ELT COLLABORATIVE RESEARCH: Investigating the Biotic and Paleoclimatic Consequences of Dust in the Late Paleozoic

合作研究：研究晚古生代尘埃对生物和古气候的影响gerilyn Soreghan，俄克拉荷马大学，ear -1338331; sarah Aciego，密歇根大学，ear -1337440; linda Hinnov，约翰霍普金斯大学，ear -1337454; nicholas Heavens，汉普顿大学，ear -1337463地质数据表明，在二叠纪-宾夕法尼亚时期（3亿年前）的热带大气是富含尘埃的。此外，晚古生代海洋生态系统以藻类为主。这些观察结果，结合气候模型的预测，提出了推动这项研究的两个主要假设：1)不寻常的热带粉尘反映了热带高地冰川产生的粉尘；2)大气粉尘使海洋生态系统肥沃。沙尘通过影响辐射强迫和大气湿度以及影响生物圈来强迫气候系统，但人们对这些影响知之甚少。在这项研究中，pi将收集数据来约束大气“粉尘”的空间（低中纬度）和时间（冰期-间冰期和更长时间）变化、粉尘来源以及粉尘与生态系统组成之间的影响，以解决其总体假设，并澄清大气粉尘、气候和生物圈之间的关系。这项研究将在冰期-间冰期尺度上揭示冰窖内粉尘、气候和生物圈之间的过程联系。由于已知尘埃对气候的直接和间接影响的重要性但又有很大的不确定性，结果将扩大对地球系统行为的理解。低海拔地区的热带冰川意味着比目前公认的更广泛的冰川，如果得到证实，将迫使科学界用新的建模方法来检验这一假设。所使用的模型与用于当前和未来气候的模型是相同的，因此，通过提议的工作所取得的改进将为一般的地球气候模型提供信息。如果大气粉尘迫使海洋生物系统向营养丰富的条件发展的假设得到证实，它意味着一个非常多尘的地球，并澄清了地球系统对粉尘源施肥的行为。这些结果与日益增长的关于控制未来气候变化的地球工程方案的讨论有关。更广泛的影响通过地质和地球化学实验室、地质学家和建模师之间的交流，以及联合实地考察和进展会议，将进行跨学科的培训。博士生将通过一个正式的暑期项目指导中学教师。本科生将撰写高级论文，并在本科生研究日和全国会议上发言。他们都将通过正式的STEM教育课程与中学生互动。主要研究人员将使用研究的组成部分在大学、博物馆和社区外展中进行教学。将建立和加强所有参与机构之间的联系，其中包括一所历史悠久的黑人大学，以及国际伙伴。这项研究将有助于点燃三名年轻研究者的研究生涯（2人没有事先获得NSF的支持）。数据将通过出版物和网络工具进行存档和共享。

Collaborative Research:Investigating the Biotic and Paleoclimatic Consequences of Dust in the Late PaleozoicbyGerilyn Soreghan, University of Oklahoma, EAR-1338331Sarah Aciego, University of Michigan, EAR-1337440Linda Hinnov, Johns Hopkins University, EAR-1337454Nicholas Heavens, Hampton University, EAR-1337463Overview Geologic data indicate that the tropical atmosphere during the Permo-Pennsylvanian (300 Million years ago) was dust-rich. In addition, algae predominated in late Paleozoic marine ecosystems. These observations, combined with predictions from climate modeling, prompt two over-arching hypotheses driving the proposed research: 1) the unusual tropical dustiness reflects dust production by tropical upland glaciers, and 2) atmospheric dustiness fertilized marine ecosystems. Dust forces the climate system by affecting radiative forcing and atmospheric moisture, and by influencing the biosphere, but these effects are poorly known. In this research, PIs will collect data to constrain spatial (low-mid latitude) and temporal (glacial-interglacial and longer) variations in atmospheric 'dustiness,' sources of the dust, and influences between dust and ecosystem composition in order to address their over-arching hypotheses, and clarify the relationships among atmospheric dustiness, climate, and the biosphere.Intellectual MeritThis research will reveal process links among dust, climate, and the biosphere within an icehouse, at glacial-interglacial scales. Owing to the known importance but great uncertainty of both the direct and indirect effects of dust on climate, results will expand understanding of Earth-system behavior. Tropical glaciation at low elevations implies much more widespread glaciation than currently accepted, and --if verified-- would force the community to test this hypothesis with new modeling approaches. The models to be used are identical to those used for present and future climate, and thus improvements made through the proposed work will inform modeling of Earth's climate in general. If the hypothesis that atmospheric dustiness forced marine biotic systems toward nutrient-rich conditions is confirmed, it implies a remarkably dusty Earth, and clarifies Earth-system behavior to dust-sourced fertilization. These results are relevant to growing discussions regarding geo-engineering schemes to control future climate change. Broader ImpactsCross-disciplinary training will occur via exchanges between geological and geochemical labs, geologists and modelers, and in joint field excursions and progress meetings. PhD students will mentor middle-school teachers through a formal summer program. Undergraduates will conduct senior theses and present at Undergraduate Research Day and national meetings. Both will interact with middle- and high-school students through a formal course on STEM education. The lead investigators will use components of the research to teach at university levels, as well as in museum, and community outreach. Ties will be established and strengthened among all participant institutions, which includes an Historically Black University, as well as international partners. This research will help ignite the research careers of three young investigators (2 with no prior NSF support). Data will be archived and shared via publications, and web-accessible tools.