A new source of the slow solar wind

Slow solar wind has been found to exhibit a high level of variability and the source of its origin is still unclear. Helmet streamers underneath the base of the heliospheric current sheet has been suggested to be the source of slow solar wind, though low latitude coronal holes could be another source. It has been shown recently that the helmet streamers occur between coronal holes of opposite polarity as well as between coronal holes of like polarity. The former is called the bipolar closed field regions and the latter unipolar closed field regions [Zhao and Webb, 2003]. We investigate the association of slow solar wind observed by WIND, ACE and IPS with unipolar closed field regions.