Catastrophic drought in East Asian monsoon region during Heinrich event 1
Catastrophic drought in East Asian monsoon region during Heinrich event 1
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Heinrich事件1期间东亚季风区的灾难性干旱
DOI：
10.1016/j.quascirev.2016.03.029
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发表时间：
2016-06
影响因子：
4
通讯作者：
Xin Zhou;Liguang Sun;Yangxi Chu;Zehui Xia;Xinying Zhou;Xiangzhong Li;Z. Chu;XiangJun Liu
中科院分区：
文献类型：
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作者：
Xin Zhou;Liguang Sun;Yangxi Chu;Zehui Xia;Xinying Zhou;Xiangzhong Li;Z. Chu;XiangJun Liu
海因里希事件1（H1）是末次冰消期发生的一次重要的千年气候事件。石笋δ 18 O记录表明，H1期间东亚季风区季风强度的显著减弱，是由于大西洋纬向翻转环流（AMOC）的减弱/崩溃导致热带辐合带（ITCZ）南移所致。然而，从不同的亚洲季风区的记录显示不同的降水变化趋势在H1期间，这些趋势不能单独解释的ITCZ的南移。在本研究中，我们从淮河流域洪泛区沉积物中重建了25，000至10，000 a BP之间东亚季风降水的时间序列。剖面上有一个白色沉积层，其TOC、树木花粉和蕨类孢子含量显著降低，δ 13 Corg值较正，是在H1事件期间沉积的。TOC、孢粉和δ 13 Corg时间序列的测定结果，以及石笋δ 18 O的测定结果表明，江淮地区在H1期间发生了一次严重的干旱。热带太平洋的拉尼娜现象可能也是H1期间江淮地区特大干旱和亚洲季风区降水变化的原因之一。
Heinrich event 1 (H1) is an important millennial climate event during the last deglaciation. The substantial decreasing of monsoon strength in the East Asian monsoon region during the H1, as shown by stalagmite δ18O records, has been attributed to the southward shift of the intertropical convergence zone (ITCZ), which is caused by the slowdown/collapse of the Atlantic meridional overturning circulation (AMOC). However, records from different Asian monsoon regions show various trends in precipitation changes during the H1, and these trends cannot be solely interpreted by the southward shift of the ITCZ. In the present study, we reconstructed time-series of East Asian monsoon precipitation between 25,000 and 10,000 a BP from floodplain sediments in the Huai River Basin. A white sediment layer, distinct from other layers in the profile, contains significantly low TOC, tree pollen and fern spore contents, and more positive δ13Corg, and it is deposited during the H1 event. The determined TOC, pollen and δ13Corgtime-series, together with previously reported stalagmite δ18O, indicate a catastrophic (severe) drought in Jianghuai Region, one of the East Asian monsoon regions, during the H1. The La Niña condition in tropical Pacific likely also contributes to the catastrophic drought in Jianghuai Region and the precipitation variations in the Asian monsoon region during the H1.