The solar wind velocity and its correlation with cosmic-ray variations and with solar and geomagnetic activity

Abstract

Mariner 2 obtained data on the interplanetary plasma during the period August 29, 1962, through January 3, 1963. The daily average plasma velocity is presented and compared with data on cosmic‐ray diurnal variations and with indices of solar and geomagnetic activity for this period. The only strong correlation found is that between plasma velocity and the geomagnetic index Kp. The plasma velocity showed a very strong 27‐day recurrence tendency and a close association with M‐region geomagnetic storms, indicating that solar M‐regions are emitters of high‐velocity plasma. No dependence of plasma velocity on solar distance between 1.0 and 0.7 AU could be detected.

Solar wind interaction with Comet Bennett (1969i)

“…The Kp indices for April 2 and 3 were relatively low (Kp:5: 2 on April 2; Kp:5: 4 on April 3) suggesting speeds:5:· 400 km/sec (Snyder et al(1963). The uncertainties in obtaining V in this way are, however, rather large.…”

“…In fact, it is still not even known whther fast solar-wind streams come from active regions or~uite regions on the sun. Similarly, there is only a weak correlation between solar-wind conditions and geomagnetic activity as measured by the D<:P index (Snyder et al, 1963;Ogilvie et al, 1968). Thus, to obtain definitive results concerning the short-term variations in comet tails, it is necessary to relate comet observations directly to solar-wind measurements.…”

The Wide-Field Imager for Solar Probe Plus (WISPR)

“…The solar wind, the constant outflow of plasma and magnetic field from the Sun's outer layer, the solar corona, was one of the first scientific discoveries of the space era (Parker 1958;Snyder et al 1963). Its basic properties are well understood around the Earth and, to a lesser degree, in the inner heliosphere thanks to in-situ measurements by a large number of solar probes over the years.…”

Solar wind stream interfaces in corotating interaction regions: New SWICS/Ulysses results

“…In-ecliptic fast and slow solar winds have already been observed for nearly 35 years [e.g., Snyder et al, 1963]. It has long been known that high-speed streams originate in coronal holes [Krieger et al, 1973] and that the slow solar wind originates in the streamer belt [Gosling et al, 1981].…”