On the Connection of Coronal Loop Plasma with the Ambient Magnetic Field

Abstract Solar coronal loops are magnetically confined plasma structures whose properties are closely linked to the ambient magnetic field. Using 3D magnetohydrodynamic simulations of kink-unstable coronal flux tubes, we investigate how the intensity of the ambient magnetic field influences the thermal regime of coronal loops. The simulations, performed with the PLUTO code, explore field strengths between 10 and 80 G under continuous photospheric twisting that drives magnetic reconnection and heating through anomalous resistivity. After an initial transient, the system reaches a statistically steady state characterized by persistent nanoflare-like energy release. We find that the differential emission measure distributions increase in magnitude and shift to higher temperatures with increasing magnetic field strength, while being largely insensitive to other parameters such as resistivity and resolution. Extending the classical Rosner–Tucker–Vaiana scaling laws, we derive a scaling relation for the loop temperature, T ∝ B 4/7 , which quantitatively matches the simulation results. This study demonstrates that the strength of the ambient coronal magnetic field is the primary factor determining the thermal state of coronal loops, providing a physically grounded connection between magnetic field measurements and observed coronal temperatures.