Data-model comparison of the Younger Dryas event

Abstract

The Younger Dryas cooling event is well established in the North Atlantic region through numerous climate proxy records. Although the climatological controls vary from site to site, it is considered to have taken place between about 10 000 and 11 000 BP (radiocarbon years) (~11 500-13 000 calendar years ago). Outside the North Atlantic region, climate proxy records and chronology commonly become problematic because of weaker signals and less dating control. In addition to this evidence, oceanic records reveal conflicting evidence for Younger Dryas forcing mechanisms and the timing of events. We compare proxy evidence with the results from an ocean general circulation model coupled to the energy-moisture balance atmospheric model. The model results reveal a global pattern and regional magnitude which generally agree with temperature changes interpreted from paleoclimate reconstructions. The model also supports the general duration of global cooling of the Younger Dryas. Although proxy data can be controversial outside of the North Atlantic region, the authors believe that there is enough evidence to support the Younger Dryas event on a global scale. They also recognize, however, that more concrete evidence is needed before the question can be unequivocally answered.