COLLABORATIVE RESEARCH: Patterns, Dynamics, and Vulnerability of Arctic Polygonal Ecosystems: From Ice-Wedge Polygon to Pan-Arctic Landscapes

合作研究：北极多边形生态系统的模式、动态和脆弱性：从冰楔多边形到泛北极景观

• 批准号: 2051888
• 负责人: Anna Liljedahl
• 金额: $ 31.69万
• 依托单位: Woodwell Climate Research Center, Inc.
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-02-29 至 2024-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2051888&HistoricalAwards=false
• 关键词: COLLABORATIVE; RESEARCH; Patterns; Dynamics; Vulnerability

The warming Arctic is reshaping the tundra landscape as ground-ice that is thousands of years old thaws, resulting in differential ground settlement that alters the distribution of water and snow in a region with desert-like precipitation. Field measurements across the Arctic have documented long-term and gradual warming of permafrost and recently the observations have also included rapid ice-wedge degradation in response to a single and unusually warm summer. The goal of this project is to understand the complex and interlinked processes responsible for the evolution of the pan-Arctic ice-wedge polygon tundra landscape by combining field measurements from nine Canadian, Russian, and Alaskan field sites, numerical modeling, and very high spatial resolution optical imagery that has recently become available for the entire Arctic tundra domain. A combination of detailed imagery and advanced processing algorithms will allow pan-Arctic mapping of ice-wedge polygon extent and types (low- and high-centered). A map of that extent and detail does not yet exisxt, but is necessary to link carbon, water, and energy processes occurring at the ice-wedge polygon scale to the larger Arctic land-ocean-atmosphere system. Currently, permafrost thaw and subsequent carbon release is, at best, described in global models via gradual increases in active layer thickness, while field observations clearly show additional dramatic changes to the tundra ecosystem due to rapid differential ground subsidence as ice-wedges melt. A low-centered polygon landscape, which evolved over several thousand years via the slow process of ice-wedge growth, can harbor a sea of shallow ponds throughout the summer that supports a myriad of migratory birds during the breeding season. In just two years, the scene could change dramatically with exposed dry mounds where the shallow water bodies once were, while the surface water area can shrink into narrow elongated beads of deeper ponds above the melted ice-wedges. A complicated set of sub-polygon to watershed scale responses will determine the fate of the landscape. These mechanisms, part of the soil-vegetation-water continuum, will be defined via a numerical biogeophysical model informed by field measurements and repeat imagery of ice-wedge evolution. The new knowledge will support the research community in refining the role of the Arctic in the global climate system. Broader impacts of this project include training of the new generation of Arctic researchers by supporting a graduate student, a post-doctoral fellow, and an early-career scientist. Fairbanks, Alaska, the base for several of the investigators, offers an excellent opportunity to show K-12 students the results of ice-wedge degradation. The products, such as the maps of ice-wedge polygon types and the projected transformation of the vegetation, water, and topography, are at spatial and temporal scales that are relevant to managers. Digital maps of ice-wedge polygon type and ground-ice estimates will be given to state and federal agencies operating in Alaska in a half-day workshop along with ice-wedge polygon ecosystem projections. The information could inform management decisions about habitat protection, or surface-water dependent oil and gas exploration activities. There will also be support for field travel for a journalist and a photographer.

变暖的北极正在将苔原景观重塑为底冰，这是数千年的融化，导致地面差异定居点，改变了一个带有沙漠状降水的地区的水和雪的分布。整个北极的野外测量已记录了长期和逐渐变暖的多年冻土，最近观察结果还包括快速的冰川降解，以响应一个单一且异常温暖的夏天。该项目的目的是通过结合九个加拿大，俄罗斯和阿拉斯加野外现场的现场测量，数值建模，以及非常高的空间分辨率的光学成像，这些田野测量值可用于全面可用于整个Arctic Tundra domain。详细的图像和高级处理算法的组合将允许泛北极绘制冰对叶边的多边形范围和类型（低中心和高中）。该程度和细节的地图尚未ExiSXT，但必须将发生在Ice-Wedge Polygon量表上的碳，水和能量过程与较大的北极地区大气系统联系起来。当前，永久冻结和随后的碳释放充其量是在全球模型中通过逐渐增加的层厚度来描述的，而现场观察结果清楚地显示了苔原生态系统的其他急剧变化，因为随着冰翼融化，快速差分地面沉降。一个低个性的多边形景观通过缓慢的冰卫山生长过程发展了数千年，可以在整个夏季藏有浅池塘，在繁殖季节中支持无数的候鸟。在短短两年内，现场可能会随着浅水体曾经是裸露的丘陵而发生的巨大变化，而地表水区域则可以缩小到融化的冰芯上方的较深池塘的狭窄细长珠子中。一组复杂的子分水果对流域量表反应将决定景观的命运。这些机制是土壤蔬菜 - 水连续体的一部分，将通过数值生物地球体物理模型来定义，该模型通过现场测量和重复的冰 - 北方进化图像告知。新知识将支持研究界完善北极在全球气候系统中的作用。该项目的更广泛影响包括通过支持研究生，博士后研究员和早期职业科学家来培训新一代北极研究人员。阿拉斯加费尔班克斯（Fairbanks）是几位调查人员的基地，为向K-12学生展示Ice-Wedge退化的结果提供了一个绝佳的机会。这些产品，例如冰叶多边形类型的地图以及植被，水和地形的预计转化，是与经理有关的空间和时间尺度。在半天的研讨会上，将对在阿拉斯加运营的州和联邦机构以及Ice-Wedge Polygon生态系统的预测，将对在阿拉斯加运营的州和联邦机构进行数字地图。这些信息可以为管理层保护或依赖于地表水的石油和天然气勘探活动提供信息。还将为记者和摄影师提供野外旅行的支持。

项目成果

An Object-Based Approach for Mapping Tundra Ice-Wedge Polygon Troughs from Very High Spatial Resolution Optical Satellite Imagery

• DOI: 10.3390/rs13040558
• 发表时间: 2021-02
• 期刊: Remote. Sens.
• 作者: C. Witharana;Md Abul Ehsan Bhuiyan;A. Liljedahl;M. Kanevskiy;T. Jorgenson;B. Jones;R. Daanen;H. Epstein;C. Griffin;K. Kent;Melissa K. Ward Jones

Ice-wedge polygon detection in satellite imagery from pan-Arctic regions, Permafrost Discovery Gateway, 2001-2021

泛北极地区卫星图像中的冰楔多边形检测，永久冻土发现网关，2001-2021 年

• DOI: 10.18739/a2kw57k57
• 发表时间: 2023
• 期刊: NSF Arctic Data Center
• 作者: Witharana, Chandi;Udawalpola, Mahendra R.;Perera, Amal S.;Hasan, Amit;Manos, Elias;Liljedahl, Anna;Kanevskiy, Mikhail;Jorgenson, M. Torre;Daanen, Ronald;Jones, Benjamin
• 通讯作者: Jones, Benjamin

Rapid transformation of tundra ecosystems from ice-wedge degradation

冰楔退化导致苔原生态系统快速转变

• DOI: 10.1016/j.gloplacha.2022.103921
• 发表时间: 2022
• 期刊: Global and Planetary Change
• 影响因子: 3.9
• 作者: Jorgenson, M.T.;Kanevskiy, M.Z.;Jorgenson, J.C.;Liljedahl, A.;Shur, Y.;Epstein, H.;Kent, K.;Griffin, C.G.;Daanen, R.;Boldenow, M.
• 通讯作者: Boldenow, M.