Polar coronal holes and cosmic-ray modulation.
A comparison of the size of polar coronal holes with the cosmic-ray intensity observed during the most recent sunspot cycle shows close correspondence. This lends support to recent suggestions that the well-known sunspot-cycle modulation of cosmic rays is a three-dimensional effect, probably related to the global character of the interplanetary magnetic field.
Hundhausen
A J
AJ
Sime
D G
DG
Hansen
R T
RT
Hansen
S F
SF