Subsurface Flow Across Polygonal Tundra Measured by Bromide Tracer, Utqiagvik (Barrow), Alaska, 2015-2016

A bromide tracer study with the primary focus on hydrology in the active layer of polygonal tundra in the Barrow Environmental Observatory in Utqiagvik (Barrow), Alaska from July 2015 to September 2016. Sampling devices placed at various depths in the polygon centers, rims, and troughs were used to monitor tracer concentrations during thaw seasons. The tracer was continually monitored simultaneously on a low- and high-centered polygon throughout thaw seasons. Included is one data file of the bromide tracer concentrations. Also included are measurements taken throughout the experiment - one data file each of frost table depth and precipitation; and twelve water table elevation data files. Water level data, meteorological data, and thaw depth measurements were taken throughout the experiment. Our approach permits a comparison of hydrological behaviors in low- and high-centered polygons over the same time period and meteorological conditions.The Next-Generation Ecosystem Experiments: Arctic (NGEE Arctic), was a 10-year research effort (2012-2022) 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).

本数据集源自2015年7月至2016年9月在美国阿拉斯加州乌特恰维克（Utqiagvik，原称巴罗Barrow）的巴罗环境观测站开展的溴化物示踪剂（bromide tracer）研究，核心聚焦于北极多边形冻土苔原（polygonal tundra）活动层（active layer）的水文过程。
研究人员在多边形中心、边缘与沟槽的不同深度布设采样装置，于解冻季（thaw seasons）监测示踪剂浓度。本研究同时在低中心多边形与高中心多边形的解冻季持续同步监测示踪剂浓度变化。
数据集包含1份溴化物示踪剂浓度数据文件；另有实验全程采集的冻土上限深度（frost table depth）数据、降水数据各1份，以及12份地下水位高程（water table elevation）数据。实验全程还同步采集了水位数据、气象数据与解冻深度测量数据。本研究方法可对比相同时段与气象条件下，低中心与高中心多边形的水文行为差异。
下一代北极生态系统实验（Next-Generation Ecosystem Experiments: Arctic，以下简称NGEE Arctic）是一项为期10年（2012-2022年）的研究计划，旨在通过深化对富碳北极生态系统的预测性认知及其对气候的反馈机制，降低地球系统模型（Earth System Models）的不确定性。该项目由美国能源部生物与环境研究办公室资助。
NGEE Arctic项目设有两个野外研究站点：1）位于阿拉斯加州乌特恰维克（巴罗）附近的北坡巴罗环境观测站（Barrow Environmental Observatory，简称BEO）的北极多边形冻土苔原沿海区域；2）位于阿拉斯加州诺姆以北苏厄德半岛的不连续多年冻土区（discontinuous permafrost region）的多个区域。
通过观测、实验与现有数据集综合分析，NGEE Arctic为多尺度建模提供了增强型知识库，并助力美国能源部地球系统模型——能源极端尺度地球系统模型（Energy Exascale Earth System Model，简称E3SM），尤其是其E3SM陆面模型组件（ELM），在全球泛北极尺度上改进过程表征。