Modulation of inter-hemispheric temperature gradients on the Holocene Asian-Australian summer monsoon

The Asian-Australian monsoon system (A-AuMS) is the most typical cross-equatorial monsoon system and thus inter-hemispheric comparison is essential to explore its dynamics. Although the evolution of Holocene Asian summer monsoon has been extensively studied, changes in Australian summer monsoon (AuSM) is less investigated due to the lack of identified high-resolution paleoclimate records. Here we obtain a 13.5 kyr AuSM record from lacustrine sediments in northeastern Australia. It suggests that the weakening of the AuSM during the early to middle Holocene was regulated by Northern Hemisphere high-latitude ice volume, while the strengthening of the AuSM during the middle to late Holocene was mainly controlled by increased Southern Hemisphere summer insolation. The combination of Asian and Australian monsoon records show that the coupling evolution of A-AuMS was dominated by the temperature gradient between two hemispheres, which involve the changes of the AMOC, Northern Hemisphere ice volumes and solar insolation in both hemispheres.