Solar Wind Density Falloff and Mass Flux: Slow and Fast Streams Under Spherical Expansion

For a steady spherical outflow the product of density, speed and the square of distance is conserved, which fixes both the density profile and the solar mass-loss rate from conditions at a single distance. This study evaluates that bookkeeping for a slow stream anchored at 6.0 particles per cubic centimetre and 350 kilometres per second at 1 AU, and a fast stream anchored at 2.5 per cubic centimetre and 750 kilometres per second. The slow-stream density reaches 600 per cubic centimetre at 0.1 AU. The mass-loss rates are 9.88e+08 kilograms per second for the slow case and 8.82e+08 for the fast case, corresponding to 1.57e-14 solar masses per year for the slow stream; the slow-to-fast particle flux ratio at 1 AU is only 1.12 despite the density differing by more than a factor of two, because the fast stream's speed nearly compensates its low density. The study is simulated and computed from stated assumptions, not measured.