Subglacial hydrology modeling predicts high winter water pressure and spatially variable transmissivity at Helheim Glacier, Greenland
Water pressure beneath glaciers influences ice velocity. Subglacial hydrology models are helpful for gaining insight into basal conditions, but models depend on unconstrained parameters, and a current challenge is reproducing elevated water pressures in winter. We eliminate terms related to englacia...
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ftdoajarticles:oai:doaj.org/article:34e2fff669c340e78d4aa9af0cef9668 2023-07-16T03:58:12+02:00 Subglacial hydrology modeling predicts high winter water pressure and spatially variable transmissivity at Helheim Glacier, Greenland Aleah Sommers Colin Meyer Mathieu Morlighem Harihar Rajaram Kristin Poinar Winnie Chu Jessica Mejia https://doi.org/10.1017/jog.2023.39 https://doaj.org/article/34e2fff669c340e78d4aa9af0cef9668 EN eng Cambridge University Press https://www.cambridge.org/core/product/identifier/S0022143023000394/type/journal_article https://doaj.org/toc/0022-1430 https://doaj.org/toc/1727-5652 doi:10.1017/jog.2023.39 0022-1430 1727-5652 https://doaj.org/article/34e2fff669c340e78d4aa9af0cef9668 Journal of Glaciology, Pp 1-13 Glacier hydrology Glacier modeling ice-sheet modeling basal melt subglacial processes Environmental sciences GE1-350 Meteorology. Climatology QC851-999 article ftdoajarticles https://doi.org/10.1017/jog.2023.39 2023-06-25T00:35:32Z Water pressure beneath glaciers influences ice velocity. Subglacial hydrology models are helpful for gaining insight into basal conditions, but models depend on unconstrained parameters, and a current challenge is reproducing elevated water pressures in winter. We eliminate terms related to englacial storage, opening by sliding, and melt due to changes in the pressure-melting-point temperature, to create a minimalist version of the Subglacial Hydrology And Kinetic, Transient Interactions (SHAKTI) model, and apply this model to Helheim Glacier in east Greenland to explore the winter base state of the subglacial drainage system. Our results suggest that meltwater produced at the bed alone supports active winter drainage with large areas of elevated water pressure and preferential drainage pathways, using a continuum approach that allows for transitions between flow regimes. Transmissivity varies spatially over several orders of magnitude from 10ā4 to 103 m2sā1, with regions of weak transmissivity representing poorly connected regions of the system. Bed topography controls the location of primary drainage pathways, and high basal melt rates occur along the steep valley walls. Frictional heat from sliding is a dominant source of basal melt; different approaches for calculating basal shear stress produce significantly different basal melt rates and subglacial discharge. Article in Journal/Newspaper East Greenland glacier Greenland Ice Sheet Journal of Glaciology Directory of Open Access Journals: DOAJ Articles Greenland Journal of Glaciology 1 13 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Glacier hydrology Glacier modeling ice-sheet modeling basal melt subglacial processes Environmental sciences GE1-350 Meteorology. Climatology QC851-999 |
spellingShingle |
Glacier hydrology Glacier modeling ice-sheet modeling basal melt subglacial processes Environmental sciences GE1-350 Meteorology. Climatology QC851-999 Aleah Sommers Colin Meyer Mathieu Morlighem Harihar Rajaram Kristin Poinar Winnie Chu Jessica Mejia Subglacial hydrology modeling predicts high winter water pressure and spatially variable transmissivity at Helheim Glacier, Greenland |
topic_facet |
Glacier hydrology Glacier modeling ice-sheet modeling basal melt subglacial processes Environmental sciences GE1-350 Meteorology. Climatology QC851-999 |
description |
Water pressure beneath glaciers influences ice velocity. Subglacial hydrology models are helpful for gaining insight into basal conditions, but models depend on unconstrained parameters, and a current challenge is reproducing elevated water pressures in winter. We eliminate terms related to englacial storage, opening by sliding, and melt due to changes in the pressure-melting-point temperature, to create a minimalist version of the Subglacial Hydrology And Kinetic, Transient Interactions (SHAKTI) model, and apply this model to Helheim Glacier in east Greenland to explore the winter base state of the subglacial drainage system. Our results suggest that meltwater produced at the bed alone supports active winter drainage with large areas of elevated water pressure and preferential drainage pathways, using a continuum approach that allows for transitions between flow regimes. Transmissivity varies spatially over several orders of magnitude from 10ā4 to 103 m2sā1, with regions of weak transmissivity representing poorly connected regions of the system. Bed topography controls the location of primary drainage pathways, and high basal melt rates occur along the steep valley walls. Frictional heat from sliding is a dominant source of basal melt; different approaches for calculating basal shear stress produce significantly different basal melt rates and subglacial discharge. |
format |
Article in Journal/Newspaper |
author |
Aleah Sommers Colin Meyer Mathieu Morlighem Harihar Rajaram Kristin Poinar Winnie Chu Jessica Mejia |
author_facet |
Aleah Sommers Colin Meyer Mathieu Morlighem Harihar Rajaram Kristin Poinar Winnie Chu Jessica Mejia |
author_sort |
Aleah Sommers |
title |
Subglacial hydrology modeling predicts high winter water pressure and spatially variable transmissivity at Helheim Glacier, Greenland |
title_short |
Subglacial hydrology modeling predicts high winter water pressure and spatially variable transmissivity at Helheim Glacier, Greenland |
title_full |
Subglacial hydrology modeling predicts high winter water pressure and spatially variable transmissivity at Helheim Glacier, Greenland |
title_fullStr |
Subglacial hydrology modeling predicts high winter water pressure and spatially variable transmissivity at Helheim Glacier, Greenland |
title_full_unstemmed |
Subglacial hydrology modeling predicts high winter water pressure and spatially variable transmissivity at Helheim Glacier, Greenland |
title_sort |
subglacial hydrology modeling predicts high winter water pressure and spatially variable transmissivity at helheim glacier, greenland |
publisher |
Cambridge University Press |
url |
https://doi.org/10.1017/jog.2023.39 https://doaj.org/article/34e2fff669c340e78d4aa9af0cef9668 |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
East Greenland glacier Greenland Ice Sheet Journal of Glaciology |
genre_facet |
East Greenland glacier Greenland Ice Sheet Journal of Glaciology |
op_source |
Journal of Glaciology, Pp 1-13 |
op_relation |
https://www.cambridge.org/core/product/identifier/S0022143023000394/type/journal_article https://doaj.org/toc/0022-1430 https://doaj.org/toc/1727-5652 doi:10.1017/jog.2023.39 0022-1430 1727-5652 https://doaj.org/article/34e2fff669c340e78d4aa9af0cef9668 |
op_doi |
https://doi.org/10.1017/jog.2023.39 |
container_title |
Journal of Glaciology |
container_start_page |
1 |
op_container_end_page |
13 |
_version_ |
1771545217559691264 |