The magnetic susceptibility recorded millennial-scale variability in central Asia during last glacial and interglacial

Abstract

The abrupt, millennial-scale climatic fluctuations have been identified in a worldwide region. However, it lacks of such record in central Asia which is climatically characterized by arid and sensitive to climate change. Here, we present the results of magnetic analysis of a loess section in Tajikistan which reveals 22 millennial-scale climate oscillations and 5 Heinrich events during the last glacial-interglacial cycle. In particular, millennial-scale climate variations are strongly evidenced for the interval from 50 to 30 ka. The systemic investigation suggests the magnetic enhancement mechanism is same between Tajikistan loess and Chinese Loess Plateau (CLP) loess which are both due to increasing pedogenic fine-grained maghemite and magnetite. In turn, the magnetic results support the climatic variation presents an in-phase pattern between central Asia and Monsoon Asia during last glacial, with humidity increased during interstadials and decreased during stadials. The magnetic records reveal the humidity in central Asia is sensitive to millennial-scale climate oscillations during Last Glacial.