THEORETICAL INTERPRETATION OF N2O5 MEASUREMENTS

Recent measurements by Webster et al. [1990] have confirmed quantitatively the chemistry controlling the night-time decay of NO2. Simple equations describing the night-time behaviour of NO2 and N2O5 are presented here. With measurements of the night-time ozone and NO2 concentrations, these equations can be used to predict the amount of N2O5 produced at any time during the night. In this way the N2O5 night-time emission measurement of Roscoe [1982], Kunde et al. [1988] and sunrise measurements of the ATMOS experiment [Rinsland et al., 1989] are all used to test theory. The measurements are found to be both self consistent and confirm our understanding of night-time NO2 conversion to N2O5. The variation of N2O5 by a factor of two between measurements is found to be consistent with theory.