WSA

The Wang-Sheeley-Arge (WSA) model has two components: the WSA Potential Field + Current Sheet (WSA PF+CS) Model and the WSA Inner Heliosphere (WSA-IH) Model.

The WSA-PF+CS model is the inner coronal component of the complete WSA model. These combine a Potential Source Surface Model with the 'Schatten' current sheet model, to produce a model of the global coronal magnetic field between the solar surface and a bounding spherical surface, typically set at 5 solar radii. The magnetic field is assumed to be radial at this outer surface. At this outer surface the model computes the solar wind speed using an empirical relationship based on the divergence of the magnetic field and the proximity of the selected open field line to the nearest coronal hole boundary, to determine the local solar wind speed. The surface magnetic field is determined from synoptic magnetogram data. Currently we download magnetograms from both Kitt Peak and Mount Wilson.

Photospheric Synoptic Magnetograms produced by either the National Solar Observatory or the GONG network.

Images displaying wind speed at outer boundary of the models Current Sheet Component; Wind speed and IMF polarity timelines at L1.