The odd hydrogen species, especially OH and HO2 are important in the chemistry of the natural stratosphere because of their direct reactions with O and O3 and their role in nitrogen oxide (NOx) cycles. When chlorine is added to the stratosphere the interaction of NOx, HOx and ClX species yields several potential feedback effects for O3 perturbations, some stabilizing and some destabilizing. Here we focus on the effects of HOx on O3 changes due to ClX injections. As ClX selectively attacks the ozone layer above 28 km the layer below tends to be thickened by the increased incidence of solarUV. If HOx densities are high they dampen this radiative feedback and prevent the healing at low altitudes. We demonstrate how the ozone‐layer shape changes under the influence of injected ClX for several choices of key HOx reaction rates. These same reaction rates exert partial control over the apportioning of Cl atoms among HCl, ClO and Cl, over the total amount of HOx, the ratios of OH to HO2 and H2O2 and the ratio of [NO + NO2] to [HNO3]. The uncertainty in these rates leads to at least a factor of three uncertainty in predicted ozone reductions due to ClX injections. © 1976 by the Chinese Geophysical Society

Results are described of a self consistent one dimensional coupled flow calculation for O(x), NO(x), HO(x), ClX, H2O, H2, CH4, H2O2, and N2O densities between 10 and 120 km. The results agree well with observations for the normal mid latitude atmosphere over this altitude range. ClX, NO(x) and H2O were varied independently in the model. It is shown that the effect of depletion of ozone by ClX is to remove ozone preferentially above 30 km and to lower the altitude of maximum ozone density. This leads to enhanced solar heating of the lower stratosphere and tropopause and suggests the possibility of an increased flux of water into the stratosphere. Increasing water vapor in the stratosphere greatly enhances the rate of destruction of O3 by ClX and also causes an increase in the rate of destruction of O3 in the NO(x) perturbed atmosphere.

Stratospheric ozone is destroyed catalytically by nitrogen oxides originating from N2O produced by denitrifying bacteria at the surface of the earth. Concern has been expressed that major perturbations in N2O production will result by the beginning of the 21st century because of increased use of industrially produced fertilizers. It is pointed out here that the reservoir of fixed nitrogen is so large that the time required to produce a significant increase in N2O production from denitrification is probably many hundreds of years. Copyright 1976 by the American Geophysical Union.