NONLOCAL COMMUNICATION IN SELF-ORGANIZING MODELS OF SOLAR-FLARE OCCURRENCE

Recent avalanche models of solar flare occurrence which consider the m agnetised solar atmosphere to be in a state of self-organised critical ity have concentrated mainly on the magnetic field as the means by whi ch individual energy release sites communicate with neighbouring sites . This, however, neglects the possibility of remote triggering of ener gy release via fast particles. In this paper we augment the standard a valanche models of flare occurrence to include this possibility of 'no n-local' communication between sites. Non-local communication with jus t one or two remote sites does not observably modify the flare size di stribution (this quantity remains consistent with observations). Non-l ocal triggering of too many remote sites can, however, destroy the sel f-organised critical state. Our simulations also produce more general conclusions on the robustness of the self-organised critical state.