  Standard models of force balance along Jovian field lines predict the
location of the Io plasma torus to be the centrifugal equator of Jupiter's
magnetosphere, i.e. the position along the magnetic field lines farthest away
from Jupiter's rotational axis. In many models, the centrifugal equator is
assumed to lay on a plane, calculated from a (shifted) dipole magnetic field,
rather than on a warped surface which incorporates Jupiter's higher magnetic
field moments. In this work, we use Hubble Space Telescope observations of the
Io Main Footprint to constrain density, scale height and lateral position of
the Io Plasma Torus. Therefore, we employ the leading angle of the footprints
to calculate expected travel times of Alfven waves and carry out an inversion
of the observations. For the magnetic field we use the JRM33 magnetic field
model. The inversion results show peak densities between 1830 and 2032
particles per cubic centimenter and scale heights between 0.92 and 0.97 Jupiter
radii consistent with current literature values. Using a warped multipole
centrifugal equator instead of a planar dipole increases the quality of the fit
by about twenty-five percent. We additionally develop two tests to confirm that
the multipole centrifugal equator from the JRM33 model fits explains the
applied data set better than the dipole centrifugal equator. The quadropole
moments alter Io's relative position to the torus, which changes the plasma
density around Io by up to twenty percent.
