PALEO-PGEM v1.0: a statistical emulator of Pliocene–Pleistocene climate

Resumo

We describe the development of the “Paleoclimate PLASIM-GENIE (Planet Simulator–Grid-Enabled Integrated Earth system model) emulator” PALEO-PGEM and its application to derive a downscaled high-resolution spatiotemporal description of the climate of the last 5 106 years. The 5 106-year time frame is interesting for a range of paleo-environmental questions, not least because it encompasses the evolution of humans. However, the choice of time frame was primarily pragmatic; tectonic changes can be neglected to first order, so that it is reasonable to consider climate forcing restricted to the Earth’s orbital configuration, ice-sheet state, and the concentration of atmosphere CO2. The approach uses the Gaussian process emulation of the singular value decomposition of ensembles of the intermediate-complexity atmosphere–ocean GCM (general circulation model) PLASIM-GENIE. Spatial fields of bioclimatic variables of surface air temperature (warmest and coolest seasons) and precipitation (wettest and driest seasons) are emulated at 1000-year intervals, driven by time series of scalar boundary-condition forcing (CO2, orbit, and ice volume) and assuming the climate is in quasi-equilibrium. Paleoclimate anomalies at climate model resolution are interpolated onto the observed modern climatology to produce a high-resolution spatio-temporal paleoclimate reconstruction of the Pliocene–Pleistocene.

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Citação

HOLDEN, Philip B.; EDWARDS, Neil R.; RANGEL, Thiago F.; PEREIRA, Elisa B.; TRAN, Giang T.; WILKINSON, Richard D. PALEO-PGEM v1.0: a statistical emulator of Pliocene-Pleistocene climate. Geoscientific Model Development Discussions, Munich, v. 12, n. 12, p. 1-26, 2019. DOI: 10.5194/gmd-12-5137-2019. Disponível em: https://gmd.copernicus.org/articles/12/5137/2019. Acesso em: 27 mar. 2023.