The transport of trace gaseous species from the bulk atmosphere across aqueous surfaces was studied in order to determine the relevant uptake coefficients. A direct observation of the distribution of the trace species in the gas phase above the surface between the gas and aqueous phase was conducted in an impinging flow field using a laser-spectroscopic detection technique. By analyzing the experimental results and comparing them to simulation results, the applicability of the present method to obtaining the uptake coefficients was demonstrated in the case of SO2.