0 20 40 60 80 100 c$_{s}$t /a 10 -4 10 -3 10 -2 10 -1 10 0 Q$_{i}$ $_{e}$ = 1x10 -4 $_{e}$ = 2x10 -4 $_{e}$ = 4x10 -4 $_{e}$ = 8x10 -4 FIG. 6: Competing growth of ITG, microtearing and IBM instabilities determine onset times and intensities of the blowout time traces Q$_{i}$ ( t ) when scaling with the local plasma beta: for β$_{e}$ = 10 − 4 only an ITG micro-instability is growing around t = 50 and saturating on a low H-mode transport level. For β$_{e}$ = 2 · 10 − 4 the IBM instability dominates and leads to a clean ELM signal around t = 20. In the nominal case ( β$_{e}$ = 2 · 10 − $^{4}$) ITG and IBM MHD growth compete initially with similar growth rates but the ideal ballooning mode takes over around t = 30 and further determines the blowout. For β$_{e}$ = 8 · 10 − 4 a microtearing instability is saturating on a gyro-Bohm transport level around t = 20 and is transformed into more violent ITG MHD turbulence after deterioration of the initial electron temperature gradient ( t > 50) . of ρ$_{i}$ at unit order, in turn, necessitates a nonlinear gyrofluid model (and at some later date, a nonlinear gyrokinetic model). The characteristics of the blowout at various plasma beta is studied for 0 . 5 · 10 − 4 < β$_{e}$ < 8 · 10 − $^{4}$, with the absolute β a factor of 4 . 8 higher due to the T$_{i}$/T$_{e}$ = 1 . 2 value. A competition between unstable growth of ITG high-n modes and IBM low-n modes is observed: For low β an early onset of ITG turbulence degenerates the profile and influences the strength of the IBM. For large β the nonlinear saturation is acting faster and stronger. The two effects lead to a rather nondistinctive result concerning the peak ELM flux as shown in Fig. 6, with a continuous transition between ITG and IBM triggered onset of the turbulent aftermath. The presence or absence of background current gradient terms, which in this model are set by replacing ( ˜ J$_{|}$$_{|}$ → ˜ J$_{|}$$_{|}$ + J 0 ) everywhere the electron parallel velocity ˜ ν$_{|}$$_{|}$ appears in the equations, with J 0 given by the q profile, was found to have no discernible effect on the result. Indeed self-consistent inclusion of ∇ J 0 effects with possible role in the L-to-H 23