Ozone accommodation coefficients

Tang, I. N. Lee, J. H. Accommodation coefficients of ozone and sulfur dioxide Their implications on SO2 oxidation in cloud water. American Chemical Society Symposium Series,... 

Accommodation Coefficients of Ozone and S02 Implications on S02 Oxidation in Cloud Water... 

Interfacial mass transfer of trace gases into aqueous pnase is investigated in a UV absorption-stop flow apparatus. For the first time, the mass accommodation coefficients are determined for O3 (5.3x10" ) and for SO2 (>2x10 2) The results are incorporated into a simple model considering the coupled interfacial mass transfer and aqueous chemistry in cloud drops. It is shown that dissolution of O3 into a drop is fast compared with its subsequent oxidation of dissolved S02 In addition, the conversion rate of S(IV) to S(VI) in aqueous drops by ozone reactions is not limited by interfacial resistance. 

The mass accommodation coefficients have been measured for the first time for O3 and SO2 on water surfaces. Model studies using the measured accommodation coefficients indicate that the conversion rate of S(IV) to S(VI) in aqueous drops by ozone reactions is not limited by interfacial resistance. 

Absorption, HSC>3, 180 Accommodation coefficients calculations, 111 measurements, 104-105 ozone, 109-116 sulfur dioxide, 109-116,154 Accuracy, estimation for an instrument, 188 Acetate ions, introduction into precipitation, 219-227 Acetic acid... 

The rate-determining step in this reaction sequence is reaction (reaction (2.85)) making ozone destruction linearly dependent on [XO]. The fraction of HOX that photolyses to give back OH depends critically on the accommodation coefficient of HOX on aerosols. Currently, there is a large uncertainty in this parameter. An important side effect of Cycle II is the potential for the reduction of the [H02]/[0H] ratio by consumption of HO2. The inorganic halogen chemistry described is summarised in Figure 24. 

---