Current Sheet Source Surface (CSSS) model incorporates the horizontal and volume currents in the corona and makes use of the approximation that the coronal magnetic field can be derived from a potential, neglecting all the currents within the photoshere and the source surface. In this model, the potential field approximation is applied between photosphere and a cusp surface, placed at a height of about 2.5 R_sun. This location corresponds roughly to the base of the helmet steamers. And, the source surface, in the CSSS model, can be placed at any distance, in principle, beyond the cusp surface but usually around 15 -30 R_sun.

I am using this model to see how to improve the predicted solar wind speed and magnetic field in the heliosphere. [Details will be added later.]