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| Titel |
An elevated large-scale dust veil from the Taklimakan Desert: Intercontinental transport and three-dimensional structure as captured by CALIPSO and regional and global models |
| VerfasserIn |
K. Yumimoto, K. Eguchi, I. Uno, T. Takemura, Z. Liu, A. Shimizu, N. Sugimoto |
| 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 ; 9, no. 21 ; Nr. 9, no. 21 (2009-11-11), S.8545-8558 |
| Datensatznummer |
250007742
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| Publikation (Nr.) |
 copernicus.org/acp-9-8545-2009.pdf |
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| Zusammenfassung |
An intense dust storm occurred during 19–20 May 2007 over the Taklimakan
Desert in northwestern China. Over the following days, the space-borne lidar
CALIOP tracked an optically thin, highly elevated, horizontally extensive
dust veil that was transported intercontinentally over eastern Asia, the
Pacific Ocean, North America, and the Atlantic Ocean. A global aerosol
transport model (SPRINTARS) simulated the dust veil quite well and provided
a three-dimensional view of the intercontinental dust transport. The
SPRINTARS simulation revealed that the dust veil traveled at 4–10 km
altitudes with a thickness of 1–4 km along the isentropic surface between
310 and 340 K. The transport speed was about 1500 km/day. The estimated dust
amount exported to the Pacific was 30.8 Gg, of which 65% was deposited in
the Pacific and 18% was transported to the North Atlantic. These results
imply that dust veils can fertilize open oceans, add to background dust, and
affect the radiative budget at high altitudes through scattering and
absorption.
The injection mechanism that lifts dust particles into the free atmosphere
is important for understanding the formation of the dust veil and subsequent
long-range transport. We used a regional dust transport model (RC4) to
analyze the dust emission and injection over the source region. The RC4
analysis revealed that strong northeasterly surface winds associated with
low pressures invaded the Taklimakan Desert through the eastern corridor.
These winds then formed strong upslope wind along the high, steep
mountainsides of the Tibetan Plateau and blew large amounts of dust into the
air. The updraft lifted the dust particles farther into the upper
troposphere (about 9 km above mean sea level, MSL), where westerlies are
generally present. The unusual terrain surrounding the Taklimakan Desert
played a key role in the injection of dust to the upper troposphere to form
the dust veil. |
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