Pavlyukevich, Ekaterina; Popovnin, Viсtor; Gubanov, Afanasy; Ivanov, Viсtor; Averina, Alena; Ibraev, Kirill; Voevodina, Anastasia; Durmanov, Ivan; Khomiakova, Victoria; Chizhova, Julia N; Kozachek, Anna V; Ekaykin, Alexey A; Tsyplenkov, Anatoly; Zheleznova, Irina (2026): Hydrological, meteorological and glaciological observations and isotopes sampling results during 2021-2024 (glaciological data from 2019-2020 included) at Djankuat Glacier Station in the North Caucasus, Russia [dataset bundled publication]. PANGAEA, https://doi.org/10.1594/PANGAEA.989847

This is the second update of a dataset comprising long-term complex glaciological, hydrological, and meteorological observations, including isotope sampling, from the highly underreported alpine zone of the North Caucasus, described in Rets et al., 2019 (https://doi.org/10.5194/essd-11-1463-2019). The data were collected in the Djankuat research basin (9.1 km², elevations of 2500–4000 m, 30% glacier cover). The Djankuat glacier, located in the basin under study, is a World Meteorological Organization reference glacier with a mass-balance record exceeding 50 years. The original dataset covers 2007-2017 (https://doi.org/10.1594/PANGAEA.894807), with the first update for 2019-2020 (https://doi.org/10.1594/PANGAEA.940839). This second update extends the series to 2021-2024. It also includes previously unpublished data of glacier ablation, snow height, and snow density measurements in the spatially distributed net for the 2019-2020 period. A significant enhancement since 2021 is the operation of an additional year-round hydrological gauging station on the Djankuat River 1 km downstream of the main one. The dataset includes results from annual measurements of snow thickness and density; snow and ice melt dynamics; water runoff, conductivity, turbidity, temperature, δ¹⁸O, and δ²H at gauging stations; isotopic sampling of precipitation, snow, ice, firn, and groundwater; and high-resolution meteorological data (precipitation, air temperature, humidity, radiation, pressure, wind). The observations were primarily conducted during the summer ablation seasons (June-October), with gradient and eddy covariance measurements for turbulent flux estimation. This dataset is invaluable for developing and validating hydrological, glaciological, and meteorological models, assessing climate change impacts on mountain hydrology, and applying isotopic methods in high-altitude research. The dataset will be periodically updated.

The research was supported by Russian Science Foundation, grant no. 25-77-10049 (in part of hydrological observations), grant no. 22-17-00133 (in part of glaciological observations), and was carried out under the Governmental Order to Water Problems Institute, Russian Academy of Sciences, subject no. FMWZ-2025-0003 (in part of meteorological observations).