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| Titel |
A 12-year observation of water-soluble ions in TSP aerosols collected at a remote marine location in the western North Pacific: an outflow region of Asian dust |
| VerfasserIn |
S. K. R. Boreddy, K. Kawamura |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1680-7316
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| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 15, no. 11 ; Nr. 15, no. 11 (2015-06-12), S.6437-6453 |
| Datensatznummer |
250119808
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| Publikation (Nr.) |
 copernicus.org/acp-15-6437-2015.pdf |
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| Zusammenfassung |
| In order to characterize the long-term trend of remote marine aerosols, a
12-year observation was conducted for water-soluble ions in TSP (total suspended
particulate) aerosols
collected from 2001 to 2012 in the Asian outflow region at Chichijima Island
in the western North Pacific. We found a clear difference in chemical
composition between the continentally affected and marine background air
masses over the observation site. Asian continental air masses are delivered
from late autumn to spring, whereas marine air masses were dominated in
summer. Concentrations of non-sea salt (nss-) SO42−, NO3−, NH4+,
nss-K+ and nss-Ca2+ are high in winter and spring and low in
summer. On the other hand, MSA− (methanesulfonate) exhibits higher concentrations during
spring and winter, probably due to springtime dust bloom or due to the direct
continental transport of MSA− to the observation site. We could not find
any clear decadal trend for Na+, Cl−, Mg2+ and nss-Ca2+
in all seasons, although there exists a clear seasonal trend. However,
concentrations of nss-SO42− continuously decreased from 2007 to 2012,
probably due to the decreased SO2 emissions in East Asia especially in
China. In contrast, nss-K+ and MSA− concentrations continuously
increased from 2001 to 2012 during winter and spring seasons, demonstrating
that biomass burning and/or terrestrial biological emissions in East Asia are
being increasingly transported from the Asian continent to the western North
Pacific. This study also demonstrates that Asian dusts can act as an
important source of nutrients for phytoplankton and thus sea-to-air emission
of dimethyl sulfide over the western North Pacific. |
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