Title :

Aerosol Mineralogical Study Using Laboratory and IASI Measurements: Application to East Asian Deserts

Author(s) :

Alalam, Perla [Auteur]
Laboratoire d’Optique Atmosphérique - UMR 8518 [LOA]
Deschutter, Lise [Auteur]
Physicochimie des Processus de Combustion et de l’Atmosphère - UMR 8522 [PC2A]
Laboratoire d’Optique Atmosphérique - UMR 8518 [LOA]
Al Choueiry, Antoine [Auteur]
Herbin, Herve [Auteur]
Laboratoire d'Optique Atmosphérique (LOA) - UMR 8518

Journal title :

Remote Sensing

Volume number :

14

Pages :

-

Publication date :

2022-08-06

ISSN :

2072-4292

Keyword(s) :

remote sensing
mineral dust
aerosols
laboratory measurements
optical properties
chemical properties
land surface emissivity
mineralogical extinction weight

English abstract : [en]

East Asia is the second-largest mineral dust source in the world, after the Sahara. When dispersed in the atmosphere, mineral dust can alter the Earth’s radiation budget by changing the atmosphere’s absorption and ...
Show more >East Asia is the second-largest mineral dust source in the world, after the Sahara. When dispersed in the atmosphere, mineral dust can alter the Earth’s radiation budget by changing the atmosphere’s absorption and scattering properties. Therefore, the mineralogical composition of dust is key to understanding the impact of mineral dust on the atmosphere. This paper presents new information on mineralogical dust during East Asian dust events that were obtained from laboratory dust measurements combined with satellite remote sensing dust detections from the Infrared Atmospheric Sounding Interferometer (IASI). However, the mineral dust in this region is lifted above the continent in the lower troposphere, posing constraints due to the large variability in the Land Surface Emissivity (LSE). First, a new methodology was developed to correct the LSE from a mean monthly emissivity dataset. The results show an adjustment in the IASI spectra by acquiring aerosol information. Then, the experimental extinction coefficients of pure minerals were linearly combined to reproduce a Gobi dust spectrum, which allowed for the determination of the mineralogical mass weights. In addition, from the IASI radiances, a spectral dust optical thickness was calculated, displaying features identical to the optical thickness of the Gobi dust measured in the laboratory. The linear combination of pure minerals spectra was also applied to the IASI optical thickness, providing mineralogical mass weights. Finally, the method was applied after LSE optimization, and mineralogical evolution maps were obtained for two dust events in two different seasons and years, May 2017 and March 2021. The mean dust weights originating from the Gobi Desert, Taklamakan Desert, and Horqin Sandy Land are close to the mass weights in the literature. In addition, the spatial variability was linked to possible dust sources, and it was examined with a backward trajectory model. Moreover, a comparison between two IASI instruments on METOP-A and -B proved the method’s applicability to different METOP platforms. Due to all of the above, the applied method is a powerful tool for exploiting dust mineralogy and dust sources using both laboratory optical properties and IASI detections. Keywords: remote sensing; mineral dust; aerosols; laboratory measurements; optical properties; chemical properties; land surface emissivity; mineralogical extinction weightShow less >

Audience :

Internationale

Popular science :

Non

Administrative institution(s) :

Université de Lille
CNRS

Collections :

• Laboratoire d'Optique Atmosphérique (LOA) - UMR 8518

Submission date :

2024-01-16T22:48:17Z
2024-02-12T12:56:40Z