Reconciling persistent sub-zero temperatures in the McMurdo Dry Valleys, Antarctica, with Neogene dynamic marine ice-sheet fluctuations

Abstract In the Ross Sea sector of Antarctica, periodic large-scale marine ice-sheet fluctuations since mid-Miocene are recorded by drill core and seismic data, revealing a dynamic response to past increases in temperature atmospheric CO2. adjacent, predominantly ice-free McMurdo Dry Valleys (MDVs), preserved terrestrial landscapes reflect persistent cold conditions have been interpreted as indicators stable polar ice sheet, implying that Antarctic Ice Sheet was largely insensitive during warm periods. These disparate data-based perspectives highlight long-standing debate around stability Sheet, with direct implications for future ongoing climate warming. We reconcile records behavior episodic open-marine nearby ancient recording consistent cold-polar conditions. Coupled regional models nested at high resolution used investigate surface temperatures MDVs find high-elevation regions remain below freezing even when prevail Sea. compare observed spatial extent modeled required preservation these features, demonstrating frozen could coexisted receded or collapsed sheets