Impacts of Recent Perennial Sea Ice Reduction on BrO Observations at Barrow, Alaska
Abstract
Polar sunrise in the Arctic has been associated with production of reactive halogens from sea salt(e.g. Br, BrO). While effects of these halogen species are well known(e.g. ozone depletion, mercury deposition), their production is not fully understood, but thought to be linked to heterogeneous chemistry taking place on saline ice surfaces(e.g saline snow, first year sea ice). Given the recent decline of perennial sea ice in the Arctic, it is imperative to understand the role of younger, more saline, first year ice in halogen activation processes. We used multiple axis differential optical absorption spectroscopy(MAX-DOAS) at Barrow, Alaska to observe BrO during the spring/early summer of 2008,2009,2012, and 2013. While average BrO boundary layer vertical column densities(BL-VCD) agreed within error during 2008 and 2009, the average observed BL-VCD doubled from 1e13 mol/cm^2 in 2008 and 2009, to 2e13 mol/cm^2 in 2012. We explore potential explanations for this observed increase using satellite maps of synoptic sea ice classes, MODIS imagery of local sea ice features, and back trajectory modelling. Potential impacts of the 2012 record minimum sea ice extent on observed halogen activation during the spring of 2013 are also discussed.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2013
- Bibcode:
- 2013AGUFM.C12A..02P
- Keywords:
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- 0365 ATMOSPHERIC COMPOSITION AND STRUCTURE Troposphere: composition and chemistry;
- 0750 CRYOSPHERE Sea ice