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607529 
Journal Article 
Measurement of black carbon at Syowa station, Antarctica: seasonal variation, transport processes and pathways 
Hara, K; Osada, K; Yabuki, M; Hayashi, M; Yamanouchi, T; Shiobara, M; Wada, M 
2008 
Yes 
Atmospheric Chemistry and Physics Discussions
ISSN: 1680-7367
EISSN: 1680-7375 
8 
3 
9883-9929 
Measurement of black carbon (BC) was carried out at Syowa station Antarctica (69δ S, 39δ E) from February 2004 until January 2007. The BC concentration at Syowa ranged from below detection to 176 ngm-3 during the measurements. Higher BC concentra tions were observed mostly under strong wind (blizzard) conditions due to the approach of a cyclone and blocking event. The BC-rich air masses traveled from the lower troposphere of the Atlantic and Indian Oceans to Syowa (Antarctic coast). During the summer (November-February), the BC concentration showed a diurnal variation together with surface wind speed and increased in the katabatic wind from the Antarctic continent. Considering the low BC source strength in the Antarctic continent, the higher BC concentration in the continental air (katabatic wind) might be caused by long range transport of BC via the free troposphere from mid- and low- latitudes. The seasonal variation of BC at Syowa had a maximum in August, while at the other coastal stations (Halley, Neumayer, and Ferraz) and the continental station (Amundsen-Scott), the maximum occurred in October. This difference may result from different transport pathways and scavenging of BC by precipitation during the transport from the source regions. During the austral summer, long-range transport of BC via the free troposphere is likely to make an important contribution to the ambient BC concentration. The BC transport flux indicated that BC injection into the Antarctic region strongly depended on the frequency of storm (blizzard) conditions. The seasonal variation of BC transport flux increased by 290 mg m-2 month-1 in winter-spring when blizzards frequently occurred, whereas the flux decreased to lower than 50 mg m-2 month-1 in the summer with infrequent blizzards. ABSTRACT FROM AUTHOR Copyright of Atmospheric Chemistry & Physics Discussions is the property of European Geosciences Union and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts) 
CARBON; TROPOSPHERE; PRECIPITATION (Meteorology); CYCLONES; ANTARCTICA