Large-scale drivers of Caucasus climate variability in meteorological records and Mt Elbrus ice cores
Anna Kozachek1,2,3, Vladimir Mikhalenko2, Valérie Masson-Delmotte3, Alexey Ekaykin1,4, Patrick Ginot5,6, Stanislav Kutuzov2, Michel Legrand5, Vladimir Lipenkov1, and Susanne Preunkert51Climate and Environmental Research Laboratory, Arctic and Antarctic Research Institute, Saint Petersburg, 199397, Russia 2Institute of Geography, Russian Academy of Sciences, Moscow, 119017, Russia 3Laboratoire des Sciences du Climat et de l’Environnement, CEA/CNRS/UVSQ/IPSL, Gif-sur-Yvette, 91191, France 4Institute of Earth Sciences, Saint Petersburg State University, Saint Petersburg, 199178, Russia 5Laboratoire de Glaciologie et Géophysique de l’Environnement, CNRS/UGA, Grenoble, 38400, France 6Observatoire des Sciences de l’Univers de Grenoble, IRD/UGA/CNRS, Grenoble, 38400, France
Received: 09 Jun 2016 – Accepted for review: 27 Jun 2016 – Discussion started: 28 Jun 2016
Abstract. A 181.2 m ice core was recovered from a borehole drilled into bedrock on the western plateau of Mt. Elbrus (43°20’53.9’’ N, 42°25’36.0’’ E; 5115 m a.s.l.) in the Caucasus, Russia, in 2009 (Mikhalenko et al., 2015). Here, we report on the results of the water stable isotope composition from this ice core in comparison with results from shallow ice cores. There is a distinct seasonal cycle of the isotopic composition which allowed dating by annual layer counting. Dating has been performed for the upper 126 m of the deep core combined with shallow cores data. The whole record covers one century from 2013 back to 1914. Due to the high accumulation rate (1380 mm w.e. per year) and limited melting we obtained the isotopic composition and accumulation rate records with seasonal resolution. These values were compared with available meteorological data from 13 weather stations in the region, and also with atmosphere circulation indices, back-trajectories calculations and GNIP data in order to decipher the drivers of accumulation and ice core isotopic composition in the Caucasus region. In the summer season the isotopic composition depends on the local temperature, while in winter, the atmospheric circulation is the predominant driver of the ice core isotopic composition. The snow accumulation rate correlates well with the precipitation rate in the region all year round, this made it possible to reconstruct and expand the precipitation record at the Caucasus highlands from 1914 till 1966 when the reliable meteorological observations of precipitation at high elevation began.
Kozachek, A., Mikhalenko, V., Masson-Delmotte, V., Ekaykin, A., Ginot, P., Kutuzov, S., Legrand, M., Lipenkov, V., and Preunkert, S.: Large-scale drivers of Caucasus climate variability in meteorological records and Mt Elbrus ice cores, Clim. Past Discuss., doi:10.5194/cp-2016-62, in review, 2016.