Zirin and his collaborators will use the frequency-agile interferometer at Owens Valley Radio Observatory to map coronal magnetic fields and electrical currents in active regions and near flares. They will also investigate the microwave spectra of active regions, small bipolar magnetic regions, and flares. Solar flares and other forms of activity near sunspots have dramatic effects on Earth. They are caused by electrical currents running in the solar corona. The radio detector developed by Zirin and Hurford, the "frequency-agile interferometer" at Owens Valley Radio Observatory, is the only instrument able to make detailed three-dimensional maps of these coronal currents. The mapping procedure will be perfected in time for the vigorous solar activity anticipated during the next solar maximum, in about 1990-1991.
