CAREER: Improving Estimates of Changing Firn Meltwater Storage and Flux in Temperate Glacier Systems

职业：改进对温带冰川系统中冰雪融水储存和通量变化的估计

• 批准号: 2239668
• 负责人: Seth Campbell
• 金额: $ 62.39万
• 依托单位: University of Maine
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-06-01 至 2028-05-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2239668&HistoricalAwards=false
• 关键词: CAREER; Improving; Estimates; Changing; Firn

Glaciers are created from annual snowfall which does not entirely melt during summer months. Over time, this accumulated snow condenses to form glacier ice. Firn is a highly porous middle stage between snow and ice which often stores surface meltwater in its pore space. Unfortunately, we don’t have a good estimate of how much meltwater is stored in firn, how this water storage varies from glacier to glacier, or how this storage amount is changing due to climate change. This project will determine several firn properties such as firn thicknesses, pore volume, water storage, and changes in water storage over time across the Juneau Icefield located in Southeast Alaska. We will use field observations and modeling to answer these questions and to estimate firn properties more broadly across Alaska and Canada. This is important because Alaska and Canada glaciers are retreating (melting) faster than any other glacier system on Earth. Therefore, we expect changes in meltwater storage to occur. Meltwater stored in firn has the potential to raise sea level by a significant amount and impact other Earth systems such as ocean microscopic life forms and fisheries if it is rapidly released from glaciers. We will use results from this project in an interactive educational video game we build for classrooms and the Mendenhall Glacier Visitors Center which receives over 600,000 visitors per year. We will train hundreds of students to use the game and help with further game development. Lastly, this project will partially support an annual Culture Camp with indigenous communities in Alaska and Northwestern Canada where strategies for reducing impacts from environmental changes will be developed.This project will quantify spatial and temporal variations in firn thickness, density, porosity, water content, and volume change, across the Juneau Icefield (JIF) in Southeast Alaska and Northwest Canada. We will use a range of observations acquired during this project, previously acquired data, data assimilation, and modeling, to understand the impacts of firn volume change on meltwater storage, meltwater flux, and down-glacier impacts from changing meltwater processes. We have selected the JIF for this study because it is an appropriate analog to thousands of temperate glaciers across the globe experiencing firn loss and thinning. This research will characterize spatial and temporal variability of meltwater and meltwater movement within firn over hourly-to-yearly timescales and cm-to-km spatial scales, resolutions rarely achieved across any glacier system. Temperate firn is poorly constrained and densification models of firn do not yet incorporate empirical observations of melt. Additionally, spatial data on firn thickness, changes to firn volume due to glacier retreat, and the associated changes to firn meltwater storage and down-glacier meltwater flux (thereby influencing down-glacier ecosystems), are largely unknown. This proposal will help tackle these challenges. This is important because Alaskan and Canadian glaciers are retreating faster than any other glacier system on Earth, so we expect changes in firn meltwater storage to occur. Meltwater stored in firn has the potential to raise sea level by a significant amount and impact down-glacier terrestrial and marine ecosystems due to climate change. As part of this project, we will build an interactive educational video game for use in classrooms and the Mendenhall Glacier Visitors Center (600,000 annual visitors). We will also train over 500 students to use the game and help with further game development. Lastly, this project will partially support an annual Culture Camp with indigenous communities in Alaska and Northwestern Canada to brainstorm collaborative strategies for reducing impacts from environmental changes being observed in these regions.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.

冰川是由年度降雪产生的，在夏季的月份并不完全融化。随着时间的流逝，这种积雪凝结形成冰川冰。 FIRN是雪地和冰之间的高度多孔中间阶段，通常将表面融合物存储在其孔隙空间中。不幸的是，我们对FIRN中存储了多少融水，从冰川到冰川的多样性或由于气候变化而导致的存储量如何变化。该项目将确定几种FIR厚度，例如FIR厚度，孔隙体积，水存储以及随着时间的推移储存的变化。我们将使用现场观察和建模来回答这些问题，并在阿拉斯加和加拿大更广泛地估算FIR属性。这很重要，因为阿拉斯加和加拿大冰川比地球上任何其他冰川系统都更快地撤退（熔化）。在地球上。因此，我们预计融水存储会发生变化。储存在FIRN中的融合水有可能提高海平面，并影响其他地球系统，例如海洋微观生命形式和渔业，如果它迅速从冰川中释放出来。我们将在我们为教室和Mendenhall Glacier访问者中心建造的互动教育视频游戏中使用该项目的结果，该游戏每年接待60万名访问者。我们将培训数百名学生使用游戏并帮助进一步的游戏开发。最后，该项目将部分支持在阿拉斯加和加拿大西北部的各个社区的年度文化营，其中将开发出降低环境变化影响的策略。该项目将量化Alaska和Northeast Alaska和Northeast Alaska和Northeast Alaska和Northeast Alaska和Northeast Alaska和Cansa Cansa的FIRN厚度，密度，密度，孔隙，孔隙率，水含量和体积变化的空间和临时变化。我们将使用此项目期间获得的一系列观察结果，以前获得的数据，数据同化和建模，以了解FIRN体积变化对融合水存储，融合水的助焊剂以及变化融化过程的影响的影响。我们选择了本研究的JIF，因为它是与全球数千个温度冰川的合适类似物，经历了FIRN损失和变薄。这项研究将表征融合水和融水运动在每小时至每年的时间表和CM至KM空间尺度内的空间和临时变异性，这些决议在任何冰川系统中都很少实现。温带FIR的约束较差，FIR的致密化模型尚未包含熔体的经验观察。此外，关于FIR厚度的空间数据，由于冰川撤退而导致的FIR体积变化以及对FIR融化的储存和山水融化液的相关变化（从而影响下降冰淇淋生态系统）是未知的。该建议将有助于应对这些挑战。这很重要，因为阿拉斯加和加拿大冰川的撤退速度比地球上的任何其他冰川系统都快，因此我们预计会发生Fir Meltwater存储的变化。储存在FIR中的融合物有可能由于气候变化而增加大量的海平面并影响下降陆地陆地和海洋生态系统。作为该项目的一部分，我们将建立一个交互式教育视频游戏，用于教室和门登霍尔冰川访客中心（60万名年度访问者）。我们还将培训500多名学生使用游戏并帮助进一步的游戏开发。最后，该项目将部分支持在阿拉斯加和加拿大西北部的土著社区的年度文化营，以集思广益协作策略，以减少这些地区观察到的环境变化影响的影响。该奖项反映了NSF的法定任务，并认为通过基金会的知识分子优点和广泛的范围来评估，这被认为是宝贵的支持。