Transfer of mass-independent fractionation in ozone to other oxygen-containing radicals in the atmosphere

Mass-independent fractionation (MIF) of ozone has been observed in both the troposphere and stratosphere. Because ozone is a photochemically active species, its MIF signature can be imparted to other atmospheric molecules. Using a photochemical equilibrium model for short-lived radical species, I have computed the expected MIF for typical mid-latitude conditions. The model accounts for about ˜ 70% of recent measurements of Δ¹⁷O for H₂O₂ in rainwater, and predicts large MIF for NO_x and CIO species (˜40-70 ‰), and their products (CIONO₂ and HNO₃). Furthermore, in the stratosphere oxygen exchange reactions between OH and NO_x yield OH with Δ¹⁷O from 2 to 45 ‰. Stratospheric water produced during H abstraction by OH would be similarly mass-independently fractionated. In the troposphere rapid exchange between OH and H₂O erases any MIF signature in OH. These model results depend on several O exchange reactions with unknown activation energies or with rate coefficients known only as upper limits.