The WSA-Enlil movie shows the predicted solar wind density and radial velocity at Earth (green dot), STEREO A (red dot) and STEREO B (blue dot). It allows to make a 1-4 day advance warning of solar wind structures, such as co-rotating interaction regions (CIRs), high speed streams (HSS) and Earth-directed coronal mass ejections (CMEs) that cause geomagnetic storms.

The underlying heliosphere model runs every 2h and is driven by observations of the solar surface magnetic field. When an Earth-directed CME is detected, the CME (characterised by the "conefile parameters", derived from observations) is propagated for prediction of the CME intensity, arrival time at Earth and duration.

Shown video:

• Left part: Equatorial (overhead) and meridional (-60°- 60°) (side) view of the predicted density & radial velocity visualizing the solar wind structure over a large radial distance. The yellow dot represents the Sun, the green dot is for Earth, and the red and blue dot represents the location of resp. the STEREO A and B spacecraft.


• Right part: The predicted solar wind density (top) and velocity (bottom) values for the location of Earth (green curve), STEREO A (red curve), STEREO B (blue curve) as function of time (days).