Modeling Halogen Chemistry during Ozone Depletion Events in Polar Spring: A Model Study

• Main Author: Piot, Matthias
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: 2007
• Subjects: 530; 530 Physics; Antarc*; Antarctic; Arctic
• Online Access: https://archiv.ub.uni-heidelberg.de/volltextserver/7876/; https://archiv.ub.uni-heidelberg.de/volltextserver/7876/1/PhD_thesis.pdf; https://doi.org/10.11588/heidok.00007876; https://nbn-resolving.org/urn:nbn:de:bsz:16-opus-78764

This thesis presents box and one-dimensional model results of the halogen chemistry during springtime Ozone Depletion Events in the polar boundary layer. These tropospheric ozone depletions occur regularly in spring, both in the Arctic and Antarctic and last from several hours to several days. Catalytic cycles involving reactive halogens are responsible for the rapid ozone depletion. The main intention of these model studies was to investigate, first, the chemistry influencing the occurrence of these ozone depletions, namely, the role of HCHO, H2O2, DMS, Cl2, C2H4, C2H6, HONO, NO2, and RONO2. Second, the potential importance of frost flowers, recycling on snow, and open leads for these depletions was investigated. The importance of calcium carbonate precipitation out of the brine, the influence of an “Arctic Haze” event and the potential direct release of bromine from frost flowers were also investigated. Third, the iodine chemistry in the Antarctic was investigated, and the likelihood of the different potential sources of iodine was evaluated. A strong flux of molecular iodine, prescribed from the surface, was found necessary to induce observed mixing ratios of IO and OIO in the gas phase.