Effect of Initial Current Sheet and Stratification on Reconnection and Coronal Heating

Abstract Understanding the mechanisms behind fast magnetic reconnection and subsequent plasma heating is essential to explain the temperatures of a few million kelvin observed in the solar corona. This study investigates the influence of initial current sheet width and stratification on the reconnection process and coronal temperature within a large-scale magnetohydrodynamics framework. Additionally, it further addresses the contribution of small- to large-scale dynamics through the Hall term. Using numerical simulations, we demonstrate that even modest reductions in the initial current sheet width significantly speed up the reconnection process, yielding faster rates of temperature rise and achieving high peak values without requiring external fluctuations. Moreover, introducing a dependence on scale height in the initial coronal magnetic field and density profiles enhances reconnection rates and temperature increases. We also observe earlier evolution of fast reconnection with narrower current sheets and shorter scale heights, resulting in a more frequent formation of magnetic islands and X-points that evolve dynamically over time. Under these initial settings, the Hall term’s curl is amplified by three orders of magnitude, reaching 1% of the characteristic scale required to influence large-scale dynamics and offering insight into the multiscale interactions essential for coronal heating processes. This study underscores the significance of minor adjustments in initial conditions for enhancing magnetic reconnection, coronal heating, and amplifying the Hall term’s influence on large-scale dynamics.