The middle to late Holocene (8,200 years ago to present) in the Arctic is characterized by cooling temperatures and the regrowth and advance of glaciers. Whether this Neoglaciation was a threshold response to linear cooling, or was driven by a regional or Arctic-wide acceleration of cooling, is unknown. Here we examine the largest-yet-compiled multiproxy database of Arctic Holocene temperature change, along with model simulations, to investigate regional and Arctic-wide increases in cooling rate, the synchronicity of Neoglacial onset, and the observed and simulated rates of temperature change. We find little support for an Arctic-wide onset of Neoglacial cooling but do find intervals when regions experienced rapid increases in long-term cooling rate, both in the observations and in climate model simulations. In the model experiments, Neoglacial cooling is associated with indirectly forced millennial-scale variability in meridional heat transport superposed on the long-term decline of summer insolation.
ASJC Scopus subject areas
- Earth and Planetary Sciences(all)