NONRADIAL MAGNETIC-FIELD STRUCTURES IN THE SOLAR CORONA

We report on the structure and geometry of coronal magnetic fields inf erred from the observations of meter-decimeter type HI and moving type IV radio bursts, associated with a Halpha flare. This is the first re port of type III radio bursts from the Nanc ay radioheliograph after i t acquired the two-dimensional multifrequency capability. Dispersion o f the radio source positions with frequency suggests that open and clo sed field lines are considerably inclined to the radial direction whic h is consistent with the connectivity observed in the magnetogram. We suggest that multiple arch systems are involved in the type IV emissio n. From the polarization and dispersion characteristics of the type IV source, we infer that the emission is due to fundamental plasma emiss ion.