Scalar time signatures for the periodic release of alternating‐sign magnetic structures in case M2. (a) Maximum value of u over the computational domain plotted against time. (b) Maximum values of B_x (solid line) and the modulus of the minimum value of B_x (dashed line) vs. time. It can be seen that, after an initial increase and then saturation at equilibrium values, this state becomes unstable to the shear‐buoyant instability. Strong magnetic fields of alternating sign in the emerging structures dominate the magnetic measure, and oscillations in the maximum of u appear, showing that the background shear velocity is affected in this process.