Convective instability in ice I with non-Newtonian rheology: Application to the icy Galilean satellites

Details Convective instability in ice I with non-Newtonian rheology: Application to the icy Galilean satellites Convective instability in ice I with non-Newtonian rheology: Application to the icy Galilean satellites

Dec 2004

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2004jgre..10912008b&link_type=abstract

Journal of Geophysical Research, Volume 109, Issue E12, CiteID E12008

Mathematics

Logic

16

Planetology: Comets And Small Bodies: Satellites, Planetology: Solar System Objects: Jovian Satellites, Planetology: Solid Surface Planets: Interiors (8147)

Scientific paper

At the temperatures and stresses associated with the onset of convection in an ice I shell of the Galilean satellites, ice behaves as a non-Newtonian fluid with a viscosity that depends on both temperature and strain rate. The convective stability of a non-Newtonian ice shell can be judged by comparing the Rayleigh number of the shell to a critical value. Previous studies suggest that the critical Rayleigh number for a non-Newtonian fluid depends on the initial conditions in the fluid layer, in addition to the thermal, rheological, and physical properties of the fluid. We seek to extend the existing definition of the critical Rayleigh number for a non-Newtonian, basally heated fluid by quantifying the conditions required to initiate convection in an ice I layer initially in conductive equilibrium. We find that the critical Rayleigh number for the onset of convection in ice I varies as a power (-0.6 to -0.5) of the amplitude of the initial temperature perturbation issued to the layer, when the amplitude of perturbation is less than the rheological temperature scale. For larger-amplitude perturbations, the critical Rayleigh number achieves a constant value. We characterize the critical Rayleigh number as a function of surface temperature of the satellite, melting temperature of ice, and rheological parameters so that our results may be extrapolated for use with other rheologies and for a generic large icy satellite. The values of critical Rayleigh number imply that triggering convection from a conductive equilibrium in a pure ice shell less than 100 km thick in Europa, Ganymede, or Callisto requires a large, localized temperature perturbation of a few kelvins to tens of kelvins to soften the ice and therefore may require tidal dissipation in the ice shell.

Affiliated with

Also associated with

No associations

Rating

Convective instability in ice I with non-Newtonian rheology: Application to the icy Galilean satellites does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Convective instability in ice I with non-Newtonian rheology: Application to the icy Galilean satellites, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Convective instability in ice I with non-Newtonian rheology: Application to the icy Galilean satellites will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1085922