Multi-layer detailed snowpack models are increasingly used to predict snow conditions based on meteorological observations, forecast and climate projections for a wide range of applications such as meteorological forecast, avalanche hazard forecast, water resources and climate research and services. Often coupled to or embedded in land surface models, they attempt to represent the main physical processes occurring at the boundary and within the snowpack. Most processes occurring in the snowpack depend on the vertical and horizontal distribution of its physical properties, which primarily emerge from the microstructure of snow (density, specific surface area, other geometric properties). Conversely, snow metamorphism modifies snow microstructure leading to feedback loops between the macroscopic behaviour of the snowpack and processes occurring at the microstructure-scale. Appropriately representing snow metamorphism in snowpack models, both in terms of the choice of the prognostic variables used and their time and space evolution, has implications for our modelling capabilities of snowpack processes, and in particular the possibilities to use radiative transfer models (optical and microwave) accounting for snowpack properties in land surface data assimilation schemes.
Recent developments have provided to the community new measurement techniques for high resolution profiling of snow microstructure in the field, which can be used for snowpack model evaluation. In addition, laboratory experiments, and microstructure-scale modelling of physical processes involved in metamorphism provide means to develop and test direct modelling or parameterizations of snow metamorphism which can be used in multi-layer detailed snowpack models.
This session, organized by the IACS Working Group “MicroSnow : From quantitative stratigraphy to microstructure-based modelling of snow”, invites contributions addressing one or several aspects of the challenges relevant to developing, evaluating and using observation methods and snowpack models especially regarding their representation of snow microstructure. The objective of the session is in particular to provide a discussion platform regarding new avenues in microstructure-based snowpack modelling, its linkages with other processes which must also be addressed by snowpack models (e.g. phase change and percolation, compaction, mechanical properties) and the use of such models for various applications and assimilation activities.