Correlations between cosmic-ray fluctuations and solar-wind parameters

There have long been theoretical and experimental researches on cosmic-ray fluctuations, but there is still a lack of clarity on the correlation between them and processes on the Sun, in interplanetary space, and in the Earth's magnetosphere and atmosphere. Here we relate these fluctuations to changes in the solar-wind parameters having periods close to 160 min. The studies have been based on the five-minute and hourly measurements on the neutron intensity at Tbilisi and Moscow stations together with the solar-wind parameters; at the epoch of solar minimum activity (in 1985), when there were few perturbation sources on the Sun, it was more likely that there was an unambiguous effect from solar oscillations on the solar wind than at maximum activity. Autocorrelation and spectral-analysis methods have been applied to segments of the recordings in April and May 1985 at Tbilisi and Moscow.