Radiating Current Sheets in the Solar Chromosphere

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