Paleoclimatic modulation of high- and low-latitude signals in mid-latitude Asian loess since the late Pleistocene

According to Milankovitch theory, changes in summer insolation at high northern latitudes are the primary driver of Quaternary climate cycles. However, the significance of low-latitude forcing is less clear. We report a paleoclimate record from a new loess section (BYH) in arid Central Asia, which we integrate with other paleoclimate records from the westerly and monsoon regions of mid-latitude Asia. Geological records and climate simulations both indicate that climate variability at our sites exhibited different sensitivities to high- and low-latitude forcing across glacial-interglacial cycles. Heinrich events significantly influenced Asian dust emissions via wind modulation by the westerlies and the Siberian High since 120 ka. This study reports for the first time a half-precession (12–9 ka) moisture signal in Central Asian loess deposits, which exhibits higher amplitudes during interglacials and lower amplitudes during glacials. We propose that this half-precession moisture signal in mid-latitude Asian loess records reflects moisture variations at time of maximum equatorial insolation. These variations induce changes in western equatorial Pacific sea surface temperature, which are propagated through southeastern atmospheric pathways. These findings demonstrate the combined effects of both high- and low-latitude systems on climate change in mid-latitude Asia, and they emphasize the significance of the low-latitude forcing of Quaternary climatic variability in this region.