Over-expansion of coronal mass ejections modelled using 3D MHD EUHFORIA simulations

Coronal mass ejections (CMEs) are large scale eruptions observed close to the Sun. They travelling through heliosphere and possibly interacting with Earth environment creating interruptions or even damaging new technology instruments. Most of time their physical conditions (velocity, density, pressure) only measured in situ at one point space, no possibility have information on variation these parameters during journey from Sun Earth. Our aim is understand evolution internal a set three particular fast halo CMEs. These CMEs were launched between 15 18 July 2002. Surprisingly, related interplanetary (ICMEs), near Earth, low, case very plasma density. We use EUropean Heliosphere FORecasting Information Asset (EUHFORIA) model simulate propagation background solar wind by placing virtual spacecraft along Sun--Earth line. up initial 0.1 au, first cone then linear force free spheromak model. A relatively good agreement simulation results observations concerning speed, density arrival times ICMEs obtained adapting CME parameters. In particular, this achieved increasing magnetic pressure so that expansion induced inner heliosphere. This implied develop First, we show configuration an out balance mitigates EUHFORIA assumptions uniform velocity. Second, over-expansion ejected plausible origin for low some 1 au. The has possible coronal two ICMEs.