Multi-scale analysis of the Asian Monsoon change in the last millennium

Abstract. The change rule and the driving mechanism of the Asian monsoon (AM) is widely concerned. In this paper, we have decomposed the Huangye cave δ¹⁸O_R datasets (proxy for AM) into variations at different time scales with the Ensemble Empirical Mode Decomposition (EEMD) method, obtained the main cycles of the Asian monsoon changes and drought and wet periods in the last millennial history, analysed and predicted the precipitation trend at the local site in the future. Meantime, we have also decomposed ¹⁰Be (proxy for solar activity) and average Northern Hemisphere Temperature (NHT) datasets with the EEMD method. The relationship among the components of δ¹⁸O_R, ¹⁰Be and NHT shows that NHT as well as solar activity has the obvious driving effect on the AM at millennial scales, and NHT with the frequency and amplitude modulations can influence the intensity of the AM more directly and obviously than the solar activity in the last 1000 years.