Better boundary conditions for glacier and ice-sheet modelling

更好的冰川和冰盖建模边界条件

• 批准号: RGPIN-2015-05722
• 负责人: Flowers, Gwenn
• 金额: $ 2.99万
• 依托单位: Simon Fraser University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2017
• 资助国家: 加拿大
• 起止时间: 2017-01-01 至 2018-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=633683
• 关键词: Better; boundary; conditions; glacier; ice

Glaciers and ice sheets store two-thirds of Earth’s freshwater and are currently contributing to rising sea levels. While these ice masses act as long-term integrators of climate, their internal dynamics can complicate their behaviour on the short timescales relevant to society. Fundamental to our ability to decipher the underlying causes of glacier and ice-sheet change, and therefore pre-requisite to its reliable future projection, are accurate “boundary conditions” for glacier and ice-sheet models. The motivation for the proposed research is therefore to inform models we use to make projections of glacier change through process-based studies at the glacier surface and bed, and where the glacier comes into contact with freshwater reservoirs. The specific objectives of the research program are to (1) evaluate the robustness of glacier mass-balance models to uncertainties in accumulation processes, (2) develop statistical models of subglacial processes at scales commensurate with ice-sheet models and (3) investigate the influence of glacier-freshwater interactions on glacier dynamics and retreat. A fourth cross-cutting objective is to develop statistically robust practices for model calibration and to quantify associated model uncertainties. Observational, computational and statistical methods will be combined to achieve the above objectives in a number of individual studies suitable for graduate-level research. These studies involve new field work in British Columbia and Yukon to measure meteorological quantities, glacier mass balance, subglacial variables and properties of ice-marginal lakes. This research program capitalizes on emergent collaborations with local and international colleagues, as well as a new collaboration based at SFU between statisticians and earth scientists. It also involves partnership with local industry to develop novel instrumentation for monitoring subglacial properties. Built into the program are training opportunities for 6 new graduate students, along with 2 undergraduates and 1 northern community member per year. The anticipated impact of the research program will be an improved ability to (1) accurately model regional glacier mass-balance, (2) implement realistic representations of subglacial processes in large-scale ice-sheet models and (3) include glacier-freshwater feedbacks in future assessments of glacier change. Collectively, the proposed research will advance our understanding of externally driven- versus internally forced glacier change, toward more confident interpretations of short-term glacier variations and improved future projections. These projections are broadly relevant to issues of Canada’s water security, economic development and environmental resilience.

冰川和冰盖储存了地球三分之二的淡水，目前正在导致海平面上升。虽然这些冰团作为气候的长期整合者，但它们的内部动态可能使它们在与社会相关的短时间尺度上的行为复杂化。对于我们能够破译冰川和冰盖变化的根本原因的能力来说，冰川和冰盖模型的准确“边界条件”是其可靠的未来预测的先决条件。因此，拟议研究的动机是为我们用于预测冰川变化的模型提供信息，这些模型是通过对冰川表面和河床以及冰川与淡水水库接触的地方进行基于过程的研究来进行的。该研究计划的具体目标是：（1）评估冰川质量平衡模型对积累过程中不确定性的鲁棒性，（2）开发与冰盖模型相当的冰下过程统计模型，（3）调查冰川-淡水相互作用对冰川动力学和退缩的影响。第四个贯穿各领域的目标是为模型校准制定统计上可靠的做法，并量化相关的模型不确定性。将结合观察，计算和统计方法，以实现上述目标，在一些适合研究生水平的研究个别研究。这些研究包括在不列颠哥伦比亚省和育空地区进行新的实地工作，以测量气象量、冰川物质平衡、冰下变量和冰缘湖的特性。这项研究计划利用了与当地和国际同事的紧急合作，以及统计学家和地球科学家之间在SFU的新合作。它还涉及与当地工业界合作开发监测冰下特性的新型仪器。该计划每年为6名新研究生、沿着2名本科生和1名北方社区成员提供培训机会。该研究计划的预期影响将是提高以下能力：（1）准确模拟区域冰川质量平衡，（2）在大规模冰盖模型中实现冰下过程的现实表示，（3）在未来的冰川变化评估中包括冰川-淡水反馈。总的来说，拟议的研究将促进我们对外部驱动与内部强迫冰川变化的理解，对短期冰川变化和改善未来预测的更有信心的解释。这些预测与加拿大的水安全、经济发展和环境复原力问题广泛相关。