Schimmenti Danielle E, Marcantonio Franco, Roxana Sierra-Hernández M, Schmidt Matthew W
Department of Geology and Geophysics, Texas A&M University, College Station, TX, USA.
Byrd Polar and Climate Research Center, The Ohio State University, Columbus, OH, USA.
Nat Commun. 2025 Jul 1;16(1):5567. doi: 10.1038/s41467-025-60773-7.
We present high-resolution records of detrital Pb and Nd isotopes from marine core site MV1014-02-17JC (00° 10.8297'S, 85° 52.0042'W) in the Eastern Equatorial Pacific (EEP) and use a Bayesian isotope mixing model, MixSIAR, to quantify global dust source contributions since the onset of the last glaciation 30,000 yr ago. We find that in addition to South American dust from the Andean margin, North African dust from the Saharan desert makes up significant proportions of the EEP dust delivered to the site of study. The proportion of North African dust was significantly enhanced during the cold Northern Hemisphere stadials, Heinrich Stadial 1 and the Younger Dryas, when dust fluxes were also higher. During the warm Bølling-Allerød and African Humid Periods, dust fluxes were decreased, and the proportion of South American dust was enhanced. We suggest the variability in the proportions of northern vs. southern hemisphere sourced dust in the EEP is indicative of large climate-related meridional shifts (>7°) in the average position of the Intertropical Convergence Zone, a major precipitation belt which, today, affects the lives of billions across our planet.
我们展示了来自赤道东太平洋（EEP）海洋岩芯站点MV1014 - 02 - 17JC（南纬00°10.8297′，西经85°52.0042′）的碎屑铅和钕同位素的高分辨率记录，并使用贝叶斯同位素混合模型MixSIAR来量化自3万年前末次冰期开始以来全球沙尘源的贡献。我们发现，除了来自安第斯边缘的南美沙尘外，来自撒哈拉沙漠的北非沙尘在输送到研究站点的EEP沙尘中占相当大的比例。在北半球寒冷的stadials、海因里希事件1期和新仙女木期，当沙尘通量也较高时，北非沙尘的比例显著增加。在温暖的波令 - 阿勒罗德期和非洲湿润期，沙尘通量下降，南美沙尘的比例增加。我们认为，EEP中来自北半球与南半球沙尘比例的变化表明，热带辐合带（一条主要的降水带，如今影响着全球数十亿人的生活）的平均位置出现了与气候相关的大幅经向移动（>7°）。
