Aethalometer multiple scattering correction <i>C</i><sub>ref</sub> for mineral dust aerosols
In this study we provide a first estimate of the Aethalometer multiple scattering correction <i>C</i><sub>ref</sub> for mineral dust aerosols. <i>C</i><sub>ref</sub> is an empirical constant used to correct the aerosol absorption coefficient measure...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2017-08-01
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| Series: | Atmospheric Measurement Techniques |
| Online Access: | https://www.atmos-meas-tech.net/10/2923/2017/amt-10-2923-2017.pdf |
| _version_ | 1818174927349481472 |
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| author | C. Di Biagio P. Formenti M. Cazaunau E. Pangui N. Marchand J.-F. Doussin |
| author_facet | C. Di Biagio P. Formenti M. Cazaunau E. Pangui N. Marchand J.-F. Doussin |
| author_sort | C. Di Biagio |
| collection | DOAJ |
| description | In this study we provide a first estimate of the Aethalometer multiple
scattering correction <i>C</i><sub>ref</sub> for mineral dust aerosols.
<i>C</i><sub>ref</sub> is an empirical constant used to correct the aerosol
absorption coefficient measurements for the multiple scattering artefact of
the Aethalometer; i.e. the filter fibres on which aerosols are deposited
scatter light and this is miscounted as absorption. The <i>C</i><sub>ref</sub> at 450 and 660 nm was obtained from the
direct comparison of Aethalometer data (Magee Sci. AE31) with (i) the absorption
coefficient calculated as the difference between the extinction and
scattering coefficients measured by a Cavity Attenuated Phase Shift
Extinction analyser (CAPS PMex) and a nephelometer respectively at 450 nm
and (ii) the absorption coefficient from a MAAP (Multi-Angle Absorption
Photometer) at 660 nm. Measurements were performed on seven dust aerosol samples
generated in the laboratory by the mechanical shaking of natural parent soils
issued from different source regions worldwide. The single scattering albedo
(SSA) at 450 and 660 nm and the size distribution of the aerosols were also
measured.
<br><br>
<i>C</i><sub>ref</sub> for mineral dust varies between 1.81 and 2.56 for a SSA of
0.85–0.96 at 450 nm and between 1.75 and 2.28 for a SSA of 0.98–0.99 at
660 nm. The calculated mean for dust is 2.09 (±0.22) at 450 nm and 1.92 (±0.17)
at 660 nm. With this new <i>C</i><sub>ref</sub> the dust absorption coefficient by
the Aethalometer is about 2 % (450 nm) and 11 % (660 nm) higher
than that obtained by using <i>C</i><sub>ref</sub> = 2.14 at both 450 and
660 nm, as usually assumed in the literature. This difference induces a
change of up to 3 % in the dust SSA at 660 nm. The <i>C</i><sub>ref</sub>
seems to be independent of the fine and coarse particle size fractions, and
so the obtained <i>C</i><sub>ref</sub> can be applied to dust both close to sources
and following transport. Additional experiments performed with pure kaolinite
minerals and polluted ambient aerosols indicate <i>C</i><sub>ref</sub> of 2.49
(±0.02) and 2.32 (±0.01) at 450 and 660 nm (SSA = 0.96–0.97)
for kaolinite, and <i>C</i><sub>ref</sub> of 2.32 (±0.36) at 450 nm and 2.32
(±0.35) at 660 nm for pollution aerosols (SSA = 0.62–0.87 at
450 nm and 0.42–0.76 at 660 nm). |
| first_indexed | 2024-12-11T19:52:10Z |
| format | Article |
| id | doaj.art-e51bc4b08129459b847daaac8c6309f1 |
| institution | Directory Open Access Journal |
| issn | 1867-1381 1867-8548 |
| language | English |
| last_indexed | 2024-12-11T19:52:10Z |
| publishDate | 2017-08-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Atmospheric Measurement Techniques |
| spelling | doaj.art-e51bc4b08129459b847daaac8c6309f12022-12-22T00:52:45ZengCopernicus PublicationsAtmospheric Measurement Techniques1867-13811867-85482017-08-01102923293910.5194/amt-10-2923-2017Aethalometer multiple scattering correction <i>C</i><sub>ref</sub> for mineral dust aerosolsC. Di Biagio0P. Formenti1M. Cazaunau2E. Pangui3N. Marchand4J.-F. Doussin5Laboratoire Interuniversitaire des Systèmes Atmosphériques (LISA), UMR 7583, CNRS, Université Paris Est Créteil et Université Paris Diderot, Institut Pierre et Simon Laplace, Créteil, FranceLaboratoire Interuniversitaire des Systèmes Atmosphériques (LISA), UMR 7583, CNRS, Université Paris Est Créteil et Université Paris Diderot, Institut Pierre et Simon Laplace, Créteil, FranceLaboratoire Interuniversitaire des Systèmes Atmosphériques (LISA), UMR 7583, CNRS, Université Paris Est Créteil et Université Paris Diderot, Institut Pierre et Simon Laplace, Créteil, FranceLaboratoire Interuniversitaire des Systèmes Atmosphériques (LISA), UMR 7583, CNRS, Université Paris Est Créteil et Université Paris Diderot, Institut Pierre et Simon Laplace, Créteil, FranceAix Marseille Univ., CNRS, LCE, Marseille, FranceLaboratoire Interuniversitaire des Systèmes Atmosphériques (LISA), UMR 7583, CNRS, Université Paris Est Créteil et Université Paris Diderot, Institut Pierre et Simon Laplace, Créteil, FranceIn this study we provide a first estimate of the Aethalometer multiple scattering correction <i>C</i><sub>ref</sub> for mineral dust aerosols. <i>C</i><sub>ref</sub> is an empirical constant used to correct the aerosol absorption coefficient measurements for the multiple scattering artefact of the Aethalometer; i.e. the filter fibres on which aerosols are deposited scatter light and this is miscounted as absorption. The <i>C</i><sub>ref</sub> at 450 and 660 nm was obtained from the direct comparison of Aethalometer data (Magee Sci. AE31) with (i) the absorption coefficient calculated as the difference between the extinction and scattering coefficients measured by a Cavity Attenuated Phase Shift Extinction analyser (CAPS PMex) and a nephelometer respectively at 450 nm and (ii) the absorption coefficient from a MAAP (Multi-Angle Absorption Photometer) at 660 nm. Measurements were performed on seven dust aerosol samples generated in the laboratory by the mechanical shaking of natural parent soils issued from different source regions worldwide. The single scattering albedo (SSA) at 450 and 660 nm and the size distribution of the aerosols were also measured. <br><br> <i>C</i><sub>ref</sub> for mineral dust varies between 1.81 and 2.56 for a SSA of 0.85–0.96 at 450 nm and between 1.75 and 2.28 for a SSA of 0.98–0.99 at 660 nm. The calculated mean for dust is 2.09 (±0.22) at 450 nm and 1.92 (±0.17) at 660 nm. With this new <i>C</i><sub>ref</sub> the dust absorption coefficient by the Aethalometer is about 2 % (450 nm) and 11 % (660 nm) higher than that obtained by using <i>C</i><sub>ref</sub> = 2.14 at both 450 and 660 nm, as usually assumed in the literature. This difference induces a change of up to 3 % in the dust SSA at 660 nm. The <i>C</i><sub>ref</sub> seems to be independent of the fine and coarse particle size fractions, and so the obtained <i>C</i><sub>ref</sub> can be applied to dust both close to sources and following transport. Additional experiments performed with pure kaolinite minerals and polluted ambient aerosols indicate <i>C</i><sub>ref</sub> of 2.49 (±0.02) and 2.32 (±0.01) at 450 and 660 nm (SSA = 0.96–0.97) for kaolinite, and <i>C</i><sub>ref</sub> of 2.32 (±0.36) at 450 nm and 2.32 (±0.35) at 660 nm for pollution aerosols (SSA = 0.62–0.87 at 450 nm and 0.42–0.76 at 660 nm).https://www.atmos-meas-tech.net/10/2923/2017/amt-10-2923-2017.pdf |
| spellingShingle | C. Di Biagio P. Formenti M. Cazaunau E. Pangui N. Marchand J.-F. Doussin Aethalometer multiple scattering correction <i>C</i><sub>ref</sub> for mineral dust aerosols Atmospheric Measurement Techniques |
| title | Aethalometer multiple scattering correction <i>C</i><sub>ref</sub> for mineral dust aerosols |
| title_full | Aethalometer multiple scattering correction <i>C</i><sub>ref</sub> for mineral dust aerosols |
| title_fullStr | Aethalometer multiple scattering correction <i>C</i><sub>ref</sub> for mineral dust aerosols |
| title_full_unstemmed | Aethalometer multiple scattering correction <i>C</i><sub>ref</sub> for mineral dust aerosols |
| title_short | Aethalometer multiple scattering correction <i>C</i><sub>ref</sub> for mineral dust aerosols |
| title_sort | aethalometer multiple scattering correction i c i sub ref sub for mineral dust aerosols |
| url | https://www.atmos-meas-tech.net/10/2923/2017/amt-10-2923-2017.pdf |
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