Water tracks intensify surface energy and mass exchange in the Antarctic McMurdo Dry Valleys
The hydrologic cycle in the Antarctic McMurdo Dry Valleys (MDV) is mainly controlled by surface energy balance. Water tracks are channel-shaped high-moisture zones in the active layer of permafrost soils and are important solute and water pathways in the MDV. We evaluated the hypothesis that water t...
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ftdoajarticles:oai:doaj.org/article:d5bde354031c478ea3267ae8a23d81b6 2023-05-15T13:57:55+02:00 Water tracks intensify surface energy and mass exchange in the Antarctic McMurdo Dry Valleys T. Linhardt J. S. Levy C. K. Thomas 2019-08-01T00:00:00Z https://doi.org/10.5194/tc-13-2203-2019 https://doaj.org/article/d5bde354031c478ea3267ae8a23d81b6 EN eng Copernicus Publications https://www.the-cryosphere.net/13/2203/2019/tc-13-2203-2019.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 doi:10.5194/tc-13-2203-2019 1994-0416 1994-0424 https://doaj.org/article/d5bde354031c478ea3267ae8a23d81b6 The Cryosphere, Vol 13, Pp 2203-2219 (2019) Environmental sciences GE1-350 Geology QE1-996.5 article 2019 ftdoajarticles https://doi.org/10.5194/tc-13-2203-2019 2022-12-31T06:16:55Z The hydrologic cycle in the Antarctic McMurdo Dry Valleys (MDV) is mainly controlled by surface energy balance. Water tracks are channel-shaped high-moisture zones in the active layer of permafrost soils and are important solute and water pathways in the MDV. We evaluated the hypothesis that water tracks alter the surface energy balance in this dry, cold, and ice-sheet-free environment during summer warming and may therefore be an increasingly important hydrologic feature in the MDV in the face of landscape response to climate change. The surface energy balance was measured for one water track and two off-track reference locations in Taylor Valley over 26 d of the Antarctic summer of 2012–2013. Turbulent atmospheric fluxes of sensible heat and evaporation were observed using the eddy-covariance method in combination with flux footprint modeling, which was the first application of this technique in the MDV. Soil heat fluxes were analyzed by measuring the heat storage change in the thawed layer and approximating soil heat flux at ice table depth by surface energy balance residuals. For both water track and reference locations over 50 % of net radiation was transferred to sensible heat exchange, about 30 % to melting of the seasonally thawed layer, and the remainder to evaporation. The net energy flux in the thawed layer was zero. For the water track location, evaporation was increased by a factor of 3.0 relative to the reference locations, ground heat fluxes by 1.4, and net radiation by 1.1, while sensible heat fluxes were reduced down to 0.7. Expecting a positive snow and ground ice melt response to climate change in the MDV, we entertained a realistic climate change response scenario in which a doubling of the land cover fraction of water tracks increases the evaporation from soil surfaces in lower Taylor Valley in summer by 6 % to 0.36 mm d −1 . Possible climate change pathways leading to this change in landscape are discussed. Considering our results, an expansion of water track area would make new soil ... Article in Journal/Newspaper Antarc* Antarctic Ice Ice Sheet McMurdo Dry Valleys permafrost The Cryosphere Directory of Open Access Journals: DOAJ Articles Antarctic The Antarctic McMurdo Dry Valleys Taylor Valley ENVELOPE(163.000,163.000,-77.617,-77.617) The Cryosphere 13 8 2203 2219 |
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 T. Linhardt J. S. Levy C. K. Thomas Water tracks intensify surface energy and mass exchange in the Antarctic McMurdo Dry Valleys |
topic_facet |
Environmental sciences GE1-350 Geology QE1-996.5 |
description |
The hydrologic cycle in the Antarctic McMurdo Dry Valleys (MDV) is mainly controlled by surface energy balance. Water tracks are channel-shaped high-moisture zones in the active layer of permafrost soils and are important solute and water pathways in the MDV. We evaluated the hypothesis that water tracks alter the surface energy balance in this dry, cold, and ice-sheet-free environment during summer warming and may therefore be an increasingly important hydrologic feature in the MDV in the face of landscape response to climate change. The surface energy balance was measured for one water track and two off-track reference locations in Taylor Valley over 26 d of the Antarctic summer of 2012–2013. Turbulent atmospheric fluxes of sensible heat and evaporation were observed using the eddy-covariance method in combination with flux footprint modeling, which was the first application of this technique in the MDV. Soil heat fluxes were analyzed by measuring the heat storage change in the thawed layer and approximating soil heat flux at ice table depth by surface energy balance residuals. For both water track and reference locations over 50 % of net radiation was transferred to sensible heat exchange, about 30 % to melting of the seasonally thawed layer, and the remainder to evaporation. The net energy flux in the thawed layer was zero. For the water track location, evaporation was increased by a factor of 3.0 relative to the reference locations, ground heat fluxes by 1.4, and net radiation by 1.1, while sensible heat fluxes were reduced down to 0.7. Expecting a positive snow and ground ice melt response to climate change in the MDV, we entertained a realistic climate change response scenario in which a doubling of the land cover fraction of water tracks increases the evaporation from soil surfaces in lower Taylor Valley in summer by 6 % to 0.36 mm d −1 . Possible climate change pathways leading to this change in landscape are discussed. Considering our results, an expansion of water track area would make new soil ... |
format |
Article in Journal/Newspaper |
author |
T. Linhardt J. S. Levy C. K. Thomas |
author_facet |
T. Linhardt J. S. Levy C. K. Thomas |
author_sort |
T. Linhardt |
title |
Water tracks intensify surface energy and mass exchange in the Antarctic McMurdo Dry Valleys |
title_short |
Water tracks intensify surface energy and mass exchange in the Antarctic McMurdo Dry Valleys |
title_full |
Water tracks intensify surface energy and mass exchange in the Antarctic McMurdo Dry Valleys |
title_fullStr |
Water tracks intensify surface energy and mass exchange in the Antarctic McMurdo Dry Valleys |
title_full_unstemmed |
Water tracks intensify surface energy and mass exchange in the Antarctic McMurdo Dry Valleys |
title_sort |
water tracks intensify surface energy and mass exchange in the antarctic mcmurdo dry valleys |
publisher |
Copernicus Publications |
publishDate |
2019 |
url |
https://doi.org/10.5194/tc-13-2203-2019 https://doaj.org/article/d5bde354031c478ea3267ae8a23d81b6 |
long_lat |
ENVELOPE(163.000,163.000,-77.617,-77.617) |
geographic |
Antarctic The Antarctic McMurdo Dry Valleys Taylor Valley |
geographic_facet |
Antarctic The Antarctic McMurdo Dry Valleys Taylor Valley |
genre |
Antarc* Antarctic Ice Ice Sheet McMurdo Dry Valleys permafrost The Cryosphere |
genre_facet |
Antarc* Antarctic Ice Ice Sheet McMurdo Dry Valleys permafrost The Cryosphere |
op_source |
The Cryosphere, Vol 13, Pp 2203-2219 (2019) |
op_relation |
https://www.the-cryosphere.net/13/2203/2019/tc-13-2203-2019.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 doi:10.5194/tc-13-2203-2019 1994-0416 1994-0424 https://doaj.org/article/d5bde354031c478ea3267ae8a23d81b6 |
op_doi |
https://doi.org/10.5194/tc-13-2203-2019 |
container_title |
The Cryosphere |
container_volume |
13 |
container_issue |
8 |
container_start_page |
2203 |
op_container_end_page |
2219 |
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1766265865256304640 |