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Using Ice Cores and Gaussian Process Emulation to Recover Changes in the Greenland Ice Sheet During the Last Interglacial
Author(s) -
Domingo Dario,
MalmiercaVallet Irene,
Sime Louise,
Voss Jochen,
Capron Emilie
Publication year - 2020
Publication title -
journal of geophysical research: earth surface
Language(s) - English
Resource type - Journals
eISSN - 2169-9011
pISSN - 2169-9003
DOI - 10.1029/2019jf005237
Subject(s) - greenland ice sheet , ice core , ice sheet , ice sheet model , gaussian process , parameterized complexity , emulation , geology , climate model , range (aeronautics) , computer science , climatology , environmental science , gaussian , climate change , algorithm , cryosphere , ice stream , sea ice , geomorphology , engineering , aerospace engineering , physics , quantum mechanics , economic growth , economics , oceanography
The shape and extent of the Greenland Ice Sheet (GIS) during the Last Interglacial (LIG) is a matter of controversy, with different studies proposing a wide range of reconstructions. Here, for the first time, we combine stable water isotopic information from ice cores with isotope‐enabled climate model outputs to investigate the problem. Exploring the space of possible ice sheet geometries by simulation is prohibitively expensive. We address this problem by using a Gaussian process emulator as a statistical surrogate of the full climate model. The emulator is calibrated using the results of a small number of carefully chosen simulations and then permits fast, probabilistic predictions of the simulator outputs at untried inputs. The inputs are GIS morphologies, parameterized through a dimension‐reduction technique adapted to the spherical geometry of the setting. Based on the emulator predictions, the characteristics of morphologies compatible with the available ice core measurements are explored, leading to a reduction in uncertainty on the LIG GIS morphology. Moreover, a scenario‐based approach allows to assess the gains in uncertainty reduction which would result from the availability of better dated LIG measurements in Greenland ice cores.