Collaborative Research: Arctic Observing Network For Observing Transformation of the Greenland Ice Sheet Firn Layer

合作研究：观测格陵兰冰盖冰层变化的北极观测网络

• 批准号: 2113391
• 负责人: Joel Harper
• 金额: $ 119.91万
• 依托单位: University of Montana
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-11-01 至 2026-10-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2113391&HistoricalAwards=false
• 关键词: Collaborative; Research; Arctic; Observing; Network; Collaborative; Research; Arctic; Observing; Network

This award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117-2)As the Arctic warms two-to-three times faster than the global average, the duration and intensity of melting is generally increasing on the surface of the Greenland ice sheet. About 90% of ice sheet is covered by compacted snow that is slowly transitioning into glacier ice. This aged and dense snow is called ‘firn’ and forms a porous layer that is many tens of meters thick. Much of the meltwater generated from the surface of the firn layer infiltrates into the underlying open pore space of the firn and refreezes. However, as this porous layer absorbs more melt it becomes warmer, denser, and filled with ice layers, which reduces its ability to absorb additional melt. Therefore, the thermal and structural transformation that Greenland's firn layer is presently undergoing has important implications for the ice sheet's capacity to retain future melt. This project is directly observing firn evolution with a network of instruments installed within the firn layer and with ice cores sampling the firn. The observational data collected by this project provides on-the-ground documentation of firn conditions needed to develop and test models and remote sensing tools for large-scale investigations of changes to the Greenland ice sheet. Future transformation of the firn layer will govern how much surface melt is retained locally on the ice sheet and how much runs off, thereby impacting hydrologic conditions of the ice sheet and surrounding regions, ocean salinity, and sea level rise.The researchers will install and maintain an observation network along a transect of the Greenland ice sheet to directly measure the state and transformation of firn properties. Repeat sampling of firn cores and instrumentation extending from the surface to 25 meters depth will yield the observational datasets needed by multiple scientific communities: firn temperature, density and ice content, densification rate, surface boundary processes (radiation, snow accumulation, temperature), and ice velocity. The network will yield 4-5 full-year records in this five-year Arctic Observing Network project. The project will provide comprehensive datasets for process-level investigations, testing climate model simulations of firn processes, and interpreting satellite-based measurement of surface elevation change. The project will engage and support a relatively large number of undergraduate and graduate students at R2 institutions with field research experiences and real-world classroom learning. Outreach activities will target three groups poorly represented in cryospheric science: 1) local and Indigenous residents of Greenland; 2) American Indian undergraduate students; and 3) economically disadvantaged school children.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

该奖项是根据2021年《美国救援计划法》（公法117-2）全部或部分资助的，因为北极的暖度比全球平均水平快两到三倍，在格陵兰冰盖表面上，熔化的持续时间和融化的持续时间和强度通常在增加。约90％的冰盖被压实的雪覆盖，该雪逐渐逐渐过渡到冰川冰。这种老化和致密的积雪称为“ firn”，形成了一个多孔层，厚度为数十米。从FIR层的表面产生的大部分融合水渗入了FIR的基础开放孔隙空间和重新冷冻。但是，随着该多孔层吸收更多的熔体，它变得更温暖，浓密，并充满了冰层，从而降低了其吸收额外熔体的能力。因此，呈现Greenland的FIR层的热和结构转化对冰盖保留未来熔体的能力具有重要意义。该项目直接观察了FIR演化，该仪器网络安装在FIR层中，而ICE内核进行了第一个采样。该项目收集的观察数据提供了开发和测试模型和遥感工具所需的第一个条件的现场文档，以大规模研究格陵兰冰盖的变化。 FIR层的未来转换将控制冰盖上局部保留多少表面熔体，以及多少流量，从而影响冰盖及周边地区的水文条件，海洋盐度以及海平面上升。研究人员将沿着绿地冰台的横向安装和维护一个观测网络，以直接测量火柴的状态和火焰的状态。重复对FIR内核和仪器从表面延伸到25米的仪器将产生多个科学社区所需的观察数据集：首先，该项目将在这个五年的北极观测网络项目中产生4-5个全年记录。该项目将提供全面的数据集，用于过程级别的研究，测试FIRN过程的气候模型模拟以及解释基于卫星的表面高度变化的测量。该项目将在R2机构的实地研究经验和现实世界的课堂学习中吸引并支持相对较大的本科生和研究生。外展活动将针对Cryosphere Science代表不佳的三个群体：1）格陵兰的地方和土著居民； 2）美洲印第安人本科生； 3）在经济上处于弱势群体的儿童。该奖项反映了NSF的法定任务，并被认为是通过基金会的知识分子优点和更广泛的影响审查标准来评估值得支持的。