NASA Goddard Space Flight Center, Laboratory for Extraterrestrial Physics, Greenbelt, Maryland 20771

Plasma and magnetic field variations observed on July 28-30, 1977, in the near-earth solar wind are presented and discussed. Both a corotating stream and a driven shock are present. The driver gas seems to be enveloped in the rising speed phase of this stream; this appearance is attributed to a transverse-motion-induced convoluted surface separating the two plasma domains. The magnetic field in the post shock flow (0030-1230 UT of July 29) has a large and geoeffective southward component at times; the Akasofu energy coupling coefficient 'e ' reaches ~5.4 X 10¹⁹ ergs/s. In the driver gas (1230 UT of July 29 to 0110 UT of July 30) the magnetic field is dominantly northward and has a profile resembling a magnetic cloud. Significant plasma parameter variations within the driver gas are attributed to structure in the parent solar mass ejection event and to interplanetary kinematics. The density and dynamic pressure decrease by almost 2 orders of magnitude (³ 100 to £ 2 cm^-3) from just behind the interplanetary shock to ~3 hours into the driver gas flow.

J. Geophys. Res., 87, No. A8, 5881-5887, Aug. 1982