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

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. Catal...

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Bibliographic Details
Main Author: Piot, Matthias
Format: Doctoral or Postdoctoral Thesis
Language:English
Published: 2007
Subjects:
530
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
Description
Summary: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.