Isotopic composition (δ18O, δ2H) of the snow cover in Karelia

• Published in: Ice and Snow
• Main Authors: G. Borodulina S., I. Tokarev V., M. Levichev A., Г. Бородулина С., И. Токарев В., М. Левичев А.
• Other Authors: The study was carried out under state order to the Karelian Research Centre of the Russian Academy of Sciences (Northern Water Problems Institute KRC RAS) and the field work was supported by the Russian Science Foundation (project № 18-17-00176)., Работа выполнена при финансовом обеспечении средств федерального бюджета на выполнение государственного задания Карельского научного центра РАН (Институт водных проблем Севера КарНЦ РАН) и при финансовой поддержке полевых работ РНФ (проект № 18-17-00176).
• Format: Article in Journal/Newspaper
• Language: Russian
• Published: IGRAS 2021
• Subjects: Karelia; snow cover; isotopes of oxygen and hydrogen; atmospheric precipitations; Карелия; снежный покров; изотопы кислорода и водорода; атмосферные осадки; Shuya; Arctic
• Online Access: https://ice-snow.igras.ru/jour/article/view/931; https://doi.org/10.31857/S2076673421040105

For the first time, a regional study of the isotopic composition (δ18O and δ2 H) of the snow cover in Karelia was performed using a sub-meridional and two sub-latitudinal profiles (March 2016). Snow nutrition does generally prevail here in the river and underground runoff. Integral snow samples were taken at 45 sites, three horizons were studied at 39 of them. Monitoring of the isotopic composition of atmospheric precipitation is carried out in the Petrozavodsk city from 2012 to the present. The isotopic composition of snow on the territory of Karelia varied through the following range: for δ18O it is from −15.7 to −21.1 ‰, and for δ2 H – from −118 to −158 ‰, which is significantly less than the isotopic composition of atmospheric precipitation for the same period: δ18O = −8.7 ÷ −30.9 ‰, δ2 H = −77 ÷ −239 ‰. The exception is snow in the valleys of the large Shuya and Suna rivers with light isotopes δ18O (down to −21 ‰). According to two sublatitudinal profiles in southern and central Karelia, there were no obvious trends in the isotopic composition of snow. The decrease in the contents of deuterium (δ2 H) and oxygen-18 (δ18O) in the sections of snow cover corresponds to an almost complete loss of snow at the beginning of winter due to the December thaws of 2015 and its intensive accumulation in abnormally cold January 2016. According to trajectory analysis data, air masses containing isotopically heavy moisture come mainly from the west and southwest, and those containing isotopically light moisture come from the north and east. The results of this research demonstrate that the reconstruction of the isotopic composition of winter precipitation can be approximately performed by the isotopic composition of snow cover. Приводятся результаты изотопного анализа состава снежного покрова Карелии, сформировавшегося в зимний период в 2015/16 г., и атмосферных осадков в Петрозаводске. Показано, что состав снега изменяется от −15,7 до −21,1 ‰ для δ18О и от −118 до −158 ‰ для δ2Н, а облегчение изотопного состава ...