Comparison of key absorption and optical properties between pure and transported anthropogenic dust over East and Central Asia
Asian dust particulate is one of the primary aerosol constituents in the Earth–atmosphere system that exerts profound influences on environmental quality, human health, the marine biogeochemical cycle, and Earth's climate. To date, the absorptive capacity of dust aerosol generated from the...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2016-12-01
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| Series: | Atmospheric Chemistry and Physics |
| Online Access: | https://www.atmos-chem-phys.net/16/15501/2016/acp-16-15501-2016.pdf |
| _version_ | 1818055000578850816 |
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| author | J. Bi J. Huang B. Holben G. Zhang |
| author_facet | J. Bi J. Huang B. Holben G. Zhang |
| author_sort | J. Bi |
| collection | DOAJ |
| description | Asian dust particulate is one of the primary aerosol constituents
in the Earth–atmosphere system that exerts profound influences on
environmental quality, human health, the marine biogeochemical cycle, and Earth's
climate. To date, the absorptive capacity of dust aerosol generated from the
Asian desert region is still an open question. In this article, we compile
columnar key absorption and optical properties of mineral dust over East and
Central Asian areas by utilizing the multiyear quality-assured datasets
observed at 13 sites of the Aerosol Robotic Network (AERONET). We identify
two types of Asian dust according to threshold criteria from previously
published literature. (1) The particles with high aerosol optical depth at
440 nm (AOD<sub>440</sub> ≥ 0.4) and a low Ångström wavelength exponent
at 440–870 nm (<i>α</i> < 0.2) are defined as Pure Dust (PDU),
which decreases disturbance of other non-dust aerosols and keeps high accuracy of
pure Asian dust. (2) The particles with AOD<sub>440</sub> ≥ 0.4 and
0.2 < <i>α</i> < 0.6 are designated as Transported
Anthropogenic Dust (TDU), which is mainly dominated by dust aerosol and
might mix with other anthropogenic aerosol types. Our results reveal that
the primary components of high AOD days are predominantly dust over East
and Central Asian regions, even if their variations rely on different sources,
distance from the source, emission mechanisms, and meteorological
characteristics. The overall mean and standard deviation of
single-scattering albedo, asymmetry factor, real part and imaginary part of
complex refractive index at 550 nm for Asian PDU are 0.935 ± 0.014,
0.742 ± 0.008, 1.526 ± 0.029, and 0.00226 ± 0.00056,
respectively, while corresponding values are 0.921 ± 0.021,
0.723 ± 0.009, 1.521 ± 0.025, and 0.00364 ± 0.0014 for Asian
TDU. Aerosol shortwave direct radiative effects at the top of the atmosphere
(TOA), at the surface (SFC), and in the atmospheric layer (ATM) for Asian
PDU (<i>α</i> < 0.2) and TDU (0.2 < <i>α</i> < 0.6)
computed in this study, are a factor of 2 smaller than the results of
Optical Properties of Aerosols and Clouds (OPAC) mineral-accumulated
(mineral-acc.) and mineral-transported (mineral-tran.) modes. Therefore, we are
convinced that our results hold promise for updating and improving accuracies
of Asian dust characteristics in present-day remote sensing applications and
regional or global climate models. |
| first_indexed | 2024-12-10T12:05:59Z |
| format | Article |
| id | doaj.art-ae144f860d454d5faa176d579bce99fb |
| institution | Directory Open Access Journal |
| issn | 1680-7316 1680-7324 |
| language | English |
| last_indexed | 2024-12-10T12:05:59Z |
| publishDate | 2016-12-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Atmospheric Chemistry and Physics |
| spelling | doaj.art-ae144f860d454d5faa176d579bce99fb2022-12-22T01:49:28ZengCopernicus PublicationsAtmospheric Chemistry and Physics1680-73161680-73242016-12-0116155011551610.5194/acp-16-15501-2016Comparison of key absorption and optical properties between pure and transported anthropogenic dust over East and Central AsiaJ. Bi0J. Huang1B. Holben2G. Zhang3Key Laboratory for Semi-Arid Climate Change of the Ministry of Education, College of Atmospheric Sciences, Lanzhou University, Lanzhou, 730000, ChinaKey Laboratory for Semi-Arid Climate Change of the Ministry of Education, College of Atmospheric Sciences, Lanzhou University, Lanzhou, 730000, ChinaNASA Goddard Space Flight Center, Greenbelt, Maryland, USAKey Laboratory for Semi-Arid Climate Change of the Ministry of Education, College of Atmospheric Sciences, Lanzhou University, Lanzhou, 730000, ChinaAsian dust particulate is one of the primary aerosol constituents in the Earth–atmosphere system that exerts profound influences on environmental quality, human health, the marine biogeochemical cycle, and Earth's climate. To date, the absorptive capacity of dust aerosol generated from the Asian desert region is still an open question. In this article, we compile columnar key absorption and optical properties of mineral dust over East and Central Asian areas by utilizing the multiyear quality-assured datasets observed at 13 sites of the Aerosol Robotic Network (AERONET). We identify two types of Asian dust according to threshold criteria from previously published literature. (1) The particles with high aerosol optical depth at 440 nm (AOD<sub>440</sub> ≥ 0.4) and a low Ångström wavelength exponent at 440–870 nm (<i>α</i> < 0.2) are defined as Pure Dust (PDU), which decreases disturbance of other non-dust aerosols and keeps high accuracy of pure Asian dust. (2) The particles with AOD<sub>440</sub> ≥ 0.4 and 0.2 < <i>α</i> < 0.6 are designated as Transported Anthropogenic Dust (TDU), which is mainly dominated by dust aerosol and might mix with other anthropogenic aerosol types. Our results reveal that the primary components of high AOD days are predominantly dust over East and Central Asian regions, even if their variations rely on different sources, distance from the source, emission mechanisms, and meteorological characteristics. The overall mean and standard deviation of single-scattering albedo, asymmetry factor, real part and imaginary part of complex refractive index at 550 nm for Asian PDU are 0.935 ± 0.014, 0.742 ± 0.008, 1.526 ± 0.029, and 0.00226 ± 0.00056, respectively, while corresponding values are 0.921 ± 0.021, 0.723 ± 0.009, 1.521 ± 0.025, and 0.00364 ± 0.0014 for Asian TDU. Aerosol shortwave direct radiative effects at the top of the atmosphere (TOA), at the surface (SFC), and in the atmospheric layer (ATM) for Asian PDU (<i>α</i> < 0.2) and TDU (0.2 < <i>α</i> < 0.6) computed in this study, are a factor of 2 smaller than the results of Optical Properties of Aerosols and Clouds (OPAC) mineral-accumulated (mineral-acc.) and mineral-transported (mineral-tran.) modes. Therefore, we are convinced that our results hold promise for updating and improving accuracies of Asian dust characteristics in present-day remote sensing applications and regional or global climate models.https://www.atmos-chem-phys.net/16/15501/2016/acp-16-15501-2016.pdf |
| spellingShingle | J. Bi J. Huang B. Holben G. Zhang Comparison of key absorption and optical properties between pure and transported anthropogenic dust over East and Central Asia Atmospheric Chemistry and Physics |
| title | Comparison of key absorption and optical properties between pure and transported anthropogenic dust over East and Central Asia |
| title_full | Comparison of key absorption and optical properties between pure and transported anthropogenic dust over East and Central Asia |
| title_fullStr | Comparison of key absorption and optical properties between pure and transported anthropogenic dust over East and Central Asia |
| title_full_unstemmed | Comparison of key absorption and optical properties between pure and transported anthropogenic dust over East and Central Asia |
| title_short | Comparison of key absorption and optical properties between pure and transported anthropogenic dust over East and Central Asia |
| title_sort | comparison of key absorption and optical properties between pure and transported anthropogenic dust over east and central asia |
| url | https://www.atmos-chem-phys.net/16/15501/2016/acp-16-15501-2016.pdf |
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