Climatic signals in the Chinese loess record for the Last Glacial: The influence of northern high latitues and the tropical Pacific

摘要

The high-resolution Shagou loess section near the northwest limit of the East Asian Summer monsoon, northwest China, was analyzed. The timescale of this section was set up based on a grain size age model and age controls. The record of the Shagou section shows that the millennial-scale oscillations are superimposed on an orbital-scale trend which can be correlated with the variations found in Greenland and the Sulu Sea. Differences in the corresponding Dansgaard-Oeschger cycles between the records in Greenland and the Chinese loess sections, including the orbital-scale trend, the timing and the amplitude, suggest that the climatic signals in Chinese loess might not be singularly regulated by the North Atlantic. The differences in trend and amplitude can be reasonably explained when compared with the Sulu Sea record. This suggests that the western tropical Pacific also exerted an important influence on climatic signals found in the Chinese loess record, possibly countering the impact of high latitude factors during the Last Glacial.