The Spiral Interplanetary Magnetic Field: A Polarity and Sunspot Cycle Variation

L. Svalgaard, J. M. Wilcox
1974 Science  
Spacecraft observations near the earth of the yearly average direction of the interplanetary magnetic field during the sunspot maximum year 1968 showed a deviation from the spiral field of E. N. Parker's classical description. The included angle between the average field direc-
doi:10.1126/science.186.4158.51 pmid:17818100 fatcat:mbl7mhavzjcjle2fba3x6erxry