Self‐organized Criticality from Separator Reconnection in Solar Flares

Autor:	E. J. Noonan, Dana Longcope
Rok vydání:	2000
Předmět:	Physics Solar flare Coronal hole Astronomy and Astrophysics Magnetic reconnection Astrophysics Mechanics Power law Self-organized criticality law.invention Nanoflares Space and Planetary Science law Physics::Space Physics Astrophysics::Solar and Stellar Astrophysics Magnetohydrodynamics Flare
Zdroj:	The Astrophysical Journal. 542:1088-1099
ISSN:	1538-4357 0004-637X
DOI:	10.1086/317050
Popis:	A new cellular automaton model for solar flares is presented in which a complex coronal magnetic field is stressed by photospheric shear. The minimum current corona model is used to describe the slow buildup and sudden release of stress in the field. Stress takes the form of currents flowing along the field's network of magnetic separators; it is released by magnetic reconnection. By this model we show how magnetic reconnection can occur as an avalanche, releasing stress along an extended region of the separator network. The model exhibits self-organized criticality; thus the sizes of reconnection avalanches are distributed according to a power law. Flare durations and peak emission levels are also distributed according to power laws, with different exponents. Because the model is derived from the application of magnetohydrodynamics to a coronal field, it is possible to assign physical sizes to its avalanches. These agree well with the sizes and frequencies of observed flares. The total power from flares of all sizes agrees with observation and is therefore well below the inferred coronal heating power.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::8d5f22e9b8c462f009f069604c09d192 https://doi.org/10.1086/317050 Zobrazit plný text záznamu