Air-sea gas transfer for two gases of different solubility (CO2 and O2)

7th International Symposium on Gas Transfer at Water Surfaces

Rutgersson, A.^1 ; Andersson, A.^1 ; Sahlée, E.^1

Department of Earth Sciences, Uppsala University, Uppsala, Sweden^1

关键词: Eddy covariance technique;    Enhanced efficiency;    High frequency measurements;    Least square fits;    Luminescence lifetime;    Measuring sites;    Microscale wave breaking;    Transfer velocity;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/35/1/012010/pdf
DOI  :  10.1088/1755-1315/35/1/012010

来源: IOP

【 摘 要 】

At the land-based marine measuring site Östergarnsholm in the Baltic Sea, the eddy covariance technique was used to measure air-sea fluxes of carbon dioxide and oxygen. High- frequency measurements of oxygen were taken with a Microx TX3 optode using the luminescence lifetime technique. The system gives reasonable oxygen fluxes after the limited frequency response of the sensor was corrected for. For fluxes of carbon dioxide the LICOR-7500 instrument was used. Using flux data to estimate transfer velocities indicates higher transfer velocity for oxygen compared to carbon dioxide for winds above 5 m/s. There are too few data for any extensive conclusions, but a least-square fit of the data gives a cubic wind speed dependence of oxygen corresponding to k660= 0.074U310. The more effective transfer for oxygen compared to carbon dioxide above 5 m/s is most likely due to enhanced efficiency of oxygen exchange across the surface. Oxygen has lower solubility compared with carbon dioxide and might be more influenced by near surface processes such as microscale wave breaking or sea spray.