Title: Double-diffusive erosion of the core of Jupiter,
Abstract: We present Direct Numerical Simulations of the transport of heat and heavy
elements across a double-diffusive interface or a double-diffusive staircase,
in conditions that are close to those one may expect to find near the boundary
between the heavy-element rich core and the hydrogen-helium envelope of giant
planets such as Jupiter. We find that the non-dimensional ratio of the buoyancy
flux associated with heavy element transport to the buoyancy flux associated
with heat transport lies roughly between 0.5 and 1, which is much larger than
previous estimates derived by analogy with geophysical double-diffusive
convection. Using these results in combination with a core-erosion model
proposed by Guillot et al. (2004), we find that the entire core of Jupiter
would be eroded within less than 1Myr assuming that the core-envelope boundary
is composed of a single interface. We also propose an alternative model that is
more appropriate in the presence of a well-established double-diffusive
staircase, and find that in this limit a large fraction of the core could be
preserved. These findings are interesting in the context of Juno's recent
results, but call for further modeling efforts to better understand the process
of core erosion from first principles.