From mean fluxes to a detailed experimental investigation of the gas transfer process

Three new experimental techniques are discussed which allow a much more detailed investigation of the gas transfer process than any previous techniques. Using heat as a proxy tracer for gases allows to control the flux across the interface and to measure the local transfer rate with a time resolution of several minutes in the field. The two other techniques are based on acid and alkaline gases and fluorescent pH indicators. They are used in wind/wave tunnels to measure the spatial and temporal patterns of the thickness of the mass boundary layer and time series of vertical concentration profiles within the boundary layer.