Interplanetary flow systems associated with cosmic ray modulation in 1977–1980

The hydromagnetic flow configurations associated with the cosmic ray modulation in 1977–1980 were determined using solar wind plasma and magnetic field data from Voyager 1 and 2 and Helios 1. The modulation was related to two types of large‐scale systems of flows: one containing a number of transients such as shocks and postshock flows, the other consisting primarily of a series of quasi‐stationary flows following interaction regions containing a stream interface and often bounded by a forward‐reverse shock pair. Each of three major episodes of cosmic ray modulation was associated with the passage of a system of transient flows. Plateaus in the cosmic ray intensity‐time profile were associated with the passage of systems of corotating streams.