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| Titel |
Atmospheric transport of persistent semi-volatile organic chemicals to the Arctic and cold condensation in the mid-troposphere – Part 2: 3-D modeling of episodic atmospheric transport |
| VerfasserIn |
L. Zhang, J. Ma, C. Tian, Y. Li, H. Hung |
| 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 ; 10, no. 15 ; Nr. 10, no. 15 (2010-08-09), S.7315-7324 |
| Datensatznummer |
250008688
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| Publikation (Nr.) |
 copernicus.org/acp-10-7315-2010.pdf |
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| Zusammenfassung |
| Two 3-dimensional global atmospheric transport models for
persistent organic pollutants (POPs) have been employed to investigate the
association between the large-scale atmospheric motions and poleward
transports of persistent semi-volatile organic chemicals (SVOCs). We examine
the modeled daily air concentration of α- and γ-hexachlorocyclohexane
(HCH) over a period from 1997 through 1999 during
which a number of episodic atmospheric transport events were detected in
this modeling study. These events provide modeling evidence for improving
the interpretation on the cold condensation effect and poleward atmospheric
transport of SVOCs in the mid-troposphere. Two episodic transport events of
γ-HCH (lindane) to the high Arctic (80–90° N), one from Asian
and another from Eurasian sources, are reported in this paper. Both events
suggest that the episodic atmospheric transports occurring in the
mid-troposphere (e.g. from 3000 m to 5500 m height) are driven by
atmospheric horizontal and vertical motions. The association of the
transport events with atmospheric circulation is briefly discussed. Strong
southerly winds, forced by the evolution of two semi-permanent high pressure
systems over mid-high latitudes in the Northern Hemisphere, play an
important role in the long-range transport (LRT) of HCHs to the high
latitudes from its sources. Being consistent with the cold condensation
effect and poleward atmospheric transport in a mean meridional atmospheric
circulation simulated by a 2-D atmospheric transport model, as reported by
the first part of this study, this modeling study indicates that cold
condensation is likely occurring more intensively in the mid-troposphere
where rapid declining air temperature results in condensed phase of the
chemical over and near its source regions and where stronger winds convey
the chemical more rapidly to the polar region during the episodic poleward
atmospheric transport events. |
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