Abstract:
The radial dependence of the coronal magnetic field above active regions is calculated using Type-I chain data existing in the literature. Assuming that Type-I emission is due to shock waves, the upstream shock velocity and the density jump across the shock are obtained respectively from the drift rate and the bandwidth of the Type-I chains. Making use of the shock velocity and the density jump in the Rankine-Hugoniot relation, the Alfvén velocity and hence the magnetic field in the corona is calculated. The results are compared with existing estimates.
