AN 8-MOMENT MODEL PARAMETER STUDY OF THE SOLAR-WIND - DEPENDENCE ON VARIATIONS IN CORONAL HEATING

The eight-moment two-fluid model describes, self-consistently, the pro ton (and electron) heat flux in the solar wind. This is a crucial para meter in solar wind models with a high coronal proton temperature. In the present study the eight-moment description is used to study how th e solar wind outflow from an electron-proton corona responds to variat ions in coronal heating. Most of the energy flux is deposited in the p roton gas. We find that the asymptotic flow speed of the solar wind is only weakly dependent on the amplitude of the energy flux, but it inc reases with increasing dissipation length. When most of the energy flu x is dissipated in the extended corona, where the protons are collisio nless, we obtain flow speeds characteristic of high-speed solar wind s treams: For a dissipation length of 1 to 2 solar radii the asymptotic flow speed is 700-1000 km s(-1) A relatively modest electron heating i n the inner corona may lead to an increased transition region pressure and hence a large increase in the solar wind proton flux. This increa se in proton flux may be so large that there is not enough energy avai lable to drive a high-speed wind.