Collaborative Research: Back to the Future: Assimilating Paleo Thinning Rates and Grounding Line Positions to Constrain Future Antarctic Sea Level Contributions

南极冰盖并不总是相同的形状或大小，过去的变化留下了冰量损失和增加的记录。我们的现代观测记录表明，质量损失和冰川退缩反应与气候趋势一致，但退缩的具体情况以及我们对未来变化的预测仍然是冰的内部动力学及其与周围环境的相互作用。从我们目前这一代的冰盖模型中对南极对海平面变化的贡献进行可信预测的挑战在于准确地再现过去的变化。该项目旨在将从南极冰盖周围、上方和下方收集的过去冰盖行为的存档约束与最先进的冰盖模型相结合，以改善对未来海平面上升的预测。此外，该项目将支持研究人员在各个职业阶段之间的知识交流，重点关注过去冰川重建和未来预测，并通过开发在社区大学课堂和在线学习环境中提供的模块化课程来降低进入极地科学的门槛。由于冰退地层线后退和南极洲周围相关冰面下降存在数百个限制，对过去冰盖行为的古约束的可用性不再限制将这些观测结果纳入建模工作。该项目将把全新世的古冰川学观测结果纳入用于预测未来海平面的BISICLES模型框架。本项目的目标是：（1）建立西南极洲全新世中晚期接地线迁移模式从后退到再前进的转换条件;（ii）利用强迫、地质条件、阿蒙森海和罗斯海海湾的响应之间的地理条件，以调查海洋冰盖敏感性在“不稳定”和“稳定”之间的差异。（iii）应用（i）和（ii）的研究结果，以改善对未来海平面预测的限制。调查外部强迫，内部强迫和地质反应的相互作用，在南极洲西部的冰量损失是必不可少的，以减少未来海平面上升预测的不确定性。该项目将采用一个多层面的教育计划，重点是一个导师结构，促进研究人员在每个职业阶段之间的知识交流，重点是古冰川重建和未来预测。该项目团队将与科罗拉多矿业学院Trefny创新教学中心共同制作三个教育模块，重点是古冰川重建，现代冰川观测和未来海平面上升模型。该奖项反映了NSF的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

The Antarctic Ice Sheet has not always been the same shape or size, and past changes have left behind a record of ice mass loss and gain. Our modern observational record indicates mass loss and glacial retreat responses consistent with climatic trends, but the specifics of that retreat, and our projections of future change, remain a tangle of internal dynamics of ice and its interactions with its surroundings. The challenge of making credible projections of the Antarctic contribution to sea-level change from our current generation of ice-sheet models rests on accurately reproducing past changes. This project aims to merge archived constraints on past ice-sheet behavior collected from around, above, and beneath the Antarctic Ice Sheet with a state-of-the-art ice-sheet model to improve projections of future sea-level rise. In addition, the project will support intellectual exchange between researchers across every career stage focusing on past glacial reconstructions and future projections as well as lower the barrier to entry into polar sciences by developing modular curricula to be delivered in community college classrooms and online learning environments.With hundreds of constraints on deglacial grounding-line retreat and associated ice-surface lowering around Antarctica, the availability of paleo constraints on past ice sheet behavior no longer limits integrating these observations into modeling efforts. This project will integrate paleo-glaciological observations from the Holocene into the BISICLES model framework used to project future sea level. The goals of this project are to (i) establish the conditions that switched the mode of grounding line migration from retreat to re-advance during the mid-to-late Holocene in West Antarctica; (ii) use differences in forcing, geologic conditions, and geographic conditions between responses in the Amundsen Sea and Ross Sea embayments to investigate the differences in marine ice sheet sensitivity between an "unstable" and "stable" sector of the ice sheet; and (iii) apply the findings of (i) and (ii) to improve constraints on future sea-level projections. Investigating the interplay of external forcing, internal forcing, and geological response to ice-mass loss in West Antarctica is essential for reducing uncertainty in future sea-level-rise projections. This project will employ a multidimensional education plan focused on a mentorship structure that promotes intellectual exchange between researchers across every career stage focusing on paleo-glaciological reconstructions and future projections. The project team will co-produce three educational modules with the Colorado School of Mines Trefny Innovative Instruction Center focused on paleo-glaciological reconstruction, modern glaciological observations, and models of future sea-level rise.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.