Collaborative Research: P2C2 -- Statistical estimation of past ice sheet volumes from paleo-sea level records

研究所建议建立一个统计模型，从当地海平面变化的地质指标中推断过去的平均全球海平面和冰盖体积。该模型将采用贝叶斯统计框架，将联合收割机地质观测及其不确定性与不同融水源相关的空间和时间海平面模式的地球物理模型相结合。这项工作的重点是三个具体的应用：（1）评估不同的冰盖在末次间冰期（~ 13万-11.5万年前）期间对高GSL的贡献;（2）评估从末次盛冰期（LGM）到现在的冰盖历史，特别是估算这段时间内的净冰量变化，并评估劳伦蒂德冰和南极冰的相对贡献（3）在第四纪和上新世更广泛的范围内，研究北方和南半球冰量与古气候代用指标之间的关系，过去冰盖对气候变化响应的地质记录可以作为检验不同气候情景下冰盖动力学正演物理模型的关键数据源。本项目开发的模型将努力综合这一数据集，评估其相关的不确定性，并利用它来加强对关键气候参数（如极地和环极地温度）与冰盖稳定性之间关系的理解。

The PIs propose to develop a statistical model for inferring past mean global sea level (GSL) and ice sheet volumes from geological indicators of changes in local sea levels. This model will employ a Bayesian statistical framework to combine geological observations and their uncertainties with a geophysical model of the spatial and temporal sea level patterns associated with different meltwater sources. The proposed work focuses on three specific applications: (1) evaluating the contribution of different ice sheets to high GSL during the Last Interglacial stage, ~130-115 thousand years ago; (2) assessing ice sheet history from the Last Glacial Maximum (LGM) to the present, in particular estimating the net ice volume change across this time interval and assessing the relative contributions of the Laurentide and Antarctic ice sheets to meltwater pulse 1a at ~14.3 thousand years ago; and (3) over a broader sweep of the Quaternary and Pliocene, investigating the relationship between Northern and Southern hemisphere ice volumes and paleoclimate proxies.The geological record of past ice sheet responses to climate change can serve as a key data source for testing forward physical models of ice sheet dynamics under different climate scenarios. The model developed in this project will be an effort to synthesize such a data set, evaluate its associated uncertainties, and employ it to strengthen understanding of the relationship between key climate parameters (such as polar and circum-polar temperatures) and ice sheet stability.