NGEE Arctic Tram: Periodic Soil Moisture, Temperature, and Thaw Depth Measurements across Polygonal Tundra, Utqiagvik (Barrow), Alaska, 2014-2015

Manual measurements of soil moisture, temperature, and thaw depth were collected in the footprint of the NGEE Arctic Tram starting 2014-07-20 and continuing through 2015-07-16. There were 10 periodic sampling events with measurements in one *.csv file. These measurements were collected under the Tram observational platform. Probes were inserted into ground beneath the track closest to Tram sensors measurement locations at each Tram measurement position (Position # marked on the tracks). A MiniTrase Time Domain Reflectometry (TDR) instrument was used to measure volumetric water content (VWC; units = m3/m3). Soil temperature was measured with a thermocouple probe. Depth of thawed soil was measured from the top of the moss layer or top of soil. See user guide for more information *.pdf. The Next-Generation Ecosystem Experiments: Arctic (NGEE Arctic), was a research effort to reduce uncertainty in Earth System Models by developing a predictive understanding of carbon-rich Arctic ecosystems and feedbacks to climate. NGEE Arctic was supported by the Department of Energy's Office of Biological and Environmental Research. The NGEE Arctic project had two field research sites: 1) located within the Arctic polygonal tundra coastal region on the Barrow Environmental Observatory (BEO) and the North Slope near Utqiagvik (Barrow), Alaska and 2) multiple areas on the discontinuous permafrost region of the Seward Peninsula north of Nome, Alaska. Through observations, experiments, and synthesis with existing datasets, NGEE Arctic provided an enhanced knowledge base for multi-scale modeling and contributed to improved process representation at global pan-Arctic scales within the Department of Energy's Earth system Model (the Energy Exascale Earth System Model, or E3SM), and specifically within the E3SM Land Model component (ELM).

本数据集采集了2014年7月20日至2015年7月16日期间，北极下一代生态实验（Next-Generation Ecosystem Experiments: Arctic, NGEE Arctic）有轨观测平台（Tram）观测范围内的土壤含水率、温度及冻融深度人工实测数据。
本次共开展10次周期性采样，所有测量数据均存储于单个*.csv格式文件中。
所有测量工作均在该有轨观测平台下方完成。
在每一个有轨观测平台测量点位（轨道上标注的点位编号）处，将探针插入至距离该平台传感器测量位置最近的轨道下方土层中。
采用MiniTrase时域反射仪（Time Domain Reflectometry, TDR）测量土壤体积含水率（Volumetric Water Content, VWC；单位：m³/m³）。
使用热电偶探针测量土壤温度。
冻土层厚度以苔藓层顶部或土壤表层为基准进行测量。
详细信息请参阅配套的*.pdf格式用户指南。
北极下一代生态实验（Next-Generation Ecosystem Experiments: Arctic, NGEE Arctic）是一项旨在通过深化对富碳北极生态系统及其气候反馈机制的预测性认知，以降低地球系统模型（Earth System Model）不确定性的研究项目。
该项目由美国能源部生物与环境研究办公室资助。
本项目设置两处野外研究站点：1）位于美国阿拉斯加州乌特恰维克（原巴罗）附近北坡的巴罗环境观测站（Barrow Environmental Observatory, BEO）内的北极多边形苔原海岸区域；2）位于阿拉斯加州诺姆以北苏厄德半岛不连续多年冻土区的多处区域。
通过野外观测、控制实验及与现有数据集的整合分析，NGEE Arctic项目为多尺度建模提供了更为完善的知识库，并助力美国能源部地球系统模型——能量极端计算地球系统模型（Energy Exascale Earth System Model, E3SM），尤其是其陆面模型模块（E3SM Land Model, ELM）——在全球泛北极尺度上改进了生态过程的表征精度。