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

合作研究：调查古生代晚期尘埃的生物和古气候后果Gerilyn Soreghan，俄克拉荷马州大学，邮编1338331 Sarah Aciego，密歇根大学，邮编1337440 Linda Hinnov，约翰霍普金斯大学，邮编1337454 Nicholas Heavens，汉普顿大学，邮编1337463概述地质数据表明，在二叠纪-宾夕法尼亚（3亿年前）的热带大气中富含尘埃。此外，藻类在晚古生代海洋生态系统中占主导地位。这些观察结果，结合气候模型的预测，提示两个过度假设驱动拟议的研究：1）不寻常的热带尘埃反映了热带高地冰川的尘埃生产，2）大气尘埃肥沃的海洋生态系统。沙尘通过影响辐射强迫和大气湿度以及影响生物圈来影响气候系统，但人们对这些影响知之甚少。在这项研究中，PI将收集数据，以约束空间（低中纬度）和时间（冰川-间冰期及更长时间）大气“尘埃”的变化、尘埃的来源以及尘埃与生态系统组成之间的影响，以解决其过度膨胀假说，并阐明大气尘埃、气候和生物圈之间的关系。气候和冰室内的生物圈，在冰川间冰期尺度上。由于尘埃对气候的直接和间接影响的重要性是众所周知的，但存在很大的不确定性，因此研究结果将扩大对地球系统行为的理解。低海拔的热带冰川意味着比目前接受的更广泛的冰川作用，如果得到证实，将迫使社区用新的建模方法来测试这一假设。将使用的模型与用于当前和未来气候的模型相同，因此通过拟议的工作所做的改进将为一般的地球气候建模提供信息。如果大气尘埃迫使海洋生物系统向营养丰富的条件下的假设得到证实，这意味着一个显着的多尘地球，并澄清了地球系统的行为，以灰尘为来源的施肥。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计划的讨论有关。跨学科培训将通过地质和地球化学实验室、地质学家和建模人员之间的交流以及联合实地考察和进展会议进行。博士生将通过正式的暑期项目指导中学教师。本科生将进行高级论文，并出席本科研究日和全国会议。两者都将通过正式的STEM教育课程与初中和高中学生互动。主要研究人员将使用研究的组成部分，在大学水平，以及在博物馆和社区外展教学。将建立和加强所有参与机构之间的联系，其中包括历史上的黑人大学以及国际合作伙伴。这项研究将有助于点燃三名年轻研究人员的研究生涯（其中两名没有获得NSF的支持）。数据将通过出版物和网络访问工具存档和共享。

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.