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通过腾冲北海与香格里拉纳帕海有机碳含量、δ13C、粒度等沉积指标和若干孢粉指标的对比,参照60ka BP以来孟加拉湾的沉积韵律互层与δ18O记录,发现它们同与印度季风系统存在密切关联。然而由于经纬与海陆分布的差异,夏季风和冬季风对各处的影响亦有很大差别。大约发生于37~32ka BP的强大的暖湿型气候事件在北海与纳帕海盆地的沉积序列之中反映突出,成为过去60ka间最引人瞩目的现象,但是却缺乏海域记录的有力呼应。海陆记录对比结果表明,MIS3后期区域气候事件的控制因素来自陆地而非海洋,青藏高原在此期间的特别升温导致印度冬季风的衰退及其他大气环流型式的改变有可能是重大气候事件形成的主因。此外,陆地地貌对于季风的降水效应也有不可忽视的影响。
According to sedimentary parameters and δ18O records of the Bay of Bengal since the 60 ka BP, the sedimentary indices of δ13C, grain size and other sedimentary indicators and the sporopollen in the Beihai and Shangri-La Napahai were found to be closely related to the Indian monsoon system . However, due to the differences in latitude, longitude and land-sea distribution, the effects of the summer monsoon and the winter monsoon are also quite different. The strong warm and humid climatic events, which occurred in about 37 ~ 32ka BP, are highlighted in the sedimentary sequences of the North Sea and the Napahai basin, becoming the most striking phenomenon in the past 60 ka, but lacking the strong echo of sea area records. The comparison of land and sea records shows that the controlling factors of the later MIS3 events are from land rather than the ocean. The warming of the Tibetan Plateau during this period led to the decline of the Indian winter monsoon and other types of atmospheric circulation possibly leading to the formation of major climatic events . In addition, the landform has an undeniable effect on the precipitation effect of monsoon.