Evaluation of MODIS albedo product over ice caps in Iceland and impact of volcanic eruptions on their albedo
International audience Albedo is a key variable in the response of glaciers to climate. In Iceland, large albedo variations of the ice caps may be caused by the deposition of volcanic ash (tephra). Sparse in situ measurements are insufficient to characterize the spatial variation of albedo over the...
Published in: | Remote Sensing |
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Main Authors: | , , , , , , |
Other Authors: | , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
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HAL CCSD
2017
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Online Access: | https://hal.science/hal-02351632 https://hal.science/hal-02351632/document https://hal.science/hal-02351632/file/remotesensing-09-00399.pdf https://doi.org/10.3390/rs9050399 |
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ftutoulouse3hal:oai:HAL:hal-02351632v1 |
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record_format |
openpolar |
institution |
Open Polar |
collection |
Université Toulouse III - Paul Sabatier: HAL-UPS |
op_collection_id |
ftutoulouse3hal |
language |
English |
topic |
glacier albedo volcanic eruption [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces environment |
spellingShingle |
glacier albedo volcanic eruption [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces environment Gascoin, Simon Gudmundsson, S. Adalgeirsdóttir, G. Pálsson, F. Schmidt, L. Berthier, E. Björnsson, H. Evaluation of MODIS albedo product over ice caps in Iceland and impact of volcanic eruptions on their albedo |
topic_facet |
glacier albedo volcanic eruption [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces environment |
description |
International audience Albedo is a key variable in the response of glaciers to climate. In Iceland, large albedo variations of the ice caps may be caused by the deposition of volcanic ash (tephra). Sparse in situ measurements are insufficient to characterize the spatial variation of albedo over the ice caps due to their large size. Here we evaluated the latest MCD43 MODIS albedo product (collection 6) to monitor albedo changes over the Icelandic ice caps using albedo measurements from ten automatic weather stations on Vatnajökull and Langjökull. Furthermore, we examined the influence of the albedo variability within MODIS pixels by comparing the results with a collection of Landsat scenes. The results indicate a good ability of the MODIS product to characterize the seasonal and interannual albedo changes with correlation coefficients ranging from 0.47 to 0.90 (median 0.84) and small biases ranging from −0.07 to 0.09. The root-mean square errors (RMSE) ranging from 0.08 to 0.21, are larger than that from previous studies, but we did not discard the retrievals flagged as bad quality to maximize the amount of observations given the frequent cloud obstruction in Iceland. We found a positive but non-significant relationship between the RMSE and the subpixel variability as indicated by the standard deviation of the Landsat albedo within a MODIS pixel (R = 0.48). The summer albedo maps and time series computed from the MODIS product show that the albedo decreased significantly after the 2010 Eyjafjallajökull and 2011 Grímsvötn eruptions on all the main ice caps except the northernmost Drangajökull. A strong reduction of the summer albedo by up to 0.6 is observed over large regions of the accumulation areas. These data can be assimilated in an energy and mass balance model to better understand the relative influence of the volcanic and climate forcing to the ongoing mass losses of Icelandic ice caps. |
author2 |
Centre d'études spatiales de la biosphère (CESBIO) Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3) Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP) Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales Toulouse (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales Toulouse (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE) University of Iceland Reykjavik Laboratoire d'études en Géophysique et océanographie spatiales (LEGOS) Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales Toulouse (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales Toulouse (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France-Centre National de la Recherche Scientifique (CNRS) |
format |
Article in Journal/Newspaper |
author |
Gascoin, Simon Gudmundsson, S. Adalgeirsdóttir, G. Pálsson, F. Schmidt, L. Berthier, E. Björnsson, H. |
author_facet |
Gascoin, Simon Gudmundsson, S. Adalgeirsdóttir, G. Pálsson, F. Schmidt, L. Berthier, E. Björnsson, H. |
author_sort |
Gascoin, Simon |
title |
Evaluation of MODIS albedo product over ice caps in Iceland and impact of volcanic eruptions on their albedo |
title_short |
Evaluation of MODIS albedo product over ice caps in Iceland and impact of volcanic eruptions on their albedo |
title_full |
Evaluation of MODIS albedo product over ice caps in Iceland and impact of volcanic eruptions on their albedo |
title_fullStr |
Evaluation of MODIS albedo product over ice caps in Iceland and impact of volcanic eruptions on their albedo |
title_full_unstemmed |
Evaluation of MODIS albedo product over ice caps in Iceland and impact of volcanic eruptions on their albedo |
title_sort |
evaluation of modis albedo product over ice caps in iceland and impact of volcanic eruptions on their albedo |
publisher |
HAL CCSD |
publishDate |
2017 |
url |
https://hal.science/hal-02351632 https://hal.science/hal-02351632/document https://hal.science/hal-02351632/file/remotesensing-09-00399.pdf https://doi.org/10.3390/rs9050399 |
genre |
Drangajökull Eyjafjallajökull glacier Iceland Langjökull Vatnajökull |
genre_facet |
Drangajökull Eyjafjallajökull glacier Iceland Langjökull Vatnajökull |
op_source |
ISSN: 2072-4292 Remote Sensing https://hal.science/hal-02351632 Remote Sensing, 2017, 9 (5), ⟨10.3390/rs9050399⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.3390/rs9050399 hal-02351632 https://hal.science/hal-02351632 https://hal.science/hal-02351632/document https://hal.science/hal-02351632/file/remotesensing-09-00399.pdf doi:10.3390/rs9050399 |
op_rights |
http://creativecommons.org/licenses/by-nc/ info:eu-repo/semantics/OpenAccess |
op_doi |
https://doi.org/10.3390/rs9050399 |
container_title |
Remote Sensing |
container_volume |
9 |
container_issue |
5 |
container_start_page |
399 |
_version_ |
1810441505614069760 |
spelling |
ftutoulouse3hal:oai:HAL:hal-02351632v1 2024-09-15T18:04:01+00:00 Evaluation of MODIS albedo product over ice caps in Iceland and impact of volcanic eruptions on their albedo Gascoin, Simon Gudmundsson, S. Adalgeirsdóttir, G. Pálsson, F. Schmidt, L. Berthier, E. Björnsson, H. Centre d'études spatiales de la biosphère (CESBIO) Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3) Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP) Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales Toulouse (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales Toulouse (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE) University of Iceland Reykjavik Laboratoire d'études en Géophysique et océanographie spatiales (LEGOS) Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales Toulouse (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales Toulouse (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France-Centre National de la Recherche Scientifique (CNRS) 2017 https://hal.science/hal-02351632 https://hal.science/hal-02351632/document https://hal.science/hal-02351632/file/remotesensing-09-00399.pdf https://doi.org/10.3390/rs9050399 en eng HAL CCSD MDPI info:eu-repo/semantics/altIdentifier/doi/10.3390/rs9050399 hal-02351632 https://hal.science/hal-02351632 https://hal.science/hal-02351632/document https://hal.science/hal-02351632/file/remotesensing-09-00399.pdf doi:10.3390/rs9050399 http://creativecommons.org/licenses/by-nc/ info:eu-repo/semantics/OpenAccess ISSN: 2072-4292 Remote Sensing https://hal.science/hal-02351632 Remote Sensing, 2017, 9 (5), ⟨10.3390/rs9050399⟩ glacier albedo volcanic eruption [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces environment info:eu-repo/semantics/article Journal articles 2017 ftutoulouse3hal https://doi.org/10.3390/rs9050399 2024-06-25T00:13:50Z International audience Albedo is a key variable in the response of glaciers to climate. In Iceland, large albedo variations of the ice caps may be caused by the deposition of volcanic ash (tephra). Sparse in situ measurements are insufficient to characterize the spatial variation of albedo over the ice caps due to their large size. Here we evaluated the latest MCD43 MODIS albedo product (collection 6) to monitor albedo changes over the Icelandic ice caps using albedo measurements from ten automatic weather stations on Vatnajökull and Langjökull. Furthermore, we examined the influence of the albedo variability within MODIS pixels by comparing the results with a collection of Landsat scenes. The results indicate a good ability of the MODIS product to characterize the seasonal and interannual albedo changes with correlation coefficients ranging from 0.47 to 0.90 (median 0.84) and small biases ranging from −0.07 to 0.09. The root-mean square errors (RMSE) ranging from 0.08 to 0.21, are larger than that from previous studies, but we did not discard the retrievals flagged as bad quality to maximize the amount of observations given the frequent cloud obstruction in Iceland. We found a positive but non-significant relationship between the RMSE and the subpixel variability as indicated by the standard deviation of the Landsat albedo within a MODIS pixel (R = 0.48). The summer albedo maps and time series computed from the MODIS product show that the albedo decreased significantly after the 2010 Eyjafjallajökull and 2011 Grímsvötn eruptions on all the main ice caps except the northernmost Drangajökull. A strong reduction of the summer albedo by up to 0.6 is observed over large regions of the accumulation areas. These data can be assimilated in an energy and mass balance model to better understand the relative influence of the volcanic and climate forcing to the ongoing mass losses of Icelandic ice caps. Article in Journal/Newspaper Drangajökull Eyjafjallajökull glacier Iceland Langjökull Vatnajökull Université Toulouse III - Paul Sabatier: HAL-UPS Remote Sensing 9 5 399 |