Using Ice Cores and Gaussian Process Emulation to Recover Changes in the Greenland Ice Sheet During the Holocene

The shape and extent of the Greenland Ice Sheet (GIS) during the Holocene remain a matter of considerable debate, with existing studies proposing a wide range of reconstructions. In this study, we aim to combine stable water isotopic information from ice cores with outputs from isotope-enabled climate models to investigate this problem. Directly exploring the space of possible ice sheet geometries through numerical simulations is computationally prohibitive. To address this challenge, we plan to develop a Gaussian process emulator that will serve as a statistical surrogate for the full climate model. The emulator will be trained on the results of a limited number of carefully designed simulations and will be used to enable fast, probabilistic predictions of model outputs at untried inputs. The inputs will consist of GIS morphologies, parameterized using a dimension-reduction technique adapted to the spherical geometry of the ice sheet. Using predictions from the emulator, we will explore the range of ice sheet morphologies that are compatible with available ice-core isotope measurements and other complementary observational data, including those collected during recent KANG-GLAC expeditions, with the goal of ultimately reducing uncertainty in reconstructions of Holocene GIS morphology.