Disentangling air flow dynamics in ice caves, a novel methodology
The week starts with a very fresh paper just accepted and published in early view on the journal Science of The Total Environment.
Progressive climate-change influence on ice degradation in caves pushed the C3 team to start understanding how external atmospheric conditions influence the internal circulation in caves, how it interact with morphology and the thermal characteristics of ice and the rock and ultimately how heat exchanges through these media are responsible for ice melting. All such processes are generally poor documented in real conditions.
For this purpose we focused on the Leupa ice cave in the Canin-Kanin massif. In this cave we have a pretty long-term record of air, ice and rock temperature extremely useful to validate the model set by our team.
Using a computational fluid dynamics (CFD) approach it was possible to simulate the internal air circulation pattern in relation to the external condition. The method applied in this study considers extension of well established techniques developed by the research team of Prof. Silvana di Sabatino, Department of Physics and Astronomy, University of Bologna, and is applied on a real case study. In the research team of this work were involved Beatrice Pulvirenti, Department of Industrial Engineering, University of Bologna, Barbara Bertozzi, formerly MSc student at the University of Bologna and now PhD student at the Institute of Meteorology and Climate Research at the Karlsruhe Institute of Technology (Germany). and the C3project's scientific leader Renato R. Colucci, italian National Research Council (CNR) working in the Climate and Paleoclimate research group at ISMAR, Trieste.
Results from different case studies show the formation of several vortices as well as stagnation zones which locally modifiy the energy balance between the ice surface and the inner ice cave airflow.
Differently from available studies found in the literature, this work focuses on the 3D geometry of the cave which is particularly relevant in not to loose knowledge about the localization of flow stagnation and recirculation zones, as well as spatial variability of the air temperature distribution.
The three-dimensional localization of the flow structures gives important information about the zones characteroised by high energy fluxes between air and ice surface and ice melting phenomena.
The methodology framework proposed in this paper can be extended to other ice caves and applied taking into account predictions of air forcing in climate change scenarios and allowing more robust calculations of climate feedback.
Reference:
Bertozzi B., Pulvirenti B., Colucci R.R., Di Sabatino S. (2019, in press) On the interactions between airflow and ice melting in ice caves: A novel methodology based on computational fluid dynamics modeling Science of The Total Environment
available PDF-proofs
