The Elbrus (Caucasus, Russia) ice core record – Part 2: history of desert dust deposition

• Published in: Atmospheric Chemistry and Physics
• Main Authors: Kutuzov, Stanislav, Legrand, Michel, Preunkert, Susanne, Ginot, Patrick, Mikhalenko, Vladimir, Shukurov, Karim, Poliukhov, Aleksei, Toropov, Pavel
• Other Authors: Laboratoire d'Ingénierie des Matériaux (LIM), Centre National de la Recherche Scientifique (CNRS), Institut des Géosciences de l’Environnement (IGE), Institut de Recherche pour le Développement (IRD)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes 2016-2019 (UGA 2016-2019 ), Unité de Recherche Great Ice
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2019
• Subjects: [SDE]Environmental Sciences; Pacific; ice core
• Online Access: https://hal.science/hal-02410039; https://hal.science/hal-02410039/document; https://hal.science/hal-02410039/file/acp-19-14133-2019.pdf; https://doi.org/10.5194/acp-19-14133-2019

International audience Ice cores are one of the most valuable paleo-archives. Records from ice cores provide information not only about the amount of dust in the atmosphere, but also about dust sources and their changes in the past. In 2009, a 182 m long ice core was recovered from the western plateau of Mt Elbrus (5115 m a.s.l.). This record was further extended after a shallow ice core was drilled in 2013. Here we analyse Ca 2+ concentrations, a commonly used proxy of dust, recorded in these Elbrus ice records over the time period of 1774-2013 CE. The Ca 2+ record reveals quasi-decadal variability with a generally increasing trend. Using multiple regression analysis, we found a statistically significant spatial correlation of the Elbrus Ca 2+ summer concentrations with precipitation and soil moisture content in the Levant region (specifically Syria and Iraq). The Ca 2+ record also correlates with drought indices in North Africa (r = 0.67, p<0.001) and Middle East regions (r = 0.71, p<0.001). Dust concentrations prominently increase in the ice core over the past 200 years, confirming that the recent droughts in the Fertile Crescent (1998-2012 CE) present the most severe aridity experienced in at least the past two centuries. For the most recent 33 years recorded (1979-2012 CE), significant correlations exist between Ca 2+ and Pacific circulation indices (Pacific Decadal Oscillation, Southern Oscillation Index and Niño 4), which suggests that the increased frequency of extreme El Niño and La Niña events due to a warming climate has extended their influence to the Middle East. Evidence demonstrates that the increase in Ca 2+ concentration in the ice core cannot be attributed to human activities, such as coal combustion and cement production.