Three-dimensional properties of interplanetary disturbances in 1978–1981

This paper presents the average three-dimensional configuration of solar flare- or disappearing filament-associated interplanetary disturbances on the basis of IPS (interplanetary scintillation) and spacecraft observations in 1978–1981. The angular distribution of the propagation speed at 1 AU is largely isotropic over the range of 110° in solar longitude centered at the normal of the solar source. In the latitudinal direction, the characteristic angular extent is about 60°. Thus the three-dimensional shape of an interplanetary disturbance can be approximated by a half of an ellipsoid having an axial ratio of about 1.8.Paper presented at the IAU Third Asian-Pacific Regional Meeting, held in Kyoto, Japan, between 30 September–6 October, 1984.