Re-examining the potential of using sensitive grain size of coastal muddy sediments as proxy of winter monsoon strength

摘要

Sensitive components of grain size in coastal muddy sediments of China have been widely used for reconstruction of the East Asian winter monsoon strength. However, trends of the winter monsoon strength profiles reconstructed for the past 2000 years from different sediment cores tend to be inconsistent and even contradictory. In the present study, the grain size variation sequence of the sensitive components in a sediment core, collected from the middle of the Min-Zhe Coastal Mud, with a time span of 2700 years, is determined. The striking correspondence between the reconstructed mean grain size of the sensitive component with Northern Hemisphere temperature, in particular, the Medieval Warm Period and the Little Ice Age, showed that coastal muddy sediments of China can be used to reconstruct a high resolution profile of East Asian winter monsoon strength. The inconsistencies in the winter monsoon proxy sequences from different studies are most likely caused by low-resolution of grain size-standard deviation data and direct influence of the river input materials in some studies.