Isotopic signature of precipitation in the Elbrus region

• Main Authors: Ju. Chizhova N., V. Mikhalenko N., S. Kutuzov S., K. Shukurov A., A. Kozachek V., Ю. Чижова Н., В. Михаленко Н., С. Кутузов С., К. Шукуров А., А. Козачек В.
• Other Authors: Study supported by the Megagrant project (agreement № 075-15-202-599, 8.06.2021) “Paleoecological Reconstructions as a Key to Understanding Past, Current, and Future Climate and Environmental Changes in Russia.” The review of the work on precipitation isotopic composition in mountain regions was supported within the framework of State Assignment № FMGE-2019-0004 for the RAS Institute of Geography. The trajectory analysis was carried out within the framework of the State Assignments of the RAS Obukhov Institute of Atmospheric Physics., Работа выполнена в рамках мегагранта (Соглашение № 075-15-2021-599 от 08.06.2021) “Палеоэкологические реконструкции как ключ к пониманию прошлых, текущих и будущих изменений климата и окружающей среды в России”. Обзор работ по изотопному составу осадков в горных районах выполнен в рамках государственного задания Института географии РАН № FMGE-2019-0004. Траекторный анализ выполнялся в рамках Госзаданий ИФА им. А.М. Обухова РАН.
• Format: Article in Journal/Newspaper
• Language: Russian
• Published: IGRAS 2023
• Subjects: oxygen isotope composition;hydrogen isotope composition;precipitation;Caucasus;Elbrus;temperature reconstruction; изотопный состав кислорода;изотопный состав водорода;атмосферные осадки;Кавказ;Эльбрус;реконструкция температур; The Cryosphere
• Online Access: https://ice-snow.igras.ru/jour/article/view/1149; https://doi.org/10.31857/S2076673423010052

The aim of the work was to study the isotopic characteristics of precipitation to establish the dependence of δ18O values on temperature at the time of precipitation and to get closer to understanding the processes that form the isotopic signature of the Elbrus snow cover and glacial ice. The sampling of precipitation was organized at Azau station, located at the foot of Elbrus at an altitude of 2300 m for the period from May 01.2019 to September 27.2021. The sampling was carried out once a day at 9:00 Moscow time. The air temperature was recorded at the meteorological station in the Terskol village (Roshydromet station No. 4334250). To study the main features of long-range air transport and possible sources of moisture, 5-day back trajectories were reconstructed using the NOAA HYSPLIT_4 trajectory model. The results showed that precipitation in the Elbrus region in winter was associated with the prevailing transfer from the Atlantic, in summer – with the predominance of transfer from the regions of Central Europe, the Mediterranean and Black Seas. The Mediterranean Sea in all seasons was the area from which the air and moisture were transferred to Elbrus. The values of δ18О and δ2 Н of precipitation varied from 0.52 to −28.22‰ and from 16.3 to −224.1‰, respectively, revealing regular seasonality with high values of δ18О and δ2 Н in summer and low in winter. The deuterium excess varied over a wide range from 24.8 to −14.6‰. All obtained values of δ18О and δ2 Н were approximated by the equation δ2 Н = 8δ18О + 7.06 (R2 = 0.98), which was close to the global meteoric water line. In general, for 2 years of observations, the relationship between the δ18О values of precipitation and the temperature of the surface air layer was expressed as 0.85‰/°С. Total mean absolute error in the reconstruction of air temperatures from the δ18О value of precipitation was 3.2°С due to objective reasons and also differences in meteorological conditions of two years of observations. Приведены результаты изучения изотопных ...