Seasonal features and origins of carbonaceous aerosols at Syowa Station, coastal Antarctica
<p>We have measured black carbon (BC) concentrations at Syowa Station, Antarctica, since February 2005. The measured BC concentrations in 2005–2016 were corrected to equivalent BC (EBC) concentrations using Weingartner's method. Seasonal features of EBC concentrations, long-range transpor...
| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2019-06-01
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| Series: | Atmospheric Chemistry and Physics |
| Online Access: | https://www.atmos-chem-phys.net/19/7817/2019/acp-19-7817-2019.pdf |
| _version_ | 1818997117569466368 |
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| author | K. Hara K. Sudo T. Ohnishi K. Osada M. Yabuki M. Shiobara T. Yamanouchi |
| author_facet | K. Hara K. Sudo T. Ohnishi K. Osada M. Yabuki M. Shiobara T. Yamanouchi |
| author_sort | K. Hara |
| collection | DOAJ |
| description | <p>We have measured black carbon (BC) concentrations at
Syowa Station, Antarctica, since February 2005. The measured BC
concentrations in 2005–2016 were corrected to equivalent BC (EBC)
concentrations using Weingartner's method. Seasonal features of EBC
concentrations, long-range transport from mid-latitudes to the Antarctic
coast, and their origins were characterized. Results show that daily median
EBC concentrations were below the detection limit (0.2 ng m<span class="inline-formula"><sup>−3</sup>)</span> to 63.8 ng m<span class="inline-formula"><sup>−3</sup></span>
at Syowa Station (median, 1.8 ng m<span class="inline-formula"><sup>−3</sup></span>; mean, 2.7 ng m<span class="inline-formula"><sup>−3</sup></span>
during the measurement period of February 2005–December 2016). Although
seasonal features and year-to-year variations in EBC concentrations were
observed, no long-term trend of EBC concentrations was clear during our
measurement period. Seasonal features of EBC concentrations showed a spring
maximum during September–October at Syowa Station. To elucidate EBC
transport processes, origins, and the potential source area (PSA), we
compared EBC data to backward trajectory analysis and chemical transport
model simulation. From comparison with backward trajectory, high EBC
concentrations were found in air masses from the marine boundary layer. This
finding implies that transport via the marine boundary layer was the most
important transport pathway to EBC concentrations at Antarctic coasts. Some
EBC was supplied to the Antarctic region by transport via the upper free
troposphere. Chemical transport model simulation demonstrated that the most
important origins and PSA of EBC at Syowa Station were biomass burning in
South America and southern Africa. Fossil fuel combustion in South America
and southern Africa also have important contributions. The absorption
Ångström exponent (AAE) showed clear seasonal features with 0.5–1.0
during April–October and maximum (1.0–1.5) in December–February. The AAE
features might be associated with organic aerosols and mixing states of EBC.</p> |
| first_indexed | 2024-12-20T21:40:32Z |
| format | Article |
| id | doaj.art-b4cdfd9b2a8d4939875663d6e53f04de |
| institution | Directory Open Access Journal |
| issn | 1680-7316 1680-7324 |
| language | English |
| last_indexed | 2024-12-20T21:40:32Z |
| publishDate | 2019-06-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Atmospheric Chemistry and Physics |
| spelling | doaj.art-b4cdfd9b2a8d4939875663d6e53f04de2022-12-21T19:25:50ZengCopernicus PublicationsAtmospheric Chemistry and Physics1680-73161680-73242019-06-01197817783710.5194/acp-19-7817-2019Seasonal features and origins of carbonaceous aerosols at Syowa Station, coastal AntarcticaK. Hara0K. Sudo1T. Ohnishi2K. Osada3M. Yabuki4M. Shiobara5T. Yamanouchi6Department of Earth System Science, Faculty of Science, Fukuoka University, Fukuoka, 814-0180, JapanGraduate School of Environmental Studies, Nagoya University, Nagoya, 464-8601, JapanGraduate School of Environmental Studies, Nagoya University, Nagoya, 464-8601, JapanGraduate School of Environmental Studies, Nagoya University, Nagoya, 464-8601, JapanResearch Institute for Sustainable Humanosphere, Kyoto University, Kyoto, 611-0011, JapanNational Institute of Polar Research, Tokyo, 190-0014, JapanNational Institute of Polar Research, Tokyo, 190-0014, Japan<p>We have measured black carbon (BC) concentrations at Syowa Station, Antarctica, since February 2005. The measured BC concentrations in 2005–2016 were corrected to equivalent BC (EBC) concentrations using Weingartner's method. Seasonal features of EBC concentrations, long-range transport from mid-latitudes to the Antarctic coast, and their origins were characterized. Results show that daily median EBC concentrations were below the detection limit (0.2 ng m<span class="inline-formula"><sup>−3</sup>)</span> to 63.8 ng m<span class="inline-formula"><sup>−3</sup></span> at Syowa Station (median, 1.8 ng m<span class="inline-formula"><sup>−3</sup></span>; mean, 2.7 ng m<span class="inline-formula"><sup>−3</sup></span> during the measurement period of February 2005–December 2016). Although seasonal features and year-to-year variations in EBC concentrations were observed, no long-term trend of EBC concentrations was clear during our measurement period. Seasonal features of EBC concentrations showed a spring maximum during September–October at Syowa Station. To elucidate EBC transport processes, origins, and the potential source area (PSA), we compared EBC data to backward trajectory analysis and chemical transport model simulation. From comparison with backward trajectory, high EBC concentrations were found in air masses from the marine boundary layer. This finding implies that transport via the marine boundary layer was the most important transport pathway to EBC concentrations at Antarctic coasts. Some EBC was supplied to the Antarctic region by transport via the upper free troposphere. Chemical transport model simulation demonstrated that the most important origins and PSA of EBC at Syowa Station were biomass burning in South America and southern Africa. Fossil fuel combustion in South America and southern Africa also have important contributions. The absorption Ångström exponent (AAE) showed clear seasonal features with 0.5–1.0 during April–October and maximum (1.0–1.5) in December–February. The AAE features might be associated with organic aerosols and mixing states of EBC.</p>https://www.atmos-chem-phys.net/19/7817/2019/acp-19-7817-2019.pdf |
| spellingShingle | K. Hara K. Sudo T. Ohnishi K. Osada M. Yabuki M. Shiobara T. Yamanouchi Seasonal features and origins of carbonaceous aerosols at Syowa Station, coastal Antarctica Atmospheric Chemistry and Physics |
| title | Seasonal features and origins of carbonaceous aerosols at Syowa Station, coastal Antarctica |
| title_full | Seasonal features and origins of carbonaceous aerosols at Syowa Station, coastal Antarctica |
| title_fullStr | Seasonal features and origins of carbonaceous aerosols at Syowa Station, coastal Antarctica |
| title_full_unstemmed | Seasonal features and origins of carbonaceous aerosols at Syowa Station, coastal Antarctica |
| title_short | Seasonal features and origins of carbonaceous aerosols at Syowa Station, coastal Antarctica |
| title_sort | seasonal features and origins of carbonaceous aerosols at syowa station coastal antarctica |
| url | https://www.atmos-chem-phys.net/19/7817/2019/acp-19-7817-2019.pdf |
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