INFERRING MIDDLE ATMOSPHERIC OZONE HEIGHT PROFILES FROM GROUND-BASED MEASUREMENTS OF MOLECULAR-OXYGEN EMISSION RATES .3. CAN TWILIGHT MEASUREMENTS OF THE ATMOSPHERIC BAND BE USED TO RETRIEVE AN OZONE DENSITY PROFILE

Measurements of emissions from atoms and molecules during twilight have been used to infer height profiles of various species in the atmosphere. The visible and near-infrared emissions from molecular oxygen can be used to retrieve a density height profile of ozone in the middle atmosphere. A time-dependent, four-species model of the volume emission rate of O2(1DELTA(g)) and O2(1SIGMA(g)) and the density profile of O(1D) and O3 is used to determine the suitability of the O2(1SIGMA(g)) emission to infer the O3 density. Previous studies in this series have shown the sensitivities of the model to input parameters other than ozone (part 1) and the usefulness of the O2(1DELTA(g)) emission rate to infer the shape of the O3 density profile from 50- to 110-km (part 2). The O2(1DELTA(g)) emission rate is favorable for this retrieval in part due to its long radiative lifetime (about 65 min). However, the O2(1SIGMA(g)) emission has a short radiative lifetime (12 s) and the emission rate changes rapidly during twilight. This paper details the difficulties in using the O2(1SIGMA(g)) emission to retrieve O3 profiles in the middle atmosphere. Whereas in principle the O2(1SIGMA(g)) emission can be used to retrieve O3 density profiles, in practice the temporal resolution required for the measurements may be beyond that of current airglow instrumentation.