Neutralized and unneutralized current patterns in the solar corona

Observations of the vector magnetic field at the photosphere suggest that there is a net current flowing through the corona along coronal magnetic loops from one footpoint to the other. There is also evidence that flare kernels correlate with regions of high current. The absence of any apparent return current through the corona is inconsistent with this current being generated by stresses in the photosphere or in subphotospheric layers after the loop has emerged from below the photosphere. The possibility that a return current is present and has escaped detection is discussed. If there is no return current, then a rethinking of several widely accepted ideas on solar magnetic fields and their role in solar flares is required.