Quantification of the chemical ozone loss in the northern and southern polar vortices using SCIAMACHY limb measurements

• Main Author: Sonkaew, Thiranan
• Other Authors: Burrows, John, Schrems, Otto
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: Universität Bremen 2010
• Subjects: Stratospheric ozone loss; Polar vortex; Diabatic ozone descend; SCIAMACHY; Limb measurement; 550; 550 Earth sciences and geology; ddc:550; Antarctic; Arctic; albedo; Antarc*
• Online Access: https://media.suub.uni-bremen.de/handle/elib/2759; https://nbn-resolving.org/urn:nbn:de:gbv:46-diss000117402

This study deals with the retrieval of stratospheric and lower mesospheric ozone profiles from satellite observations of limb--scattered solar radiation with SCIAMACHY on the Envisat satellite. The retrieval combines spectral information in the Chappuis and Hartley absorption bands of ozone and employs the SCIATRAN radiative transfer model. The retrieved ozone profiles are applied into two aspects.First, the sensitivity of the ozone profile retrieval to tropospheric clouds is examined using the SCIATRAN radiative transfer model. The considered clouds are vertically and horizontally homogeneous. An aerosol-free atmosphere and Mie phase functions for cloud particles are assumed. Neglecting clouds in the retrieval, the relative errors of ozone profile retrievals in a cloudy atmosphere are computed. The cloud sensitivity of the limb ozone retrievals is significant in the Chappuis bands at lower stratospheric altitudes. The relative error in the retrieved ozone concentrations gradually decreases with increasing altitude and becomes negligible above approximately 40 km. Cloud optical thickness, ground albedo and solar zenith angle have a large impact on the ozone retrievals. For a given cloud optical thickness value, clouds with different geometrical thicknesses or different cloud altitudes have a similar impact on the ozone retrievals, if the clouds are outside the field of view of the instrument. The effective radius of water droplets and the solar azimuth angle has a small influence on the error. Neglecting clouds in the ozone profile retrievals generally leads to a low bias. For the most frequent cloud types, the total error is below 6% above 15 km altitude, if clouds are completely neglected in the retrieval. Second, the stratospheric and lower mesospheric ozone profile data set of SCIAMACHY measurements of limb-scattered solar radiation in the period 2002-2009 is used to determine the chemical ozone loss in both the Arctic and Antarctic polar vortices using the vortex average method. The vortex boundary is ...