Solar Cycle Modulation of Vortex-Driven Magnetic Flux Tube Merging and Intensification

Abstract

The 11-year solar cycle governs the evolution of magnetic structures in the photosphere, influencing supergranular convection, flux tube dynamics, and energy transport to the solar corona. We present a comparative study of magnetic flux tube merging and intensification during solar minimum (2010) and solar maximum (2026) using SDO/HMI line-of-sight magnetograms. Our analysis shows that magnetic fields are substantially stronger during solar maximum (4927 G) than during solar minimum (4438 G), a 1.11-fold increase. We find that flux tube merging events are more frequent during solar maximum, with an 8-fold increase in the number of flux tubes on the full solar disk (57 compared to 7). Electric current densities at merging interfaces are 1.13 times higher during solar maximum (22,718 statamp cm^-2) compared to solar minimum (20,117 statamp cm^-2), indicating enhanced energy dissipation. Vortex dynamics differ substantially between the two epochs, with supergranular vortices exhibiting more complex, turbulent structures during solar maximum. The magnetic field intensification rate is 6.3 times higher during solar maximum (1.07 G s^-1) than during solar minimum (0.17 G s^-1). These results demonstrate that the solar cycle modulates the efficiency of magnetic field intensification through flux tube merging, with significant implications for coronal heating and solar wind acceleration.