Constraining Temporal Movement of the ITCZ in the Eastern Equatorial Pacific Using Radiogenic Isotopes

大气中的尘埃水平对气候有重要的潜在影响，包括对地球辐射平衡和海洋初级生产力的影响，从而通过地表水的“施肥”影响大气中的二氧化碳。尘埃来源和通量变化的信息对地面真实大气环流模型至关重要，该模型被用来调查尘埃对连接大陆条件和全球气候的反馈的作用。这项研究由德克萨斯农工大学的科学家进行，调查了第四纪晚期赤道东太平洋的尘埃来源变化。研究人员将沿着横跨赤道的沉积物岩芯横断面进行时间研究，并对赤道东太平洋大片地区的现代沉积物进行空间研究，分析尘埃碎片的放射性同位素和微量元素地球化学。此外，他们还将确定代表赤道东太平洋潜在尘埃源的不同终端成员样本(中国，南美洲西北部、北美洲西南部、澳大利亚、北非)的放射性同位素特征。这一古物源研究将有助于更好地了解热带地区大尺度经向大气环流的变化，进而揭示过去的气候强迫机制。资助博士生，并为本科生提供参与研究的机会。结果将被纳入首席调查员教授的课程中。

Dust levels in the atmosphere have important potential effects on climate, including impacts on the Earth's radiative balance and on marine primary productivity, and thus atmospheric CO2, via "fertilization" of surface waters. Information about changes in dust provenance and flux is critical to ground truth atmospheric circulation models, which are are used to investigate the role that dust has on feedbacks which connect continental conditions and global climate.This research, conducted by scientists at Texas A & M University, investigates dust provenance changes in the eastern equatorial Pacific during the late Quaternary. The researchers will perform a temporal study along a transect of sediment cores crossing the equator, as well as a spatial study of modern sediments from a wide area of the eastern equatorial Pacific, analyzing the radiogenic isotope and trace element geochemistry of the dust fraction. In addition, they will determine radiogenic isotope signatures of various end members samples representing the potential dust sources to the Eastern Equatorial Pacific (China, NW South America, SW North America, Australia, northern Africa). This paleo-provenance study will lead to better understanding of the large-scale meridional atmospheric circulation variability of the tropics, which in turn can shed light of past climate forcing mechanisms. Funding supports a PhD student and provides opportunities for undergraduate involvement in research. Results will be incorporated into courses taught by the lead investigator.