  Aims: Our goal is to propagate multiple eruptions - obtained through
numerical simulations performed in a previous study - to 1 AU and to analyse
the effects of different background solar winds on their dynamics and structure
at Earth. We also aim to improve the understanding of why some consecutive
eruptions do not result in the expected geoeffectiveness, and how a secondary
coronal mass ejection (CME) can affect the configuration of the preceding one.
Methods: Using the 2.5D magnetohydrodynamics (MHD) package of the code
MPI-AMRVAC, we numerically modeled consecutive CMEs inserted in two different
solar winds by imposing shearing motions onto the inner boundary. The initial
magnetic configuration depicts a triple arcade structure shifted southward, and
embedded into a bimodal solar wind. We compared our simulated signatures with
those of a multiple CME event in Sept 2009 using data from spacecraft around
Mercury and Earth. We computed and analysed the Dst index for all the
simulations performed. Results: The observed event fits well at 1 AU with two
of our simulations, one with a stealth CME and the other without. This
highlights the difficulty of attempting to use in situ observations to
distinguish whether or not the second eruption was stealthy, because of the
processes the flux ropes undergo during their propagation in the interplanetary
space. We simulate the CMEs propagated in two different solar winds, one slow
and another faster one. Only in the first case, plasma blobs arise in the trail
of eruptions. Interestingly, the Dst computation results in a reduced
geoeffectiveness in the case of consecutive CMEs when the flux ropes arrive
with a leading positive Bz. When the Bz component is reversed, the
geoeffectiveness increases, meaning that the magnetic reconnections with the
trailing blobs and eruptions strongly affect the impact of the arriving
interplanetary CME.
