Slow solar wind in different phases of solar cycle as observed by Ulysses

Abstract

In this paper we have analysed slow solar wind observations from Ulysses' full orbit to study the slow solar wind during ascending phase, maximum phase and declining phases of solar cycle 22 and 23. The slow solar wind region occurred in equatorial region near the decline phase of solar cycle 22, polar region near the maximum phase of solar cycle 23 and ecliptic region near the decline phase of solar cycle 23. In polar region, Ulysses observed slow solar wind during solar maximum and this phase coincides with the polarity reversal phase. Active regions are occupied by mixed polarities. The presence of multiporarities plays a significant role for the slow solar wind formation. The multi polarities often form closed magnetic loops and they are found to spread over wide coronal surface, accompanying small coronal holes that forms ambient solar wind from the surface of Sun. With high concentrations of proton particle, the solar wind that emerges during the polarity reversal is found to have slow solar wind. The slow solar wind near solar maximum have been studied and found that the slowing down of solar wind is associated with solar active regions of multi poles. Moreover the magnetic loops existing among the Sun’s spots restrict the free flow of solar wind plasma.