Coronal ⋌5303 intensity, geomagnetic activity and solar sources of high-speed plasma streams

Abstract

Investigations during the last 30 yr of the relationship between the green emission line corona and geomagnetism have yielded contradictory results. The papers on this subject can be separated into 2 groups; (a) papers reporting a negative correlation between green line intensity and geomagnetic activity, and (b) papers reporting a positive correlation. The negative correlation seems to be the one better supported by solar wind theory and observations. It implies that solar active regions are the base of low expansion speeds, whereas quasistationary high-speed solar plasma streams originate from regions of low density and open magnetic field structures In the present paper we have re-examined some of the analyses described in the group (b) papers. It is found that instead of indicating a positive correlation, these analyses in fact favour the negative correlation. Thus there does not appear to be any conflict at all between the different papers. The interpretation in favour of the positive correlation seems to be due to some accident of perspective having obscured the true connection