Millennial-scale climate oscillations inferred from visible spectroscopy of a sediment core in Qarhan Salt Lake of Qaidam Basin between 40 and 10 cal ka BP

Little information about millennial-scale change is known in large extremely arid area of northwest China, which is less influenced by the Asian monsoon than regions to the southeast. Visible spectroscopy of a 35 m long core taken from the Qarhan Salt Lake is used to reconstruct humidity changes of Qaidam Basin between 40 and 10 cal ka BP. High redness values (low brightness values) reflect moist climates, whereas low redness values (high brightness values) indicate dry climates. On millennial-scale, Qaidam Basin was relatively wet during the Younger Dryas and Heinrich H1-H4 events. Dry periods appear to have occurred at nearly the same time as warm periods in the North Atlantic region. These millennial-scale climate oscillations in Qaidam Basin are different from those in Asian monsoon regions that show a relatively dry climate during the occurrence of the Younger Dryas and Heinrich H1-H4 events. Our data indicate that the cooling of the North Atlantic caused a downstream cooling of the atmosphere by westerly jet and influenced the climate in Qaidam Basin.