No CrossRef data available.
Published online by Cambridge University Press: 14 August 2015
The magnetograph of the High Altitude Observatory station at Climax has been used to study changes in the longitudinal component of the magnetic field in a number of active regions. For a description of the instrument see Lee, Rust, and Zirin (1965). By securing simultaneous Hα pictures of the regions we compare the magnetic data with the optical appearance of the plages. From such studies we have selected the results of two active regions to present here.