Asynchronous 500-year summer monsoon rainfall cycles between Northeast and Central China during the Holocene

Abstract

Although the summer monsoon is the dominant source of precipitation in the East Asian monsoon region (EAMR), there is long-standing uncertainty about the spatial and temporal variability of precipitation on the centennial time scale. In this study we analyzed two well-dated, high-resolution, published paleoclimatic records in order to determine the variability of precipitation in the EAMR during the Holocene. One record is a decadal-resolution pollen record from an annually-laminated Maar lake in Northeast (NE) China, and the other is a U Th dated, multi-decadal-resolution speleothem record from Central China. Advanced time-series analysis of the two records provides unambiguous evidence for asynchronous summer monsoon rainfall variability on centennial to millennial time scales in the EAMR. The pollen and speleothem records indicate long-term and ~ 500-yr quasi-periodic changes in humid/dry climatic shifts against the background of an insolation-forced climatic trend throughout the past 8580 years. Phases of wetter climate (during ~7000–5500 cal yr BP) and drier climate (during ~1400–300 cal yr BP) in NE China are closely related to different climatic phases in Central China. However, the ~500-yr cyclic rainfall changes in Central China lag those in NE China by several decades to almost two centuries. During the ~500-yr periodic changes in the monsoon, a climatic pattern encapsulated as “Northern drought, southern flooding” prevailed during an El Niño-like phase, whereas the opposite pattern “Southern drought, northern flooding” occurred during a La Niña-like phase. The asynchronous pattern of ~500-yr climatic cyclicity between the northern and southern EAMR may have been caused by the El Niño-Southern Oscillation, linked to low-latitude oceanic and atmospheric interactions. • Holocene rainfall changes between Northeast and Central China are asynchronous. • 500-year cyclic rainfall changes in Central China lag those in Northeast China. • The lag of the 500-year rainfall cycles is several decades to almost two centuries. • Rainfall changes in Northeast and Central China are anti-phased on the millennial scale.