RAIIZ-TREES1: Hydrometeorological, subsurface, and snow data in Western Siberia near Salekhard of Yamal-Nenets Autonomous District, Russia, 2018-2021

Three observational sites (ENGAYU, RAI-IZ, LPTEG) were established in 2018 on the eastern slope of the Polar Urals range near the city of Salekhard of Yamal-Nenets Autonomous District, Russia. Each site contained four to five plots in the vicinity of about 1000 meters across a defined vegetation gradient, from the areas with tall and dense vegetation cover (FOREST), to the areas of tall and sparse vegetation (TREES), and to the areas of short vegetation dominated by sedges, mosses and dwarf shrubs (TUNDRA). At each plot, meteorological towers were erected and instrumented with above and below ground measuring equipment. The data was collected continuously from 2018 to 2021 with 30 to 60 min time interval. The data underwent quality assurance and data management protocols and were organized into three datasets: (i) subsurface and above ground observations (precipitation, air temperature, relative humidity, wind speed, four-channel radiation fluxes, net radiation, albedo, soil heat flux), (ii) below ground observations (temperature and soil water content at five depths up to 100 cm; temperature in the upper organic layer), and (iii) snow depth measurements. The data collection was a part of the project sponsored by the Office of Polar Programs (OPP) of the National Science Foundation (NSF). A specific goal of the project was to explore ecohydrological changes associated with tree and shrub encroachment into tundra areas at the scales of in situ field monitoring programs and the regional scale of the Western Siberian Plain.