On the Causes of the Slow Solar Wind: 1. The Solar Unipolar Induction Currents.

The cause of the solar wind is sought on a large‐scale (J × B) force resulting from the solar unipolar induction current, rather than coronal heating and small‐scale processes in the corona. In this paper, we consider the unipolar induction system considered by Alfven (1981, https://doi.org/10.1007/978-94-009-8374-8) the polar current (1.5 × 109 A) flowing out from the polar region of the sun spreads down longitudinally, which produces azimuthal magnetic fields. We considered two models, A and B. In Model A, the current spreads down fairly uniform in five divided regions of the heliosphere (rather than flowing only along the outer surface of the heliosphere). The resulting (J × B) force is mainly directed outward, causing an outward flow of the heliospheric plasmas. However, in this case, the speed at a distance of 1 AU is only 1 km/s, although the acceleration in each divided region is much greater than the solar gravity. In Model B, one third of the dynamo current is assumed to be concentrated in the area between 9.5 R☉ and 10.5 R☉ (where R☉denotes the solar radius) and B = 10−6 T (103 nT) at 10 R☉. The acceleration is estimated to be 1.4 × 102 m/s2 and the resulting speed at 1 AU is 200 km/s. Therefore, there is a possibility that the solar unipolar induction provides partially a new possibility for the cause of a slow, bulk flow of the solar wind. Plain Language Summary: Based on Alfven's solar unipolar induction system, it is shown that the resulting (J × B) force could generate solar wind speed of 200 km/s at 1 AU under several reasonable assumptions. Key Points: The cause of the solar wind is sought on the basis of Alfven's solar unipolar induction current system, rather than an initial heatingThe resulting (J × B) force is applied to the corona between 9.5 and 10.5 solar radii, accelerating the solar wind to 200 km/sThe result is applicable for slow and uniform solar wind with polar angle of 0–70° during the solar cycle minimum phase [ABSTRACT FROM AUTHOR]