Surface formation, preservation, and history of low-porosity crusts at the WAIS Divide site, West Antarctica
Observations at the West Antarctic Ice Sheet (WAIS) Divide site show that near-surface snow is strongly altered by weather-related processes such as strong winds and temperature fluctuations, producing features that are recognizable in the deep ice core. Prominent <q>glazed</q> surface c...
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ftdoajarticles:oai:doaj.org/article:2f77789f00604c61b7239fc9e31bea64 2023-05-15T13:34:51+02:00 Surface formation, preservation, and history of low-porosity crusts at the WAIS Divide site, West Antarctica J. M. Fegyveresi R. B. Alley A. Muto A. J. Orsi M. K. Spencer 2018-01-01T00:00:00Z https://doi.org/10.5194/tc-12-325-2018 https://doaj.org/article/2f77789f00604c61b7239fc9e31bea64 EN eng Copernicus Publications https://www.the-cryosphere.net/12/325/2018/tc-12-325-2018.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 doi:10.5194/tc-12-325-2018 1994-0416 1994-0424 https://doaj.org/article/2f77789f00604c61b7239fc9e31bea64 The Cryosphere, Vol 12, Pp 325-341 (2018) Environmental sciences GE1-350 Geology QE1-996.5 article 2018 ftdoajarticles https://doi.org/10.5194/tc-12-325-2018 2022-12-31T14:27:54Z Observations at the West Antarctic Ice Sheet (WAIS) Divide site show that near-surface snow is strongly altered by weather-related processes such as strong winds and temperature fluctuations, producing features that are recognizable in the deep ice core. Prominent <q>glazed</q> surface crusts develop frequently at the site during summer seasons. Surface, snow pit, and ice core observations made in this study during summer field seasons from 2008–2009 to 2012–2013, supplemented by automated weather station (AWS) data with short- and longwave radiation sensors, revealed that such crusts formed during relatively low-wind, low-humidity, clear-sky periods with intense daytime sunshine. After formation, such glazed surfaces typically developed cracks in a polygonal pattern likely from thermal contraction at night. Cracking was commonest when several clear days occurred in succession and was generally followed by surface hoar growth; vapor escaping through the cracks during sunny days may have contributed to the high humidity that favored nighttime formation of surface hoar. Temperature and radiation observations show that daytime solar heating often warmed the near-surface snow above the air temperature, contributing to upward mass transfer, favoring crust formation from below, and then surface hoar formation. A simple surface energy calculation supports this observation. Subsequent examination of the WDC06A deep ice core revealed that crusts are preserved through the bubbly ice, and some occur in snow accumulated during winters, although not as commonly as in summertime deposits. Although no one has been on site to observe crust formation during winter, it may be favored by greater wintertime wind packing from stronger peak winds, high temperatures and steep temperature gradients from rapid midwinter warmings reaching as high as −15 °C, and perhaps longer intervals of surface stability. Time variations in crust occurrence in the core may provide paleoclimatic information, although additional studies are ... Article in Journal/Newspaper Antarc* Antarctic Antarctica ice core Ice Sheet The Cryosphere West Antarctica Directory of Open Access Journals: DOAJ Articles Antarctic West Antarctica West Antarctic Ice Sheet Midwinter ENVELOPE(139.931,139.931,-66.690,-66.690) The Cryosphere 12 1 325 341 |
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 J. M. Fegyveresi R. B. Alley A. Muto A. J. Orsi M. K. Spencer Surface formation, preservation, and history of low-porosity crusts at the WAIS Divide site, West Antarctica |
topic_facet |
Environmental sciences GE1-350 Geology QE1-996.5 |
description |
Observations at the West Antarctic Ice Sheet (WAIS) Divide site show that near-surface snow is strongly altered by weather-related processes such as strong winds and temperature fluctuations, producing features that are recognizable in the deep ice core. Prominent <q>glazed</q> surface crusts develop frequently at the site during summer seasons. Surface, snow pit, and ice core observations made in this study during summer field seasons from 2008–2009 to 2012–2013, supplemented by automated weather station (AWS) data with short- and longwave radiation sensors, revealed that such crusts formed during relatively low-wind, low-humidity, clear-sky periods with intense daytime sunshine. After formation, such glazed surfaces typically developed cracks in a polygonal pattern likely from thermal contraction at night. Cracking was commonest when several clear days occurred in succession and was generally followed by surface hoar growth; vapor escaping through the cracks during sunny days may have contributed to the high humidity that favored nighttime formation of surface hoar. Temperature and radiation observations show that daytime solar heating often warmed the near-surface snow above the air temperature, contributing to upward mass transfer, favoring crust formation from below, and then surface hoar formation. A simple surface energy calculation supports this observation. Subsequent examination of the WDC06A deep ice core revealed that crusts are preserved through the bubbly ice, and some occur in snow accumulated during winters, although not as commonly as in summertime deposits. Although no one has been on site to observe crust formation during winter, it may be favored by greater wintertime wind packing from stronger peak winds, high temperatures and steep temperature gradients from rapid midwinter warmings reaching as high as −15 °C, and perhaps longer intervals of surface stability. Time variations in crust occurrence in the core may provide paleoclimatic information, although additional studies are ... |
format |
Article in Journal/Newspaper |
author |
J. M. Fegyveresi R. B. Alley A. Muto A. J. Orsi M. K. Spencer |
author_facet |
J. M. Fegyveresi R. B. Alley A. Muto A. J. Orsi M. K. Spencer |
author_sort |
J. M. Fegyveresi |
title |
Surface formation, preservation, and history of low-porosity crusts at the WAIS Divide site, West Antarctica |
title_short |
Surface formation, preservation, and history of low-porosity crusts at the WAIS Divide site, West Antarctica |
title_full |
Surface formation, preservation, and history of low-porosity crusts at the WAIS Divide site, West Antarctica |
title_fullStr |
Surface formation, preservation, and history of low-porosity crusts at the WAIS Divide site, West Antarctica |
title_full_unstemmed |
Surface formation, preservation, and history of low-porosity crusts at the WAIS Divide site, West Antarctica |
title_sort |
surface formation, preservation, and history of low-porosity crusts at the wais divide site, west antarctica |
publisher |
Copernicus Publications |
publishDate |
2018 |
url |
https://doi.org/10.5194/tc-12-325-2018 https://doaj.org/article/2f77789f00604c61b7239fc9e31bea64 |
long_lat |
ENVELOPE(139.931,139.931,-66.690,-66.690) |
geographic |
Antarctic West Antarctica West Antarctic Ice Sheet Midwinter |
geographic_facet |
Antarctic West Antarctica West Antarctic Ice Sheet Midwinter |
genre |
Antarc* Antarctic Antarctica ice core Ice Sheet The Cryosphere West Antarctica |
genre_facet |
Antarc* Antarctic Antarctica ice core Ice Sheet The Cryosphere West Antarctica |
op_source |
The Cryosphere, Vol 12, Pp 325-341 (2018) |
op_relation |
https://www.the-cryosphere.net/12/325/2018/tc-12-325-2018.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 doi:10.5194/tc-12-325-2018 1994-0416 1994-0424 https://doaj.org/article/2f77789f00604c61b7239fc9e31bea64 |
op_doi |
https://doi.org/10.5194/tc-12-325-2018 |
container_title |
The Cryosphere |
container_volume |
12 |
container_issue |
1 |
container_start_page |
325 |
op_container_end_page |
341 |
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1766058496932970496 |