A global OClO stratospheric layer discovered in GOMOS stellar occultation measurements



[1] The stratospheric ozone depletion observed in polar regions is caused by several catalytic cycles induced by reactive chlorine and bromine species. By reacting with BrO, ClO causes the formation of OClO which is considered as a proxy of the halogen activation. We present the first global determination of the stratospheric OClO distribution measured during the year 2003 by the stellar occultation spectrometer GOMOS. Besides its expected polar abundance, we discovered the presence of a worldwide OClO layer in the upper stratosphere. At lower altitudes, OClO seems also to be present beyond the limit of the polar vortices, an unreported feature.