Solar wind stream structure during the early phase of solar cycles 20 and 21

We compare average values of solar wind stream amplitude, maximum velocity and half-width for periods shortly after the minima preceding Solar Cycles 20 and 21. The differences between average amplitudes and half-widths are not significant, but higher maximum velocities were observed for streams during the early part of Cycle 21. Comparing with previously published results, we conclude that, except for the large streams seen late in the solar cycle, the variation of these stream parameters is nearly as large from cycle to cycle as it is within a solar cycle.