Numerical MHD Simulations of Reconnection in Solar Flares: Effects of the Magnetic-Field Strength in the Current Sheet

We simulate the evolution of reconnection in solar flares to study the influence of magnetic-field strength and thermal conduction on the dynamics of the magnetic-reconnection and energy-conversion processes. For this, we solve the 2.5D resistive magnetohydrodynamics (MHD) equations with thermal conduction on a domain that contains the chromosphere-corona interface. The flare is triggered at a null point where a Gaussian resistivity distribution is maximum, and further evolution is tracked. The parameter space considers magnetic-field strength [B-0] between 22 G and 50 G, and thermal conductivity [kappa] in the range from zero to 10(-11) W m(-1)K(-7/2). In this parameter space, we find that the magnetic field determines the reconnection rate, which can change by a 100% in the range of B-0, whereas thermal conduction can induce a rate change of at most 10%. We also measure the evolution of magnetic, internal, and kinetic energies in a region just above the reconnection point and measure their interplay. For all simulations, magnetic energy dominates initially and relaxes on a time scale of about 20 seconds. In this interval, the magnetic energy drops by approximate to 50%, whereas the internal energy grows by approximate to 100%. During the process, part of the energy becomes kinetic, which pushes the reconnection jet upwards and is bigger for the bigger B-0 and smaller kappa.