Airborne measurements during the Arctic Stratospheric Experiment: Observation of O 3 and NO 2

During winter 1991/92 DOAS (Differential Optical Absorption Spectroscopy) measurements were performed from a C130 Transall aircraft within the framework of the EASOE (European Arctic Stratospheric Ozone Experiment) campaign. The campaign extended from Dec. 1991 until March 1992 with a series of flights in the Arctic (60° W to 60° E , 85° N to 48° N ). Two spectrometers were operated on the aircraft: an UV‐instrument (see Brandtjen et al., this issue) and a DOAS‐vis instrument to detect O 3 , O 4 , NO 2 and NO 3 in the visible band (363 nm–680 nm). The DOAS‐vis ozone measurements were largely influenced by the presence of the Mt Pinatubo aerosol cloud. A correction of the data by actual Mie‐profiles is described. A NO 2 depletion with minimum values of 2.3*10 14 / cm ² in Jan. 92 was observed. Occasionally, OClO could also be detected.