Simulation Of Climate Across the Permian-Triassic Boundary with a Focus on Phytogeographical Data Analysis
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Date
2018-12-06Author
Gautam, Mitali Dinesh
0000-0001-5357-7506
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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.