Die Ozonverteilungen der Nordhemisphäre 1997 - 2000 gemessen mit GOME: Einfluss von Dynamik und Chemie in der Stratosphäre

Abstract

Measurements of stratospheric ozone over the Northern hemisphere forthe winter/spring periods of 1997 to 2000 taken with the GOMEinstrument were used to derive the chemical ozone depletion inside thepolar vortex. GOME onboard the ERS-2 satellite measures radiationcoming from the Earth in the UV/vis spectral range.To discern the chemical depletion from dynamical influences, a modelwas developed to calculate vortex averaged diabatic descent ratesusing the radiative transfer model MIDRAD and the FURM ozoneprofiles. The permeability of the Arctic vortex was analysed by usingthe trajectory model TANGO in conjunction with a reverse domainfilling algorithm, developed within the framework of this thesis.The chemical ozone depletion at 475 K for the stratospheric coldwinter/spring period in 1997 was found to be 1.6 ppmv with a depletionrate of 22 ppbv/d for a strong, long lasting vortex until beginning ofMay. The chemical depletion of ozone in 1998, a comparingly warm year,was narrowed to a period at the end of February with 0.5 ppmv and arate of 8 ppbv/d. 1999 was quite warm and the vortex was veryinstable. A depletion of 0.3 ppmv was measured, but this is in partdue to intrusion of air from outside the vortex. 2000 was the coldestyear on record. The vortex was detected very early by GOME at the endof January. A chemical depletion of 1.8 ppmv (32 ppbv/d) until thebeginning of April was found, when the vortex broke down.