青藏高原末次冰消期气候演化特点及其与格陵兰、欧洲的异同

根据生物、湖泊及冰川地层记录,分析了青藏高原末次冰消期的气候演化特点,并将其与格陵兰、欧洲气候演化序列进行了对比分析.结果表明,末次冰消期的气候演化大致可分为两个阶段:前一阶段为暖期,但波动频繁;格陵兰、欧洲在经历了H1事件后,迅速转暖,Bolling期比Allerod期气候更为适宜;而青藏高原渐趋回暖,夏季风降水逐渐增加,存在由冰融水与降水增加所形成的高湖面,气候温湿,进入一次湖泊扩涨期;大部分记录指示Allerod期比Bolling期气候更为适宜.后一阶段为冷期,格陵兰、欧洲气候恶化并显示出有回返冰期的气候特点;青藏高原气候严酷、荒漠扩展、冰流推进、湖面下降.气候演化的这种异同性表明:格陵兰、欧洲与青藏高原气候系统彼此存在联系,特别是在冷期;而在暖期,气候演化表现出各自的特点.气候演化格局所呈现的可比性,可能是通过冷期的一致而体现的.

Climatic Evolution of the Tibetan Plateau during the Last Deglaciation:Correlation with Europe and Greenland

On the basis of biological, lacustrine and glacial sediment stratigraphy records, the paper analyzed the features of climate change during the last deglaciation in the Tibetan Plateau, and correlated to the climatic evolution sequences in Europe and Greenland. It is found that the climatic evolution sequence during the last deglaciation generally can be divided into two phases at the three regions. The first phase was warm and humid with a series of abrupt returns to cold climate. In Europe and Greenland, the climate turned warm rapidly after Henirich 1(H1), and Bolling stage was warmer than Allerod stage. While in the Tibetan Plateau, temperature and precipitation gradually increased for the strengthening of summer monsoon little by little (i.e., Allerod a little warmer than Bolling); which caused high lake level in some catchments, especially in the ones with glaciers in high mountains.;On the contrary, the second phase was cold, with deteriorated climate in some degree and showed a feature of turning to glaciation, especially in Europe and Greenland. The climate in the Tibetan Plateau was cold and dry, with desert expanding, ice advancing and lake level lowering.;The similarities and differences of climatic evolution sequence between the three regions suggested that the climatic system of the Atlantic Ocean might impact on the Tibetan Plateau in some degree during the cold period of north hemisphere for the westerlies farther shifting to low latitude in cold stage; while during the warm period of north hemisphere, the relationship of climate systems among the three regions became weak for the westerlies shifting to high latitude; thus in this interval the climate evolution sequence of the Tibetan Plateau and Europe or Greeland was different.;Concluding, it was suggested that for the cold phase——the best-known Younger Dryas event being, the climatic evolution pattern of these three regions in general, was similar, i.e., from warm phase to cold phase.