Local Insolation Drives Afro-Asian Monsoon at Orbital-Scale in Holocene

Insolation changes play an important role in driving monsoon changes at orbital time scales. One key issue that has remained outstanding is whether the Asian monsoon is driven by local insolation from the Northern Hemisphere (NH) or remote insolation from the Southern Hemisphere (SH) at orbital band. Here, we perform a set of sensitivity experiments to quantify the impacts of local and remote insolation changes on the Afro-Asian summer monsoon at 11 ka BP relative to the present. We show that the Afro-Asian summer monsoon is overwhelmingly driven by the precession induced local insolation change in the tropical-subtropical NH. The insolation from NH high latitudes also affects the Afro-Asian summer monsoon. In contrast, the insolation from SH plays a negligible role. Our model experiments support the idea that the Afro-Asian summer monsoon are driven predominantly by the direct forcing of NH low latitudes summer insolation for the Holocene.