A hydromagnetic model of corotating conductive solar wind streams (Q1068631)

Under the assumption of quasi-azimuthal symmetry the governing equations of a steady hydromagnetic flow in a thermally conductive flux tube possess six invariants. Four of them represent constancy of mass efflux, energy efflux, angular momentum efflux and magnetic flux. Based on the entropy equation we obtain useful approximation in explicit expressions for the two remaining invariants. One of them provides the constraint which determines the compatible heat flux to ensure a vanishing pressure at infinity. Thus, the admissible solution that represents a corotating solar wind stream in terms of specified interplanetary condition can be calculated by an algebraic method, without the necessity of numerical integration. A two-point relationship is then derived, which correlates the solar wind properties at two separated interplanetary sites measured at two properly separated instants. This relationship may be applied to observational data from space crafts and earth-bound satellites to discern the corotation feature in the solar wind.