Ice Volume and Insolation Forcing of Abrupt Strengthening of East Asian Winter Monsoon During Glacial Inceptions

It is generally accepted that the glacial-interglacial variations of the East Asian winter monsoon (EAWM) are controlled by the volume of the Northern Hemisphere ice sheets (NHIS), but the fact that they exhibit different evolution patterns during glacial inceptions is often overlooked. By generating an independent chronology framework and integrating multi-proxy records from the loess sections on the central Chinese Loess Plateau, here we show that the rapid intensifying of the EAWM during glacial inceptions reflects millennial perturbations in the large-scale atmospheric circulation in East Asia in response to insolation-triggered abrupt North Atlantic cooling. This climate teleconnection between North Atlantic and East Asia is found to be particularly effective only when the NHIS reaches a critical large size. Our integrated multi-proxy records thus highlight the key role of ice volume in modulating the response of the EAWM to insolation-triggered North Atlantic cooling during the interglacial-glacial transitions.

Automated summary

By integrating multi-proxy records from the loess sections on the central Chinese Loess Plateau, we find that the intensification of the East Asian winter monsoon during glacial inceptions is associated with millennial perturbations in the atmospheric circulation in response to abrupt North Atlantic cooling triggered by insolation. This climate teleconnection between the North Atlantic and East Asia is particularly effective when the Northern Hemisphere ice sheets reach a critical size.