Empirical inner boundary conditions and rotation rates for solar wind models

To date, the inner boundary conditions for solar wind models are either directly or indirectly based on magnetic field extrapolation models of the photosphere. Furthermore, between the photosphere and Earth, there are no other direct empirical constraints on models. New breakthroughs in coronal rotation tomography, applied to coronagraph observations, allow maps of the coronal electron density to be made in the heliocentric height range 4-12 solar radii (Rs). We show that these maps (i) give a new empirical boundary condition for solar wind structure at a height where the coronal magnetic field has become radial, thus avoiding the need to model the complex inner coronal magnetic field, and (ii) give accurate rotation rates for the corona, of crucial importance to the accuracy of solar wind models and forecasts.