Local-scale spatial variability in firn properties in Southwest Greenland
The increasing mass loss from the Greenland ice sheet is becoming growingly important to present-day global sea level rise. Meltwater export to the ocean may be amplified by near-surface ice layers in firn (i.e., snow that has survived at least one melt season) which prevent infiltration. Such ice l...
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ftdoajarticles:oai:doaj.org/article:91b35884f8f047bbba806aa8affffc9d 2023-05-15T16:26:48+02:00 Local-scale spatial variability in firn properties in Southwest Greenland Jing Xiao Åsa K. Rennermalm Federico Covi Regine Hock Sasha Z. Leidman Clément Miège Michael J. MacFerrin Samira Samimi 2022-10-01T00:00:00Z https://doi.org/10.3389/feart.2022.938246 https://doaj.org/article/91b35884f8f047bbba806aa8affffc9d EN eng Frontiers Media S.A. https://www.frontiersin.org/articles/10.3389/feart.2022.938246/full https://doaj.org/toc/2296-6463 2296-6463 doi:10.3389/feart.2022.938246 https://doaj.org/article/91b35884f8f047bbba806aa8affffc9d Frontiers in Earth Science, Vol 10 (2022) ice and climate ice core ice-sheet mass balance polar firn Greenland local-scale variability Science Q article 2022 ftdoajarticles https://doi.org/10.3389/feart.2022.938246 2022-12-30T20:30:55Z The increasing mass loss from the Greenland ice sheet is becoming growingly important to present-day global sea level rise. Meltwater export to the ocean may be amplified by near-surface ice layers in firn (i.e., snow that has survived at least one melt season) which prevent infiltration. Such ice layers have been documented at various sites in southwest Greenland, but little is known about the local-scale (less than 1 km) variability in firn and ice properties. Here we investigate the local variability in firn density and ice content (ice layer thickness fraction) by analyzing 45 shallow firn cores retrieved from 15 sites in southwest Greenland between 2012 and 2019. The core dataset contains groups of cores that were collected at the same site (1–632 m apart from each other) and in the same year (here referred to as same site/year cores). The two-sided Mann-Whitney U-tests suggest that most same site/year cores do not have statistically significant differences in median density or ice content over the upper 0–4.5, 4.5–9, and 9–13.5 m sections below the winter snow layer. That said, the same site/year cores still exhibit substantial density and ice content differences as well as variable ice layer stratigraphy (especially the distribution of centimeters-thick ice lenses) not explainable by measurement uncertainties. The local-scale variability in density and ice content (calculated from the same site/year cores) over the three 4.5-m sections is 4% and 19–29%, respectively. The variability is comparable to the regional gradient in our study area within an elevation difference of up to ∼200 m. The local variability is non-negligible particularly at mid- to high-elevation sites (>2,000 m a.s.l.), where firn structure changes such as ice layer formation are more recent phenomena compared to lower elevations. This study confirms that single cores can provide representative bulk statistics such as mean density and ice content of one site. However, these mean values mask substantial local variability which can ... Article in Journal/Newspaper Greenland ice core Ice Sheet Directory of Open Access Journals: DOAJ Articles Greenland Frontiers in Earth Science 10 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
ice and climate ice core ice-sheet mass balance polar firn Greenland local-scale variability Science Q |
spellingShingle |
ice and climate ice core ice-sheet mass balance polar firn Greenland local-scale variability Science Q Jing Xiao Åsa K. Rennermalm Federico Covi Regine Hock Sasha Z. Leidman Clément Miège Michael J. MacFerrin Samira Samimi Local-scale spatial variability in firn properties in Southwest Greenland |
topic_facet |
ice and climate ice core ice-sheet mass balance polar firn Greenland local-scale variability Science Q |
description |
The increasing mass loss from the Greenland ice sheet is becoming growingly important to present-day global sea level rise. Meltwater export to the ocean may be amplified by near-surface ice layers in firn (i.e., snow that has survived at least one melt season) which prevent infiltration. Such ice layers have been documented at various sites in southwest Greenland, but little is known about the local-scale (less than 1 km) variability in firn and ice properties. Here we investigate the local variability in firn density and ice content (ice layer thickness fraction) by analyzing 45 shallow firn cores retrieved from 15 sites in southwest Greenland between 2012 and 2019. The core dataset contains groups of cores that were collected at the same site (1–632 m apart from each other) and in the same year (here referred to as same site/year cores). The two-sided Mann-Whitney U-tests suggest that most same site/year cores do not have statistically significant differences in median density or ice content over the upper 0–4.5, 4.5–9, and 9–13.5 m sections below the winter snow layer. That said, the same site/year cores still exhibit substantial density and ice content differences as well as variable ice layer stratigraphy (especially the distribution of centimeters-thick ice lenses) not explainable by measurement uncertainties. The local-scale variability in density and ice content (calculated from the same site/year cores) over the three 4.5-m sections is 4% and 19–29%, respectively. The variability is comparable to the regional gradient in our study area within an elevation difference of up to ∼200 m. The local variability is non-negligible particularly at mid- to high-elevation sites (>2,000 m a.s.l.), where firn structure changes such as ice layer formation are more recent phenomena compared to lower elevations. This study confirms that single cores can provide representative bulk statistics such as mean density and ice content of one site. However, these mean values mask substantial local variability which can ... |
format |
Article in Journal/Newspaper |
author |
Jing Xiao Åsa K. Rennermalm Federico Covi Regine Hock Sasha Z. Leidman Clément Miège Michael J. MacFerrin Samira Samimi |
author_facet |
Jing Xiao Åsa K. Rennermalm Federico Covi Regine Hock Sasha Z. Leidman Clément Miège Michael J. MacFerrin Samira Samimi |
author_sort |
Jing Xiao |
title |
Local-scale spatial variability in firn properties in Southwest Greenland |
title_short |
Local-scale spatial variability in firn properties in Southwest Greenland |
title_full |
Local-scale spatial variability in firn properties in Southwest Greenland |
title_fullStr |
Local-scale spatial variability in firn properties in Southwest Greenland |
title_full_unstemmed |
Local-scale spatial variability in firn properties in Southwest Greenland |
title_sort |
local-scale spatial variability in firn properties in southwest greenland |
publisher |
Frontiers Media S.A. |
publishDate |
2022 |
url |
https://doi.org/10.3389/feart.2022.938246 https://doaj.org/article/91b35884f8f047bbba806aa8affffc9d |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
Greenland ice core Ice Sheet |
genre_facet |
Greenland ice core Ice Sheet |
op_source |
Frontiers in Earth Science, Vol 10 (2022) |
op_relation |
https://www.frontiersin.org/articles/10.3389/feart.2022.938246/full https://doaj.org/toc/2296-6463 2296-6463 doi:10.3389/feart.2022.938246 https://doaj.org/article/91b35884f8f047bbba806aa8affffc9d |
op_doi |
https://doi.org/10.3389/feart.2022.938246 |
container_title |
Frontiers in Earth Science |
container_volume |
10 |
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1766015779697852416 |