Spatial-Temporal Variability of the δ18O Values and the Snow Cover Structure on the Territory of the Meteorological Observatory of the Lomonosov Moscow State University

• Main Authors: S. Sokratov A., A. Komarov Yu., Yu. Vasil’chuk K., N. Budantseva A., J. Vasil’chuk Yu., Yu. Seliverstov G., P. Grebennikov B., D. Frolov M., С. Сократов А., А. Комаров Ю., Ю. Васильчук К., Н. Буданцева А., Дж. Васильчук Ю., Ю. Селиверстов Г., П. Гребенников Б., Д. Фролов М.
• Other Authors: This research project was supported by the Russian Science Foundation (grant № 19–77–30004, “Integrated technology for environment assessment of Moscow megacity based on chemical analysis of microparticle composition in the ‘atmosphere – snow – road dust – soil – surface water’ system Megacity”, isotope analyses, and the State Assignment “Danger and risk of naturel processes and phenomena” (121051300175-4), field work and analysis of the obtained results, Работа выполнена при поддержке РНФ (грант № 19–77–30004 “Технология оценки экологического состояния Московского мегаполиса на основе анализа химического состава микрочастиц в системе “атмосфера–снег– дорожная пыль–почвы–поверхностные воды” Мегаполис”), изотопные определения, и по теме гос. задания “Опасность и риск природных процессов и явлений” (121051300175-4), полевые исследования и анализ полученных результатов
• Format: Article in Journal/Newspaper
• Language: Russian
• Published: IGRAS 2024
• Subjects: snow cover; stable water isotopes; snow stratigraphy; spatial variability; winter precipitations; temporal variability; снежный покров; стабильные изотопы воды; стратиграфия снежного покрова; пространственная неоднородность; зимние осадки; изменение во времени; Permafrost and Periglacial Processes; The Cryosphere
• Online Access: https://ice-snow.igras.ru/jour/article/view/1285; https://doi.org/10.31857/S2076673423040154

The isotopic composition (δ18O values) of snow layers, constructing snow cover to the time of reaching maximum snow water equivalent (SWE), was compared with the isotopic content of snow precipitated over the whole the winter season 2018/19 on the territory of the Meteorological Observatory of the Lomonosov Moscow State University (Moscow, Russia). Snow-sampling was carried out in a trench 20 m long simultaneously with detailed measurements of spatial variability of the structural characteristics of snow depth. Sampling was conducted for each precipitation event over the winter season, with the amount of precipitation also documented. It was found that the spatially-distributed enrichment with heavy oxygen isotopes along the trench fell within the range of 0–3.5‰, with average values for the four main formed snow layers changing from 1.3 to 2.5‰. The enrichment was not much dependent on the age of snow layer in the snowpack, and it was even more pronounced in the upper layers. This suggests that the post-precipitated change in the isotopic composition of snow cover for the conditions of the investigated site mainly took place when the snow was exposed to the atmosphere (due to sublimation and evaporation), while the processes of dry and wet metamorphism were either less important or even led to leveling the effects of isotopic fractionation. A positive correlation was found between the isotope composition of snow and the spatially varying snow density in each layer. This is most probably related to involvement of wind influence into the snow accumulation resulting in more dense snow. The spatial variability of the isotope composition of snow in each layer was smaller than changes in snow density and snow water equivalent. Представлены результаты сравнения изотопного состава (значений δ18O) разновозрастных слоёв снега, слагающих снежную толщу к моменту максимального водозапаса, с изотопным составом осадков, сформировавших эти слои в течение зимнего сезона 2018/19 г. на территории метеообсерватории МГУ. ...