Cooling patterns in rotating thin spherical shells: Application to Ganymede’s and Titan’s buried oceans

 

 

 

 

 

The exploration of Jupiter’s and Saturn’s systems, by the Galileo and Cassini-Huygens missions respectively, has revealed that several moons harbor salty water oceans underneath their icy crusts. Magnetic induction caused by the moons’ orbits in a tilted Jovian magnetosphere enabled the identification of globalscale  conductive  layers  in  Europa,  Ganymede  and  Callisto. The presence of an ocean was confirmed by the detection of an abnormally high obliquity and gravitational tides, indicating the existence of a liquid layer at depth decoupling the outer shell from the deep solid interior.  I use rotating convection simulations in a thin spherical shell to study  fluid  dynamics  in  subsurface  oceans  of  icy  moons. I find  two  types  of  persistent results, characterized by larger outer boundary heat flux either at polar regions or at the equatorial region. The polar cooling scenario is in agreement with inferences for the heat flux at the top of Titan’s ocean, which may provide a dynamical constraint for the vigor of convection in this layer.  My results may help unravel the internal dynamics and the interactions among the different layers within the hydrosphere of Titan. Possible implications for the deep interiors of other icy moons are also envisaged.

 

 

 

 

Link da transmissão: https://www.youtube.com/c/AstronomiaIAGUSP/live