Comparison of solar wind streams and coronal structure near solar minimum

We examine the relationship between high speed streams of solar wind and coronal structure during the period September-December, 1976. The solar wind streams during this period were generally of lower amplitude, lower maximum velocity, and shorter duration than those in the preceding Skylab period. Solar wind data are compared with X-ray images of the corona taken on 16 September and 17 November, 1976. A moderate sized stream was seen during September when no equatorial coronal holes were observed. Although there was an equatorial extension from the North polar hole, it was smaller and less well-defined than those of the Skylab period; thus it seems to be a poor candidate for the source of the stream. The November image shows a better-defined extension from the South polar hole; it may well be the source of a small solar wind stream with peak of approx.510 km/sec. These results suggest that either there has been a change in the solar wind-coronal hole relationship or that the relationship is not as general as might be inferred from the Skylab period