Year: 2024
Type: article
Abstract: The stratospheric polar vortex (SPV) significantly influences current weather and climate patterns. However, its state in the geological past remains largely unexplored. This study investigates SPV variations in the past 250 million years, using a fully coupled Earth System Model. It is found that midlatitude paleogeography primarily drove substantial SPV variations in the deep time, while changes in CO2 concentrations and solar insolation play a minor role. Both the Arctic and Antarctic SPV were strengthened when the supercontinent Pangea broke up. The increased asymmetry of midlatitude land‐sea contrast tended to weaken the upward propagation of wavenumber‐1 planetary waves, thereby strengthening the SPV. This SPV strengthening correlated with the decelerated stratospheric Brewer‐Dobson circulation and uplift of the polar tropopause. Our results highlight the crucial role of paleogeography in regulating SPV variations and stratosphere–troposphere coupling in deep‐time climate.
Source: Geophysical Research Letters
DOI: 10.1029/2024gl111251
Language: English
Subfield: Global and Planetary Change
Field: Environmental Science
Domain: Physical Sciences
SDG: Climate action
Open Access status: gold
Estimated APC paid: $2,900
Awards: G2412347888, G3868355205, G6489415602
OpenAlex ID: W4402634223