The Importance of Freeze/Thaw Cycles on Lateral Transport in Ice-Wedge Polygons: Modeling Archive

This Modeling Archive is in support of an NGEE Arctic publication "The importance of freeze/thaw cycles on lateral transport in ice-wedge polygons".The dataset includes xml input/configuration files. These files are compatible with the ATS version 1.0 and higher. The mesh folder contains mesh files used for high-centered polygon (hcp) and low-centered polygon (lcp). The mesh files represent the transect of the polygonal tundra (Fig 1). Here we used two types of mesh with impermeable layer and without. The mesh with an impermeable layer corresponds to the synthetic permafrost (no freezeup case). The freeze up case uses mesh without impermeable layer to simulated frozen ground start at the same depth where the impermeable layer is for the no freezeup case. The meteorological data used drive the model saved in the ‘inputs’ folder. The processed tracer flow rates are saved in the ‘tracer-flow-rates’ folder. To plot figures 1 and 2, we used VisIt software. To plot all the flow rates, we used ipython notebook script. All required inputs are saved in ‘freezeup’ and ‘no freezeup’ folders. Each folder includes the corresponding ‘lcp’ and ‘hcp’ folders. The ‘freezeup’ folder has also flat-centered polygon (fcp) case, low porosity ‘lpor’, and low permeability ‘lper’ cases.NGEE Arctic Project Summary: 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).

本建模存档旨在支持下一代北极生态系统实验（Next-Generation Ecosystem Experiments: Arctic，简称NGEE Arctic）的一篇发表论文《冻融循环对冰楔多边形侧向输运的重要性》。本数据集包含可扩展标记语言（XML）格式的输入与配置文件，这些文件兼容ATS 1.0及更高版本。

mesh文件夹包含用于高中心多边形（high-centered polygon, HCP）与低中心多边形（low-centered polygon, LCP）的网格文件，这些网格文件表征了多边形苔原的样带（图1）。本次研究使用了两类网格：带有不透水层与不带不透水层的网格。其中带有不透水层的网格对应合成永久冻土场景（无冻结工况）；冻结工况则采用不带不透水层的网格，其模拟的冻土起始深度与无冻结工况中不透水层的所在深度一致。

驱动模型的气象数据存储于"inputs"文件夹中；经处理的示踪剂流速数据存储于"tracer-flow-rates"文件夹。绘制图1与图2使用了VisIt可视化软件，绘制所有流速曲线则采用了IPython Notebook脚本。所有必要的输入文件分别存储于"freezeup"（冻结工况）与"no freezeup"（无冻结工况）文件夹中，每个文件夹均包含对应的"lcp"与"hcp"子文件夹。其中"freezeup"文件夹还涵盖平中心多边形（flat-centered polygon, FCP）、低孔隙度（lpor）以及低渗透率（lper）工况。

### NGEE Arctic项目概述
下一代北极生态系统实验（NGEE Arctic）是一项为期10年（2012-2022年）的研究计划，旨在通过构建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（原巴罗）附近北坡的巴罗环境观测站（Barrow Environmental Observatory, BEO）的北极多边形苔原沿海区域；2）位于阿拉斯加州诺姆以北苏厄德半岛的不连续永久冻土区多个区域。

通过观测、实验以及与现有数据集的综合分析，NGEE Arctic为多尺度建模提供了增强型知识库，并推动了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的过程表征精度提升。