Articles | Volume 4, issue 5
Atmos. Chem. Phys., 4, 1407–1417, 2004
Atmos. Chem. Phys., 4, 1407–1417, 2004

  27 Aug 2004

27 Aug 2004

Investigation of Arctic ozone depletion sampled over midlatitudes during the Egrett campaign of spring/summer 2000

D. E. M. Ross1,*, J. A. Pyle1,2, N. R. P. Harris1,3, J. D. McIntyre1, G. A. Millard1, A. D. Robinson1, and R. Busen4 D. E. M. Ross et al.
  • 1Centre for Atmospheric Sciences, Department of Chemistry, University of Cambridge, Cambridge, UK
  • 2NCAS-ACMSU, Department of Chemistry, University of Cambridge, Cambridge, UK
  • 3European Ozone Research Coordinating Unit, University of Cambridge, Cambridge, UK
  • 4Deutsches Zentrum für Luft- und Raumfahrt (DLR), Oberpfaffenhofen, Germany
  • *now at: JMP Consulting, London, UK

Abstract. A unique halocarbon dataset has been obtained using the Australian high altitude research aircraft, the Grob G520T Egrett, during May-June 2000 with GC instrument (DIRAC), which has been previously deployed on balloon platforms. The halocarbon data generally shows a good anticorrelation with ozone data obtained simultaneously from commercial sensors. On 5 June 2000, at 380K, the Egrett entered a high latitude tongue of air over the U.K. CFC-11 and O3 data obtained on the flight show evidence of this feature. The dataset has been used, in conjunction with a 3D chemical transport model, to infer ozone depletion encountered in the midlatitude lower stratosphere during the flight. We calculate that ozone is depleted by 20% relative to its winter value in the higher latitude airmass. A suite of ozone loss tracers in the model have been used to track ozone depletion according to location relative to the vortex and chemical cycle responsible. The model, initialised on 9 December, indicates that 50% of the total chemical ozone destruction encountered in June in the middle latitudes occurred in the 90-70°N equivalent latitude band and that 70% was due to halogen chemistry.

Final-revised paper