An MHD model of a Hydrogen plasma with flow , an energy equation , NLTE ionization and radiative cooling , and an Ohm ’ s law with anisotropic electrical conduction and thermoelectric effects is used to self-consistently generate atmospheric layers over a 50 km height range .
A subset of these solutions contain current sheets , and have properties similar to those of the lower and middle chromosphere .
The magnetic field profiles are found to be close to Harris sheet profiles , with maximum field strengths \sim 25 - 150 G. The radiative flux F _ { R } emitted by individual sheets is \sim 4.9 \times 10 ^ { 5 } -4.5 \times 10 ^ { 6 } ergs-cm ^ { -2 } -s ^ { -1 } , to be compared with the observed chromospheric emission rate of \sim 10 ^ { 7 } ergs-cm ^ { -2 } -s ^ { -1 } .
Essentially all emission is from regions with thicknesses \sim 0.5 - 13 km containing the neutral sheet .
About half of F _ { R } comes from sub-regions with thicknesses 10 times smaller .
A resolution \lesssim 5 - 130 m is needed to resolve the properties of the sheets .
The sheets have total H densities \sim 10 ^ { 13 } -10 ^ { 15 } cm ^ { -3 } .
The ionization fraction in the sheets is \sim 2 - 20 times larger , and the temperature is \sim 2000 - 3000 K higher than in the surrounding plasma .
The Joule heating flux F _ { J } exceeds F _ { R } by \sim 4 - 34 \% , the difference being balanced in the energy equation mainly by a negative compressive heating flux .
Proton Pedersen current dissipation generates \sim 62 - 77 \% of the positive contribution to F _ { J } .
The remainder of this contribution is due to electron current dissipation near the neutral sheet where the plasma is weakly magnetized .