Comparison of ClO measurements by airborne and spaceborne microwave radiometers in the Arctic winter stratosphere 1993

In February 1993 measurements of chlorine monoxide ClO, one of the key substances in catalytic ozone destruction, were performed over Scandinavia by two microwave receivers, the Submillimeter Atmospheric Sounder (SUMAS) on board the German research aircraft FALCON and the Microwave Limb Sounder (MLS) on board the Upper Atmospheric Research Satellite (UARS). High ClO concentrations (>1ppb) inside the polar vortex at approximately 20km altitude were detected by both experiments. A comparison shows good agreement of both sensors in the location of enhanced ClO.