Ways of far-distance dust transport onto Caucasian glaciers and chemical composition of snow on the Western plateau of Elbrus

• Published in: Ice and Snow
• Main Authors: S. Kutuzov S., V. Mikhalenko N., M. Shahgedanova V., P. Ginot, A. Kozachek V., T. Kuderina M., I. Lavrentiev I., G. Popov V., С. Кутузов C., В. Михаленко Н., M. Шахгеданова, П. Жино, А. Козачек В., И. Лаврентьев И., Т. Кудерина М., Г. Попов В.
• Format: Article in Journal/Newspaper
• Language: Russian
• Published: IGRAS 2015
• Subjects: Aerosols;atmospheric transport;Caucasus high mountains;ice cores; Атмосферный перенос;аэрозоли;высокогорье Кавказа;ледниковые керны; The Cryosphere
• Online Access: https://ice-snow.igras.ru/jour/article/view/51; https://doi.org/10.15356/2076-6734-2014-3-5-15

We present and discuss the chronology of dust deposition events documented by the shallow firn and ice cores extracted on the Western Plateau, Mt. Elbrus (5150 m a.s.l.) in 2009, 2012 and 2013. Snow and ice samples were analysed for major ions and minor element concentrations including heavy metals. Dust layers are formed on the surface of the glaciers as a result of atmospheric transport of mineral dust and aerosol particles to the Caucasus region. Satellite imagery (SEVIRI), trajectory models, and meteorological data were used for accurate dating of each the dust layers revealed in the ice cores. Then we tried to determine origins of the dust clouds and to investigate their transport pathways with high resolution (50–100 km). It was found that the desert dust is deposited on Caucasus glaciers 3–7 times in a year and it comes mainly from deserts of the Middle East and more rarely from the Northern Sahara desert. For the first time average annual dust flux (264 µg/cm2 per a year) and average mass concentration (1.7 mg/kg) over the period 2007–2013 were calculated for this region. The deposition of dust resulted in elevated concentrations consists of mostly ions, especially Ca2+, Mg2+, K+, and sulphates. Dust originated from various sources in the Middle East, including Mesopotamia, or similar dust clouds passing over the Middle East are characterised by high concentrations of nitrates and ammonia that may be related to atmospheric transport of ammonium from agricultural lands that may explain high concentrations of ammonium in the dust originating from this region. Mean values of crustal enrichment factors (EF) for the measured minor elements including heavy metals were calculated. We believe that high content of Cu, Zn and Cd can be a result of possible contribution from anthropogenic sources. Studies of the Caucasus ice cores may allow obtaining new independent data on the atmosphere circulation and high-altitude environment of this region. Исследованы образцы из снежных шурфов и керна из неглубоких скважин, ...