Further study of theθcomponent of the interplanetary magnetic field

Measurements of the interplanetary magnetic field taken with Imp 3, Pioneer 6, and Explorer 34 constitute a large portion of the data available at low and moderate solar activity and provide nearly continuous coverage from mid-1965 through 1966 without radial effects. Study of these observations provides further evidence for the following Bθ effect initially discovered with Mariners 2, 4, and 5. At low or moderate solar activity, the mean value of Bθ is negative (approximately northward in our observations) above the solar equatorial plane and positive below it for an interplanetary field directed outward from the sun, and vice versa, for an inward field. Thus, for an outward field, the γ−θ component of a line of magnetic force above or below the equatorial plane was skewed relative to in the direction away from the equatorial plane. Comparisons between different spacecraft are discussed.