea gas exchange, ultimately remote sensing techniques will be needed to provide the necessary temporal and spatial sampling to capture seasonal and interannual variations of gas exchange for all oceanic regions. Satellite methods, however, remain problematic due to difficulties in parameterizing the gas/chemical transfer processes and accurately determining and retrieving the essential satellite-derived inputs. The focus of this study is to assess and improve the parameterization of the gas transfer velocity for carbon dioxide, ozone, and dimethylsulfide by using satellite inputs in the physically-based COARE gas transfer model. The COARE model has been implemented for application with satellite-derived inputs. Global estimates of these gas transfer velocities from COARE will be presented and compared with more simplified parameterizations based solely on wind speed. Satellite-derived transfer velocity errors, due to errors in satellite inputs, and their relationship to satellite observables will be derived and described. Comparisons of the satellite-derived gas transfer velocity to direct observations from the 1998 and 2001 GasEx cruises and 2008 Southern Ocean Experiment will provide validation of the satellite-derived estimates.