“…The piston could thus be attributed to the front of the CME itself, or the full CME bubble or loops, as has been reported by several observational studies (Patsourakos and Vourlidas, 2012). Some observational reports reinforce this picture (Kienreich, Temmer, and Veronig, 2009;Patsourakos and Vourlidas, 2009;Veronig et al, 2010;Grechnev et al, 2011b). If this is the case, the faster lobe of sectors 29 -34 could be related with a piston provided by a CME structure, probably stretched, non-radially rising, i.e.…”