Sulfur Dioxide Fluorescence Imaging

Sulfur dioxide is an ideal tracer to study the partitioning of the resistance of gas transfer across the water interface between air and water because the pH value in water controls the effective solubility of sulfur dioxide. Friman and Jähne (2019) already demonstrated that it is possible to measure sulfur dioxide concentration profiles with laser induced fluorescence (LIF), but the best excitation wavelength under standard atmosphericconditions was not known. Here, we report the result of our investigation to select the best excitation wavelength for sulfur dioxide fluorescence to reach maximum intensity with the lowest possible absorption.