Estimating the abundance of ClO from simultaneous remote sensing measurements of HO2, OH, and HOCl

Using a simple photochemical model we derive the mixing ratio profile of ClO in the altitude range 20–38 km from simultaneous measurements of HO2, OH, HOCl, temperature, pressure, and ozone. The measurements were made with the FIRS-2 far-infrared spectrometer during a balloon flight on September 29, 1992. We compare the derived ClO with the ClO profile obtained by the SLS instrument while flying on the same gondola. The good agreement between the two profiles validates our simple model and confirms the relevant rate constants and photolysis cross sections.