Continental-Hemispheric Scale Dust Events Driven by Last Glacial Alpine Ice Sheet Dynamics

Greenland ice cores demonstrate that transient last glacial cold climate events (stadials) were associated with greatly enhanced atmospheric dust loading. Detailed radiocarbon dating of loess in central Europe reveals concurrent increases in dust activity in dust-emitting regions. However, the causes of these changes in dust emission and the role of dust in rapid climate change remain unclear. We address this uncertainty through multi-proxy analysis of loess sources in Hungary. Our results demonstrate that loess particles were dominantly produced by subglacial grinding processes in the eastern Alps. These particles were released along with stadial Alpine Ice Sheet-driven meltwater pulses, turning major river systems into efficient dust sources for loess deposition in Europe. Concurrent strengthened anticyclonic circulation over northern Europe would have caused wider dispersal of Alpine Ice Sheet-derived dust as far as Greenland. Resultant continental-hemispheric scale changes in atmospheric dust loading likely amplified concomitant North Atlantic climate cooling and ice sheet decay during Greenland stadials.