Interdecadal to centennial climate variability surrounding the 8.2 ka
event in Beijing revealed through speleothem record
Abstract
The 8.2 ka event has been extensively studied, whereas its structure is
ambiguous in North China. Here we present a high-resolution
(~1 year) δ18O record of annual laminated speleothem
from Beijing to characterize the detailed variability across this event
in North China. Our record indicates a dry 8.2 ka event spanning
8.254‒8.107 ka BP with a two-stage structure superimposed by three
prominent positive excursions. The identical structure of speleothem
δ18O records between North and central China during the event suggests a
common forcing/response in East China, whereas the progressively
increased offset between their average values may reflect changes in
moisture source or rainout effect. A close comparison with the Greenland
ice core records suggest a strong linear response of the Asian summer
monsoon to the North Atlantic climate changes across the early and
middle stages of the event, but a different mechanism in the termination
process.