EGU2020-9074
https://doi.org/10.5194/egusphere-egu2020-9074
EGU General Assembly 2020
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

Exploring Mesozoic Climates - Modeling and Evaluation of Proxy Distributions

Jan Landwehrs1,2, Georg Feulner2, Matthias Hofmann2, Stefan Petri2, Benjamin Sames1, and Michael Wagreich1
Jan Landwehrs et al.
  • 1University of Vienna, Department of Geodynamics and Sedimentology, Wien, Austria (jan.landwehrs@univie.ac.at)
  • 2Potsdam Institute for Climate Impact Research, Earth System Analysis, Potsdam, Germany

The Mesozoic Era (~252-66 Ma) is a decisive period in Earth’s history. It is marked by a tectonic transition from the Pangea supercontinent towards a modern continental configuration as well as the ecological success of the dinosaurs and the evolution of mammals, flowering plants, stony corals and important groups of planktic calcifiers. The Mesozoic is generally considered as a greenhouse climate period, with especially high global temperatures during the Triassic and the Late Cretaceous. Here, we present novel modeling results on the evolution of global climatic conditions through the Mesozoic.

An ensemble of equilibrium climate states for 40 geological timeslices between 255 and 60 Ma is simulated with the CLIMBER-3α Earth System Model of Intermediate Complexity. The influence of changing paleogeography, sea level, vegetation cover, solar luminosity, orbital configuration and atmospheric CO2 concentration is systematically tested based on constraints from published geological proxy reconstructions and previous modeling work.

Atmospheric pCO2 is found to be the strongest driver of global mean temperatures, which are generally elevated above the present and reach 20°C in the Late Triassic to Early Jurassic and the mid-Cretaceous if a recently published pCO2 proxy compilation is employed. The simulated seasonal latitudinal shift of high precipitation zones exhibits a maximum during the mid-Triassic to Early Jurassic and therefore supports the notion of a “Megamonsoon” during this time. Simulated humid and arid climate zones generally agree well with spatial distributions of geologic climate indicators like coal and evaporites, although some discrepancies exist. The same applies to the correlation of fossil stony coral reef distributions with regions where seawater temperatures would have been suitable for (modern) coral reefs. We will discuss which changes of Earth System parameters throughout the Mesozoic can best explain shifts in these distributions.

How to cite: Landwehrs, J., Feulner, G., Hofmann, M., Petri, S., Sames, B., and Wagreich, M.: Exploring Mesozoic Climates - Modeling and Evaluation of Proxy Distributions, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-9074, https://doi.org/10.5194/egusphere-egu2020-9074, 2020

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