Precipitation in eastern China over the past millennium varied with large-scale climate patterns

Abstract

Modern precipitation variability over East China is known to be characterized by meridional tripole and dipole structures, linked to atmosphere and ocean dynamics. As the instrumental data may be influenced by anthropogenic global warming, it is unclear whether the physical mechanism underlying the tripole and dipole pattern have remained constant since the pre-industrial period. Here we investigate spatiotemporal precipitation variability over the past 1150 years using three high-resolution stalagmite δ18O records from southern, central and northern China. Principal component analysis results suggest that the first principal component, reflecting large-scale Asian monsoon strength, is closely linked to solar variability. The second and third principal components, which reflect rainfall, reveal tripole and dipole patterns that persist over the last millennium and are driven by the Pacific Decadal Oscillation (PDO) and Atlantic Multidecadal Oscillation (AMO). We find that interactions between the monsoon, PDO, and AMO influence spatiotemporal rainfall patterns in East China.