Models and observational constraints for fast ice flow and marine ice sheet dynamics

快速冰流和海洋冰盖动力学的模型和观测约束

基本信息

批准号：
357193-2008
负责人：
Schoof, Christian
金额：
$ 1.46万
依托单位：
University of British Columbia
依托单位国家：
加拿大
项目类别：
Discovery Grants Program - Individual
财政年份：
2010
资助国家：
加拿大
起止时间：
2010-01-01 至 2011-12-31
项目状态：
已结题

来源：
https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=459839
关键词：
Models observational constraints fast ice

项目摘要

The ice sheets of Greenland and West Antarctica contain sufficient fresh water to raise global sea levels by about 13 metres. At present, there are no reliable predictions of how fast these ice sheets may shrink under projected climate change, and the future rate of sea level rise cannot be forecast accurately. Better predictions of ice sheet behaviour will require a number of physical processes to be represented more accurately in numerical models. Ice sheets do not flow evenly, but contain channels of fast flow known as ice streams. How these ice streams form, evolve and ultimately shut down again is only partially understood, and much of the physics involved is not represented in currebt ice sheet models. Similarly, the physics that controls the evolution of the edges of ice sheets (and hence their horizontal extent) is only partially understood. In particular, the edges of the Greenland and Antarctic ice sheets are defined in many places by the location where ice begins to float and forms an ice shelf. The rate at which ice flows through these junctions between ice sheets and ice shelves cannot be predicted accurately by present models, hampering efforts to estimate future sea level changes. The proposed research program will target these weaknesses in current ice sheet models by addressing the fundamental physics involved in ice stream flow and in the evolution of the margins of ice sheets. The research program will take a two-pronged approach, using sophisticated modern mathematical methods in conjunction with data from a new field program to derive improved representation of ice sheet physics for use in numerical simulations.

格陵兰岛和西南极洲的冰原含有足够的淡水，足以使全球海平面上升约13米。目前，还没有可靠的预测来预测这些冰盖在预计的气候变化下会以多快的速度收缩，也无法准确预测未来海平面上升的速度。更好地预测冰盖行为需要在数值模型中更准确地表示许多物理过程。冰盖流动不均匀，但包含快速流动的通道，称为冰流。这些冰流是如何形成、演化并最终再次关闭的，目前人们只了解了一部分，而且所涉及的大部分物理原理都没有在当前的冰盖模型中得到体现。同样，控制冰盖边缘演化（及其水平范围）的物理学也只是部分了解。特别是，格陵兰岛和南极冰盖的边缘在许多地方都是由冰开始漂浮并形成冰架的位置定义的。目前的模型无法准确预测冰流过冰盖和冰架之间交界处的速度，这阻碍了估计未来海平面变化的努力。拟议的研究计划将通过解决冰流流动和冰盖边缘演化所涉及的基础物理学来解决当前冰盖模型中的这些弱点。该研究计划将采取双管齐下的方法，使用复杂的现代数学方法结合新实地计划的数据，以改进冰盖物理的表示，以用于数值模拟。