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| Titel |
Rapid transport of East Asian pollution to the deep tropics |
| VerfasserIn |
M. J. Ashfold, J. A. Pyle, A. D. Robinson, E. Meneguz, M. S. M. Nadzir, S. M. Phang, A. A. Samah, S. Ong, H. E. Ung, L. K. Peng, S. E. Yong, N. R. P. Harris |
| 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. 6 ; Nr. 15, no. 6 (2015-03-31), S.3565-3573 |
| Datensatznummer |
250119589
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| Publikation (Nr.) |
 copernicus.org/acp-15-3565-2015.pdf |
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| Zusammenfassung |
| Anthropogenic emissions from East Asia have increased over recent decades.
These increases have led to changes in atmospheric composition as far afield
as North America under the prevailing westerly winds. Here we show that,
during Northern Hemisphere (NH) winter, pollution originating in East Asia
also directly affects atmospheric composition in the deep tropics. We present
observations of marked intra-seasonal variability in the anthropogenic tracer
perchloroethene (C2Cl4) collected at two locations in Borneo
(117.84° E, 4.98° N and 118.00° E, 4.22° N) during
the NH winter of 2008/2009. We use trajectories calculated with the Numerical
Atmospheric-dispersion Modelling Environment to show that the
observed enhancements in C2Cl4 mixing ratio are caused by rapid
meridional transport, in the form of "cold surges", from the relatively
polluted East Asian land mass. In these events air masses can move from
~35° N to Borneo in 4 days. We then present data from the
Monitoring Atmospheric Composition and Climate reanalysis which suggest that
air masses high in C2Cl4 may also contain levels of the
pollutants carbon monoxide and ozone that are approximately double the
typical "background" levels in Borneo. In addition to strengthening the
meridional transport from the north, cold surges can enhance convection in
Southeast Asia, and further trajectory calculations indicate that the
polluted air masses can subsequently be lifted to the tropical upper
troposphere. This suggests a potentially important connection between
midlatitude pollution sources and the very low stratosphere. |
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