Collaborative Research: Impact of subglacial discharge on turbulent plume dynamics and ocean-glacier heat and mass transfer

合作研究：冰下排放对湍流羽流动力学和海洋-冰川传热传质的影响

• 批准号: 1504521
• 负责人: David Sutherland
• 金额: $ 20.12万
• 依托单位: University of Oregon Eugene
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-09-01 至 2019-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1504521&HistoricalAwards=false
• 关键词: Collaborative; Research; Impact; subglacial; discharge

Recent and on-going retreat of many Northern hemisphere marine-terminating glaciers is contributing significantly to sea level rise. It is driven by poorly understood processes occurring at the ice-ocean interface, such as subglacial discharge into the ocean, turbulent plume dynamics, submarine melting, and iceberg calving. These processes are (1) inherently interdisciplinary, requiring expertise in both glaciology and oceanography and (2) difficult to observe, requiring innovative field techniques and careful site selection. This project will address the relationship between subglacial discharge, turbulent plume dynamics, and submarine melting through a comprehensive field campaign at LeConte Glacier, Alaska, supplemented by a state-of-the-art modeling effort. The field site is ideal because it spans a wide range of forcings on daily to seasonal time scales and because the near-terminus fjord environment is accessible year round. A successful project will provide a unique data set and improved models for projecting contributions to future sea level rise.This interdisciplinary project, at the interface of the the fields of glaciology and oceanography, provides support for an early-career principal investigator (PI) (Amundson) from a predominantly undergraduate institution (University of Alaska Southeast) and an additional early career PI at University of Oregon. More mature PIs at Oregon State University and University of Alaska Fairbanks Campus will mentor the younger team members, promoting workforce development. Additional workforce development will be promoted through interaction with high school students and at the participating universities. The team of PIs will entrain select students from a local Alaska high school to participate in aspects of the field work and engage with the school to integrate their observations into the curriculum. The project will also provide support for the training two graduate students and a post-doctoral scholar. The associated mentoring plan is very good. Outreach to the general public will be enhanced by leveraging the PIs? home institutions? activities. The PIs will continue established interactions with the National Park Service and the US Forest Service. These include public lectures, as well as training for interpretive rangers who can reach a broad cross-cut of the public. Finally, they will develop a brochure concerning their work to further enhance their public outreach.This project will develop a parameterization of a plume, driven by subglacial discharge, as it interacts with the face of a marine-terminating glacier. This is a goal that has been endorsed by the international community. It will be accomplished by conducting three intensive field campaigns toi. sample the upwelling plume directly with manned and autonomous vessels,ii. measure the downstream impact of the plume on near-terminus fjord circulation,iii. determine subglacial discharge and submarine melt rates, andiv. survey associated changes in glacier terminus dynamics.Subglacial discharge and ambient water properties in the proglacial fjord will be monitored throughout the project in order to providei. important context for the intensive field campaigns, andii. a range of parameter space to be explored by a turbulence-resolving hydrodynamic plume model.Data from the intensive field campaigns will be used to validate the plume model, which will then be used to explore the wider range of parameter space that is provided by long-term measurements. The latter will allow investigation of the impact of submarine melting on glacier dynamics over seasonal timescales.

许多北半球海洋末端冰川的近期和正在进行的撤退正在大大促进海平面上升。 它是由在冰山界面上发生的鲜为人知的过程所驱动的，例如进入海洋的冰川下排放，湍流的羽流动力学，海底融化和冰山产犊。这些过程是（1）固有的跨学科，需要冰川学和海洋学方面的专业知识，以及（2）难以观察，需要创新的现场技术和仔细的现场选择。该项目将解决冰川下排放，动荡的羽流动力学和海底融化，并在阿拉斯加的Leconte Glacier的全面野外活动中融化，并补充了最先进的建模工作。该场地是理想的选择，因为它每天遍布季节性的范围，并且由于近端峡湾环境全年可访问。 一个成功的项目将提供一个独特的数据集和改进的模型，以预测未来的海平面上升。在冰河学和海洋学领域的界面上，该跨学科项目为早期研究人员（PI）（Amundson）提供了支持（主要是Alaska Southeast）（Alaska Southerausk）（Alaska Sounderational）（Alaska Sounderational）（Alaska Southeral Insucorcy）（Alaska Southerake Universitation）（Alaska Southeral Insucorcy of Alaska）和其他早期职业生涯的PRISED PICI，为PREENIS of ALASKA University提供了支持。 俄勒冈州立大学和阿拉斯加大学Fairbanks校园的更成熟的PI将指导年轻的团队成员，从而促进劳动力发展。 通过与高中生和参与大学的互动，将促进额外的劳动力发展。 PI团队将吸引来自阿拉斯加当地高中的精选学生，以参与现场工作的各个方面，并与学校互动，将他们的观察结果融入课程中。 该项目还将为培训两名研究生和一名博士后学者提供支持。 相关的指导计划非常好。 通过利用PI来增强向公众的宣传？家庭机构？活动。 PI将继续与国家公园管理局和美国森林服务局建立互动。 其中包括公开讲座，以及可以对公众进行广泛跨界的解释性护林员的培训。 最后，他们将制定有关他们的工作的小册子，以进一步增强公众的宣传。该项目将在底部排放驱动的羽流参数化，因为它与海洋终止冰川的面对面相互作用。 这是国际社会认可的目标。 这将通过进行三个密集的现场活动来实现。直接用载人和自主船只直接对上升的羽流进行样品，ii。测量羽流对近端峡湾循环的下游影响，iii。确定冰川下排放和海底熔体速率，安迪夫。与调查相关的冰川末端动力学的变化。在整个项目中，将监测前冰峡谷中的冰川排放和环境水性质，以提供。强化现场活动的重要背景，Andii。通过解决湍流的流体动力羽流模型可以探索的一系列参数空间。密集型现场活动的数据将用于验证羽流模型，然后将使用长期测量提供的较宽的参数空间范围。后者将允许研究海底熔化对冰川动力学对季节性时间尺度的影响。