"Collaborative Research: Atmospheric Dust as an Archive and Agent of Climate Change During the Late Paleozoic Icehouse"

“合作研究：大气尘埃作为晚古生代冰室期间气候变化的档案和媒介”

• 批准号: 0746107
• 负责人: Vladimir Davydov
• 金额: $ 14.25万
• 依托单位: Boise State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-03-15 至 2014-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0746107&HistoricalAwards=false
• 关键词: Collaborative; Research; Atmospheric; Dust; Archive

COLLABORATIVE RESEARCH: Atmospheric Dust as an Archive and Agent of Climate Change During the Late Paleozoic Icehouse Gerilyn Soreghan, Michael Soreghan, University of Oklahoma Ear-0746042 Vadimir Davydov, Boise State University, EAR-0746107 Natalie Mahowald, Cornell University, EAR-0745961 Timothy W. Lyons, Univ. California, Riverside, EAR-0745602 Abstract Atmospheric dust archives and drives climate change. Dust preserved in marine and continental sediments and ice has shed light on recent climate change, and dust also impacts climate via direct and indirect effects on the amount of solar energy received at Earth's surface, and by fertilization that stimulates primary productivity and thus the carbon cycle. However, the character and magnitude of the aerosol effect remains a poorly constrained variable in climate models, thus limiting the predictive capability of these models. In this research, PIs propose to assess the 'dust effect' by investigating the geologic record of a particularly dusty interval on Earth. The late Paleozoic world, 300 million years ago, was remarkably dusty, with dust flux varying on both million-year and millennial scales. This time period is also attractive as the last time that Earth's climate was analogous to today's, with large polar ice sheets. Here, PIs propose to test the overarching hypothesis that the abundant dust played a significant role in driving changes in late Paleozoic climate and linked (e.g. biotic) systems, through direct, indirect, and feedback effects. They will investigate how dust flux, atmospheric circulation, and dust transport varied between glacials and interglacials, how dust forced changes in tropical climate, and how the biosphere responded to such high atmospheric dustiness. To address these questions, PIs are targeting two time slices in localities spanning the girth of the tropics. They will examine dust distribution, assess atmospheric dustiness and wind strength and direction, and use geochemistry to examine effects on marine life. They will correlate among localities using fossils and radioisotopic dating. PIs will use the data they collect as input for climate- and dust-modeling experiments, to assess the direct and indirect effects of dust on atmospheric behavior and undertake biogeochemical modeling aimed at assessing the impact of variable nutrient fluxes on cycling of carbon. Intellectual Merit-- Results of this research will provide a high-resolution reconstruction of climate for the tropics and reveal the effects of dust on climate and life in a world characterized by variable dust flux on various timescales, within a 'glacial' world like today's. Owing to the known importance but remaining uncertainty of the roles of dust and associated aerosols in the climate system, our data will have predictive utility in expanding our understanding of Earth-system behavior across geologic time, and will provide important constraints useful for improving climate modeling. Broader Impacts--This project will involve heavy student participation (graduate and undergraduate levels), cross-disciplinary training among geologists, geochemists, and climate modelers, both in the field and laboratory. Undergraduates (geology and education majors) and minority middle-schoolers will take part through mentoring programs. Data will be archived and shared using newly developed web-accessible tools. Finally, we will use results of this research to guide the development of a traveling exhibit on the 'Paleozoic Dust Bowl' in conjunction with the Oklahoma Museum of Natural History and incorporate results in an outreach course taught (by co-PIs) at the Museum.

合作研究：在已故古生代Icehous Gerilyn Soreghan，Michael Soreghan，俄克拉荷马大学EAR-0746042 VADIMIR DAVYDOV，EAR-0746107 NATALIE MAHOWALD，NATALIE MAHOWALD，CORNEL UNIVER，EAR-07445961中。加利福尼亚，河滨，EAR-0745602抽象的大气尘埃档案，并驱动气候变化。在海洋和大陆沉积物中保存的尘埃和冰揭示了最近的气候变化，灰尘还通过直接和间接影响地球表面收到的太阳能的量以及刺激原发性生产力的施肥以及碳循环的施肥来影响气候。然而，气溶胶效应的特征和大小在气候模型中仍然是一个受限制的变量，因此限制了这些模型的预测能力。在这项研究中，PI建议通过研究地球上特别尘土间隔的地质记录来评估“灰尘效应”。 3亿年前，已故的古生代世界非常尘土飞扬，尘埃通量在百万年度和千禧年尺度上都不同。这个时期也很有吸引力，因为最后一次地球的气候类似于今天的极地冰盖。在这里，PIS建议测试总体假设，即丰富的粉尘在驱动晚期的古生代气候和连接（例如生物）系统的变化中发挥了重要作用，通过直接，间接和反馈效应。他们将调查冰川，大气循环和粉尘转运如何在冰川和冰川间之间变化，粉尘在热带气候中的强迫变化以及生物圈如何响应如此高的大气尘土。为了解决这些问题，PI的目标是在热带地区的围栏的地方进行两次切片。他们将检查灰尘分布，评估大气尘土和风强度和方向，并使用地球化学来检查对海洋生物的影响。它们将使用化石和放射性病的约会在地区之间关联。 PI将使用他们收集的数据作为气候和尘埃模型实验的输入，以评估灰尘对大气行为的直接和间接影响，并进行生物地球化学建模，旨在评估可变养分通量对碳循环的影响。智力优点 - 这项研究的结果将为热带地区提供高分辨率的气候重建，并揭示尘埃对气候和生命的影响，其特征是在当今的“冰川”世界中，以可变的尘埃通量对各种时间标准的变化。由于已知的重要性，但仍然是气候系统中灰尘和相关气溶胶作用的不确定性，我们的数据将具有预测的实用性，可以扩展我们对地质时代的地球系统行为的理解，并将提供对改善气候建模有用的重要约束。更广泛的影响 - 该项目将涉及大量的学生参与（研究生和本科阶段），地质学家，地球化学家和气候建模者之间的跨学科培训，包括现场和实验室。本科生（地质和教育专业）和少数中学者将通过指导计划参加。数据将使用新开发的Web访问工具进行存档和共享。最后，我们将使用这项研究的结果来指导与俄克拉荷马州自然历史博物馆一起在“古生代尘埃碗”上进行旅行展览的发展，并将结果纳入了博物馆（由Co-pis）教授（由Co-pis）的宣传课程中。