solidFIDEMO – a firn densification model for volumetric mass balances

solidFIDEMO â 体积质量平衡的冷冻致密化模型

• 批准号: 403642112
• 负责人: Professorin Dr. Angelika Humbert
• 金额: --
• 依托单位: Fachgebiet Kontinuumsmechanik
• 依托单位国家: 德国
• 项目类别: Infrastructure Priority Programmes
• 财政年份: 2018
• 资助国家: 德国
• 起止时间: 2017-12-31 至 2021-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/403642112?language=en
• 关键词: solidFIDEMO; firn; densification; model; volumetric

Firn describes the intermediate stage product between snow and glacier ice. The ongoing compaction of snow to ice is commonly called firn densification. Knowledge about this process is for example needed to transform measured height changes of the ice shields to mass changes or to perform climate reconstructions from ice cores.Throughout our project SolidFIDEMO we developed an efficient framework for firn densification modelling. In our previous work we used this framework and a growing amount of data to advance the development of a process based firn densification model. We were able to utilise our model within an application simulating the firn density and age at the surface of 79°N Glacier, Greenland. Furthermore, we paid special attention to the very first stage of firn densification, assessing a constitutive relation describing the process of grain boundary sliding in firn. One of our findings throughout this study was that the common one dimensional model approach in firn density modelling is not sufficient to represent the stress regime acting within the firn body.We therefore propose for a one year extension of our project. Within this one year period we want to extend our model framework to three spatial dimensions. In this way we were able to investigate the influence of horizontal stresses acting on the firn, neglected in most firn densification models so far. Further this extension would enable us to analyse the influence of surface polar glacial surface features such as snow dunes and sastrugi on the lateral variability of the firn density.As we see a strong demand from other research fields, especially from the altimetry community for firn density products, we also want to hold a two day workshop at TU Darmstadt to meet researchers from different fields within the community. We want to discuss how an interconnection between different models can be established and what kind of data products, applications and services we can provide to the community.

Firn描述了雪和冰川冰之间的中间阶段产物。雪到冰的持续压实通常被称为积雪致密化。例如，将测量到的冰盾高度变化转化为质量变化或根据冰芯进行气候重建都需要了解这一过程。在我们的SolidFIDEMO项目中，我们开发了一个有效的积雪致密化建模框架。在我们以前的工作中，我们使用这个框架和越来越多的数据，以推进基于过程的积雪致密化模型的发展。我们能够在一个应用程序中利用我们的模型模拟格陵兰岛79°N冰川表面的积雪密度和年龄。此外，我们特别注意到的第一阶段的积雪致密化，评估本构关系描述的过程中，在积雪晶界滑动。我们在整个研究中的一个发现是，通用的一维模型方法在积雪密度建模是不足以代表的应力制度在积雪体内的作用。因此，我们建议我们的项目延长一年。在这一年的时间里，我们希望将我们的模型框架扩展到三个空间维度。通过这种方式，我们能够研究作用在积雪上的水平应力的影响，到目前为止，在大多数积雪致密化模型中被忽略了。此外，这种扩展将使我们能够分析表面极地冰川表面功能，如雪沙丘和雪脊对积雪密度的横向变化的影响。我们看到了来自其他研究领域的强烈需求，特别是从测高社区的积雪密度产品，我们也想在TU达姆施塔特举行为期两天的研讨会，以满足来自不同领域的研究人员在社区内。我们希望讨论如何建立不同模型之间的互连，以及我们可以为社会提供什么样的数据产品，应用程序和服务。