Constraining the Magnitude of Abrupt Changes in Atmospheric Circulation During the Last Glacial Period
Year: 2023
Type: dissertation
Abstract: Water isotopes serve as a useful proxy for past climate conditions at ice core sites and their respective moisture sources. Here we present the application of a novel numerical model to reconstruct absolute surface temperature, condensation temperature, and source-region evaporation temperature for all publicly accessible Greenland ice core records that yield the necessary data. We apply this analysis to the last glacial period, which was punctuated by a series of rapid climate oscillations—records of which are particularly well-defined in Greenland ice cores. Reconstructed moisture source temperatures are deconvolved from paleo- sea surface temperature variability in the Northern Hemisphere Atlantic to derive changes in moisture source latitude during this time. We attribute shifts in moisture source latitude principally to atmospheric variability. We pair this analysis with investigation into other potential forcings on moisture source latitude and find that changes in atmospheric circulation persists as the dominant contributor of variability. Our reconstructions show dynamic shifts in moisture source latitude (up to 20 degrees within a given abrupt climate event), indicative of a significant atmospheric reorganization during the last glaciation. These results provide a framework from which to assess the role of atmospheric circulation during the abrupt climate shifts that marked the last ice age.
Author: Bennett, Hayley I.
Language: English
Subfield: Atmospheric Science
Field: Earth and Planetary Sciences
Domain: Physical Sciences
SDG: Climate action
Open Access status: green
OpenAlex ID: W7036512905