Flare energy release by flux pile-up magnetic reconnection in a turbulent current sheet

The power output of flux pile-up magnetic reconnection is known to be deter mined by the total hydromagnetic pressure outside the current sheet. The ma ximum energy-release rate is reached for optimized solutions that balance t he maximum dynamic and magnetic pressures. An optimized solution is determi ned in this paper for a current sheet with anomalous, turbulent electric re sistivity. The resulting energy dissipation rate W-a is a strong function o f the maximum, saturated magnetic field B-s: W-a similar to B-s(4). Numeric ally, W-a can exceed the power output based on the classical resistivity by more than 2 orders of magnitude for three-dimensional pile-up, leading to solar flarelike energy-release rates of the order of 10(28) ergs s(-1). It is also shown that the optimization prescription has its physical basis in relating the flux pile-up solutions to the Sweet-Parker reconnection model.