HR: 10:50h
AN: A12B-02    [Abstracts]
TI: OOTI (Out On The Ice)
AU: Hoenninger, G
A12B-02 AF: Department of Chemistry and Geophysical Institute, University of Alaska Fairbanks, Fairbanks, AK 99775-6160 United States
AU: Hoenninger, G
A12B-02 AF: Air Quality Research Branch, Environment Canada, 4905 Dufferin Street, Toronto, ON M3H 5T4 Canada
AU: Staebler, R
A12B-02 AF: Air Quality Research Branch, Environment Canada, 4905 Dufferin Street, Toronto, ON M3H 5T4 Canada
AU: Morin, S
A12B-02 AF: Air Quality Research Branch, Environment Canada, 4905 Dufferin Street, Toronto, ON M3H 5T4 Canada
AU: Morin, S
A12B-02 AF: Laboratoire de Glaciologie et G‚ophysique de l'Environnement, 54 rue Moliere, BP 96, St Martin d'HŠres Ce, 38402 France
AU: Netcheva, S
A12B-02 AF: Air Quality Research Branch, Environment Canada, 4905 Dufferin Street, Toronto, ON M3H 5T4 Canada
AU: Simpson, W
A12B-02 AF: Department of Chemistry and Geophysical Institute, University of Alaska Fairbanks, Fairbanks, AK 99775-6160 United States
AU: Savarino, J
A12B-02 AF: Laboratoire de Glaciologie et G‚ophysique de l'Environnement, 54 rue Moliere, BP 96, St Martin d'HŠres Ce, 38402 France
AU: * Bottenheim, J
EM: Jan.Bottenheim@ec.gc.ca
AF: Air Quality Research Branch, Environment Canada, 4905 Dufferin Street, Toronto, ON M3H 5T4 Canada
AB: Ozone depletion episodes in the Arctic spring are believed to be driven by BrOx chemistry where the active bromine originates from activation of sea-salt bromide. As a result of extensive laboratory studies, intensive field campaigns and modeling exercises there is broad consensus about the mechanism of depletions although the trigger that initiates the halogen chemistry is still unclear. Most measurements of the phenomenon are made at coastal observatories, and there is ample reason to suggest that ozone (and the related mercury) depletion episodes at those locations appear episodic due to meteorological modulation implying that the rate of change in the ozone concentration or its duration has little bearing on the mechanism or timescale of the depletion process itself. We therefore developed a small, highly mobile instrument package that could be transported on the frozen Arctic ocean to try to observe the depletion process in situ. Of special interest were areas of frost flowers in view of the wide speculation that these features might be prime candidates to enhance the BrOx cycles and hence accelerate the ozone depletion process. The package was deployed in 2004 near Alert NU, and in 2005 near Barrow AK. Near Alert the ocean was completely frozen and hence frost flowers were virtually absent. The Barrow campaign took place at the edge of the annual open lead, and some measurements were made close to large fields of frost flowers. The 2004 results convincingly showed a rapid change in the ozone concentration due to changes in air mass transport. Results from the 2005 campaign were more complicated. The most striking result appears to be the lack of strong signals in the BrO concentrations over frost flower fields. We will explore the implications of these and other results from the OOTI campaigns in the context of the OASIS program.
DE: 0365 Troposphere: composition and chemistry
DE: 0368 Troposphere: constituent transport and chemistry
DE: 9315 Arctic region (0718, 4207)
SC: Atmospheric Sciences [A]
MN: Fall Meeting 2005