Coronal holes and solar-terrestrial relationships

Abstract

The role of long-lived and unstable coronal holes in perturbing the solar wind and disturbing the Earth's environment is discussed. Evidences of their relationship with galactic cosmic-ray flux at Earth, geomagnetic storms sudden commence-ments, and aurorae are presented. A discussion about the capability of coronal holes to produce such effects is also included, as well as some comments on their relation to solar transient events such as flares, eruptive prominences, and coronal mass ejections.