High concentrations of chlorine monoxide at low altitudes in the Antarctic spring stratosphere: secular variation (original) (raw)
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Abstract
We have reported the observation of millimetre-wave emission from abnormally high concentrations of chlorine monoxide, ClO, in the lower stratosphere over McMurdo Station, Antarctica during the period 1-22 September 1986 and demonstrated1 its diurnal behaviour. Here we report on the secular variation of daytime ClO in the lower stratosphere with a time resolution of 4 or 5 days, during the period 1 September to 16 October. We show that the ClO concentration declines during the latter half of September and disappears by early October. As ClO is directly involved in a catalytic ozone destruction cycle, these observations give evidence that the Antarctic ozone hole2 is caused by a chemical depletion mechanism which operates in the early spring. This is also consistent with models in which large quantities of ClO are maintained through chemical reactions3-5 on the surface of polar stratospheric cloud particles which evaporate with the warming of the stratosphere.
Publication:
Nature
Pub Date:
July 1987
DOI:
Bibcode: