Using Antarctica's response in the mid-Pliocene warm period to understand uncertainties about long-term future sea level rise

海平面上升对沿海人口和生态系统构成生存威胁。南极冰盖对气候变化的反应是未来海平面预测中最不确定的。研究这些不确定性的主要工具是通过使用冰盖模型来模拟不同排放情景下的冰盖演变。然而，到目前为止，大多数建模工作都集中在本世纪末的预测上。已经对南极冰盖进行了数千年模拟的模型，要么都在模型复杂性上妥协，要么使用的网格分辨率太粗，无法有力地模拟接地线的后退。该项目将使用BISICLES冰盖模型对未来南极冰盖的未来演变进行千年尺度的模拟，该模型使用自适应网格细化来提高接地线的分辨率。直到最近，由于缺乏与这些时间尺度相关的固体地球过程，BISICLES还无法进行数千年的模拟。该项目将在以前工作的基础上进行扩展，该工作将这些过程添加到BISICLES中，并用它来模拟南极冰盖在中上新世暖期的演化。它将利用上新世的信息来限制未来海平面的上升。然后，它将使用统计模型模拟BISICLES，以更深入地探索未来海平面预测中的不确定性，产生到2300年和几千年后海平面的完全概率分布。

Sea level rise represents an existential threat to coastal populations and ecosystems. The response of the Antarctic ice sheet to climate change is the highest uncertainty in future sea level projections. The primary vehicle for studying these uncertainties is through the use of ice sheet models to simulate ice sheet evolution under different emission scenarios. However, the majority of modelling efforts to date have focused on end of the century projections. Models that have run multi-millennial simulations of the Antarctic ice sheet all either compromise on model complexity or use a grid resolution that is too coarse to robustly model grounding line retreat. This project will conduct millennial-scale simulations of future Antarctic ice sheet evolution using the BISICLES ice sheet model, which uses Adaptive Mesh Refinement to improve resolution at the grounding line. Until recently, BISICLES was incapable of conducting multi-millennial simulations due to lacking the solid Earth processes that become relevant on these timescales. This project will expand on previous work, which added these processes to BISICLES and used it to simulate Antarctic ice sheet evolution during the Mid-Pliocene Warm Period. It will use information from the Pliocene to put constraints on future sea level rise. It will then emulate BISICLES using a statistical model to explore the uncertainties in future sea level projections in more depth, producing full probabilitydistributions for sea level by 2300 and after multiple millennia.