Possible link between Holocene East Asian monsoon and solar activity obtained from the EMD method
- College of Geography Science, Nanjing Normal University, Nanjing, 210046, China
Abstract. It is thought that East Asian monsoon (EAM) is linked and sensitive to solar activity. In this paper, we have decomposed the Dongge cave speleothem δ18O record (proxy for EAM), and Δ14C and 10Be (proxies for solar activity) time series into variations at different time scales with the empirical mode decomposition (EMD) method to reveal the possible link between the EAM variability and solar activity. There are some common cycles in the EAM and solar variability from centennial to millennial scales, indicating a possible link between EAM and solar activity at these time scales. The correlation between EAM and solar activity is much higher at millennial scales than at centennial scales, which means direct responses to the solar variation are more likely at time scales longer than a few hundred years. At ~30, 60 and 600 yr time scales, the variation in EAM is amplified by the solar amplitude modulation at ~100, 200 and 2200 yr time scales.