A model sensitivity study of the impact of clouds on satellite detection and retrieval of volcanic ash
Volcanic ash is commonly observed by infrared detectors on board Earth-orbiting satellites. In the presence of ice and/or liquid-water clouds, the detected volcanic ash signature may be altered. In this paper the sensitivity of detection and retrieval of volcanic ash to the presence of ice and liqui...
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ftdoajarticles:oai:doaj.org/article:1f7e912cf07e4764bc41427ef4a0d5ac 2023-05-15T16:09:29+02:00 A model sensitivity study of the impact of clouds on satellite detection and retrieval of volcanic ash A. Kylling N. Kristiansen A. Stohl R. Buras-Schnell C. Emde J. Gasteiger 2015-05-01T00:00:00Z https://doi.org/10.5194/amt-8-1935-2015 https://doaj.org/article/1f7e912cf07e4764bc41427ef4a0d5ac EN eng Copernicus Publications http://www.atmos-meas-tech.net/8/1935/2015/amt-8-1935-2015.pdf https://doaj.org/toc/1867-1381 https://doaj.org/toc/1867-8548 1867-1381 1867-8548 doi:10.5194/amt-8-1935-2015 https://doaj.org/article/1f7e912cf07e4764bc41427ef4a0d5ac Atmospheric Measurement Techniques, Vol 8, Iss 5, Pp 1935-1949 (2015) Environmental engineering TA170-171 Earthwork. Foundations TA715-787 article 2015 ftdoajarticles https://doi.org/10.5194/amt-8-1935-2015 2022-12-31T00:24:52Z Volcanic ash is commonly observed by infrared detectors on board Earth-orbiting satellites. In the presence of ice and/or liquid-water clouds, the detected volcanic ash signature may be altered. In this paper the sensitivity of detection and retrieval of volcanic ash to the presence of ice and liquid-water clouds was quantified by simulating synthetic equivalents to satellite infrared images with a 3-D radiative transfer model. The sensitivity study was made for the two recent eruptions of Eyjafjallajökull (2010) and Grímsvötn (2011) using realistic water and ice clouds and volcanic ash clouds. The water and ice clouds were taken from European Centre for Medium-Range Weather Forecast (ECMWF) analysis data and the volcanic ash cloud fields from simulations by the Lagrangian particle dispersion model FLEXPART. The radiative transfer simulations were made both with and without ice and liquid-water clouds for the geometry and channels of the Spinning Enhanced Visible and Infrared Imager (SEVIRI). The synthetic SEVIRI images were used as input to standard reverse absorption ash detection and retrieval methods. Ice and liquid-water clouds were on average found to reduce the number of detected ash-affected pixels by 6–12%. However, the effect was highly variable and for individual scenes up to 40% of pixels with mass loading >0.2 g m −2 could not be detected due to the presence of water and ice clouds. For coincident pixels, i.e. pixels where ash was both present in the FLEXPART (hereafter referred to as "Flexpart") simulation and detected by the algorithm, the presence of clouds overall increased the retrieved mean mass loading for the Eyjafjallajökull (2010) eruption by about 13%, while for the Grímsvötn (2011) eruption ash-mass loadings the effect was a 4% decrease of the retrieved ash-mass loading. However, larger differences were seen between scenes (standard deviations of ±30 and ±20% for Eyjafjallajökull and Grímsvötn, respectively) and even larger ones within scenes. The impact of ice and liquid-water clouds ... Article in Journal/Newspaper Eyjafjallajökull Directory of Open Access Journals: DOAJ Articles Atmospheric Measurement Techniques 8 5 1935 1949 |
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Directory of Open Access Journals: DOAJ Articles |
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topic |
Environmental engineering TA170-171 Earthwork. Foundations TA715-787 |
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Environmental engineering TA170-171 Earthwork. Foundations TA715-787 A. Kylling N. Kristiansen A. Stohl R. Buras-Schnell C. Emde J. Gasteiger A model sensitivity study of the impact of clouds on satellite detection and retrieval of volcanic ash |
topic_facet |
Environmental engineering TA170-171 Earthwork. Foundations TA715-787 |
description |
Volcanic ash is commonly observed by infrared detectors on board Earth-orbiting satellites. In the presence of ice and/or liquid-water clouds, the detected volcanic ash signature may be altered. In this paper the sensitivity of detection and retrieval of volcanic ash to the presence of ice and liquid-water clouds was quantified by simulating synthetic equivalents to satellite infrared images with a 3-D radiative transfer model. The sensitivity study was made for the two recent eruptions of Eyjafjallajökull (2010) and Grímsvötn (2011) using realistic water and ice clouds and volcanic ash clouds. The water and ice clouds were taken from European Centre for Medium-Range Weather Forecast (ECMWF) analysis data and the volcanic ash cloud fields from simulations by the Lagrangian particle dispersion model FLEXPART. The radiative transfer simulations were made both with and without ice and liquid-water clouds for the geometry and channels of the Spinning Enhanced Visible and Infrared Imager (SEVIRI). The synthetic SEVIRI images were used as input to standard reverse absorption ash detection and retrieval methods. Ice and liquid-water clouds were on average found to reduce the number of detected ash-affected pixels by 6–12%. However, the effect was highly variable and for individual scenes up to 40% of pixels with mass loading >0.2 g m −2 could not be detected due to the presence of water and ice clouds. For coincident pixels, i.e. pixels where ash was both present in the FLEXPART (hereafter referred to as "Flexpart") simulation and detected by the algorithm, the presence of clouds overall increased the retrieved mean mass loading for the Eyjafjallajökull (2010) eruption by about 13%, while for the Grímsvötn (2011) eruption ash-mass loadings the effect was a 4% decrease of the retrieved ash-mass loading. However, larger differences were seen between scenes (standard deviations of ±30 and ±20% for Eyjafjallajökull and Grímsvötn, respectively) and even larger ones within scenes. The impact of ice and liquid-water clouds ... |
format |
Article in Journal/Newspaper |
author |
A. Kylling N. Kristiansen A. Stohl R. Buras-Schnell C. Emde J. Gasteiger |
author_facet |
A. Kylling N. Kristiansen A. Stohl R. Buras-Schnell C. Emde J. Gasteiger |
author_sort |
A. Kylling |
title |
A model sensitivity study of the impact of clouds on satellite detection and retrieval of volcanic ash |
title_short |
A model sensitivity study of the impact of clouds on satellite detection and retrieval of volcanic ash |
title_full |
A model sensitivity study of the impact of clouds on satellite detection and retrieval of volcanic ash |
title_fullStr |
A model sensitivity study of the impact of clouds on satellite detection and retrieval of volcanic ash |
title_full_unstemmed |
A model sensitivity study of the impact of clouds on satellite detection and retrieval of volcanic ash |
title_sort |
model sensitivity study of the impact of clouds on satellite detection and retrieval of volcanic ash |
publisher |
Copernicus Publications |
publishDate |
2015 |
url |
https://doi.org/10.5194/amt-8-1935-2015 https://doaj.org/article/1f7e912cf07e4764bc41427ef4a0d5ac |
genre |
Eyjafjallajökull |
genre_facet |
Eyjafjallajökull |
op_source |
Atmospheric Measurement Techniques, Vol 8, Iss 5, Pp 1935-1949 (2015) |
op_relation |
http://www.atmos-meas-tech.net/8/1935/2015/amt-8-1935-2015.pdf https://doaj.org/toc/1867-1381 https://doaj.org/toc/1867-8548 1867-1381 1867-8548 doi:10.5194/amt-8-1935-2015 https://doaj.org/article/1f7e912cf07e4764bc41427ef4a0d5ac |
op_doi |
https://doi.org/10.5194/amt-8-1935-2015 |
container_title |
Atmospheric Measurement Techniques |
container_volume |
8 |
container_issue |
5 |
container_start_page |
1935 |
op_container_end_page |
1949 |
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1766405364945780736 |