Coronal holes near the equatorial plane and the solar wind abundance of iron

Abstract

Composition analysis of the solar wind from two equatorial coronal holes has been carried out with the Ion Composition Instrument on the ISEE‐3 spacecraft. The abundances of oxygen, neon and iron were determined as coronal hole‐related material flowed past the spacecraft. The results show that the edges of the hole‐related flow are sharply defined with abundances closer to the abundances in the photosphere than in the slower solar wind. These results are similar to those found in flows from the southern polar coronal hole and suggest an underlying unity between the polar and equatorial regions of the sun.