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

南极冰盖的形状或大小并不总是相同的，过去的变化留下了冰质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的反应与气候趋势一致，但这种退缩的细节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相互作用的错综复杂的问题。要从我们这一代冰盖模型中可信地预测南极对海平面变化的贡献，这一挑战取决于准确地再现过去的变化。该项目旨在将从南极冰盖周围、上方和下方收集的对过去冰盖行为的存档限制与最先进的冰盖模型合并，以改进对未来海平面上升的预测。此外，该项目将支持各个职业阶段的研究人员之间的智力交流，重点放在过去的冰川重建和未来预测上，并通过开发将在社区大学课堂和在线学习环境中教授的模块课程来降低进入极地科学的门槛。由于南极洲周围对去冰川接地线后退和相关冰面下降的数百个限制，对过去冰盖行为的古限制不再限制将这些观测纳入建模工作。该项目将把全新世以来的古冰川观测纳入用于预测未来海平面的BISICLES模型框架。该项目的目标是：(1)建立在西南极全新世中晚期将接地线迁移模式从后退转变为重新推进的条件；(2)利用阿蒙森海和罗斯海海湾反应之间在强迫、地质条件和地理条件方面的差异，调查冰盖“不稳定”和“稳定”部分之间海洋冰盖敏感性的差异；(3)应用(1)和(2)的结果，改善对未来海平面预测的限制。研究南极洲西部冰块减少的外力、内力和地质响应之间的相互作用，对于减少未来海平面上升预测的不确定性至关重要。该项目将采用一个多层面的教育计划，重点是导师结构，促进研究人员在每个职业阶段之间进行智力交流，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特雷弗尼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优势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.