Uptake coefficient of H₂O₂ on ice

Abstract. H₂O₂ uptake coefficients on ice surfaces, over a temperature range from 190 to 220 K, have been studied in a flow reactor coupled with a differentially pumped quadrupole mass spectrometer. The initial uptake coefficient increases with an increase in H₂O₂ pressure and a decrease in temperature. The results were analyzed using surface kinetics, and the analysis shows that the uptake involves both H₂O₂ adsorption and surface aggregation. H₂O₂ desorption kinetics supports lateral attractive interactions among adsorbed H₂O₂ on ice. The result can be used to model the heterogeneous H₂O₂ loss on snow/ice surfaces and cirrus clouds as a function of the H₂O₂ concentration and temperature.