Fractality of Magnetic Helicity Distribution in the Solar Corona
We find a universal power-law scaling of magnetic helicity distribution in the solar corona. Magnetic helicity is a dynamical invariant for ideal magnetohydrodynamics (MHD) and characterizes complex magnetic field structure by measuring the degree of knottiness of its field lines. We treat turbulent...
Saved in:
| Main Authors: | , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
IOP Publishing
2025-01-01
|
| Series: | The Astrophysical Journal |
| Subjects: | |
| Online Access: | https://doi.org/10.3847/1538-4357/adaaed |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| Summary: | We find a universal power-law scaling of magnetic helicity distribution in the solar corona. Magnetic helicity is a dynamical invariant for ideal magnetohydrodynamics (MHD) and characterizes complex magnetic field structure by measuring the degree of knottiness of its field lines. We treat turbulent solar magnetic field as a superposition of random waves and develop a statistical topology method regarding the randomly tangled field lines. Based on the statistical behavior of the field lines, we consider their topology-specified structure and theoretically derive power laws for the distribution of magnetic flux and helicity. We find a power law of −7/4 to the magnetic helicity distribution when the field line topology is equivalent to handle and −5/4 when the field line topology is local open curve. We verify the universality of this new magnetic helicity fractality by observation to a number of 185 sunspots in newly emerging active regions during the 23rd and 24th solar cycle. This new distribution law reveals the fractal structure of the solar magnetic field. |
|---|---|
| ISSN: | 1538-4357 |