ORCID Identifier(s)

0000-0001-5357-7506

Graduation Semester and Year

2018

Language

English

Document Type

Thesis

Degree Name

Master of Science in Earth and Environmental Science

Department

Earth and Environmental Sciences

First Advisor

Arne Winguth

Abstract

The present study aims at reconstructing the paleoclimate across the Permian-Triassic Boundary (PTB, 251.9 ± 0.024 Ma) which encompasses one of the major mass extinction events of the Earth’s history. Results are analyzed from sensitivity experiments that have been previously been carried out with a community climate system model (CCSM3) for 4x CO2 higher than the pre-industrial levels of 280 ppmv, 12.7x CO2 and 12.7x CO2 with a lower cloud cover . This study attempts to reconstruct the climate using the floristic patterns derived from plant-fossil data. Finally, simulated biomes are compared with data-derived biomes, in order to validate the amount of radiative forcing needed to reconstruct the climate across the PTB. The climate simulations yield a rise in seasonality in surface temperatures over Pangea with increasing greenhouse gas concentrations. The simulations for precipitation predict large arid continental interiors and mega-monsoonal trends in the tropics. The change in floristic patterns follows the transitions into the extreme climatic conditions. The phytogeographical patterns show a coherence with the simulated climate. The correspondence analysis indicates an association between the genera and localities co-occuring with each other. The discrepancies in the floristic patterns are being discussed. Reconstructed biome are in reasonable agreement with the biome inferred from time-slice climate simulations across the PTB. Consideration of higher model resolution and interactive paleovegetation dynamics in the climate model could lead to a reduction of model-data biases.

Keywords

Permian-Triassic Boundary (PTB), Phytogeographical analysis

Disciplines

Earth Sciences | Physical Sciences and Mathematics

Comments

Degree granted by The University of Texas at Arlington

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