Global heliospheric disturbances near 1 AU caused by the launch of solar transients on January 1 and September 23, 1978.

We revisit the transient events of January and September 1978. In the January event the ejecta (an interplanetary magnetic cloud, IMC) was studied using multiple spacecraft observations [Burlaga et al., 1981]. In the September event Reames et al., 1997 studied the spectral characteristics of the energetic particles of this big particle event with a driven shock passage observed at longitudes nearly 180° apart. Here we present a combined analysis of the overall solar wind and energetic particles (EP) features of the shock and the driver, observed at different locations in longitude. We further evaluate the Rankine-Hugoniot properties of the shock at the locations its passage is observed and add modeling of the driven shock using a three dimensional MHD code which, at this stage of the analysis, does not include the magnetic structure of the ejecta. For the study of the shock velocity we use remote type II radio burst observations from near Earth (the September event), and at different longitude locations we examine: (a) flux intensity of the energetic particles, (b) shock strength, (c) timing of the shock structure and the driver passage at each spacecraft to infer the possible location of the nose of the shock. A preliminary assessment on the connection between the global nature of the shock and the observed level of energetic particle flux will be presented. The data sets include the kilometric radio measurements on ISEE3, and the 3 to 80 MeV energetic proton flux data from IMP-8, and a similar energy range from Helios at wide longitudinal locations relative to Earth. For the solar wind parameters we use magnetic field and plasma parameters from instruments at Helios 1, and 2, and ISEE3 and IMP-8. The data set is completed with the Dst index (Kyoto). We acknowledge partial support from NSF and NASA grants, and the NSSDC for on-line access to their space science data archives. Burlaga LF, E. Sittler, F. Mariani, and R. Schwenn, Magnetic loop behind an interplanetary shock: Voyager, Helios, and IMP-8 observations, J. Geophys. Res., 86, 6673, 1981. Reames, DV, SW Kahler,, and CK Ng, Spatial and temporal invariance in the spectra of gradual particles in gradual solar events, Astrophys. J., 491, 414, 1997.