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)

该项目的目标是利用最近从莱恩群岛海岭采集的一组海洋沉积物岩心，研究太平洋中西部过去15万年来尘埃沉积的变化，这些岩心构成了一条横跨现代热带辐合带（ITCZ）、西经160°附近的大致南北向的断面。地球的气候从完整的冰川期转变为近百万年来最温暖的间冰期之一。在间冰期高峰之后，全球气候经历了多个20，000年的周期变化，而在末次冰消和全新世间冰期之前的末次冰盛期（LGM），全球气候趋于恢复到完整的冰川条件。风沙在影响和记录气候方面具有重要作用。在大气层中，尘埃对行星云有贡献，并充当云凝结核。在海洋中，灰尘可以通过添加关键的微量营养素来提高生物生产力，并为颗粒沉降提供压舱物，从而增加海洋表层的碳输出，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、规模和去除过程提供了线索。该项目将促进对气候、尘埃、生产力和水文循环的自然变化的理解，并将促进对一些早期职业科学家和本科生的培训和学习。 该研究小组还将通过Lamont-Doherty地球观测站的Earth 2Class计划，与初中和高中科学教师合作，利用他们的研究和教育工作。

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.