Complex refractive index of volcanic ash ...
Type de document :
Article dans une revue scientifique: Article original
DOI :
PMID :
URL permanente :
Titre :
Complex refractive index of volcanic ash aerosol in the infrared, visible, and ultraviolet
Auteur(s) :
Deguine, Alexandre [Auteur]
Laboratoire d’Optique Atmosphérique - UMR 8518 [LOA]
Physicochimie des Processus de Combustion et de l’Atmosphère - UMR 8522 [PC2A]
Université libre de Bruxelles [ULB]
Petitprez, Denis [Auteur]
Physicochimie des Processus de Combustion et de l'Atmosphère (PC2A) - UMR 8522
Clarisse, Lieven [Auteur]
Université libre de Bruxelles [ULB]
Gudmundsson, Snævarr [Auteur]
Outes, Valeria [Auteur]
Instituto Andino Patagónico de Tecnologías Biológicas y Geoambientales [Bariloche] [IPATEC]
Villarosa, Gustavo [Auteur]
Instituto Andino Patagónico de Tecnologías Biológicas y Geoambientales [Bariloche] [IPATEC]
Herbin, Herve [Auteur]
Laboratoire d'Optique Atmosphérique (LOA) - UMR 8518
Laboratoire d’Optique Atmosphérique - UMR 8518 [LOA]
Physicochimie des Processus de Combustion et de l’Atmosphère - UMR 8522 [PC2A]
Université libre de Bruxelles [ULB]
Petitprez, Denis [Auteur]
Physicochimie des Processus de Combustion et de l'Atmosphère (PC2A) - UMR 8522
Clarisse, Lieven [Auteur]
Université libre de Bruxelles [ULB]
Gudmundsson, Snævarr [Auteur]
Outes, Valeria [Auteur]
Instituto Andino Patagónico de Tecnologías Biológicas y Geoambientales [Bariloche] [IPATEC]
Villarosa, Gustavo [Auteur]
Instituto Andino Patagónico de Tecnologías Biológicas y Geoambientales [Bariloche] [IPATEC]
Herbin, Herve [Auteur]
Laboratoire d'Optique Atmosphérique (LOA) - UMR 8518
Titre de la revue :
Applied optics
Nom court de la revue :
Appl. Optics
Numéro :
59
Pagination :
-
Date de publication :
2021-03-10
ISSN :
1559-128X
Discipline(s) HAL :
Planète et Univers [physics]/Océan, Atmosphère
Résumé en anglais : [en]
Very fine silicate-rich volcanic ash, generated by explosive volcanic eruptions, can efficiently be traced downwind with infrared satellite sounders. Their measurements can also be used to derive physical parameters, such ...
Lire la suite >Very fine silicate-rich volcanic ash, generated by explosive volcanic eruptions, can efficiently be traced downwind with infrared satellite sounders. Their measurements can also be used to derive physical parameters, such as optical depths and effective radii. However, one of the key requirements for accurate retrievals is a good knowledge of the complex refractive index (CRI) of the ash under investigation. In the past, the vast majority of the studies used the CRIs from Pollack et al. [ Icarus 19 , 372 ( 1973 ) ICRSA5 0019-1035 10.1016/0019-1035(73)90115-2 ], which are based on measurements of thin slices of volcanic rock, and therefore are not representative for airborne volcanic ash particles. Here, we report measurements of the CRI of volcanic ash in suspension, generated from samples collected from recent high-impact eruptions in Chile (Puyehue-Cordón Caulle, Calbuco, and Chaitén), Iceland (Eyjafjallajökull and Grímsvötn), and Italy (Etna). The samples cover a wide range of S i O 2 content (46% to 76%) as confirmed by an X-ray fluorescence analysis. In the experimental setup, volcanic ash was suspended in nitrogen through mechanical agitation. Extinction spectra were recorded in the infrared, visible, and ultraviolet spectral regions. The particle size distribution within the airflow was also recorded. An iterative algorithm allowed us to obtain fully consistent CRIs for the six samples, compatible with the observed extinction spectra and the Kramers–Krönig relations. While a good agreement is found with other recently reported CRIs in the UV/Vis, larger differences are found in the longwave infrared spectral region.Lire moins >
Lire la suite >Very fine silicate-rich volcanic ash, generated by explosive volcanic eruptions, can efficiently be traced downwind with infrared satellite sounders. Their measurements can also be used to derive physical parameters, such as optical depths and effective radii. However, one of the key requirements for accurate retrievals is a good knowledge of the complex refractive index (CRI) of the ash under investigation. In the past, the vast majority of the studies used the CRIs from Pollack et al. [ Icarus 19 , 372 ( 1973 ) ICRSA5 0019-1035 10.1016/0019-1035(73)90115-2 ], which are based on measurements of thin slices of volcanic rock, and therefore are not representative for airborne volcanic ash particles. Here, we report measurements of the CRI of volcanic ash in suspension, generated from samples collected from recent high-impact eruptions in Chile (Puyehue-Cordón Caulle, Calbuco, and Chaitén), Iceland (Eyjafjallajökull and Grímsvötn), and Italy (Etna). The samples cover a wide range of S i O 2 content (46% to 76%) as confirmed by an X-ray fluorescence analysis. In the experimental setup, volcanic ash was suspended in nitrogen through mechanical agitation. Extinction spectra were recorded in the infrared, visible, and ultraviolet spectral regions. The particle size distribution within the airflow was also recorded. An iterative algorithm allowed us to obtain fully consistent CRIs for the six samples, compatible with the observed extinction spectra and the Kramers–Krönig relations. While a good agreement is found with other recently reported CRIs in the UV/Vis, larger differences are found in the longwave infrared spectral region.Lire moins >
Langue :
Anglais
Audience :
Internationale
Vulgarisation :
Non
Établissement(s) :
Université de Lille
CNRS
CNRS
Collections :
Date de dépôt :
2024-01-16T22:05:47Z
2024-02-14T08:37:07Z
2024-02-14T08:37:07Z