A 249 kyr stack of eight loess grain size records from northern China documenting millennial‐scale climate variability
A 249 kyr stack of eight loess grain size records from northern China documenting millennial‐scale climate variability
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DOI：
10.1002/2013gc005113
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发表时间：
2014-03
期刊：
影响因子：
3.7
通讯作者：
Shiling Yang;Z. Ding
中科院分区：
文献类型：
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作者：
Shiling Yang;Z. Ding
为了建立中国北方千年尺度变化的叠加气候记录，对8个厚黄土剖面的12，330个样品进行了粒度测量。这些粒度记录的截面之间的相关性表明，虽然小的沉积间断可能存在于一个单一的部分，大部分部分的部分显示连续的灰尘沉积。通过将这8个记录与中国石笋δ 18 O记录进行关联，构建了一个249 kyr长的粒度时间序列叠加，称为“CHNOMOS”记录，这是第一个记录中国北方千年尺度变化的高分辨率叠加。这一叠加显示了千年尺度的气候事件叠加在最后一次和倒数第二次冰期期间的显著冷却趋势上，与全球冰量增加的模式一致。然而，这种冷却趋势在石笋记录中被抑制，在低纬度海洋记录中被完全抑制。因此，远离低纬海洋的黄土高原主要受北方高纬冰盖的影响，而中国南方近端石笋则主要记录来自低纬海洋的信号。高、低纬度气候记录的交叉相关分析表明，千年尺度的气候突变起源于北方极地，主要通过东亚冬季风传播到东亚。CHEMIMOS的记录也证实了过去249 kyr中最干燥和最冷的时间段发生在MIS 6晚期，MIS 7d非常寒冷和干燥，类似于MIS 6的Stadial条件。
In order to construct a stacked climatic record of millennial‐scale variability for northern China, grain size was measured for 12,330 samples from eight thick loess sections. Between section correlation of these grain size records shows that, although small depositional hiatuses may be present within a single section, most parts of the sections display continuous dust deposition. By correlating the eight records with the precisely dated Chinese stalagmite δ18O record, a stacked 249 kyr‐long grain size time series was constructed, termed the “CHILOMOS” record, which is the first high‐resolution stack documenting millennial‐scale variability in northern China. This stack shows millennial‐scale climatic events superimposed on a prominent cooling trend during the last and penultimate glaciations, consistent with the pattern of increasing global ice volume. However, this cooling trend is dampened in the stalagmite record and totally suppressed in the low‐latitude ocean record. It follows that the Loess Plateau, far from the low‐latitude ocean, is largely influenced by the northern high‐latitude ice sheets, while the proximal stalagmites of southern China primarily document signals from the low‐latitude ocean. Cross correlations of climatic records from high and low latitudes demonstrate that the millennial‐scale abrupt changes originated in the northern polar area and were propagated into East Asia largely through the East Asian winter monsoon. The CHILOMOS record also confirms that the driest and coldest interval of the last 249 kyr occurred in the late MIS 6, and that MIS 7d was extremely cold and dry, similar to the stadial conditions of MIS 6.