75th Annual Meeting of the APS Division of Fluid Dynamics (November 20, 2022 — November 22, 2022)

V0031: Snow-driven flows in planetary interiors

Authors
  • Quentin Kriaa, Aix Marseille Université, CNRS, Centrale Marseille, IRPHE, Marseille, France
  • Benjamin Favier, Aix Marseille Université, CNRS, Centrale Marseille, IRPHE, Marseille, France
  • Michaël Le Bars, Aix Marseille Université, CNRS, Centrale Marseille, IRPHE, Marseille, France
DOI: https://doi.org/10.1103/APS.DFD.2022.GFM.V0031

Small rocky planets like Ganymede, a natural satellite of Jupiter, generate their own magnetic field by internal snow-driven flows: dense solid iron particles ('iron flakes') settle in liquid metal towards the center of the planet, and drag fluid with them as they do so. When reaching too large temperatures, they remelt. The resulting molten snow is denser than the ambient fluid, so it sinks at depth, forcing additional motions which generate the magnetic field. Modelling such flows is also of paramount importance for climate modelling: underneath clouds, precipitation can drag air downward but if drops additionally evaporate, the cooling air becomes so dense that it sinks even faster. To gain insight, we perform analog experiments with dissolving grains of sugar (aka melting snow flakes) in water (aka liquid metal in planets or air in the atmosphere). Our experiments enable to scan through the clouds and investigate their interaction with the fluid they set in motion.

This work is licensed under the Creative Commons Attribution-NonCommercial 4.0 International License. Any reuse must credit the author(s) and provide a link back to this page.