![]() One is a fully-coupled version which uses a T31 spectral dynamical core for the atmospheric (Community Atmosphere Model version 4, CAM4 25) and land (Community Land Model version 4, CLM4 26) components (horizontal grid of 3.75° × 3.75°) with 26 atmospheric layers in the vertical. Two versions of the CESM1.2.2 are used in this study. The fully coupled CESM has been successfully implemented for simulating past and modern climates 17, 18, 19, 20, 21, 22, 23, 24. The CESM1.2.2 is a coupled climate model that consists of atmosphere, ocean, land, sea-ice and river components, which are linked through a coupler that interacts and exchanges state information and fluxes among the components 16. It can be referenced and cross validated by research fields across geology, paleobiology, geochemistry, etc. It offers elaborate global distributions of monthly surface temperatures and precipitation throughout the Phanerozoic Eon. The dataset has a high resolution of 0.9° × 1.25° in latitude and longitude. Here, we perform 55 snapshot simulations for the Phanerozoic Eon with a time interval of 10 Myr, using the Community Earth System Model version 1.2.2 (CESM1.2.2). 15 conducted 109 time-slice simulations that cover the entire Phanerozoic, using a coupled atmosphere–ocean–vegetation model. The Bristol Research Initiative for the Dynamic Global Environment (BRIDGE) group at University of Bristol has produced large datasets of paleoclimate simulations 12, 13, 14. 11 performed 40 time-slice simulations for the period from 255 million years ago (Ma) to 60 Ma, using the CLIMBER-3α Earth System Model of Intermediate Complexity (EMIC) that has a relatively coarse spatial resolution. ![]() To our knowledge, there have been few simulation studies covering the whole Phanerozoic Eon. Paleoclimate simulations for a long span of time are computationally expensive and time-consuming. It not only makes up the defects of proxy records but also can be used to check the reliability of proxies. Especially, climate models are able to generate global distributions of climate variables with rather fine spatial resolution, and climate variables are self-constrained by dynamical, physical and chemical processes in climate models. Alternatively, climate models are a useful tool to simulate paleoclimates. ![]() For example, only climatic zonation has been inferred from compilations of lithologic climate indicators, such as coals and evaporites in the Phanerozoic Eon 5, 7, 8, 9, 10. However, due to unavoidable uncertainties of proxy records, sparse records with limited spatial coverage, and the fact that many proxies may respond to multiple climatic variables or even non-linear combinations of variables 6, it is far from adequate for proxy records to provide global climate patterns. It is acknowledged that proxy records provide precious evidence for paleoclimate studies. The classical feature of Phanerozoic climate history is the “double hump” temperature variations 2, 3, 4, with warm climate in the Early Paleozoic, cooler climate in the Late Paleozoic, followed by warmer climate in the Mesozoic and Early Cenozoic and cooler climate in the Late Cenozoic 5. Climate states over the Phanerozoic Eon consist of alternating warm and cool intervals. The Phanerozoic Eon, comprising the Paleozoic, Mesozoic, and Cenozoic Eras, covers the last 542 million years (Myr) of Earth’s history, which is about 12% of the history of our planet 1. This open access climate dataset is useful for multidisciplinary research, such as paleoclimate, geology, geochemistry, and paleontology. ![]() The climate simulation dataset includes global distributions of monthly surface temperatures and precipitation, with a 1° horizontal resolution of 0.9° × 1.25° in latitude and longitude. Here we perform 55 snapshot simulations for the past 540 million years, with a 10-million-year interval, using the Community Earth System Model version 1.2.2 (CESM1.2.2). Apart from observational paleoclimate proxy datasets, climate simulations provide an alternative approach to investigate past climate conditions of the Earth, especially for long time span in the deep past. Only by studying climate changes in the past can we understand the driving mechanisms for climate changes in the future and make reliable climate projections. Therefore, the evolution of the climate system in this Eon is worthy of extensive research. The Phanerozoic Eon has witnessed considerable changes in the climate system as well as abundant animals and plant life. ![]()
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