The Sun's Magnetic Field

During the course of the approximately 11 year sunspot cycle, the magnetic field of the Sun reverses. The last time this happened was around the year 2000.

Using magnetograms from the SOHO/MDI and SDO/HMI instruments, it is possible to examine possible configurations of the magnetic field above the photosphere. These magnetic configurations are important in understanding potential conditions of severe space weather.

The magnetic field in this animation is constructed using the Potential Field Source Surface (PFSS) model. The PFSS model is one of the simplest yet realistic models we can explore. Using the solar magnetograms as the 'source surface' of the field, it builds the field structure from the photosphere out to about two solar radii (an altitude of 1 solar radius). These visuals were generated using the SolarSoft package.

In this visualization, the white magnetic field lines are considered 'closed'. The move up, and then return to the solar surface. The green and violet lines represenent field lines that are considered 'open'. Green represents positive magnetic polarity, and violet represents negative polarity. These field lines do not connect back to the Sun but with more distant magnetic fields in space. These field lines act as easy 'roads' for the high-speed solar wind.