Stratospheric photochemical studies using Nimbus 7 data: 2. Development of inferred trace specie distributions

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Abstract
The limb infrared monitor of the stratosphere, stratospheric and mesospheric sounder, and solar backscatter ultraviolet satellite measurements of stratospheric T, O3, NO2, HNO3, H2O, CH4, and solar flux are used in conjunction with a zero‐dimensional, stratospheric, photochemical model to infer distributions of other constituents. For periods in October and December 1978 and in March and May 1979, latitude‐altitude distributions of O(3P), O(1D), OH, HO2, H2O2, NO, NO3, N2O5, HNO4, HCℓ, Cℓ, CℓO, CℓNO3, HOCℓ, total odd nitrogen, and total odd hydrogen are derived and presented. Results are presented for altitudes from 20.5 km to 53.5 km and for latitudes from 60°S to 80°N with some variation depending upon season. The techniques used are described. They require the specification of the distribution of the total odd chlorine due to the absence of satellite measurements of chlorine species. Two‐dimensional model results for odd chlorine, scaled to provide the required level of total odd chlorine for the 1978–1979 time period, were used. Sensitivity of results to input values of CH4 (for which some extrapolation was required) and odd chlorine is presented and discussed. Uncertainties in the inferred species due to uncertain chemical rates, cross sections, and measurement errors are presented. Results provide a useful climatology of these infrequently measured species for the four time periods. Of particular interest are maximum odd nitrogen (≡NO + NO2 + NO3 + HNO3 + HNO4 + CℓNO3 + 2 × N2O5) levels which range between 24 and 27 ppbv, significantly higher than predicted by most contemporary models.