## Abstract

Abstract: Based on data obtained from numerical modeling of an active region (AR) of the Sun with the codes of radiation magnetohydrodynamics (MURaM), the horizontal gradient of the vertical component of the magnetic field on three layers in the vicinity of the photosphere ∇_{h}B_{z} and the horizontal component of the electric current density j_{h} for the AR of the flare were calculated. It was found that ≈90% of the calculated pixels contain j_{h} and ∇_{h}B_{z} of the same order, but these quantities are weakly correlated. The correlation coefficient is calculated for several groups of pixels that are distinguished by the magnitude of the horizontal current and the magnetic-field configuration. The correlation coefficients for these cases did not exceed 0.34 for the lower layer and 0.54 for the upper one. The contours of the strong j_{h} and ∇_{h}B_{z} (in units of electric current density) are also weakly correlated. The result may indicate that caution must be taken when the horizontal-field gradient is used for approximation of the horizontal current in the photosphere (in particular, in the development of methods for the forecasting of flares). In additional, the probability-density functions PDF(|in AR photosphere are constructed. They show that the median value of the ratio of the horizontal current to the vertical current is 3.5. This is consistent with the few estimates of various components of currents in real solar ARs and indicates the importance of the further study of horizontal currents.

Original language | English (US) |
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Pages (from-to) | 956-963 |

Number of pages | 8 |

Journal | Geomagnetism and Aeronomy |

Volume | 61 |

Issue number | 7 |

DOIs | |

State | Published - Dec 2021 |

Externally published | Yes |

## All Science Journal Classification (ASJC) codes

- Geophysics
- Space and Planetary Science