Improved representation of the contemporary Greenland ice sheet firn layer by IMAU-FDM v1.2G
The firn layer that covers 90 % of the Greenland ice sheet (GrIS) plays an important role in determining the response of the ice sheet to climate change. Meltwater can percolate into the firn layer and refreeze at greater depths, thereby temporarily preventing mass loss. However, as global warming l...
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Online Access: | https://doi.org/10.5194/gmd-15-7121-2022 https://gmd.copernicus.org/articles/15/7121/2022/ |
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ftcopernicus:oai:publications.copernicus.org:gmd97530 2023-05-15T16:27:16+02:00 Improved representation of the contemporary Greenland ice sheet firn layer by IMAU-FDM v1.2G Brils, Max Kuipers Munneke, Peter Berg, Willem Jan Broeke, Michiel 2022-09-21 application/pdf https://doi.org/10.5194/gmd-15-7121-2022 https://gmd.copernicus.org/articles/15/7121/2022/ eng eng doi:10.5194/gmd-15-7121-2022 https://gmd.copernicus.org/articles/15/7121/2022/ eISSN: 1991-9603 Text 2022 ftcopernicus https://doi.org/10.5194/gmd-15-7121-2022 2022-09-26T16:22:41Z The firn layer that covers 90 % of the Greenland ice sheet (GrIS) plays an important role in determining the response of the ice sheet to climate change. Meltwater can percolate into the firn layer and refreeze at greater depths, thereby temporarily preventing mass loss. However, as global warming leads to increasing surface melt, more surface melt may refreeze in the firn layer, thereby reducing the capacity to buffer subsequent episodes of melt. This can lead to a tipping point in meltwater runoff. It is therefore important to study the evolution of the Greenland firn layer in the past, present and future. In this study, we present the latest version of our firn model, IMAU-FDM (Firn Densification Model) v1.2G, with an application to the GrIS. We improved the density of freshly fallen snow, the dry-snow densification rate and the firn's thermal conductivity using recently published parametrizations and by calibration to an extended set of observations of firn density, temperature and liquid water content at the GrIS. Overall, the updated model settings lead to higher firn air content and higher 10 m firn temperatures, owing to a lower density near the surface. The effect of the new model settings on the surface elevation change is investigated through three case studies located at Summit, KAN-U and FA-13. Most notably, the updated model shows greater inter- and intra-annual variability in elevation and an increased sensitivity to climate forcing. Text Greenland Ice Sheet Copernicus Publications: E-Journals Greenland Geoscientific Model Development 15 18 7121 7138 |
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Open Polar |
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Copernicus Publications: E-Journals |
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ftcopernicus |
language |
English |
description |
The firn layer that covers 90 % of the Greenland ice sheet (GrIS) plays an important role in determining the response of the ice sheet to climate change. Meltwater can percolate into the firn layer and refreeze at greater depths, thereby temporarily preventing mass loss. However, as global warming leads to increasing surface melt, more surface melt may refreeze in the firn layer, thereby reducing the capacity to buffer subsequent episodes of melt. This can lead to a tipping point in meltwater runoff. It is therefore important to study the evolution of the Greenland firn layer in the past, present and future. In this study, we present the latest version of our firn model, IMAU-FDM (Firn Densification Model) v1.2G, with an application to the GrIS. We improved the density of freshly fallen snow, the dry-snow densification rate and the firn's thermal conductivity using recently published parametrizations and by calibration to an extended set of observations of firn density, temperature and liquid water content at the GrIS. Overall, the updated model settings lead to higher firn air content and higher 10 m firn temperatures, owing to a lower density near the surface. The effect of the new model settings on the surface elevation change is investigated through three case studies located at Summit, KAN-U and FA-13. Most notably, the updated model shows greater inter- and intra-annual variability in elevation and an increased sensitivity to climate forcing. |
format |
Text |
author |
Brils, Max Kuipers Munneke, Peter Berg, Willem Jan Broeke, Michiel |
spellingShingle |
Brils, Max Kuipers Munneke, Peter Berg, Willem Jan Broeke, Michiel Improved representation of the contemporary Greenland ice sheet firn layer by IMAU-FDM v1.2G |
author_facet |
Brils, Max Kuipers Munneke, Peter Berg, Willem Jan Broeke, Michiel |
author_sort |
Brils, Max |
title |
Improved representation of the contemporary Greenland ice sheet firn layer by IMAU-FDM v1.2G |
title_short |
Improved representation of the contemporary Greenland ice sheet firn layer by IMAU-FDM v1.2G |
title_full |
Improved representation of the contemporary Greenland ice sheet firn layer by IMAU-FDM v1.2G |
title_fullStr |
Improved representation of the contemporary Greenland ice sheet firn layer by IMAU-FDM v1.2G |
title_full_unstemmed |
Improved representation of the contemporary Greenland ice sheet firn layer by IMAU-FDM v1.2G |
title_sort |
improved representation of the contemporary greenland ice sheet firn layer by imau-fdm v1.2g |
publishDate |
2022 |
url |
https://doi.org/10.5194/gmd-15-7121-2022 https://gmd.copernicus.org/articles/15/7121/2022/ |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
Greenland Ice Sheet |
genre_facet |
Greenland Ice Sheet |
op_source |
eISSN: 1991-9603 |
op_relation |
doi:10.5194/gmd-15-7121-2022 https://gmd.copernicus.org/articles/15/7121/2022/ |
op_doi |
https://doi.org/10.5194/gmd-15-7121-2022 |
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Geoscientific Model Development |
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15 |
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18 |
container_start_page |
7121 |
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7138 |
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1766016399285682176 |