末次间冰期以来中国西北部沙漠边缘区夏季风变化初步研究

Initial Research of Summer Monsoon Change at Desert Marginal Zone in the North-west of China Since the Last Interglacial

通过对祁连山东段沙沟河黄土剖面CaCO3含量、色度代用指标的综合分析 ,结合1 4 C和热释光测年结果 ,揭示出了沙漠边缘区夏季风在末次间冰期 (S1 )表现出 5次增强时期。从指标曲线上能够反映出千年尺度的气侯变化 ,与GRIP孔的气候记录有很好的耦合性。这种气候不稳定性可能受控于高纬冰盖的变化 ,体现出全球气候性特点。在末次冰期 ,夏季风的反映就弱得多 ,气候长期表现为干冷 ,可能由于青藏高原的抬升 ,以及靠近沙漠边缘区 ,使夏季风在冰期难以到达 。

Through composite analysis of CaCO\-3 content, colour substitute parameter in the Shagou loess section in the east of Qilian mountain and dating result of \{\} 14 C,TL, it is suggested that summer monsoon has five enhancing periods in the last interglacial,reflecting the climatic change of millenium scale from parameter curves, which is well consistent with GRIP record. The climatic instability may be controlled by the change of high latitude ice\|sheet and shows the character of the globe climate.In the last glacial, summer monsoon was weak, climate was dry and cold in the long period, which maight be resulted by the uplift of Qinghai-Xizang plateau and the research region was adjacent to the Tengger desert, which made it difficult for summer monsoon to reach in the last glacial,so it showed regional climatic character.