EIT Waves, Coronal Shock Waves, and Solar Energetic Particle Events

EIT waves are often associated with Solar type II radio bursts as recently revealed by Klassen et al. [2000]. It is well-known that Solar type II radio bursts are generated by shock waves traveling through the corona of the Sun. Since both phenomena are causally connected with each other, they can be used as a diagnostic tool of the magnetic field in the corona. Thus, a magnetic field of 2.2 G and 0.5 G is deduced to be at the photosphere and at a distance of 2 Solar radii above quiet Solar regions, respectively. Such a behaviour of the magnetic field leads to a local maximum of the Alfven speed of about 740 km/s at a distance of 3.8 Solar radii. The occurrence of such a maximum has important consequences for the formation and development of shock waves in the Solar corona and the near-sun interplanetary space and their ability to accelerate particles leading to Solar energetic particle events.