Detection of abrupt changes in East Asian monsoon from Chinese loess and speleothem records

Abrupt climate changes, especially at millennial timescales, have become a key topic in paleoclimatology because of their link with the tipping point theory and extensive impacts on future scenarios. Although best documented ice-cores marine sediments, they are also recorded different archives land, among which Chinese loess speleothem records particular interest. These effectively document orbital-to-millennial monsoon variability during Pleistocene, but dominant periodicity revealed by proxy from these two types is different. Nevertheless, millennial-scale oscillations seem highly similar over last several glacial cycles. Such fluctuations can be varying amplitudes, either more or less abrupt depending type record. The observed abruptness usually depends sedimentation rates sampling resolution records. However, it refined comparisons multiple physicochemical isotopic proxies. Here, we apply robust statistical method to detect changes grain size δ18O As first step, compared reference (i.e. NGRIP ice-core Hulu records) change verify robustness our detecting well-recognized events glaciation. This result allows us, second compare high-resolution grain-size stacks CHILOMOS, LGS640 datasets) composite record built Sanbao visually rapid variations were previously interpreted as representing variations, analysis confirms that whether robustly identified dependent time studied In third detected transitions MGSQ stack, covering 3.6 Myrs. Our results show both winter summer monsoons co-varied glacial-interglacial reflecting three-stage evolution increasing intensity: (1) Ma 2.6 Ma, (2) 1.2 (3) present. finally employed for synchronizing global scale.