P2C2: Collaborative Research: Dust Deposition, Paleo-Export Production, and Migration of the (ITCZ) Through the Last Glacial Cycle in the West-Central Pacific (Line Islands)

该项目的目标是研究太平洋中西部15万年来尘埃沉积的变化，这些沉积物是最近从莱恩群岛海脊采集的一套海洋沉积物岩芯，构成了一条横跨160°W经度的现代热带间辐合带(ITCZ)的大致南北横断面。在该项目感兴趣的间隔期间，地球气候从完全冰川转变为过去100万年来最温暖的间冰期之一。在那次间冰期高峰期之后，全球气候在两万年的多个周期中发生变化，同时有恢复到最后一次冰川消融和全新世间冰期之前的最后一次冰盛期(LGM)的完全冰川条件的趋势。风沙在影响和记录气候方面起着重要作用。在大气中，尘埃贡献了行星的反照率，并作为云的凝结核。在海洋中，尘埃可以通过添加关键的微量营养物质来肥沃生物生产力，并为颗粒下沉提供压舱物，从而增加海洋表层的碳出口，并减少大气中的二氧化碳。在深海沉积物中，尘埃沉积的数量、位置和类型为重建其过去的来源、路径、规模和清除过程提供了线索。这些移除过程包括热带海洋上方热赤道上ITCZ雨带的变化。该项目将促进对气候、沙尘、生产力和水文循环自然变化的了解，并将促进几名早期职业科学家以及本科生的培训和学习。研究团队还将通过Lamont-Doherty地球天文台的Earth2Class计划，与中学和高中科学教师合作，利用他们的研究和教育努力。

This project's goal is to examine variations in dust deposition throughout the last 150,000 years in the west-central Pacific from a suite of ocean sediment cores recently recovered from the Line Islands Ridge and constituting a roughly north-south transect across the modern Inter-Tropical Convergence Zone (ITCZ) near 160°W longitude.During the interval of interest for the project, the Earth's climate shifted from full glaciation to one of the warmest interglacials in the last million years. Following that peak interglacial, global climate varied through multiple 20,000 year cycles while trending toward a return to full glacial conditions at the last glacial maximum (LGM) before the last deglaciation and Holocene interglacial. Windblown dust plays important roles in influencing and recording climate. In the atmosphere, dust contributes to the planetary albedo and serves as cloud condensation nuclei. In the ocean, dust may fertilize biological productivity through the addition of crucial trace nutrients, and provide ballast for the sinking of particles, thus enhancing carbon export from the surface ocean and drawing down atmospheric carbon dioxide. In deep-sea sediments, the amount, location and type of dust deposition provide clues for reconstructing its past sources, pathways, magnitude and removal processes. These removal processes include the shifting rain belts of the ITCZ that follows the thermal equator over the tropical ocean.The project will advance understanding of natural variations in climate, dust, productivity, and the hydrological cycle, and will promote training and learning for several early career scientists as well as undergraduate students. The research team will also leverage their research and education efforts in collaboration with middle school and high school science teachers through the Lamont-Doherty Earth Observatory's Earth2Class program.