Firn layer impact on glacial runoff: a case study at Hofsjökull, Iceland
Abstract A mass balance–runoff model is applied to Hofsjökull, an 880 km 2 ice cap in Iceland, in order to assess the importance of the firn layer for glacial runoff. The model is forced by daily temperature and precipitation data from a nearby meteorological station. Water is routed through the gla...
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crwiley:10.1002/hyp.6201 2024-06-23T07:53:03+00:00 Firn layer impact on glacial runoff: a case study at Hofsjökull, Iceland de Woul, Mattias Hock, Regine Braun, Matthias Thorsteinsson, Thorsteinn Jóhannesson, Tómas Halldórsdóttir, Stefanía 2006 http://dx.doi.org/10.1002/hyp.6201 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fhyp.6201 https://onlinelibrary.wiley.com/doi/pdf/10.1002/hyp.6201 en eng Wiley http://onlinelibrary.wiley.com/termsAndConditions#vor Hydrological Processes volume 20, issue 10, page 2171-2185 ISSN 0885-6087 1099-1085 journal-article 2006 crwiley https://doi.org/10.1002/hyp.6201 2024-06-04T06:47:42Z Abstract A mass balance–runoff model is applied to Hofsjökull, an 880 km 2 ice cap in Iceland, in order to assess the importance of the firn layer for glacial runoff. The model is forced by daily temperature and precipitation data from a nearby meteorological station. Water is routed through the glacier using a linear reservoir model assuming different storage constants for firn, snow and ice. The model is calibrated and validated using mass balance data and satellite‐derived snow facies maps. Simulated mass balances and snowline retreats are generally in good agreement with observations. Modelled cumulative mass balance for the entire ice cap over the period 1987/1988 to 2003/2004 is − 7·3 m, with uninterrupted negative mass balances since 1993/1994. Perturbing the model with a uniform temperature (+1 K) and precipitation (+10%) increase yields static mass balance sensitivities of − 0·95 m a −1 and +0·23 m a −1 respectively. Removing the firn layer under otherwise likewise conditions results in almost unchanged total runoff volumes, but yields a redistribution of discharge within the year. Early summer discharge (June to mid August) is amplified by roughly 5–10%, whereas late‐summer/autumn discharge (mid August to November) is reduced by 15–20% as a result of accelerated water flow through the glacial hydrological system. In comparison, applying a climate‐model‐based temperature and precipitation scenario for Iceland until 2050 results in higher runoff throughout the year, increasing total runoff by roughly one‐third. The results emphasize the role of the firn layer in delaying water flow through glaciers, and the influence on discharge seasonality when firn areas shrink in response to climate‐change‐induced glacier wastage. Copyright © 2006 John Wiley & Sons, Ltd. Article in Journal/Newspaper glacier Hofsjökull Ice cap Iceland Wiley Online Library Hydrological Processes 20 10 2171 2185 |
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Wiley Online Library |
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English |
description |
Abstract A mass balance–runoff model is applied to Hofsjökull, an 880 km 2 ice cap in Iceland, in order to assess the importance of the firn layer for glacial runoff. The model is forced by daily temperature and precipitation data from a nearby meteorological station. Water is routed through the glacier using a linear reservoir model assuming different storage constants for firn, snow and ice. The model is calibrated and validated using mass balance data and satellite‐derived snow facies maps. Simulated mass balances and snowline retreats are generally in good agreement with observations. Modelled cumulative mass balance for the entire ice cap over the period 1987/1988 to 2003/2004 is − 7·3 m, with uninterrupted negative mass balances since 1993/1994. Perturbing the model with a uniform temperature (+1 K) and precipitation (+10%) increase yields static mass balance sensitivities of − 0·95 m a −1 and +0·23 m a −1 respectively. Removing the firn layer under otherwise likewise conditions results in almost unchanged total runoff volumes, but yields a redistribution of discharge within the year. Early summer discharge (June to mid August) is amplified by roughly 5–10%, whereas late‐summer/autumn discharge (mid August to November) is reduced by 15–20% as a result of accelerated water flow through the glacial hydrological system. In comparison, applying a climate‐model‐based temperature and precipitation scenario for Iceland until 2050 results in higher runoff throughout the year, increasing total runoff by roughly one‐third. The results emphasize the role of the firn layer in delaying water flow through glaciers, and the influence on discharge seasonality when firn areas shrink in response to climate‐change‐induced glacier wastage. Copyright © 2006 John Wiley & Sons, Ltd. |
format |
Article in Journal/Newspaper |
author |
de Woul, Mattias Hock, Regine Braun, Matthias Thorsteinsson, Thorsteinn Jóhannesson, Tómas Halldórsdóttir, Stefanía |
spellingShingle |
de Woul, Mattias Hock, Regine Braun, Matthias Thorsteinsson, Thorsteinn Jóhannesson, Tómas Halldórsdóttir, Stefanía Firn layer impact on glacial runoff: a case study at Hofsjökull, Iceland |
author_facet |
de Woul, Mattias Hock, Regine Braun, Matthias Thorsteinsson, Thorsteinn Jóhannesson, Tómas Halldórsdóttir, Stefanía |
author_sort |
de Woul, Mattias |
title |
Firn layer impact on glacial runoff: a case study at Hofsjökull, Iceland |
title_short |
Firn layer impact on glacial runoff: a case study at Hofsjökull, Iceland |
title_full |
Firn layer impact on glacial runoff: a case study at Hofsjökull, Iceland |
title_fullStr |
Firn layer impact on glacial runoff: a case study at Hofsjökull, Iceland |
title_full_unstemmed |
Firn layer impact on glacial runoff: a case study at Hofsjökull, Iceland |
title_sort |
firn layer impact on glacial runoff: a case study at hofsjökull, iceland |
publisher |
Wiley |
publishDate |
2006 |
url |
http://dx.doi.org/10.1002/hyp.6201 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fhyp.6201 https://onlinelibrary.wiley.com/doi/pdf/10.1002/hyp.6201 |
genre |
glacier Hofsjökull Ice cap Iceland |
genre_facet |
glacier Hofsjökull Ice cap Iceland |
op_source |
Hydrological Processes volume 20, issue 10, page 2171-2185 ISSN 0885-6087 1099-1085 |
op_rights |
http://onlinelibrary.wiley.com/termsAndConditions#vor |
op_doi |
https://doi.org/10.1002/hyp.6201 |
container_title |
Hydrological Processes |
container_volume |
20 |
container_issue |
10 |
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2171 |
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2185 |
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1802644524603801600 |