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| Titel |
Characteristics of mineral aerosol deposited on the glaciers of Mt. Elbrus, Caucasus, Russia. |
| VerfasserIn |
Stanislav Kutuzov, Maria Shahgedanova, Vladimir Mikhalenko, Patrick Ginot, Ivan Lavrentiev, Gregory Popov |
| Konferenz |
EGU General Assembly 2014
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 16 (2014) |
| Datensatznummer |
250086566
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| Publikation (Nr.) |
 EGU/EGU2014-457.pdf |
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| Zusammenfassung |
| Records of mineral aerosol (desert dust) stored in glaciers provide data on frequency and
intensity of deposition events, source regions and atmospheric pathways of mineral dust. We
present and discuss a chronology of dust deposition events recorded in the shallow firn and
ice cores extracted on the Western Plateau, Mt. Elbrus (5150 m a.s.l.), Caucasus
Mountains, Russia and covering the period of 2009-2013. Particle size distribution and
chemical analysis (major ions, trace elements) were peformed using Coulter Counter
Multisizer III, Abacus particle counter, IC and ICPMS analysis. Sampling was
performed using continuous flow analysis (CFA) system. Annual average dust flux (264
μg/cm2 a-1) and average mass concentration (1.7 mg/kg) over the period 2007-2013
were calculated for the first time for this region. A combination of satellite imagery
(MSG SEVIRI), trajectory models (FLEXTA, HYSPLIT) and meteorological data
were used to accurately date each of the dust layers observed in shallow cores and
investigate provenance of the dust and its pathways. Desert dust originating from the
Middle East and Sahara was deposited on the Caucasus glaciers 3-6 times a year.
Although less frequent, Saharan events are characterized by considerably higher dust
loads than the more frequent Middle Eastern events. The mass median diameter
of dust particles ranged between 2 and 9 μm. The deposition of dust resulted in
elevated concentrations of most ions, especially Ca2+, Mg2+, K+, and sulphates. Dust
originated from or passing over the Middle East was characterised by the elevated
concentrations of nitrates and ammonia. This may be related to dust emissions from
agricultural fields which, if abandoned due to droughts, become important sources
of dust. By contrast, samples of the Saharan dust originated from natural sources
showed lower concentrations of ammonium. The mean values of crustal enrichment
factors for the measured trace elements including metals were calculated. Overall,
the enrichment factors were lower for such elements as V, Cr, Mn, Co, Ni, and
Pb, indicating that these metals originated from rocks and soil. The enrichment
factors for Cu, Zn and Cd were lower pointing at the contribution of anthropogenic
sources.
The research leading to these results has received funding from the European Union
Seventh Framework Programme FP7-PEOPLE-2010-IIF under grant agreement
PIIF-GA-2010-275071 Russian Foundation for Basic Research (grants 11-05-00304 and
13-05-10069). |
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