On the explosive nature of auroral substorms and solar flares: The electric current approach

Abstract. The sequence of phenomena consisting of solar flares, coronal mass ejections (CMEs), auroral substorms, and geomagnetic storms is mostly a manifestation of electromagnetic energy dissipation. Thus, first of all, it is natural to consider each of them in terms of a sequence of power supply (dynamo), power transmission (electric currents/circuits), and dissipation (mostly observed phenomena), i.e., as an input–output process and the electric current line approach. Secondly, extending this concept, it is attempted in this paper to consider the whole solar–terrestrial relationship in terms of electric currents. This approach enables us to follow through not only the sequence in solar flares, auroral substorms, and geomagnetic storms but also to connect all phenomena naturally as a continuous flow of magnetic energy (V[B2∕8π]) from the sun across the magnetopause. This consideration gives some insight into all the processes involved equally well compared with the magnetic field line approach, which has been adopted almost exclusively in the past.

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Four Subjects in Solar Physics from the Point of View of the Electric Current Approach

Global Journal of Science Frontier Research ◽

10.34257/gjsfravol21is3pg33 ◽

2020 ◽

pp. 33-45

Author(s):

Syun-Ichi Akasofu

Keyword(s):

Solar Wind ◽

Electric Current ◽

Solar Flares ◽

Solar Physics ◽

Current Approach ◽

Point Of View ◽

Coronal Temperature ◽

The Past ◽

Electromagnetic Processes ◽

Difficult Subjects

Four major subjects in solar physics, the heating of the corona, the cause of the solar wind, the formation of sunspots and the cause of solar flares, are discussed on the basis of the electric current approach, a sequence of processes consisting of power supply(dynamo), transmission (currents/circuits) and dissipation(high coronal temperature, solar wind, sunspots and solar flares).This is because the four subjects have hardly been considered in terms of the electric current approach in the past, in spite of the fact that these subjects are various manifestations of electromagnetic processes. It is shown that this approach provides a new systematic way of considering each subject; (1) the long-standing issue of the coronal temperature, (2)the long-standing problem on the cause of the solar wind, (3)the presence of single spots(forgotten or dismissed in the past) and its relation to unipolar magnetic regions and (4) the crucial power/energy source and subsequent explosive processes of solar flares. The four subjects are obviously extremely complicated and difficult subjects, but it is hoped that the electric current approach might provide a new insight in considering the four subjects.

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Auroral Substorms: Search for Processes Causing the Expansion Phase in Terms of the Electric Current Approach

Space Science Reviews ◽

10.1007/s11214-017-0363-7 ◽

2017 ◽

Vol 212 (1-2) ◽

pp. 341-381 ◽

Cited By ~ 15

Author(s):

Syun-Ichi Akasofu

Keyword(s):

Electric Current ◽

Current Approach ◽

Expansion Phase ◽

Auroral Substorms

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Photospheric dynamo as the power supply process for solar flares: Electric current approach

Physics & Astronomy International Journal ◽

10.15406/paij.2018.02.00093 ◽

2018 ◽

Vol 2 (3) ◽

pp. 243-250

Author(s):

Syun Ichi Akasofu

Keyword(s):

Electric Current ◽

Power Supply ◽

Solar Flares ◽

Current Approach

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A Review of Studies of Geomagnetic Storms and Auroral/Magnetospheric Substorms Based on the Electric Current Approach

Frontiers in Astronomy and Space Sciences ◽

10.3389/fspas.2020.604750 ◽

2021 ◽

Vol 7 ◽

Author(s):

Syun-Ichi Akasofu

Keyword(s):

Electric Current ◽

Geomagnetic Storms ◽

Current Approach ◽

Space Physics ◽

Point Of View ◽

Magnetospheric Substorms ◽

New Science ◽

Auroral Substorms ◽

The Magnetic Field ◽

Present Understanding

The progress of space physics is reviewed from my personal point of view, particularly how I have reached my present understanding of auroral substorms and geomagnetic storms from the time of the earliest days of space physics. This review is somewhat unique in two ways. First of all, instead of taking the magnetic field line approach (including magnetic reconnection), I have taken the electric current approach; it consists of power supply (dynamo), transmission (currents/circuits), and dissipation (auroral/magnetospheric substorms). This is the basic way to study electromagnetic phenomena and it is much more instructive in understanding the physics involved in the chain processes. Secondly, this is not a textbook-like review, but it is hoped that my humble experience may be useful to see how a new science of space physics has evolved with a number of controversies. On the other hand, it can be seen that the electric current approach is still in a very rudiment stage. Thus, new generations of researchers are most welcome in taking this new way of studying auroral/magnetospheric substorms and geomagnetic storms.

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