中国热带晚第四纪冷波动的地带性探讨

The Zonation of Cooling Fluctuation During Late Quaternary in China's Tropics

分析孢粉、氧碳同位素、硅藻、沉积、史籍记载等约70个实例，表明中国热带末次冰期晚期（MIS2）以来有12期主要的冷波动。冷波动的地区分布具有热带南部和北部的纬度地带性，冷波动分布和降温程度的经度地带性表现在西区、中区、东区、台湾岛4个区的分异。西区位于热带西部，属南亚季风区，冷波动少，降温幅度小；中区、东区、台湾岛位于热带东部，属东亚季风区，冬季风的强度有东西向的交替变化，中区的冷波动最明显。各期冷波动的降温幅度大多为0．5～2℃，少数为3～5℃。

In China＇s tropics, twelve times of cooling fluctuation occurred during late Quaternary. The more examples of cooling events with larger amplitude of drop in temperature distributed in the nortbe.m zone of tropics,showing the latitude zonation. The longitude zonation of cooling events can be divided into four regions： western region, central region, eastern region and Taiwan Island. The cooling fluctuation is most obvious in central region, every cooling events had occurred in this region. There were seventy two examples of cooling events, in which thirty four examples distributed in central region. Statistics of amplitude of drop in temperature for thirty seven examples showed that there were ten examples with drop amplitude of 3～5 ℃, in which six examples distributed in central region. The drop amplitude of the other twenty seven examples is 0.5 ～2 ℃. In China＇ s tropics, there are three routes of cold wave from northern China： the east way, central way and west way, the cold wave through central way is the strongest,so that the cooling fluctuation was obvious in the central region. Very little about cooling events is known in the western region, because this region is located at the area of South Asia Monsoon which is only of tropical circulation with prosperous southwest monsoon, and thus the climatic influence from high latitude area is less intense. In the southem zone of tropics, the cooling events distributed mostly in the central region, but there were also in the region of South China Sea showing that the east way of cold wave can reach to South China Sea. In the northern zone of tropics, the examples of every cooling fluctuation can be found in every region. However, the strength of winter monsoon appeared three times of shift change from east to west during late stage of the Latest Glaciation, from warming return stage to Zhou Dynasty cooling stage and after Warring States-Western Han Dynasty cooling stage,respectively.