High concentrations of chlorine monoxide at low altitudes in the Antarctic spring stratosphere: diurnal variation

Abstract

The Stony Brook ground-based remote sensing mm-wave spectrometer was used to measure chlorine monoxide in the stratosphere over McMurdo Station, Antarctica during the austral spring of 1986. From the data collected, we find strong evidence for abnormally high concentrations of CIO at low altitudes—as much as two orders of magnitude greater than standard theories predict at 20-km altitude at mid-latitudes. This low-altitude CIO changes cyclically on a diurnal basis, and also secularly during the September–October observing period. A study of the diurnal variation of the low-altitude ClO is presented here. We conclude that chlorine is crucially involved in the springtime destruction of Antarctic ozone.