The use of geophysical tools for subsurface characterization is a common
practice in environmental studies and georesources engineering. The
electrical conductivity of the subsurface is strongly influenced by the
different properties of the subsurface such as pore fluid chemistry, and
consequently, by subsurface processes that affect the spatial
distribution of that chemistry, such as the mixing dynamics of pore
fluids. In the context of freshwater-saline water interaction in coastal
areas, changes in solute spatial distribution are coupled to
density-driven flow, which can thus be monitored via geoelectrical
measurements. Here, we study the Rayleigh Taylor instability and
subsequent convection occurring due to the density difference between
two miscible liquids when the lighter one is positioned on top of the
denser one, a configuration that is relevant for saltwater-freshwater
interactions in coastal aquifers. We simulate the convective process and
monitor it numerically by computing the transverse apparent conductivity
of the medium in time, as the convection develops. We then look for
correlations between the geoelectrical signal and a global scalar
measure of the convective process' advancement, namely the variance of
the solute concentration field.