Title :

Microscopic Observations of Core-Shell Particle Structure and Implications for Atmospheric Aerosol Remote Sensing

Author(s) :

Unga, Florin [Auteur]
Laboratoire d’Optique Atmosphérique - UMR 8518 [LOA]
Choël, Marie [Auteur]
Laboratoire Avancé de Spectroscopie pour les Intéractions la Réactivité et l'Environnement (LASIRE) - UMR 8516
Derimian, Yevgeny [Auteur]
Laboratoire d'Optique Atmosphérique (LOA) - UMR 8518
Deboudt, Karine [Auteur]
Laboratoire de Physico-Chimie de l'Atmosphère [LPCA]
Dubovik, Oleg [Auteur]
Laboratoire d’Optique Atmosphérique - UMR 8518 [LOA]
Goloub, Philippe [Auteur]
Laboratoire d'Optique Atmosphérique (LOA) - UMR 8518
LOA

Journal title :

Journal of Geophysical Research. Atmospheres

Volume number :

123

Pages :

13,944-13,962

Publication date :

2018-12

HAL domain(s) :

Chimie/Chimie théorique et/ou physique

English abstract : [en]

Although atmospheric aerosol particles can have complex heterogeneous microstructure, simplified homogeneous particle models are often used in remote sensing applications. In this study, the internal structure of individual ...
Show more >Although atmospheric aerosol particles can have complex heterogeneous microstructure, simplified homogeneous particle models are often used in remote sensing applications. In this study, the internal structure of individual atmospheric particles was imaged with the aim of parameterizing particle structural heterogeneity. To this end, ambient urban pollution, desert dust, and biomass burning particles were sampled in northern Europe and western Africa and analyzed by transmission electron microscopy coupled with energy dispersive X-ray spectroscopy. Among 8,441 observed particles, about 60% of urban and 20% of desert dust particles presented residuals of coating compounds in the form of a halo surrounding a solid core. Graphic outlining of core and halo areas by image analysis revealed a dependence between halo and core dimensions as well as a greater ratio of halos thickness to total particle diameter (core plus halo) for smaller cores than for larger ones. In the case of urban pollution, the mean ratio for submicrometer and supermicrometer size fractions was 0.25 and 0.19, respectively. The corresponding mean values in the desert dust case were somewhat lower (0.22 and 0.14, respectively), but show a similar decreasing trend. Under the assumption that the halo dimension is proportional to the thickness of the particle shell, the obtained core versus shell dependencies were implemented in numerical calculations of aerosol optical characteristics. Different scenarios of the core-shell dependencies were analyzed with respect to the influence on aerosol optical characteristics, bringing insights into sensitivity to parameterization of the core-shell particle model in remote sensing algorithms.Show less >

Language :

Anglais

Audience :

Internationale

Popular science :

Non

Administrative institution(s) :

CNRS
ENSCL
Université de Lille

Collections :

• Laboratoire Avancé de Spectroscopie pour les Intéractions la Réactivité et l'Environnement (LASIRE) - UMR 8516
• Laboratoire d'Optique Atmosphérique (LOA) - UMR 8518

Research team(s) :

Physicochimie de l’Environnement (PCE)

Submission date :

2021-11-16T08:23:33Z
2024-02-21T08:58:40Z