FASB 295. To attend via Zoom, register at https://utah.zoom.us/meeting/register/tJUrceirrT0oGdA2sM5lhZq1GylgdHDzqXzc
Jonathon Preece, Department of Geography, University of Georgia
Abstract: The marked acceleration of Greenland Ice Sheet mass loss since the turn of the century has been one of the most visible changes in the climate system. The flux of freshwater storage from Greenland to the surrounding ocean has contributed to sea-level rise at a rate far exceeding that of the Antarctic Ice Sheet and approximately equal to that of all other glaciers combined. Meltwater runoff is currently the leading source of Greenland Ice Sheet mass loss, spurred by a change in atmospheric conditions that has fostered frequent bouts of exceptional surface melt in recent decades. While this increase in melt is ostensibly consistent with an Arctic that has warmed at approximately four times the global average rate, an extensive body of work has shown that a major contributor to the observed surface mass loss has been a pronounced increase in the incidence of anomalous persistent weather patterns, which promote extensive melt of the ice sheet by delivering warm, moist air from lower latitudes. Though there are several hypotheses which argue that amplified warming at high latitudes may encourage more persistent atmospheric circulation patterns, it is unclear whether this relatively short-lived circulation trend is a consequence of climate change. Highlighting the interconnected nature of the earth system, this talk presents evidence from both observation-based datasets and prescribed global climate model simulations that the rapid retreat of spring snow cover in a warming climate has favored the atmospheric circulation patterns that have accelerated melt of the Greenland Ice Sheet.
Dr. Preece is a proud alumnus of the University of Utah, where he received his B.S. in Atmospheric Sciences in 2014. He then completed a M.A. in Geography and Water Resources at the University of Wyoming before earning a Ph.D. in Geography at the University of Georgia, where he now works as a Postdoctoral Teaching and Research Associate focusing on interactions between climate and the cryosphere. His research has examined atmospheric controls on precipitation over snowpack-critical headwater basins in the US Rocky Mountains and the bidirectional coupling between the atmosphere and the Arctic cryosphere.