  We investigate the evolution of both normal and inverse CMEs ejected at
different initial velocities, and observe the effect of the background wind
density and their magnetic polarity on their evolution up to 1 AU. We performed
2.5D simulations by solving the magnetohydrodynamic equations on a radially
stretched grid, employing a block-based adaptive mesh refinement scheme based
on a density threshold to achieve high resolution following the evolution of
the magnetic clouds and the leading bow shocks. All the simulations discussed
in the present paper were performed using the same initial grid and numerical
methods. The polarity of the internal magnetic field of the CME has a
substantial effect on its propagation velocity and on its deformation and
erosion during its evolution towards Earth. We quantified the effects of the
polarity of the internal magnetic field of the CMEs and of the density of the
background solar wind on the arrival times of the shock front and the magnetic
cloud. We determined the positions and propagation velocities of the magnetic
clouds and thus also the stand-off distance of the leading shock fronts (i.e.
the thickness of the magnetic sheath region) and the deformation and erosion of
the magnetic clouds during their evolution from the Sun to the Earth. Inverse
CMEs were found to be faster than normal CMEs ejected in the same initial
conditions, but with smaller stand-off distances. They also have a higher
magnetic cloud length, opening angle, and mass. Synthetic satellite time series
showed that the shock magnitude is not affected by the polarity of the CME.
However, the density peak of the magnetic cloud is dependent on the polarity
and, in case of inverse CMEs, also on the background wind density. The
magnitude of the z-component of the magnetic field was not influenced by either
the polarity or the wind density.
