Application of ALOS/PALSAR to estimate carbon dioxide transfer velocities compared with satellite wind speed data 2007–2008

Abstract

Gas exchange contributes to the mitigation of an anthropogenic greenhouse effect through absorption of excess atmospheric CO₂ by the oceans. The gas transfer velocity requires computation in order to describe gas exchange and interaction. The absolute calibration of the relationship between air and sea CO₂ transfer velocity and wind speed (U ₁₀) has been under debate for a long time because the global averages of the CO₂ exchange coefficients, deduced from many experimental data relationships, disagreed with each other. In this research, the CO₂ transfer velocity () was derived from satellite wind speeds that were computed using three different parameterizations (k–U) and was then compared with the derived from Phased Array type L-band Synthetic Aperture Radar (PALSAR) (k _P). To obtain the transfer velocity of CO₂ between the atmosphere and ocean using PALSAR in the Bali Sea area close to the Indian Ocean, daily sea surface temperature, wind friction velocity (U*) from PALSAR images and oceanography data were collected and analysed. Additionally, values were computed from the QuikSCAT satellite wind speed and compared to three different k–U relationships suggested by different authors. The three algorithms of parameterization were used with QuikSCAT daily data and produced a value that was close to that of derived from PALSAR (k _P).

Acknowledgements

The work presented in this article was supported by the Centre of Remote Sensing and Ocean Science (CReSOS) and a Department of National Education (DIKNAS) scholarship from the Indonesia government.