Intercomparison of surface meltwater routing models for the Greenland ice sheet and influence on subglacial effective pressures
Each summer, large volumes of surface meltwater drain off the Greenland ice sheet (GrIS) surface through moulins to the bed, impacting subglacial hydrology and ice flow dynamics. Supraglacial surface routing delays may propagate to englacial and subglacial hydrologic systems, requiring accurate asse...
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Online Access: | https://doi.org/10.5194/tc-14-3349-2020 |
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ftncar:oai:drupal-site.org:articles_23726 2024-04-28T08:21:17+00:00 Intercomparison of surface meltwater routing models for the Greenland ice sheet and influence on subglacial effective pressures Yang, Kang (author) Sommers, Aleah (author) Andrews, Lauren C. (author) Smith, Laurence C. (author) Lu, Xin (author) Fettweis, Xavier (author) Li, Manchun (author) 2020-10-07 https://doi.org/10.5194/tc-14-3349-2020 en eng The Cryosphere--The Cryosphere--1994-0424 articles:23726 ark:/85065/d7mp56j5 doi:10.5194/tc-14-3349-2020 Copyright author(s). This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License. article Text 2020 ftncar https://doi.org/10.5194/tc-14-3349-2020 2024-04-04T17:32:42Z Each summer, large volumes of surface meltwater drain off the Greenland ice sheet (GrIS) surface through moulins to the bed, impacting subglacial hydrology and ice flow dynamics. Supraglacial surface routing delays may propagate to englacial and subglacial hydrologic systems, requiring accurate assessment to correctly estimate subglacial effective pressures. We compare hourly supraglacial moulin discharge simulations from three surface meltwater routing models - the synthetic unit hydrograph (SUH), the bareice component of surface routing and lake filling (SRLF), and the rescaled width function (RWF) - for four internally drained catchments on the southwestern Greenland ice sheet surface. The routing models are forced identically using surface runoff from the Modele Atmospherique Regionale regional climate model (RCM). For each catchment, simulated moulin hydrographs are input to the SHAKTI subglacial hydrologic model to simulate diurnally varying subglacial effective-pressure variations in the vicinity of a single moulin. Overall, all three routing models produce more realistic moulin discharges than simply using RCM runoff outputs without surface routing but produce significant differences in peak moulin discharge and time to peak. In particular, the RWF yields later, smaller peak moulin discharges than the SUH or SRLF due to its representation of slow interfluve flow between supraglacial meltwater channels, and it can readily accommodate the seasonal evolution of supraglacial stream and river networks. Differences among the three routing models are reflected in a series of simple idealized subglacial hydrology simulations that yield different diurnal effective-pressure amplitudes; however, the supraglacial hydrologic system acts as short-term storage for surface meltwater, and the temporal mean effective pressure is relatively consistent across routing models. Article in Journal/Newspaper Greenland Ice Sheet The Cryosphere OpenSky (NCAR/UCAR - National Center for Atmospheric Research/University Corporation for Atmospheric Research) The Cryosphere 14 10 3349 3365 |
institution |
Open Polar |
collection |
OpenSky (NCAR/UCAR - National Center for Atmospheric Research/University Corporation for Atmospheric Research) |
op_collection_id |
ftncar |
language |
English |
description |
Each summer, large volumes of surface meltwater drain off the Greenland ice sheet (GrIS) surface through moulins to the bed, impacting subglacial hydrology and ice flow dynamics. Supraglacial surface routing delays may propagate to englacial and subglacial hydrologic systems, requiring accurate assessment to correctly estimate subglacial effective pressures. We compare hourly supraglacial moulin discharge simulations from three surface meltwater routing models - the synthetic unit hydrograph (SUH), the bareice component of surface routing and lake filling (SRLF), and the rescaled width function (RWF) - for four internally drained catchments on the southwestern Greenland ice sheet surface. The routing models are forced identically using surface runoff from the Modele Atmospherique Regionale regional climate model (RCM). For each catchment, simulated moulin hydrographs are input to the SHAKTI subglacial hydrologic model to simulate diurnally varying subglacial effective-pressure variations in the vicinity of a single moulin. Overall, all three routing models produce more realistic moulin discharges than simply using RCM runoff outputs without surface routing but produce significant differences in peak moulin discharge and time to peak. In particular, the RWF yields later, smaller peak moulin discharges than the SUH or SRLF due to its representation of slow interfluve flow between supraglacial meltwater channels, and it can readily accommodate the seasonal evolution of supraglacial stream and river networks. Differences among the three routing models are reflected in a series of simple idealized subglacial hydrology simulations that yield different diurnal effective-pressure amplitudes; however, the supraglacial hydrologic system acts as short-term storage for surface meltwater, and the temporal mean effective pressure is relatively consistent across routing models. |
author2 |
Yang, Kang (author) Sommers, Aleah (author) Andrews, Lauren C. (author) Smith, Laurence C. (author) Lu, Xin (author) Fettweis, Xavier (author) Li, Manchun (author) |
format |
Article in Journal/Newspaper |
title |
Intercomparison of surface meltwater routing models for the Greenland ice sheet and influence on subglacial effective pressures |
spellingShingle |
Intercomparison of surface meltwater routing models for the Greenland ice sheet and influence on subglacial effective pressures |
title_short |
Intercomparison of surface meltwater routing models for the Greenland ice sheet and influence on subglacial effective pressures |
title_full |
Intercomparison of surface meltwater routing models for the Greenland ice sheet and influence on subglacial effective pressures |
title_fullStr |
Intercomparison of surface meltwater routing models for the Greenland ice sheet and influence on subglacial effective pressures |
title_full_unstemmed |
Intercomparison of surface meltwater routing models for the Greenland ice sheet and influence on subglacial effective pressures |
title_sort |
intercomparison of surface meltwater routing models for the greenland ice sheet and influence on subglacial effective pressures |
publishDate |
2020 |
url |
https://doi.org/10.5194/tc-14-3349-2020 |
genre |
Greenland Ice Sheet The Cryosphere |
genre_facet |
Greenland Ice Sheet The Cryosphere |
op_relation |
The Cryosphere--The Cryosphere--1994-0424 articles:23726 ark:/85065/d7mp56j5 doi:10.5194/tc-14-3349-2020 |
op_rights |
Copyright author(s). This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License. |
op_doi |
https://doi.org/10.5194/tc-14-3349-2020 |
container_title |
The Cryosphere |
container_volume |
14 |
container_issue |
10 |
container_start_page |
3349 |
op_container_end_page |
3365 |
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1797583712086392832 |