Sources and Deposition Processes Linking Atmospheric Chemistry and Firn Records from Four Glacier Accumulation Zones in the McMurdo Dry Valleys, Antarctica
Samples of snow and firn from accumulation zones on the Victoria Upper Glacier, the Clark Glacier, the Commonwealth Glacier and the Blue Glacier in the McMurdo Dry Valleys (~77 to 78º S and 161 to 164º E), Antarctica, are evaluated chemically and isotopically to determine the relative importance of...
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ftmaineuniv:oai:digitalcommons.library.umaine.edu:etd-1105 2023-06-11T04:05:25+02:00 Sources and Deposition Processes Linking Atmospheric Chemistry and Firn Records from Four Glacier Accumulation Zones in the McMurdo Dry Valleys, Antarctica Williamson, Bruce R. 2006-01-01T08:00:00Z application/pdf https://digitalcommons.library.umaine.edu/etd/108 https://digitalcommons.library.umaine.edu/context/etd/article/1105/viewcontent/WilliamsonBR2006.pdf unknown DigitalCommons@UMaine https://digitalcommons.library.umaine.edu/etd/108 https://digitalcommons.library.umaine.edu/context/etd/article/1105/viewcontent/WilliamsonBR2006.pdf Electronic Theses and Dissertations glaciochemistry climatic changes Earth Sciences Glaciology text 2006 ftmaineuniv 2023-05-04T17:59:55Z Samples of snow and firn from accumulation zones on the Victoria Upper Glacier, the Clark Glacier, the Commonwealth Glacier and the Blue Glacier in the McMurdo Dry Valleys (~77 to 78º S and 161 to 164º E), Antarctica, are evaluated chemically and isotopically to determine the relative importance of local (site-specific) factors versus regional-scale climatic influences in defining regional glaciochemistry. Two approaches for distinguishing these controls are examined: comparing chemical concentrations using multivariate statistical analysis, and examining the effect of physical filtration (capturing particulate material largely originating in close proximity to each site) on sample values. These techniques provide constraints for interpretation of connections between Dry Valleys climate and the broader Ross Sea and East Antarctic Ice Sheet climate systems. Spatial variation in snow and firn chemistry confirms documented trends within individual valleys regarding ion deposition relative to elevation and to distance from the coast. The results here, however, demonstrate that intra-valley trends break down when chemistry is compared among valleys. Temporally, major ions (with the exception of methane sulfonate and to a lesser extent calcium ion) yield common seasonal signals at each site for the time period 1989 - 2002. Trace metals have concentration peaks offset from ion peaks; using Empirical Orthogonal Function (EOF) analysis to clarify this distinction, a secondary climate pattern accounting for ~13% to 33% of dataset variability contains opposing deposition patterns for 10-cm averages of major ions compared to corresponding 10-cm samples of trace metals. Differing resolutions between these data sets, however, dictate caution in this assessment. Site-specific exposure to marine and local chemical sources plays a dominant role over trends in elevation or in distance from the coast in defining snow and firn chemistry along the coastal axis of the Dry Valleys. Physical filtration of samples from the Victoria ... Text Antarc* Antarctic Antarctica Commonwealth Glacier E. Antarctica Ice Sheet McMurdo Dry Valleys Ross Sea The University of Maine: DigitalCommons@UMaine Antarctic Ross Sea McMurdo Dry Valleys East Antarctic Ice Sheet Blue Glacier ENVELOPE(164.167,164.167,-77.833,-77.833) Commonwealth Glacier ENVELOPE(163.317,163.317,-77.583,-77.583) Victoria Upper Glacier ENVELOPE(161.417,161.417,-77.267,-77.267) Clark Glacier ENVELOPE(162.417,162.417,-77.417,-77.417) |
institution |
Open Polar |
collection |
The University of Maine: DigitalCommons@UMaine |
op_collection_id |
ftmaineuniv |
language |
unknown |
topic |
glaciochemistry climatic changes Earth Sciences Glaciology |
spellingShingle |
glaciochemistry climatic changes Earth Sciences Glaciology Williamson, Bruce R. Sources and Deposition Processes Linking Atmospheric Chemistry and Firn Records from Four Glacier Accumulation Zones in the McMurdo Dry Valleys, Antarctica |
topic_facet |
glaciochemistry climatic changes Earth Sciences Glaciology |
description |
Samples of snow and firn from accumulation zones on the Victoria Upper Glacier, the Clark Glacier, the Commonwealth Glacier and the Blue Glacier in the McMurdo Dry Valleys (~77 to 78º S and 161 to 164º E), Antarctica, are evaluated chemically and isotopically to determine the relative importance of local (site-specific) factors versus regional-scale climatic influences in defining regional glaciochemistry. Two approaches for distinguishing these controls are examined: comparing chemical concentrations using multivariate statistical analysis, and examining the effect of physical filtration (capturing particulate material largely originating in close proximity to each site) on sample values. These techniques provide constraints for interpretation of connections between Dry Valleys climate and the broader Ross Sea and East Antarctic Ice Sheet climate systems. Spatial variation in snow and firn chemistry confirms documented trends within individual valleys regarding ion deposition relative to elevation and to distance from the coast. The results here, however, demonstrate that intra-valley trends break down when chemistry is compared among valleys. Temporally, major ions (with the exception of methane sulfonate and to a lesser extent calcium ion) yield common seasonal signals at each site for the time period 1989 - 2002. Trace metals have concentration peaks offset from ion peaks; using Empirical Orthogonal Function (EOF) analysis to clarify this distinction, a secondary climate pattern accounting for ~13% to 33% of dataset variability contains opposing deposition patterns for 10-cm averages of major ions compared to corresponding 10-cm samples of trace metals. Differing resolutions between these data sets, however, dictate caution in this assessment. Site-specific exposure to marine and local chemical sources plays a dominant role over trends in elevation or in distance from the coast in defining snow and firn chemistry along the coastal axis of the Dry Valleys. Physical filtration of samples from the Victoria ... |
format |
Text |
author |
Williamson, Bruce R. |
author_facet |
Williamson, Bruce R. |
author_sort |
Williamson, Bruce R. |
title |
Sources and Deposition Processes Linking Atmospheric Chemistry and Firn Records from Four Glacier Accumulation Zones in the McMurdo Dry Valleys, Antarctica |
title_short |
Sources and Deposition Processes Linking Atmospheric Chemistry and Firn Records from Four Glacier Accumulation Zones in the McMurdo Dry Valleys, Antarctica |
title_full |
Sources and Deposition Processes Linking Atmospheric Chemistry and Firn Records from Four Glacier Accumulation Zones in the McMurdo Dry Valleys, Antarctica |
title_fullStr |
Sources and Deposition Processes Linking Atmospheric Chemistry and Firn Records from Four Glacier Accumulation Zones in the McMurdo Dry Valleys, Antarctica |
title_full_unstemmed |
Sources and Deposition Processes Linking Atmospheric Chemistry and Firn Records from Four Glacier Accumulation Zones in the McMurdo Dry Valleys, Antarctica |
title_sort |
sources and deposition processes linking atmospheric chemistry and firn records from four glacier accumulation zones in the mcmurdo dry valleys, antarctica |
publisher |
DigitalCommons@UMaine |
publishDate |
2006 |
url |
https://digitalcommons.library.umaine.edu/etd/108 https://digitalcommons.library.umaine.edu/context/etd/article/1105/viewcontent/WilliamsonBR2006.pdf |
long_lat |
ENVELOPE(164.167,164.167,-77.833,-77.833) ENVELOPE(163.317,163.317,-77.583,-77.583) ENVELOPE(161.417,161.417,-77.267,-77.267) ENVELOPE(162.417,162.417,-77.417,-77.417) |
geographic |
Antarctic Ross Sea McMurdo Dry Valleys East Antarctic Ice Sheet Blue Glacier Commonwealth Glacier Victoria Upper Glacier Clark Glacier |
geographic_facet |
Antarctic Ross Sea McMurdo Dry Valleys East Antarctic Ice Sheet Blue Glacier Commonwealth Glacier Victoria Upper Glacier Clark Glacier |
genre |
Antarc* Antarctic Antarctica Commonwealth Glacier E. Antarctica Ice Sheet McMurdo Dry Valleys Ross Sea |
genre_facet |
Antarc* Antarctic Antarctica Commonwealth Glacier E. Antarctica Ice Sheet McMurdo Dry Valleys Ross Sea |
op_source |
Electronic Theses and Dissertations |
op_relation |
https://digitalcommons.library.umaine.edu/etd/108 https://digitalcommons.library.umaine.edu/context/etd/article/1105/viewcontent/WilliamsonBR2006.pdf |
_version_ |
1768375432576499712 |