Changes of atmospheric circulation since the last interstadial as indicated by the lake-status record in China

The effective precipitation and the frame of atmospheric circulation in the past three key periods, i.e. 30 ka BP, 18 ka BP and 6 ka BP, have been ana lyzed on the basis of the palaeolake status record produced by the Chinese Lake Status Data Base. The results show that the west-central part of China was characterized by high lake-levels at 30 ka BP, resulting from strength ened southwest monsoons; whereas the high lake stand, occurring in the west -central part of China at 18 ka BP, was caused by the southward shift and t he strengthening of westerlies although the high-stand distribution was red uced. Meanwhile, the east-central part of China was under the control of st rong winter monsoons at 18 ka BP. The high lake-levels, which occurred in t he east-central part of China at 6 ka BP, are related to the enhanced East- Asian summer monsoons; while the lowering of the lake-level in the west-cen tral part of China at 6 ka BP was due to the northward shift and correspond ing shrink of the westerlies. A comparison between the lake status and the palaeoclimate models has shown that there do exist discrepancies between the geological evidence and the model simulations. The agreement between them provides a possible mechanica l explanation on the geological phenomena, but the discrepancy shows that t he model needs to be revised to a great extent.