STATISTICAL PROPERTIES OF MAGNETIC ACTIVITY IN THE SOLAR CORONA

The long-time statistical behavior of a two-dimensional section of a c oronal loop subject to random magnetic forcing is presented. The highl y intermittent nature of dissipation is revealed by means of magnetohy drodynamic (MHD) turbulence numerical simulations. Even with a moderat e magnetic Reynolds number, intermittency is clearly present in both s pace and time. The response of the loop to the random forcing, as desc ribed either by the time series of the average and maximum energy diss ipation or by its spatial distribution at a given time, displays a Gau ssian noise component that may be subtracted to define discrete dissip ative events. Distribution functions of both maximum and average curre nt dissipation, for the total energy content, the peak activity, and t he duration of such events are all shown to display robust scaling law s, with scaling indices delta that vary from delta similar or equal to -1.3 to delta similar or equal to -2.8 for the temporal distribution functions, while delta similar or equal to -2.6 for the overall spatia l distribution of dissipative events.