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

合作研究：由俄克拉荷马大学Gerilyn Soreghan，密歇根大学EAR-1338331 Sarah Aciego，John Hopkins University，EAR-1337454 Nicholas Heaven，Hampton University，EAR-1337454调查古生代晚期沙尘的生物和古气候后果。概述地质数据表明，二叠纪-宾夕法尼亚纪(3亿年前)热带大气尘土丰富。此外，晚古生代海洋生态系统中以藻类为主。这些观察结果与气候模型的预测相结合，促使两个总体假设推动了拟议的研究：1)异常的热带沙尘反映了热带高地冰川产生的沙尘，2)大气沙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，以及通过影响生物圈，迫使气候系统，但这些影响鲜为人知。在这项研究中，PI将收集数据，以限制大气灰尘的空间(中低纬度)和时间(冰期-间冰期和更长时间)的变化，沙尘的来源，以及沙尘和生态系统组成之间的影响，以便解决他们的总体假设，并澄清大气沙尘、气候和生物圈之间的关系。智力价值本研究将揭示冰川-间冰期尺度上冰室内尘埃、气候和生物圈之间的过程联系。由于已知沙尘对气候的直接和间接影响的重要性，但不确定性很大，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，将迫使该社区用新的建模方法来检验这一假设。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总体上为地球气候建模提供信息。如果大气沙尘迫使海洋生物系统进入营养丰富条件的假设得到证实，这意味着地球上尘土飞扬，并澄清了地球系统对灰尘来源肥料的行为。这些结果与越来越多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、地质学家和模型师之间的交流，以及联合实地考察和进展会议，将进行跨学科培训。博士生将通过一个正式的暑期项目来指导中学教师。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表论文。两者都将通过STEM教育的正式课程与初中生和高中生互动。首席调查人员将利用这项研究的组成部分在大学一级教学，以及在博物馆和社区推广。将在包括历史悠久的黑人大学在内的所有参与机构以及国际合作伙伴之间建立和加强联系。这项研究将有助于点燃三名年轻研究人员的研究生涯(其中两名之前没有得到NSF的支持)。数据将通过出版物和网络可访问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.