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)

该项目的目标是通过最近从莱恩群岛山脊（Line Islands Ridge）恢复的一套海洋沉积物岩心，研究过去15万年中西太平洋地区尘埃沉积的变化，该岩心构成了一个大致横跨西经160°附近的现代热带辐合带（ITCZ）的南北样带。在对该项目感兴趣的期间，地球气候从完全冰期转变为过去100万年中最温暖的间冰期之一。在这个间冰期高峰之后，全球气候经历了多个2万年周期的变化，同时趋向于回到末次冰灭和全新世间冰期之前的末次冰盛期（LGM）的完全冰期条件。风沙对气候具有重要的影响和记录作用。在大气中，尘埃对行星反照率有贡献，并起到云凝结核的作用。在海洋中，灰尘可以通过添加重要的微量营养物质来提高生物生产力，并为颗粒的下沉提供压舱物，从而增加海洋表面的碳输出，并吸收大气中的二氧化碳。在深海沉积物中，粉尘沉积的数量、位置和类型为重建其过去的来源、路径、大小和去除过程提供了线索。这些移除过程包括沿热赤道在热带海洋上方的ITCZ的雨带移动。该项目将促进对气候、尘埃、生产力和水文循环等自然变化的了解，并将促进对几名早期职业科学家和本科生的培训和学习。研究小组还将通过Lamont-Doherty地球天文台的Earth2Class项目与初中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.