Mass transport and recycling of molecular haloens near the snowpack surface in Barrow, Alaska
Abstract
Oxidation pathways in the Arctic springtime atmosphere are often controlled by halogen chemistry. Molecular halogens are produced from the sunlit surface snowpack above coastal tundra, as well as sea ice. However, the magnitude of molecular halogen production from coastal snowpacks is not well constrained, and little is known about the extent of near-surface vertical mixing and the importance of recycling on aerosols. Here we present the first vertical profile measurements of halogens more than 1 m above the snowpack and the first high frequency (2 Hz) measurements of the molecular halogens (Br2 and Cl2), which were made using chemical ionization mass spectrometry in Barrow, Alaska during March and April 2016 as part of the PHOX:MELT (Photochemical Halogen and Ozone eXperiment : Mass Exchange in the Lower Troposphere) campaign. High frequency halogen data will be used to estimate fluxes of molecular halogens (Cl2 and Br2) from the coastal Arctic snowpack. Additionally, vertical profiles of Br2 and Cl2 between 1 m and 7 m above the snowpack will be used to examine the sources, sinks, and recycling of halogens near the coastal Arctic tundra. Vertical profiles of aerosol number concentrations will also allow for the examination of the importance of halogen recycling on aerosols. These data will inform one-dimensional modeling of near-surface halogen chemistry, constrained by measurements of near surface turbulence.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2016
- Bibcode:
- 2016AGUFM.C13A0802R
- Keywords:
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- 0305 Aerosols and particles;
- ATMOSPHERIC COMPOSITION AND STRUCTUREDE: 0365 Troposphere: composition and chemistry;
- ATMOSPHERIC COMPOSITION AND STRUCTUREDE: 0736 Snow;
- CRYOSPHEREDE: 0750 Sea ice;
- CRYOSPHERE