Very old firn air linked to strong density layering at Styx Glacier, coastal Victoria Land, East Antarctica
Firn air provides plenty of old air from the near past, and can therefore be useful for understanding human impact on the recent history of the atmospheric composition. Most of the existing firn air records cover only the last several decades (typically 40 to 55 years) and are insufficient to unders...
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2019
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Online Access: | https://doi.org/10.5194/tc-13-2407-2019 https://doaj.org/article/c7dafa71c5964d3c8ad8d4ce80c44cfa |
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ftdoajarticles:oai:doaj.org/article:c7dafa71c5964d3c8ad8d4ce80c44cfa 2023-05-15T14:05:31+02:00 Very old firn air linked to strong density layering at Styx Glacier, coastal Victoria Land, East Antarctica Y. Jang S. B. Hong C. Buizert H.-G. Lee S.-Y. Han J.-W. Yang Y. Iizuka A. Hori Y. Han S. J. Jun P. Tans T. Choi S.-J. Kim S. D. Hur J. Ahn 2019-09-01T00:00:00Z https://doi.org/10.5194/tc-13-2407-2019 https://doaj.org/article/c7dafa71c5964d3c8ad8d4ce80c44cfa EN eng Copernicus Publications https://www.the-cryosphere.net/13/2407/2019/tc-13-2407-2019.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 doi:10.5194/tc-13-2407-2019 1994-0416 1994-0424 https://doaj.org/article/c7dafa71c5964d3c8ad8d4ce80c44cfa The Cryosphere, Vol 13, Pp 2407-2419 (2019) Environmental sciences GE1-350 Geology QE1-996.5 article 2019 ftdoajarticles https://doi.org/10.5194/tc-13-2407-2019 2022-12-31T14:03:33Z Firn air provides plenty of old air from the near past, and can therefore be useful for understanding human impact on the recent history of the atmospheric composition. Most of the existing firn air records cover only the last several decades (typically 40 to 55 years) and are insufficient to understand the early part of anthropogenic impacts on the atmosphere. In contrast, a few firn air records from inland sites, where temperatures and snow accumulation rates are very low, go back in time about a century. In this study, we report an unusually old firn air effective CO 2 age of 93 years from Styx Glacier, near the Ross Sea coast in Antarctica. This is the first report of such an old firn air age ( >55 years) from a warm coastal site. The lock-in zone thickness of 12.4 m is larger than at other sites where snow accumulation rates and air temperature are similar. High-resolution X-ray density measurements demonstrate a high variability of the vertical snow density at Styx Glacier. The CH 4 mole fraction and total air content of the closed pores also indicate large variations in centimeter-scale depth intervals, indicative of layering. We hypothesize that the large density variations in the firn increase the thickness of the lock-in zone and, consequently, increase the firn air ages because the age of firn air increases more rapidly with depth in the lock-in zone than in the diffusive zone. Our study demonstrates that all else being equal, sites where weather conditions are favorable for the formation of large density variations at the lock-in zone preserve older air within their open porosity, making them ideal places for firn air sampling. Article in Journal/Newspaper Antarc* Antarctica East Antarctica Ross Sea The Cryosphere Victoria Land Directory of Open Access Journals: DOAJ Articles East Antarctica Ross Sea Victoria Land Styx Glacier ENVELOPE(163.850,163.850,-74.033,-74.033) The Cryosphere 13 9 2407 2419 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Environmental sciences GE1-350 Geology QE1-996.5 |
spellingShingle |
Environmental sciences GE1-350 Geology QE1-996.5 Y. Jang S. B. Hong C. Buizert H.-G. Lee S.-Y. Han J.-W. Yang Y. Iizuka A. Hori Y. Han S. J. Jun P. Tans T. Choi S.-J. Kim S. D. Hur J. Ahn Very old firn air linked to strong density layering at Styx Glacier, coastal Victoria Land, East Antarctica |
topic_facet |
Environmental sciences GE1-350 Geology QE1-996.5 |
description |
Firn air provides plenty of old air from the near past, and can therefore be useful for understanding human impact on the recent history of the atmospheric composition. Most of the existing firn air records cover only the last several decades (typically 40 to 55 years) and are insufficient to understand the early part of anthropogenic impacts on the atmosphere. In contrast, a few firn air records from inland sites, where temperatures and snow accumulation rates are very low, go back in time about a century. In this study, we report an unusually old firn air effective CO 2 age of 93 years from Styx Glacier, near the Ross Sea coast in Antarctica. This is the first report of such an old firn air age ( >55 years) from a warm coastal site. The lock-in zone thickness of 12.4 m is larger than at other sites where snow accumulation rates and air temperature are similar. High-resolution X-ray density measurements demonstrate a high variability of the vertical snow density at Styx Glacier. The CH 4 mole fraction and total air content of the closed pores also indicate large variations in centimeter-scale depth intervals, indicative of layering. We hypothesize that the large density variations in the firn increase the thickness of the lock-in zone and, consequently, increase the firn air ages because the age of firn air increases more rapidly with depth in the lock-in zone than in the diffusive zone. Our study demonstrates that all else being equal, sites where weather conditions are favorable for the formation of large density variations at the lock-in zone preserve older air within their open porosity, making them ideal places for firn air sampling. |
format |
Article in Journal/Newspaper |
author |
Y. Jang S. B. Hong C. Buizert H.-G. Lee S.-Y. Han J.-W. Yang Y. Iizuka A. Hori Y. Han S. J. Jun P. Tans T. Choi S.-J. Kim S. D. Hur J. Ahn |
author_facet |
Y. Jang S. B. Hong C. Buizert H.-G. Lee S.-Y. Han J.-W. Yang Y. Iizuka A. Hori Y. Han S. J. Jun P. Tans T. Choi S.-J. Kim S. D. Hur J. Ahn |
author_sort |
Y. Jang |
title |
Very old firn air linked to strong density layering at Styx Glacier, coastal Victoria Land, East Antarctica |
title_short |
Very old firn air linked to strong density layering at Styx Glacier, coastal Victoria Land, East Antarctica |
title_full |
Very old firn air linked to strong density layering at Styx Glacier, coastal Victoria Land, East Antarctica |
title_fullStr |
Very old firn air linked to strong density layering at Styx Glacier, coastal Victoria Land, East Antarctica |
title_full_unstemmed |
Very old firn air linked to strong density layering at Styx Glacier, coastal Victoria Land, East Antarctica |
title_sort |
very old firn air linked to strong density layering at styx glacier, coastal victoria land, east antarctica |
publisher |
Copernicus Publications |
publishDate |
2019 |
url |
https://doi.org/10.5194/tc-13-2407-2019 https://doaj.org/article/c7dafa71c5964d3c8ad8d4ce80c44cfa |
long_lat |
ENVELOPE(163.850,163.850,-74.033,-74.033) |
geographic |
East Antarctica Ross Sea Victoria Land Styx Glacier |
geographic_facet |
East Antarctica Ross Sea Victoria Land Styx Glacier |
genre |
Antarc* Antarctica East Antarctica Ross Sea The Cryosphere Victoria Land |
genre_facet |
Antarc* Antarctica East Antarctica Ross Sea The Cryosphere Victoria Land |
op_source |
The Cryosphere, Vol 13, Pp 2407-2419 (2019) |
op_relation |
https://www.the-cryosphere.net/13/2407/2019/tc-13-2407-2019.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 doi:10.5194/tc-13-2407-2019 1994-0416 1994-0424 https://doaj.org/article/c7dafa71c5964d3c8ad8d4ce80c44cfa |
op_doi |
https://doi.org/10.5194/tc-13-2407-2019 |
container_title |
The Cryosphere |
container_volume |
13 |
container_issue |
9 |
container_start_page |
2407 |
op_container_end_page |
2419 |
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1766277478879330304 |