Snow surveys in the south of the western Siberia (Russia)

Climate change has a significant impact on seasonal snow cover. However, obtaining robust data on snow cover remains a challenge. There is a significant lack of ground-based data for verification of remote and model data. Observation network in Siberia is quite rare, and the location of the snow stations does not always represent the characteristics of the territory. We aimed to extend the observation coverage of climate stations and to assess variability in different ecosystems. We focused on the representation of different ecosystem types in the southern West Siberian Plain and Altai low mountain area. We carried out our research in two catchments - Kasmala and Maima, located in the forest-steppe and lowland areas. The observations were conducted during the peak snow accumulation (late February - early March). In the Kasmala catchment, the observations were conducted in 2011-2014 and 2017-2019, in the Mayma catchment from 2015 to 2019. These works were funded by state projects of the Institute for Water and Environmental Problems SB RAS. In 2019, a joint 3S (South Siberian Snowpack) project funded by RFBR (2019-2022) was launched at Lomonosov Moscow State University. As part of this project, we expanded the observation network and conducted observations during the whole winter season 2019-2020 in three catchments: Kuchuk (steppe), Kasmala (forest-steppe), and Mayma (low mountains). Also, the 3S project merged existing data into a single dataset on snow properties (depth, density, SWE). Observations till 2019 were carried out on snow courses and small snow sites. Courses were 500 m to 2 km long. Depth measurements were made every 20 m, density measurements every 100/200 m. The snow sites were two perpendicular transects of 50 or 20 meters long, including 20 depth and 5 density measurements. In the 3S project, we changed the observation scheme (data 2019-2020). All observations were made at the snow sites, which included 61 depth and 13 density measurements. The sampling scheme was proposed by Jost et al., 2007. In total, in the Kasmala catchment, we carried out about 600 depth/70 density measurements, in the Mayma catchment about 800 depth/200 density measurements. Within the 3S project, we carried out 8781 depth and 1873 density measurements during the winter season. We highly recommend aggregating the data by courses, sites or catchments (do not use individual values).