220 ka以来萨拉乌苏河流域地层磁化率与气候变化

 萨拉乌苏河流域滴哨沟湾剖面磁化率变化结果表明:近220 ka来我国北方气候变化极不稳定,存在着不同尺度的频繁变化,特别是寒冷气候阶段变化尤为频繁,其中倒数第二次冰期存在5个气候旋回,末次冰期存在10个气候旋回。这些气候变化与深海氧同位素、极地冰芯反映的全球变化具有良好的对应关系,反映了该区气候变化与全球变化的一致性。控制本区气候变化的主要因素是全球冰量变化及太阳辐射影响的东亚季风变化。

Climatic Change Reflected by Stratigraphical Magnetic Susceptibility in Salawusu River Basin, North China since 220ka BP

The Salawusu River Basin is situated on the transition zone between desert and loess in North China,where belongs to the fragile ecotone and sensitively responses to the global climate change.So,the river basin is the ideal zone for global climate change research in China.Magnetic susceptibility is one of the effective indexes of reflecting environmental climate change,which has been widely applied in the research on Quaternary environment and climatic change.The variation sequence of magnetic susceptibility in the Dishaogouwan profile in Salawusu River Basin showed that the climate in North China was very unstable since 220 ka BP,and frequently changed with different time periods.The climate in cold period fluctuated especially frequently.In detail,there were five climatic cycles in the penultimate Glaciation,and nine cycles in the Last Glaciation.These climatic changes are well accordant with the global climatic change reflected by the deep-sea oxygen isotope and the polar ice core,which has proved the consistency in time of climatic change between the study area and the global area.The main factors that control the climate of the study area are the ice amount variation of the world and the vicissitude of East Asian monsoon influenced by solar radiation.