CAREER: Bound to Improve - Improved Estimates of the Glaciological Contribution to Sea Level Rise

事业：一定会改进 - 改进对冰川对海平面上升的贡献的估计

• 批准号: 1149085
• 负责人: Jeremy Bassis
• 金额: $ 57.21万
• 依托单位: Regents of the University of Michigan - Ann Arbor
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-09-01 至 2018-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1149085&HistoricalAwards=false
• 关键词: CAREER; Bound; Improve; Improved; Estimates

Bassis/1149085This CAREER award supports a project to develop physically based bounds on the amount ice sheets can contribute to sea level rise in the coming centuries. To simulate these limits, a three-dimensional discrete element model will be developed and applied to simulate regions of interest in the Greenland and Antarctic ice sheets. These regions will include Helheim Glacier, Jakobshavn Isbräe, Pine Island Glacier and sections of the Larsen Ice Shelf. In the discrete element model the ice will be discretized into distinct blocks or boulders of ice that interact through inelastic collisions, frictional forces and bonds. The spectrum of best to worst case scenarios will be examined by varying the strength and number of bonds between neighboring blocks of ice. The worst case scenario corresponds to completely disarticulated ice that behaves in a manner akin to a granular material while the best case scenario corresponds to completely intact ice with no preexisting flaws or fractures. Results from the discrete element model will be compared with those from analogous continuum models that incorporate a plastic yield stress into the more traditional viscous flow approximations used to simulate ice sheets. This will be done to assess if a fracture permitting plastic rheology can be efficiently incorporated into large-scale ice sheet models to simulate the evolution of ice sheets over the coming centuries. This award will also support to forge a partnership with two science teachers in the Ypsilanti school district in southeastern Michigan. The Ypsilanti school district is a low income, resource- poor region with a population that consists of ~70% underrepresented minorities and ~69% of students qualify for a free or reduced cost lunch. The cornerstone of the proposed partnership is the development of lesson plans and content associated with a hands-on ice sheet dynamics activity for 6th and 7th grade science students. The activity will be designed so that it integrates into existing classroom lesson plans and is aligned with State of Michigan Science Technology, Engineering and Math (STEM) curriculum goals. The aim of this program is to not only influence the elementary school students, but also to educate the teachers to extend the impact of the partnership beyond the duration of this study. Graduate students will be mentored and engaged in outreach activities and assist in supervising undergraduate students. Undergraduates will play a key role in developing an experimental, analogue ice dynamics lab designed to illustrate how ice sheets and glaciers flow and allow experimental validation of the proposed research activities. The research program advances ice sheet modeling infrastructure by distributing results through the community based Community Ice Sheet Model.

BASIS/1149085这一职业奖支持一个项目，该项目旨在制定未来几个世纪冰盖对海平面上升可能做出贡献的物理界限。为了模拟这些极限，将开发一个三维离散元模型，并将其应用于模拟格陵兰和南极冰盖中的感兴趣区域。这些区域将包括赫尔海姆冰川、雅各布港伊斯布雷冰川、松岛冰川和拉森冰架的部分地区。在离散元素模型中，冰将被离散成不同的冰块或巨石，这些冰块或巨石通过非弹性碰撞、摩擦力和结合相互作用。通过改变相邻冰块之间的结合强度和数量，将考察最好到最坏情况的范围。最坏的情况对应于完全脱节的冰，其行为类似于颗粒状物质，而最好的情况对应于完全完整的冰，没有预先存在的缺陷或裂缝。离散单元模型的结果将与类似的连续介质模型的结果进行比较，后者将塑性屈服应力纳入到用于模拟冰盖的更传统的粘性流动近似中。这样做是为了评估是否可以将允许塑性流变性的断裂有效地纳入大型冰盖模型，以模拟未来几个世纪冰盖的演变。该奖项还将支持与密歇根州东南部伊普西兰蒂学区的两名科学教师建立合作伙伴关系。伊普西兰蒂学区是一个低收入、资源贫乏的地区，人口中约70%由代表不足的少数民族组成，约69%的学生有资格享受免费或降低成本的午餐。拟议的合作伙伴关系的基石是为6年级和7年级的理科学生制定与实践冰盖动力学活动相关的教案和内容。该活动的设计将使其融入现有的课堂教学计划，并与密歇根州立大学科学技术、工程和数学(STEM)的课程目标保持一致。该计划的目的不仅是为了影响小学生，而且也是为了教育教师将合作伙伴关系的影响延伸到本研究的持续时间之外。研究生将接受辅导和参与外展活动，并协助指导本科生。本科生将在开发实验、模拟冰动力学实验室方面发挥关键作用，该实验室旨在说明冰盖和冰川是如何流动的，并允许对拟议的研究活动进行实验验证。该研究计划通过基于社区的社区冰盖模型来分发结果，从而改进了冰盖建模基础设施。