Examining the role of sea ice and meteorology in Arctic boundary layer halogen chemistry
Dissertation (Ph.D.) University of Alaska Fairbanks, 2015 Given the ubiquitous nature of ice, chemistry taking place on ice surfaces has a substantial effect on the environment, particularly in the polar regions. The return of sunlight to the polar regions releases halogen radicals (e.g. Br, Cl and...
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ftunivalaska:oai:scholarworks.alaska.edu:11122/5755 2023-05-15T14:53:11+02:00 Examining the role of sea ice and meteorology in Arctic boundary layer halogen chemistry Peterson, Peter Kevin Simpson, William Trainor, Thomas Tape, Carl Douglas, Thomas 2015-05 http://hdl.handle.net/11122/5755 en_US eng http://hdl.handle.net/11122/5755 Department of Chemistry and Biochemistry Dissertation phd 2015 ftunivalaska 2023-02-23T21:36:30Z Dissertation (Ph.D.) University of Alaska Fairbanks, 2015 Given the ubiquitous nature of ice, chemistry taking place on ice surfaces has a substantial effect on the environment, particularly in the polar regions. The return of sunlight to the polar regions releases halogen radicals (e.g. Br, Cl and their oxides, e.g. BrO) generated from salts on ice surfaces. These radicals fundamentally alter the chemistry of the Arctic boundary layer through processes such as boundary-layer ozone depletion events and mercury deposition events. Current understanding of the chemical processes involved in Arctic halogen chemistry is inhibited by a lack of knowledge about the ice surfaces on which this chemistry is thought to take place, as well as the sparsity of long-term field observations of this chemistry and its effects. This dissertation addresses both needs through a combination of laboratory experiments and long-term field studies. First, we use X-ray absorption computed micro-tomography at the Advanced Photon Source to image brine distributions within laboratory grown mimics of sea-ice features. These experiments showed that when brine is introduced to ice via wicking of brine from a saline surface, the resulting brine distribution is heterogeneous, with brine existing in distinct regions within the sample, rather than evenly spreading over the sample surface. To examine the horizontal and vertical extent of halogen chemistry in the Arctic boundary layer, we conducted long-term measurements of BrO at Barrow, Alaska using Multiple-Axis Differential Optical Absorption Spectroscopy (MAX-DOAS). We developed a method to reduce these measurements to timeseries of near-surface and total column amounts of BrO. These measurements showed that the vertical distribution is highly variable, ranging from shallow layer events confined to the lowest 200 m, to distributed column events, which have lower mixing ratios of BrO, but are more distributed throughout approximately the lowest kilometer of the atmosphere. We find that the ... Doctoral or Postdoctoral Thesis Arctic Barrow Sea ice Alaska University of Alaska: ScholarWorks@UA Arctic Fairbanks |
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Open Polar |
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University of Alaska: ScholarWorks@UA |
op_collection_id |
ftunivalaska |
language |
English |
description |
Dissertation (Ph.D.) University of Alaska Fairbanks, 2015 Given the ubiquitous nature of ice, chemistry taking place on ice surfaces has a substantial effect on the environment, particularly in the polar regions. The return of sunlight to the polar regions releases halogen radicals (e.g. Br, Cl and their oxides, e.g. BrO) generated from salts on ice surfaces. These radicals fundamentally alter the chemistry of the Arctic boundary layer through processes such as boundary-layer ozone depletion events and mercury deposition events. Current understanding of the chemical processes involved in Arctic halogen chemistry is inhibited by a lack of knowledge about the ice surfaces on which this chemistry is thought to take place, as well as the sparsity of long-term field observations of this chemistry and its effects. This dissertation addresses both needs through a combination of laboratory experiments and long-term field studies. First, we use X-ray absorption computed micro-tomography at the Advanced Photon Source to image brine distributions within laboratory grown mimics of sea-ice features. These experiments showed that when brine is introduced to ice via wicking of brine from a saline surface, the resulting brine distribution is heterogeneous, with brine existing in distinct regions within the sample, rather than evenly spreading over the sample surface. To examine the horizontal and vertical extent of halogen chemistry in the Arctic boundary layer, we conducted long-term measurements of BrO at Barrow, Alaska using Multiple-Axis Differential Optical Absorption Spectroscopy (MAX-DOAS). We developed a method to reduce these measurements to timeseries of near-surface and total column amounts of BrO. These measurements showed that the vertical distribution is highly variable, ranging from shallow layer events confined to the lowest 200 m, to distributed column events, which have lower mixing ratios of BrO, but are more distributed throughout approximately the lowest kilometer of the atmosphere. We find that the ... |
author2 |
Simpson, William Trainor, Thomas Tape, Carl Douglas, Thomas |
format |
Doctoral or Postdoctoral Thesis |
author |
Peterson, Peter Kevin |
spellingShingle |
Peterson, Peter Kevin Examining the role of sea ice and meteorology in Arctic boundary layer halogen chemistry |
author_facet |
Peterson, Peter Kevin |
author_sort |
Peterson, Peter Kevin |
title |
Examining the role of sea ice and meteorology in Arctic boundary layer halogen chemistry |
title_short |
Examining the role of sea ice and meteorology in Arctic boundary layer halogen chemistry |
title_full |
Examining the role of sea ice and meteorology in Arctic boundary layer halogen chemistry |
title_fullStr |
Examining the role of sea ice and meteorology in Arctic boundary layer halogen chemistry |
title_full_unstemmed |
Examining the role of sea ice and meteorology in Arctic boundary layer halogen chemistry |
title_sort |
examining the role of sea ice and meteorology in arctic boundary layer halogen chemistry |
publishDate |
2015 |
url |
http://hdl.handle.net/11122/5755 |
geographic |
Arctic Fairbanks |
geographic_facet |
Arctic Fairbanks |
genre |
Arctic Barrow Sea ice Alaska |
genre_facet |
Arctic Barrow Sea ice Alaska |
op_relation |
http://hdl.handle.net/11122/5755 Department of Chemistry and Biochemistry |
_version_ |
1766324594632818688 |