Controls on the East Asian monsoon during the last glacial cycle, based on comparison between Hulu Cave and polar ice-core records
Controls on the East Asian monsoon during the last glacial cycle, based on comparison between Hulu Cave and polar ice-core records
复制标题
DOI：
10.1016/j.quascirev.2009.09.007
复制
发表时间：
2009-12
影响因子：
4
通讯作者：
E. Rohling;Qingsong Liu;A. Roberts;J. Stanford;S. Rasmussen;P. Langen;M. Siddall
中科院分区：
文献类型：
--
作者：
E. Rohling;Qingsong Liu;A. Roberts;J. Stanford;S. Rasmussen;P. Langen;M. Siddall
先前的研究表明，Hulu洞穴记录（东亚季风）与格陵兰冰芯记录之间具有良好的时间相关性，这意味着北半球气候过程对季风强度的主导控制。我们提出一个客观、直接的统计评估，挑战这种普遍接受的亚轨道变异性范式。我们提出了一种更灵活的全球解释，它考虑了Hulu洞穴和极地冰芯记录中信号结构的广泛变化，而不是有限的主要转变。我们的分析采用了2005年格陵兰冰芯年表（GICC05），该年表是为格陵兰记录开发的，并且已经通过甲烷同步应用于EPICA Dronning Maud Land （EDML）的高分辨率δ 18oice系列。GICC05年代学允许这些冰芯记录与U-Th年代的Hulu洞穴记录在相对狭窄（~ 3%）的年龄不确定性范围内进行比较。根据先前的建议，我们提出的解释表明，东亚季风受到北半球“拉”（在北方温暖时期更强烈）和南半球“推”（在南方寒冷时期更强烈的季风）的组合影响。我们的分析强烈表明，在季风总体较弱的冰期，南半球气候变化对千年尺度季风变率的控制占主导地位，而在季风较强的冰期和间冰期，北半球气候变化对千年尺度季风变率的控制占主导地位。与北半球严格控制的传统先验解释相比，推导出的与南半球气候记录的时间变化关系在统计上为东亚主要季风转变与北半球（Dansgaard-Oeschger， DO）冰川时期气候事件的明显巧合提供了更合理的理由。
Previous studies have suggested a sound chronological correlation between the Hulu Cave record (East Asian monsoon) and Greenland ice-core records, which implies a dominant control of northern hemisphere climate processes on monsoon intensity. We present an objective, straightforward statistical evaluation that challenges this generally accepted paradigm for sub-orbital variability. We propose a more flexible, global interpretation, which takes into account a broad range of variability in the signal structures in the Hulu Cave and polar ice-core records, rather than a limited number of major transitions. Our analysis employs the layer-counted Greenland Ice-Core Chronology 2005 (GICC05), which was developed for Greenland records and has since been applied – via methane synchronisation – to the high-resolution δ18Oiceseries from EPICA Dronning Maud Land (EDML). The GICC05 chronology allows these ice-core records to be compared to the U–Th dated Hulu Cave record within relatively narrow (∼3%) bounds of age uncertainty. Following previous suggestions, our proposed interpretation suggests that the East Asian monsoon is influenced by a combination of northern hemisphere ‘pull’ (which is more intense during boreal warm periods), and southern hemisphere ‘push’ (which is more intense monsoon during austral cold periods). Our analysis strongly suggests a dominant control on millennial-scale monsoon variability by southern hemisphere climate changes during glacial times when the monsoon is weak overall, and control by northern hemisphere climate changes during deglacial and interglacial times when the monsoon is strong. The deduced temporally variable relationship with southern hemisphere climate records offers a statistically more plausible reason for the apparent coincidence of major East Asian monsoon transitions with northern hemisphere (Dansgaard–Oeschger, DO) climate events during glacial times, than the traditional a priori interpretation of strict northern hemisphere control.