Collaborative Research: Earth-Life Transitions: Integrated Data-Model Analysis of CO2-Climate-Vegetation Feedbacks in a Dynamic Paleo-Icehouse

合作研究：动态古冰屋中co2 -气候-植被反馈的综合数据模型分析/ isabel Montanez，加利福尼亚大学，Davis, EAR-1338281Christopher Poulsen，密歇根大学，EAR-1338200Joseph White，贝勒大学，EAR-1338247Michael Hren，康涅狄格大学，ear -1338256植被- co2 -气候反馈已被证明是气候系统的一个重要组成部分，能够在区域到全球尺度上干扰大气环流、大陆表面温度和水文循环。最近的研究表明，植被-气候反馈可能有潜力推动晚古生代气候系统在冰川期和间冰期之间的变化，并强烈地改变这些状态下的气候状况。这些反馈的性质、时间尺度和潜在影响的细节仍然难以捉摸。该多学科项目基于三个相互关联的假设，解决了这些问题，并分析了二氧化碳强迫和轨道强迫以及植被-气候反馈在促进偏速至数百万年时间尺度上的冰川期-间冰期转变中的作用：植被对主要由二氧化碳驱动的冰川期-间冰期转变的响应取决于二氧化碳强迫的时间、强度和持续时间，以及是否达到临界生态阈值。-热带植被通过生理强迫影响低纬度气候和水- C循环-在全球尺度上，植被-气候反馈-通过直接地表强迫和陆地碳- N循环的变化放大了辐射强迫的冰期-间冰期转变。这些假设正通过综合的经验、实验和多尺度建模方法在时间（10至100万年）和空间尺度（从树叶到冠层到全球气候系统）上得到检验。气候-二氧化碳-植被反馈，包括植物对气候的生理强迫作用，将通过两个阶段的建模工作进行评估，首先将利用经验和实验结果以及建模敏感性实验重新制定陆地生物圈模型（BIOME-BGC），以定义晚古生代PFTs的植物功能特征。在第二阶段，我们将把这些PFT特征纳入NCAR的全耦合群落地球系统模型，并使用该模型研究冰期-间冰期动力学。知识价值：这项研究将在LPIA期间产生第一个高分辨率，高精度的大气二氧化碳重建，当将其纳入气候模型时，将提供对地球系统过程演变的洞察，包括陆地生物圈，在与我们长期未来相关的二氧化碳水平变化的冰窖中。这项研究将是首次对陆地生物圈模型进行修正，以解释古pft特征和古植被-气候反馈的研究，从而更好地了解非被子植物通过生理强迫影响水文和碳循环的潜力。更广泛的影响：跨学科的培训和指导将通过对博士生的住院实习进行。在地球和环境科学领域，代表性不足的学生将通过一系列夏季和学年的实习和合作机构的项目得到整合。这项研究将直接有助于为史密森学会国家自然历史博物馆古生物学大厅计划的石炭纪展览。本研究产生的所有数据将通过出版物和可访问的网络工具进行存档和共享。

COLLABORATIVE RESEARCH :Integrated Data-Model Analysis of CO2-Climate-Vegetation Feedbacks in a Dynamic Paleo-IcehousebyIsabel Montanez, Univ. California, Davis EAR-1338281Christopher Poulsen, Univ. Michigan, EAR-1338200Joseph White, Baylor University, EAR-1338247Michael Hren, Univ. Conneticutt, EAR-1338256ABSTRACTOverview: Vegetation-CO¬2-climate feedbacks have been shown to be an important component of the climate system, capable of perturbing atmospheric circulation, continental surface temperatures, and hydrological cycling on regional- to global-scales. Recent work indicates that vegetation-climate feedbacks likely had the potential to push the late Paleozoic climate system between glacial and interglacial states and to strongly modify the climate regime within these states. The details of the nature, time-scales, and potential impact of these feedbacks remain elusive. This multi-disciplinary project, driven by three interlinked hypotheses, addresses these shortcomings and analyzes the roles of CO2- and orbital-forcing and vegetation-climate feedbacks in promoting glacial-interglacial transitions on eccentricity- to multi-million year time-scales: - The response of vegetation to primarily CO2-driven glacial-interglacial transitions depended on the timing, magnitude and duration of CO2 forcing and whether critical ecological thresholds were reached.- Tropical vegetation, by way of physiological forcing, impacted low-latitude climate and water & C cycling- Vegetation-climate feedbacks - on a global-scale - amplified radiatively forced glacial-interglacial transitions through changes in direct surface forcing and terrestrial C & N cycling.These hypotheses are being tested through integrated empirical, experimental and multi-scale modeling approaches across a spectrum of time- (10 to 1,000,000 yr) and spatial-scales (leaf-to-canopy-to-global climate system). Climate-CO2-vegetation feedbacks, including the role of plant physiological forcing of climate will be assessed through a two-stage modeling effort that will first reformulate a terrestrial biosphere model (BIOME-BGC) using the empirical and experimental results coupled with modeling sensitivity experiments to define plant functional traits for late Paleozoic PFTs. In the second stage, we will incorporate these PFT traits into NCAR's fully coupled Community Earth System Model and use this version to investigate glacial-interglacial dynamics.Intellectual Merit: This research will generate the first high-resolution, high-precision reconstruction of atmospheric CO2 during the LPIA, which when incorporated into the climate modeling will provide insight into the evolution of earth system processes, including the terrestrial biosphere, in an icehouse under changing CO2 levels relevant to our long-term future. This study will be the first modification of terrestrial biosphere models to account for paleo-PFT traits and investigation of paleovegetation-climate feedbacks thus providing an improved understanding of the potential of non-angiosperm plants to influence hydrologic and C cycling through physiological forcing. Broader Impacts: Cross-disciplinary training and mentoring will occur through in-residence internships for the Ph.D. students. Underrepresented students to Earth and environmental sciences will be integrated through a range of summer and academic year internships and programs at the collaborating institutions. This study will contribute directly to a Carboniferous exhibit planned for the Paleontological Halls of the National Museum of Natural History, Smithsonian Institution. All data generated by this study will be archived and shared via publications, and web-accessible tools.