A Library of Large-Eddy Simulations Forced by Global Climate Models
Advances in high-performance computing have enabled large-eddy simulations (LES) of turbulence, convection, and clouds. However, their potential to improve parameterizations in global climate models (GCMs) is only beginning to be harnessed, with relatively few canonical LES available so far. The purpose of this paper is to begin creating a public LES library that expands the training data available for calibrating and evaluating GCM parameterizations. To do so, we use an experimental setup in which LES are driven by large-scale forcings from GCMs, which in principle can be used at any location, any time of year, and in any climate state. We use this setup to create a library of LES of clouds across the tropics and subtropics, in the present and in a warmer climate, with a focus on the transition from stratocumulus to shallow cumulus over the East Pacific. The LES results are relatively insensitive to the choice of host GCM driving the LES. Driven with large-scale forcing under global warming, the LES simulate a positive but weak shortwave cloud feedback, adding to the accumulating evidence that low clouds amplify global warming.
© 2022 The Authors. Journal of Advances in Modeling Earth Systems published by Wiley Periodicals LLC on behalf of American Geophysical Union. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made. Issue Online: 16 March 2022; Version of Record online: 16 March 2022; Accepted manuscript online: 09 March 2022; Manuscript accepted: 07 March 2022; Manuscript revised: 03 March 2022; Manuscript received: 20 May 2021. We thank Yassine Tissaoui and Simone Marras for helpful discussion. We gratefully acknowledge the generous support of Eric and Wendy Schmidt (by recommendation of Schmidt Futures), the Audi Environmental Foundation, Heising-Simons Foundation, and the National Science Foundation (grant AGS-1835860). The simulations were performed on Caltech's High Performance Cluster, which is partially supported by a grant from the Gordon and Betty Moore Foundation. Part of this research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration. Data Availability Statement: CMIP5 data can be accessed at https://esgf-node.llnl.gov/projects/cmip5/. The LES codes are available online at https://zenodo.org/record/6326276. The LES library is available online at https://data.caltech.edu/records/20052 (Shen, 2022).
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