155,000 Years of West African Monsoon and Ocean Thermal Evolution
155,000 Years of West African Monsoon and Ocean Thermal Evolution
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DOI：
10.1126/science.1140461
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发表时间：
2007-06
期刊：
影响因子：
56.9
通讯作者：
S. Weldeab;D. Lea;R. Schneider;N. Andersen
中科院分区：
文献类型：
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作者：
S. Weldeab;D. Lea;R. Schneider;N. Andersen
对过去155，000年西非季风水文的详细重建表明与北方高纬度气候振荡有密切联系。赤道大西洋东部几内亚湾海洋沉积物岩芯中浮游有孔虫的Ba/Ca比值和氧同位素组成揭示了与北方高纬度冰柱和倒数第二次间冰期和末次冰消期间冰柱同步的河流淡水输入的百年尺度变化。EEA Mg/Ca基海表温度（SST）与北方高纬度千年尺度波动脱钩，主要响应大气温室气体和低纬度太阳辐射的变化。季风降水增强的发生滞后于欧洲经济区SST的变化，在冰川-间冰期过渡期长达7000年。这项研究表明，北方高纬度地区的stadial-interstadial和冰消期气候不稳定性通过大气联系对西非季风动力学施加主导控制。
A detailed reconstruction of West African monsoon hydrology over the past 155,000 years suggests a close linkage to northern high-latitude climate oscillations. Ba/Ca ratio and oxygen isotope composition of planktonic foraminifera in a marine sediment core from the Gulf of Guinea, in the eastern equatorial Atlantic (EEA), reveal centennial-scale variations of riverine freshwater input that are synchronous with northern high-latitude stadials and interstadials of the penultimate interglacial and the last deglaciation. EEA Mg/Ca-based sea surface temperatures (SSTs) were decoupled from northern high-latitude millennial-scale fluctuation and primarily responded to changes in atmospheric greenhouse gases and low-latitude solar insolation. The onset of enhanced monsoon precipitation lags behind the changes in EEA SSTs by up to 7000 years during glacial-interglacial transitions. This study demonstrates that the stadial-interstadial and deglacial climate instability of the northern high latitudes exerts dominant control on the West African monsoon dynamics through an atmospheric linkage.