Evidence of deep circulation in two perennially ice‐covered Antarctic lakes
The perennial ice covers found on many of the lakes in the McMurdo Dry Valley region of the Antarctic have been postulated to severely limit mixing and convective turnover of these unique lakes. In this work, we utilize chlorofluorocarbon (CFC) concentration profiles from Lakes Hoare and Fryxell in...
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crwiley:10.4319/lo.1998.43.4.0625 2023-12-03T10:13:12+01:00 Evidence of deep circulation in two perennially ice‐covered Antarctic lakes Tyler, Scott W. Cook, Peter G. Butt, Anya Z. Thomas, James M. Doran, Peter T. Lyons, W. Berry 1998 http://dx.doi.org/10.4319/lo.1998.43.4.0625 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.4319%2Flo.1998.43.4.0625 https://aslopubs.onlinelibrary.wiley.com/doi/pdf/10.4319/lo.1998.43.4.0625 en eng Wiley http://onlinelibrary.wiley.com/termsAndConditions#vor Limnology and Oceanography volume 43, issue 4, page 625-635 ISSN 0024-3590 1939-5590 Aquatic Science Oceanography journal-article 1998 crwiley https://doi.org/10.4319/lo.1998.43.4.0625 2023-11-09T14:20:33Z The perennial ice covers found on many of the lakes in the McMurdo Dry Valley region of the Antarctic have been postulated to severely limit mixing and convective turnover of these unique lakes. In this work, we utilize chlorofluorocarbon (CFC) concentration profiles from Lakes Hoare and Fryxell in the McMurdo Dry Valley to determine the extent of deep vertical mixing occurring over the last 50 years. Near the ice‐water interface, CFC concentrations in both lakes were well above saturation, in accordance with atmospheric gas supersaturations resulting from freezing under the perennial ice covers. Evidence of mixing throughout the water column at Lake Hoare was confirmed by the presence of CFCs throughout the water column and suggests vertical mixing times of 20–30 years. In Lake Fryxell, CFC‐11, CFC‐12, and CFC‐113 were found in the upper water column; however, degradation of CFC‐ 11 and CFC‐ 12 in the anoxic bottom waters appears to be occurring with CFC‐ 113 only present in these bottom waters. The presence of CFC‐113 in the bottom waters, in conjunction with previous work detecting tritium in these waters, strongly argues for the presence of convective mixing in Lake Fryxell. The evidence for deep mixing in these lakes may be an important, yet overlooked, phenomenon in the limnology of perennially icecovered lakes. Article in Journal/Newspaper Antarc* Antarctic Wiley Online Library (via Crossref) Antarctic The Antarctic Fryxell ENVELOPE(163.183,163.183,-77.617,-77.617) Hoare ENVELOPE(162.850,162.850,-77.633,-77.633) Lake Fryxell ENVELOPE(163.183,163.183,-77.617,-77.617) Lake Hoare ENVELOPE(162.850,162.850,-77.633,-77.633) Limnology and Oceanography 43 4 625 635 |
institution |
Open Polar |
collection |
Wiley Online Library (via Crossref) |
op_collection_id |
crwiley |
language |
English |
topic |
Aquatic Science Oceanography |
spellingShingle |
Aquatic Science Oceanography Tyler, Scott W. Cook, Peter G. Butt, Anya Z. Thomas, James M. Doran, Peter T. Lyons, W. Berry Evidence of deep circulation in two perennially ice‐covered Antarctic lakes |
topic_facet |
Aquatic Science Oceanography |
description |
The perennial ice covers found on many of the lakes in the McMurdo Dry Valley region of the Antarctic have been postulated to severely limit mixing and convective turnover of these unique lakes. In this work, we utilize chlorofluorocarbon (CFC) concentration profiles from Lakes Hoare and Fryxell in the McMurdo Dry Valley to determine the extent of deep vertical mixing occurring over the last 50 years. Near the ice‐water interface, CFC concentrations in both lakes were well above saturation, in accordance with atmospheric gas supersaturations resulting from freezing under the perennial ice covers. Evidence of mixing throughout the water column at Lake Hoare was confirmed by the presence of CFCs throughout the water column and suggests vertical mixing times of 20–30 years. In Lake Fryxell, CFC‐11, CFC‐12, and CFC‐113 were found in the upper water column; however, degradation of CFC‐ 11 and CFC‐ 12 in the anoxic bottom waters appears to be occurring with CFC‐ 113 only present in these bottom waters. The presence of CFC‐113 in the bottom waters, in conjunction with previous work detecting tritium in these waters, strongly argues for the presence of convective mixing in Lake Fryxell. The evidence for deep mixing in these lakes may be an important, yet overlooked, phenomenon in the limnology of perennially icecovered lakes. |
format |
Article in Journal/Newspaper |
author |
Tyler, Scott W. Cook, Peter G. Butt, Anya Z. Thomas, James M. Doran, Peter T. Lyons, W. Berry |
author_facet |
Tyler, Scott W. Cook, Peter G. Butt, Anya Z. Thomas, James M. Doran, Peter T. Lyons, W. Berry |
author_sort |
Tyler, Scott W. |
title |
Evidence of deep circulation in two perennially ice‐covered Antarctic lakes |
title_short |
Evidence of deep circulation in two perennially ice‐covered Antarctic lakes |
title_full |
Evidence of deep circulation in two perennially ice‐covered Antarctic lakes |
title_fullStr |
Evidence of deep circulation in two perennially ice‐covered Antarctic lakes |
title_full_unstemmed |
Evidence of deep circulation in two perennially ice‐covered Antarctic lakes |
title_sort |
evidence of deep circulation in two perennially ice‐covered antarctic lakes |
publisher |
Wiley |
publishDate |
1998 |
url |
http://dx.doi.org/10.4319/lo.1998.43.4.0625 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.4319%2Flo.1998.43.4.0625 https://aslopubs.onlinelibrary.wiley.com/doi/pdf/10.4319/lo.1998.43.4.0625 |
long_lat |
ENVELOPE(163.183,163.183,-77.617,-77.617) ENVELOPE(162.850,162.850,-77.633,-77.633) ENVELOPE(163.183,163.183,-77.617,-77.617) ENVELOPE(162.850,162.850,-77.633,-77.633) |
geographic |
Antarctic The Antarctic Fryxell Hoare Lake Fryxell Lake Hoare |
geographic_facet |
Antarctic The Antarctic Fryxell Hoare Lake Fryxell Lake Hoare |
genre |
Antarc* Antarctic |
genre_facet |
Antarc* Antarctic |
op_source |
Limnology and Oceanography volume 43, issue 4, page 625-635 ISSN 0024-3590 1939-5590 |
op_rights |
http://onlinelibrary.wiley.com/termsAndConditions#vor |
op_doi |
https://doi.org/10.4319/lo.1998.43.4.0625 |
container_title |
Limnology and Oceanography |
container_volume |
43 |
container_issue |
4 |
container_start_page |
625 |
op_container_end_page |
635 |
_version_ |
1784259913535455232 |