A loss of magnetic field confinement is believed to be the cause of coronal mass ejections (CMEs), a major form of solar activity in the corona. The mechanisms for magnetic energy storage are crucial in understanding how a field may possess enough free energy to overcome the Aly limit and open up. Previously, we have pointed out that the accumulation of magnetic helicity in the corona plays a s...

The observed zonal flows of the giant planets will, if they penetrate below the visible atmosphere, interact significantly with the planetary magnetic field outside the metallized core. The appropriate measure of this interaction is the Chandrasekhar number Q = H2 /4npvrx2 A (H = radial component of the magnetic field, v = eddy viscosity, A = magnetic diffusivity, rx1 = length scale on which A ...

Star formation occurs via accretion through a disk, which is likely to be turbulent, either because of gravitational or magnetorotational instability. Dynamo amplification of magnetic fields needs to be considered. As the disks are also stratified, the turbulence can be helical, with different signs of the helicity in each hemisphere. This provides a key ingredient for amplification of global s...