Air--sea gas transfer and micro turbulence at the ocean surface using infrared image processing

To obtain an insight into the transfer process at the air-water interface new techniques for the quantitative investigation of the gas exchange have been developed. The controlled flux technique, CFT (Jahne et al. 1989) uses heat as a proxy tracer for gases to measure the air-sea gas transfer velocity with a high spatial and temporal resolution. The results of a field cruise and a laboratory study are discussed and compared with a model (Schimpf et al.) predicting the sea surface temperature distribution based on surface renewal (Danckwerts 1970). The sea surface temperature fluctuations associated with the interplay of diffusive and turbulent transport give direct insight into the mechanisms of gas transfer. Using infrared image processing the spatial structure of the micro turbulence at the ocean surface is analyzed.