“…In wave models, they are interpreted as a fastmode wave, most likely triggered by a CME, and represent the coronal counterpart of the Moreton waves (see, e.g., Vršnak & Cliver 2008;Patsourakos & Vourlidas 2012). In the non-wave models, they are explained by other processes related to the large-scale magnetic field reconfiguration and can be interpreted as a disk projection of the expanding envelope of the CME (see, e.g., Delannée & Aulanier 1999;Chen et al 2005;Attrill et al 2007), being usually much slower and more diffuse (see, e.g., Klassen et al 2000;Warmuth et al 2004a,b). According to Klassen et al (2000), 90% of the metric type II bursts are associated with EUV waves, but there is no correlation between their speeds.…”