Abrupt cooling event over Asia due to North Atlantic climate instability ~16 ka

The last glacial termination was marked by a series of millennial-scale hemispheric climate change events. One of the most prominent examples is Heinrich event  1, which was caused by ice-sheet instabilities of the Laurentide ice-sheet between 18,000-15,000 years ago (ka) and corresponding shifts in global climate. Recent speleothem oxygen isotope data suggest the presence of yet another much more abrupt and shorter event around 16 ka.  The global extent and the origin of this elusive 16-ka event have remained a mystery. Here we present new resolution clumped isotope data from a South Korean speleothem that shed new light on this phenomenon. Combined with LA-ICPMS trace element analysis, we demonstrate that the 16-ka event likely caused abrupt cooling over Eastern Asia of ~5-7^oC and massive shifts of both the winter and summer monsoon systems.  Using an isotope-enable earth system model, we show the observed oxygen isotope evolution is consistent with an abrupt meltwater lake surge into the North Atlantic, of unknown origin, with impacts on ocean stratification, sea-ice and northern hemispheric climate.