Impact of dust deposition on the albedo of Vatnajökull ice cap, Iceland
Deposition of small amounts of airborne dust on glaciers causes positive radiative forcing and enhanced melting due to the reduction of surface albedo. To study the effects of dust deposition on the mass balance of Brúarjökull, an outlet glacier of the largest ice cap in Iceland, Vatnajökull, a stud...
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Copernicus Publications
2017
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ftdoajarticles:oai:doaj.org/article:499eeb9117374bbf954963e4df7266cb 2023-05-15T16:21:39+02:00 Impact of dust deposition on the albedo of Vatnajökull ice cap, Iceland M. Wittmann C. D. Groot Zwaaftink L. Steffensen Schmidt S. Guðmundsson F. Pálsson O. Arnalds H. Björnsson T. Thorsteinsson A. Stohl 2017-03-01T00:00:00Z https://doi.org/10.5194/tc-11-741-2017 https://doaj.org/article/499eeb9117374bbf954963e4df7266cb EN eng Copernicus Publications http://www.the-cryosphere.net/11/741/2017/tc-11-741-2017.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 1994-0416 1994-0424 doi:10.5194/tc-11-741-2017 https://doaj.org/article/499eeb9117374bbf954963e4df7266cb The Cryosphere, Vol 11, Iss 2, Pp 741-754 (2017) Environmental sciences GE1-350 Geology QE1-996.5 article 2017 ftdoajarticles https://doi.org/10.5194/tc-11-741-2017 2022-12-31T14:58:01Z Deposition of small amounts of airborne dust on glaciers causes positive radiative forcing and enhanced melting due to the reduction of surface albedo. To study the effects of dust deposition on the mass balance of Brúarjökull, an outlet glacier of the largest ice cap in Iceland, Vatnajökull, a study of dust deposition events in the year 2012 was carried out. The dust-mobilisation module FLEXDUST was used to calculate spatio-temporally resolved dust emissions from Iceland and the dispersion model FLEXPART was used to simulate atmospheric dust dispersion and deposition. We used albedo measurements at two automatic weather stations on Brúarjökull to evaluate the dust impacts. Both stations are situated in the accumulation area of the glacier, but the lower station is close to the equilibrium line. For this site ( ∼ 1210 m a.s.l.), the dispersion model produced 10 major dust deposition events and a total annual deposition of 20.5 g m −2 . At the station located higher on the glacier ( ∼ 1525 m a.s.l.), the model produced nine dust events, with one single event causing ∼ 5 g m −2 of dust deposition and a total deposition of ∼ 10 g m −2 yr −1 . The main dust source was found to be the Dyngjusandur floodplain north of Vatnajökull; northerly winds prevailed 80 % of the time at the lower station when dust events occurred. In all of the simulated dust events, a corresponding albedo drop was observed at the weather stations. The influence of the dust on the albedo was estimated using the regional climate model HIRHAM5 to simulate the albedo of a clean glacier surface without dust. By comparing the measured albedo to the modelled albedo, we determine the influence of dust events on the snow albedo and the surface energy balance. We estimate that the dust deposition caused an additional 1.1 m w.e. (water equivalent) of snowmelt (or 42 % of the 2.8 m w.e. total melt) compared to a hypothetical clean glacier surface at the lower station, and 0.6 m w.e. more melt (or 38 % of the 1.6 m w.e. melt in total) at the station located ... Article in Journal/Newspaper glacier Ice cap Iceland The Cryosphere Vatnajökull Directory of Open Access Journals: DOAJ Articles Vatnajökull ENVELOPE(-16.823,-16.823,64.420,64.420) Brúarjökull ENVELOPE(-16.157,-16.157,64.682,64.682) The Cryosphere 11 2 741 754 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Environmental sciences GE1-350 Geology QE1-996.5 |
spellingShingle |
Environmental sciences GE1-350 Geology QE1-996.5 M. Wittmann C. D. Groot Zwaaftink L. Steffensen Schmidt S. Guðmundsson F. Pálsson O. Arnalds H. Björnsson T. Thorsteinsson A. Stohl Impact of dust deposition on the albedo of Vatnajökull ice cap, Iceland |
topic_facet |
Environmental sciences GE1-350 Geology QE1-996.5 |
description |
Deposition of small amounts of airborne dust on glaciers causes positive radiative forcing and enhanced melting due to the reduction of surface albedo. To study the effects of dust deposition on the mass balance of Brúarjökull, an outlet glacier of the largest ice cap in Iceland, Vatnajökull, a study of dust deposition events in the year 2012 was carried out. The dust-mobilisation module FLEXDUST was used to calculate spatio-temporally resolved dust emissions from Iceland and the dispersion model FLEXPART was used to simulate atmospheric dust dispersion and deposition. We used albedo measurements at two automatic weather stations on Brúarjökull to evaluate the dust impacts. Both stations are situated in the accumulation area of the glacier, but the lower station is close to the equilibrium line. For this site ( ∼ 1210 m a.s.l.), the dispersion model produced 10 major dust deposition events and a total annual deposition of 20.5 g m −2 . At the station located higher on the glacier ( ∼ 1525 m a.s.l.), the model produced nine dust events, with one single event causing ∼ 5 g m −2 of dust deposition and a total deposition of ∼ 10 g m −2 yr −1 . The main dust source was found to be the Dyngjusandur floodplain north of Vatnajökull; northerly winds prevailed 80 % of the time at the lower station when dust events occurred. In all of the simulated dust events, a corresponding albedo drop was observed at the weather stations. The influence of the dust on the albedo was estimated using the regional climate model HIRHAM5 to simulate the albedo of a clean glacier surface without dust. By comparing the measured albedo to the modelled albedo, we determine the influence of dust events on the snow albedo and the surface energy balance. We estimate that the dust deposition caused an additional 1.1 m w.e. (water equivalent) of snowmelt (or 42 % of the 2.8 m w.e. total melt) compared to a hypothetical clean glacier surface at the lower station, and 0.6 m w.e. more melt (or 38 % of the 1.6 m w.e. melt in total) at the station located ... |
format |
Article in Journal/Newspaper |
author |
M. Wittmann C. D. Groot Zwaaftink L. Steffensen Schmidt S. Guðmundsson F. Pálsson O. Arnalds H. Björnsson T. Thorsteinsson A. Stohl |
author_facet |
M. Wittmann C. D. Groot Zwaaftink L. Steffensen Schmidt S. Guðmundsson F. Pálsson O. Arnalds H. Björnsson T. Thorsteinsson A. Stohl |
author_sort |
M. Wittmann |
title |
Impact of dust deposition on the albedo of Vatnajökull ice cap, Iceland |
title_short |
Impact of dust deposition on the albedo of Vatnajökull ice cap, Iceland |
title_full |
Impact of dust deposition on the albedo of Vatnajökull ice cap, Iceland |
title_fullStr |
Impact of dust deposition on the albedo of Vatnajökull ice cap, Iceland |
title_full_unstemmed |
Impact of dust deposition on the albedo of Vatnajökull ice cap, Iceland |
title_sort |
impact of dust deposition on the albedo of vatnajökull ice cap, iceland |
publisher |
Copernicus Publications |
publishDate |
2017 |
url |
https://doi.org/10.5194/tc-11-741-2017 https://doaj.org/article/499eeb9117374bbf954963e4df7266cb |
long_lat |
ENVELOPE(-16.823,-16.823,64.420,64.420) ENVELOPE(-16.157,-16.157,64.682,64.682) |
geographic |
Vatnajökull Brúarjökull |
geographic_facet |
Vatnajökull Brúarjökull |
genre |
glacier Ice cap Iceland The Cryosphere Vatnajökull |
genre_facet |
glacier Ice cap Iceland The Cryosphere Vatnajökull |
op_source |
The Cryosphere, Vol 11, Iss 2, Pp 741-754 (2017) |
op_relation |
http://www.the-cryosphere.net/11/741/2017/tc-11-741-2017.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 1994-0416 1994-0424 doi:10.5194/tc-11-741-2017 https://doaj.org/article/499eeb9117374bbf954963e4df7266cb |
op_doi |
https://doi.org/10.5194/tc-11-741-2017 |
container_title |
The Cryosphere |
container_volume |
11 |
container_issue |
2 |
container_start_page |
741 |
op_container_end_page |
754 |
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1766009650485919744 |