Aircraft search for millimeter‐wavelength emission by stratospheric ClO

Abstract

Three millimeter‐wavelength transitions of ClO were searched for in the stratospheric emission spectrum during May–August 1977 using aircraft‐based instruments. The measurements indicate that if stratospheric ClO has a vertical distribution of the form predicted by present photochemical models, then the ClO volume mixing ratio at the profile peak did not exceed 10 −9 at the time and place of the measurements. The observed spectra suggest the presence of ClO in the stratosphere but do not provide a definitive detection.