Multi-fidelity experimental design for ice-sheet simulation

Pierre Thodoroff, Markus Kaiser, Rosie Williams, Robert Arthern, Scott Hosking, Neil D. Lawrence, James Byrne, Ieva Kazlauskaite
, 2023.

Abstract

Computer simulations are becoming an essential tool in many scientific fields from molecular dynamics to aeronautics. In glaciology, future predictions of sea level change require input from ice sheet models. Due to uncertainties in the forcings and the parameter choices for such models, many different realisations of the model are needed in order to produce probabilistic forecasts of sea level change. For these reasons, producing robust probabilistic forecasts from an ensemble of model simulations over regions of interest can be extremely expensive for many ice sheet models. Multi-fidelity experimental design (MFED) is a strategy that models the high-fidelity output of the simulator by combining information from various resolutions in an attempt to minimize the computational costs of the process and maximize the accuracy of the posterior. In this paper, we present an application of MFED to an ice-sheet simulator and demonstrate potential computational savings by modelling the relationship between spatial resolutions. We also analyze the behavior of MFED strategies using theoretical results from sub-modular maximization.