Lacustrine record from the eastern Tibetan Plateau associated with Asian summer monsoon changes over the past ~ 6 ka and its links with solar and ENSO activity

Abstract

A multi-parameter, absolute-dated lacustrine record from the eastern Tibetan Plateau provides a continuous history of the Asian summer monsoon (ASM) over the past ~ 6000 years. The record broadly follows the trend in northern hemisphere summer insolation. However, it diverges during a period of increased moisture and thermal conditions during the past ~ 1300 years, broadly corresponding to the ASM “2-kyr shift”. This shift as referred by Cheng et al. (Nature 534:640–646, 10.1038/nature18591, 2016) may be related to Atlantic Meridional Overturning Circulation variations, and potentially to increased forcing by greenhouse gases coincident with reduced ENSO activity. The record is punctuated by several weak monsoon intervals. Cross-correlation of the sub-millennial-scale monsoon record with solar activity and ENSO records shows that most of the monsoon variability potentially results from changes in solar irradiation, and has a strong teleconnection with ENSO activity.