Regional differences in millennial-scale climate variability in northeastern Tibet loess deposits spanning 34 ka to 8 ka

Abstract Paleoclimate reconstructions from East Asian loess records are often inconsistent, especially at the junction between the relatively humid East Asia and more arid Central Asia regions. We present two high-resolution paleoclimatic records spanning 34–8 ka from northeastern Tibet (based on grain size, element abundance, and magnetic susceptibility), which have been temporally constrained using optically stimulated luminescence dating. Both records, from sites <200 km apart, demonstrate a significant climate shift at ca. 15 ka. In the section located farthest south, this shift manifests as an increase in humidity. By contrast, the northernmost section shows a decreasing trend in effective humidity at ca. 15 ka. The differences between these records demonstrates how regional factors can lead to marked differences in reconstructed paleoclimate in loess records. Our work additionally reveals millennial-scale signals recorded in northeastern Tibet loess deposits, and that these signals reflect a nonlinear response of the East Asian summer monsoon to insolation and other climatic components (e.g., the North Atlantic system).