Collaborative Research: A New Approach to Firn Evolution using the Taylor Dome Natural Laboratory

合作研究：利用泰勒穹顶自然实验室研究杉木进化的新方法

• 批准号: 2024163
• 负责人: Kaitlin Keegan
• 金额: $ 38.59万
• 依托单位: Board of Regents, NSHE, obo University of Nevada, Reno
• 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: 2021-09-15 至 2025-08-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2024163&HistoricalAwards=false
• 关键词: Collaborative; Research; New; Approach; Firn

The transformation of snow into firn and then glacial ice is a fundamental process in glaciology. Understanding it is critical for many applications including the conversion of satellite altimetry measurements into ice-sheet mass changes—a key measure of glacier response to climate change. Better process understanding is also critical for determining the difference in the age of ice and the gas trapped within it. This difference complicates the age-dating of ice cores. Despite its importance, the transformation of snow into firn and then ice is still poorly understood and current predictive models have limited applicability. This project aims to develop a physically based firn-compaction model for the glaciological community. The team will take the first steps toward this goal through a set of field and laboratory experiments combined with model developments. The fieldwork will be at Taylor Dome in Antarctica. This project will introduce a new combination of firn datasets designed to lead to the development of next-generation, physics-based firn models. Advances in ice-core science and satellite altimetry demand firn models that can reliably simulate firn evolution in a range of climatic conditions, in a changing climate, and on long- and short-time scales. Current firn-compaction models are largely based on a steady-state assumption and tuned to particular geographical locations. Advancing beyond these models requires (1) measuring current firn-compaction rates (2) measuring grain-scale microstructures that play a crucial role in firn compaction, and (3) quantifying processes driving evolution of those microstructures. To decouple firn’s sensitivities to accumulation and temperature, the team will measure in situ strain rates by two independent methods and observe trends in microstructure in cores from sites spanning the accumulation gradient at Taylor Dome, while maintaining the same average temperature. The team will assess the ability of phase-sensitive radar to remotely measure firn-compaction rates, potentially simplifying future in situ measurements. This work will create a roadmap for collecting future microstructural data spanning key areas of temperature-accumulation space and simplify future collaborations through the availability of an open-source Community Firn Model.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.

雪向FIRN，然后是冰川冰的转化是冰川学的一个基本过程。了解它对于许多应用至关重要，包括将卫星高度测量测量转换为冰原质量变化，这是对冰川对气候变化的关键测量。更好的过程理解对于确定冰的年龄及其中的气体的差异也至关重要。这种差异使冰芯的年龄变得复杂。尽管它的重要性，但将雪转化为FIR，然后冰的理解仍然很少，并且当前的预测模型的适用性有限。该项目旨在为冰川学界开发基于物理的FIR摄取模型。该团队将通过一组领域和实验室实验以及模型开发迈出第一步。现场工作将位于南极洲的泰勒圆顶。该项目将引入FIR数据集的新组合，旨在导致下一代基于物理的FIR模型的开发。冰核科学和卫星高度测定需求FIR模型的进步，这些模型可以可靠地模拟在一系列杂种条件下，气候变化以及长期和短期尺度上的FIR演变。当前的FIR摄入模型主要基于稳态假设，并调整为特定的地理位置。超越这些模型的前进需要（1）测量当前的FIR分配率（2）测量在FIR压实中起着至关重要作用的晶尺度微观结构，以及（3）量化驱动这些微观结构演变的过程。为了使First对积累和温度的敏感性解矛，团队将通过两种独立方法测量原位应变速率，并观察来自塔伊勒圆顶累积梯度的位点的微观结构的趋势，同时保持相同的平均温度。该团队将评估相敏感的radiar到远程测量FIRN复数率的能力，从而有可能简化未来的原位测量值。这项工作将创建一个路线图，用于收集未来的微观结构数据，涵盖温度蓄积空间的关键领域，并通过可用的开源社区FIRN模型来简化未来的合作。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和更广泛影响的评估来审查Criteria，通过评估来通过评估来获得支持。