Ash mists and brown snow:Remobilization of volcanic ash from recent Icelandic eruptions
Recent eruptions in Iceland and Chile have demonstrated that volcanic ash problems persist long after an eruption. For this reason, ash dispersion models are being extended to include ash remobilization. Critical to these models is knowledge of the ash source and the particle sizes that can be mobil...
Published in: | Journal of Geophysical Research: Atmospheres |
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Format: | Article in Journal/Newspaper |
Language: | English |
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2014
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Online Access: | https://hdl.handle.net/1983/7a193433-37d0-41e2-941e-da08c525689a https://research-information.bris.ac.uk/en/publications/7a193433-37d0-41e2-941e-da08c525689a https://doi.org/10.1002/2014JD021598 http://www.scopus.com/inward/record.url?scp=84906658171&partnerID=8YFLogxK |
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ftubristolcris:oai:research-information.bris.ac.uk:publications/7a193433-37d0-41e2-941e-da08c525689a 2024-04-28T08:18:14+00:00 Ash mists and brown snow:Remobilization of volcanic ash from recent Icelandic eruptions Liu, Emma J Cashman, Katharine V Beckett, Frances Witham, Claire Leadbetter, Susan Hort, Matthew Gudmundsson, Snaevarr 2014-08-04 https://hdl.handle.net/1983/7a193433-37d0-41e2-941e-da08c525689a https://research-information.bris.ac.uk/en/publications/7a193433-37d0-41e2-941e-da08c525689a https://doi.org/10.1002/2014JD021598 http://www.scopus.com/inward/record.url?scp=84906658171&partnerID=8YFLogxK eng eng https://research-information.bris.ac.uk/en/publications/7a193433-37d0-41e2-941e-da08c525689a info:eu-repo/semantics/restrictedAccess Liu , E J , Cashman , K V , Beckett , F , Witham , C , Leadbetter , S , Hort , M & Gudmundsson , S 2014 , ' Ash mists and brown snow : Remobilization of volcanic ash from recent Icelandic eruptions ' , Journal of Geophysical Research: Atmospheres , vol. 119 , no. 15 , pp. 9463-9480 . https://doi.org/10.1002/2014JD021598 Eyjafjallajokull forecast Grimsvotn remobilisation volcanic ash wind transport article 2014 ftubristolcris https://doi.org/10.1002/2014JD021598 2024-04-03T15:23:47Z Recent eruptions in Iceland and Chile have demonstrated that volcanic ash problems persist long after an eruption. For this reason, ash dispersion models are being extended to include ash remobilization. Critical to these models is knowledge of the ash source and the particle sizes that can be mobilized under different wind and moisture conditions. Here we characterize the physical and chemical characteristics of ash deposited on new snow in Reykjavík, Iceland, following a blizzard on 6 March 2013. Morphological, textural, and compositional analyses indicate resuspension from multiple eruptive deposits, including both Grímsvötn (2011) and Eyjafjallajökull (2010) eruptions. Grain size measurements show a mode of 32–63 µm, with particles as large as 177 µm; there is little mass in the very fine fraction, ≤10 µm (PM10). We compare our observations to predictions using the Lagrangian particle dispersion model, NAME (UK Met Office). The model output is consistent with observations in that it forecasts resuspension from both Eyjafjallajökull and Grímsvötn source regions, and shows ash deposition coincident with the timing of observed deposition in Reykjavík. The modeled deposit in Reykjavík predicts, however, a substantially lower proportion of Grímsvötn ash than observed. This discrepancy has highlighted the need to reassess the assumptions used in the simulations, particularly regarding the source area and precipitation thresholds. Furthermore, we suggest that modification of ash deposits in the form of erosion, redeposition, compaction, or cementation may influence the dynamics of resuspension over time, thus influencing the ability of model simulations to accurately forecast remobilization events. Article in Journal/Newspaper Eyjafjallajökull Iceland Reykjavík Reykjavík University of Bristol: Bristol Research Journal of Geophysical Research: Atmospheres 119 15 9463 9480 |
institution |
Open Polar |
collection |
University of Bristol: Bristol Research |
op_collection_id |
ftubristolcris |
language |
English |
topic |
Eyjafjallajokull forecast Grimsvotn remobilisation volcanic ash wind transport |
spellingShingle |
Eyjafjallajokull forecast Grimsvotn remobilisation volcanic ash wind transport Liu, Emma J Cashman, Katharine V Beckett, Frances Witham, Claire Leadbetter, Susan Hort, Matthew Gudmundsson, Snaevarr Ash mists and brown snow:Remobilization of volcanic ash from recent Icelandic eruptions |
topic_facet |
Eyjafjallajokull forecast Grimsvotn remobilisation volcanic ash wind transport |
description |
Recent eruptions in Iceland and Chile have demonstrated that volcanic ash problems persist long after an eruption. For this reason, ash dispersion models are being extended to include ash remobilization. Critical to these models is knowledge of the ash source and the particle sizes that can be mobilized under different wind and moisture conditions. Here we characterize the physical and chemical characteristics of ash deposited on new snow in Reykjavík, Iceland, following a blizzard on 6 March 2013. Morphological, textural, and compositional analyses indicate resuspension from multiple eruptive deposits, including both Grímsvötn (2011) and Eyjafjallajökull (2010) eruptions. Grain size measurements show a mode of 32–63 µm, with particles as large as 177 µm; there is little mass in the very fine fraction, ≤10 µm (PM10). We compare our observations to predictions using the Lagrangian particle dispersion model, NAME (UK Met Office). The model output is consistent with observations in that it forecasts resuspension from both Eyjafjallajökull and Grímsvötn source regions, and shows ash deposition coincident with the timing of observed deposition in Reykjavík. The modeled deposit in Reykjavík predicts, however, a substantially lower proportion of Grímsvötn ash than observed. This discrepancy has highlighted the need to reassess the assumptions used in the simulations, particularly regarding the source area and precipitation thresholds. Furthermore, we suggest that modification of ash deposits in the form of erosion, redeposition, compaction, or cementation may influence the dynamics of resuspension over time, thus influencing the ability of model simulations to accurately forecast remobilization events. |
format |
Article in Journal/Newspaper |
author |
Liu, Emma J Cashman, Katharine V Beckett, Frances Witham, Claire Leadbetter, Susan Hort, Matthew Gudmundsson, Snaevarr |
author_facet |
Liu, Emma J Cashman, Katharine V Beckett, Frances Witham, Claire Leadbetter, Susan Hort, Matthew Gudmundsson, Snaevarr |
author_sort |
Liu, Emma J |
title |
Ash mists and brown snow:Remobilization of volcanic ash from recent Icelandic eruptions |
title_short |
Ash mists and brown snow:Remobilization of volcanic ash from recent Icelandic eruptions |
title_full |
Ash mists and brown snow:Remobilization of volcanic ash from recent Icelandic eruptions |
title_fullStr |
Ash mists and brown snow:Remobilization of volcanic ash from recent Icelandic eruptions |
title_full_unstemmed |
Ash mists and brown snow:Remobilization of volcanic ash from recent Icelandic eruptions |
title_sort |
ash mists and brown snow:remobilization of volcanic ash from recent icelandic eruptions |
publishDate |
2014 |
url |
https://hdl.handle.net/1983/7a193433-37d0-41e2-941e-da08c525689a https://research-information.bris.ac.uk/en/publications/7a193433-37d0-41e2-941e-da08c525689a https://doi.org/10.1002/2014JD021598 http://www.scopus.com/inward/record.url?scp=84906658171&partnerID=8YFLogxK |
genre |
Eyjafjallajökull Iceland Reykjavík Reykjavík |
genre_facet |
Eyjafjallajökull Iceland Reykjavík Reykjavík |
op_source |
Liu , E J , Cashman , K V , Beckett , F , Witham , C , Leadbetter , S , Hort , M & Gudmundsson , S 2014 , ' Ash mists and brown snow : Remobilization of volcanic ash from recent Icelandic eruptions ' , Journal of Geophysical Research: Atmospheres , vol. 119 , no. 15 , pp. 9463-9480 . https://doi.org/10.1002/2014JD021598 |
op_relation |
https://research-information.bris.ac.uk/en/publications/7a193433-37d0-41e2-941e-da08c525689a |
op_rights |
info:eu-repo/semantics/restrictedAccess |
op_doi |
https://doi.org/10.1002/2014JD021598 |
container_title |
Journal of Geophysical Research: Atmospheres |
container_volume |
119 |
container_issue |
15 |
container_start_page |
9463 |
op_container_end_page |
9480 |
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1797582342483607552 |