Project Funding: 2007 - 2010

NRA: 2006 NASA: Ocean Biology and Biogeochemistry   

Funded by NASA

Abstract:
Understanding and quantifying the flux of CO2 between the ocean and atmosphere is necessary to obtain an accurate measurement of the uptake of CO2 by the world’s oceans. Ultimately, global measurements will require remote sensing techniques. The ability to retrieve air-sea gas fluxes using satellite methods is limited, however, due to difficulties in parameterizing the gas/chemical transfer processes and in determining the needed inputs from satellite measurements. This proposal seeks to apply the direct surface measurements of gas fluxes and concentrations obtained during the planned air-sea CO2 exchange study and past experiments to evaluate and refine satellite-based techniques for estimating gas transfer velocities and fluxes. The gases studied will depend on the projects funded, but are projected to include CO2, ozone, and dimethylsulfide (DMS). The surface measurements will be obtained through partnerships with other groups that proposed to the corresponding NOAA Climate Program Office announcement. The focus will be on characterization of the transfer velocity since this aspect represents the greatest absolute uncertainty in satellite flux estimates and is most amenable to improvements. The physically-based COARE gas transfer parameterization will be applied to the computation of satellite-derived gas transfer velocity estimates. Application of this comprehensive model will enable improvements in the accuracy of satellite-based techniques over broad ranges of conditions and the ability to better identify the role of individual contributing processes such as bubbles and chemistry. Implementation requires obtaining all the necessary inputs from satellite measurements. The resulting transfer velocity estimates will be compared with the direct surface observations, parameterized results using surface observations, and simplified satellite methods to construct a detailed error budget for satellite retrieval methods and assess the need for further refinements. The potential for incorporating additional processes into the model using satellite observables and enhancing the retrieval methods for the required inputs will be evaluated. Relationships identified between gas transfer processes and surface observations will be tested for suitability on the spatial scale of satellite observations. Refinements to the gas transfer parameterization will be pursued in collaboration with surface-based studies.

2011 NASA Carbon Cycle & Ecosystems Joint Science Workshop Poster(s)

• Assessment of gas transfer velocities computed from the COARE gas transfer model using satellite-derived inputs   --   (Gary A Wick, Darren L Jackson)   [abstract]

2008 NASA Carbon Cycle & Ecosystems Joint Science Workshop Posters

• Preliminary Satellite-Derived Estimates of the Gas Transfer Velocity   --   (Gary A Wick, Darren L Jackson)   [abstract]   [poster]

More details may be found in the following project profile(s):

• NASA Ocean Biology & Biogeochemistry (OBB) Project Profile