ENGAYU-TREES2: 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.2018年，俄罗斯亚马尔-涅涅茨自治区萨列哈尔德市附近的极地乌拉尔山脉东坡，设立了三个观测站点（ENGAYU、RAI-IZ、LPTEG）。每个站点设置4至5个样地，这些样地分布在约1000米范围内的预设植被梯度带上，覆盖梯度依次为高大茂密植被覆盖区（FOREST）、高大稀疏乔木区（TREES），以及以莎草、苔藓和矮灌木为优势种的低矮植被苔原区（TUNDRA）。每个样地均架设了气象塔，并配备了地表与地下测量设备。数据于2018年至2021年期间连续采集，采样间隔为30至60分钟。所有数据均经过质量保证与数据管理流程处理，并被整理为三类数据集：(i) 地下与地表观测数据（涵盖降水、空气温度、相对湿度、风速、四通道辐射通量、净辐射、反照率、土壤热通量）；(ii) 地下观测数据（包括5层深度达100cm的土壤温度与含水量，以及上层有机层温度）；(iii) 积雪深度测量数据。本数据采集工作隶属于由美国国家科学基金会（National Science Foundation, NSF）极地项目办公室（Office of Polar Programs, OPP）资助的研究项目。本项目的核心目标为，在原位野外监测尺度与西西伯利亚平原区域尺度下，探究林木与灌木入侵苔原区所引发的生态水文变化。