Nonlinear coupling between 100 ka periodicity of the paleoclimate records in loess and periodicities of precession and semiprecession  

作　　者：余志伟 丁仲礼 

机构地区：[1]Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China [2]Key Laboratory of Coal Resources, Ministry of Education, China University of Mining and Technology, Beijing 100083, China

出　　处：《Science China Earth Sciences》2003年第10期1077-1087,共11页中国科学（地球科学英文版）

基　　金：the National Natural Science Foundation of China(Grant No.49894170); the Chinese Academy of Sciences(Grant No.KZCX2-SW-118).

摘　　要：In this paper, we use the automatic orbital tuning method to establishthe time scales of Lingtai and Jingchuan loess-soil section, China, and Chashmanigar loess-soil section, Tadzhikistan, analyse the evolution of the ～100 ka cycles of the three paleoclimate records respectively and afterwards employ the auto-bicoherence method to detect the coupling between the ～100 ka periodicity and periodicities of obliquity, precession and semiprecession. The results show thatfrom 0.0 Ma to 0.8 Ma there exists a quadratic phase coupling between ～100 ka period and the period components of precession(16 ka) and semiprecession(about 13.8 ka, 12.4 ka, 11.1 ka), while from 1.6 Ma to 2.6 Ma, between 128 ka period and the period components of precession(19.3 ka and 16.8 ka) and semiprecession (about 10 ka). Evidence from the above calculation suggests that nonlinear interaction between precession and semiprecession waves may be the cause to produce ～100 ka cyclicity in loess records.In this paper, we use the automatic orbital tuning method to establish the time scales of Lingtai and Jingchuan loess-soil section, China, and Chashmanigar loess-soil section, Tadzhiki-stan, analyse the evolution of the ～100 ka cycles of the three paleoclimate records respectively and afterwards employ the auto-bicoherence method to detect the coupling between the ～100 ka periodicity and periodicities of obliquity, precession and semiprecession. The results show that from 0.0 Ma to 0.8 Ma there exists a quadratic phase coupling between ～100 ka period and the period components of precession (16 ka) and semiprecession (about 13.8 ka, 12.4 ka, 11.1 ka), while from 1.6 Ma to 2.6 Ma, between 128 ka period and the period components of precession (19.3 ka and 16.8 ka) and semiprecession (about 10 ka). Evidence from the above calculation suggests that nonlinear interaction between precession and semiprecession waves may be the cause to produce ～100 ka cyclicity in loess records.

关 键 词：PALEOCLIMATE periodicity  precession  semiprecession  auto-bicoherence  phase coupling. 

分 类 号：P532[天文地球—古生物学与地层学]