The magnetic field permeating the solar atmosphere is expected to originate from the bottom of the convection zone. The field is amplified in the tachocline and stored in the stably stratified overshoot region at the interface to the radiative core. When the field strength is larger than a critical value, perturbations lead to the formation of rising flux loops, which eventually emerge at the surface. The above figure shows the rise of a magnetic flux loop in the convection zone, from the onset of the instability (left) to its eruption at the stellar surface (right). The flux tube radius is shown 5 times magnified. The animation can be seen upon clicking on the figure. The initial flux tube is in mechanical equilibrium in mid-overshoot region near the bottom of the convection zone. The initial latitude is 5 degrees, and the initial magnetic field strength is 10 Tesla. The tube radius is 1000 km and is shown 5 times magnified for better visibility.

At present, we study the effects of transversal and longitudinal flows on a magnetic flux tube near the bottom of the convection zone. References to the first two papers in the series are given below.