MicroFAME

Natural ice is a fundamental element of Earth’s climate system. Almost 70 % of our global freshwater reserves is stored as ice in large natural ice bodies, especially glaciers, ice caps, and ice sheets. The ice net losses currently observed every year are already sufficient to turn glaciers, ice caps, and ice sheets into major contributors to global sea-level rise. In fact, since long the Intergovernmental Panel on Climate Change (IPCC) has recognized that the major source of uncertainty in reconstructions and projections of global sea-level rise stems from our limited understanding of the dynamics of glaciers and ice sheets.

One of the roots of our current lack of understanding of the dynamics of glaciers and ice sheets is that at the warm temperatures found on Earth’s surface, the creep viscosity of glaciers and ice sheets is strongly dependent on the ice microstructure (i.e., polycrystalline structure, porosity, and impurities), but such a dependence is complex and poorly understood.

Now, with MicroFAME we plan to advance the knowledge by exploring a ground-breaking Hypothesis of Microstructural Fading Memory (MFM) which proposes that all microstructural properties of snow, firn, and dense ice have a limited recollection of their histories, with memories that fade with characteristic relaxation times.

Thus, the objective of the MicroFAME project is to explore the full potential of the hypothesis of Microstructural Fading Memory (MFM) to provide not only a new paradigm for understanding the birth of ice from firn metamorphism, but also a powerful mathematical framework for modelling the creep viscosity of ice through the evolution of the ice microstructure, by using suitable relaxation functions and times, as done in the general theory of fading memory in continuum mechanics and thermodynamics.