Noteworthy Returns from Titan’s Schumann Resonance revealed by HASI-PWA Huygens Instrument

Abstract : After the confirmed absence of any detectable lightning activity in Titan’s atmosphere, the only conceivable generation mechanism of Titan’s Schumann Resonances comes from sets of ionopause current sheets induced by Saturn’s magnetosphere interaction. A day-­‐light/ram-­‐side atmospheric profile model applicable to Huygens descent is constrained by the Modal Equations of the observed 2nd SR Eigenmode. The same method allows to constrain the thickness and the average permittivity of the icy crust, and to reveal the presence of a liquid water ocean buried from 60 to 80 km below the surface. The model accounts for the observation of the 2nd mode only, because the meridional orientation of Saturn’s magnetic field at the Titan’s interface during bi-­‐polar condiLons. The strength of secondary magnetic field induced in the atmosphere by the current sheets is decreasing from a few nT at 1000 km down to about 0.3 nT at 200 km altitude, extending far beneath the surface and the buried ocean. The fleeting remanence of this magnetic field after Titan would have left the Saturn’s magnetosphere could explain the existence of a “fossil” field observed in such a case