Coupling of Induced Magnetic Fields of Local Asymmetric Features in Subsurface Ocean Moons

In the recent decades, both ground-based and satellite observations provided
indirect evidence for the existence of subsurface oceans within Europa’s icy
crust (Kivelson et al., 2000; Roth et al., 2014). Since then, the search for icy
moons with similar features has been ongoing (e.g., Cochrane et al., 2021).
Such a subsurface ocean interacts with the time-varying magnetic field of
its host planet, resulting in an induced magnetic field (Khurana et al., 1998;
Saur et al., 2010). To model these induction responses, a radially symmetric
interior structure is generally assumed (Zimmer et al., 2000; Schilling et al.,
2007). Geological arguments, however, can motivate cases for asymmetric
features, e.g. tidal heating and the existence of chaos terrain on Europa
(Styczinski et al., 2022). We approximate such an asymmetric feature by
modelling a radially symmetric subsurface ocean together with a local small-
scale water reservoir of spherical shape. This results in a non-linear coupling
mechanism between the induction responses of ocean and reservoir. In our
presentation we will discuss the nature of such a non-linear coupled induction
and its effects on the potential detectability of small-scale water features for
future missions such as Europa CLIPPER.