Figure 4. A full disk magnetogram of the Sun displaying the line of sight component of the magnetic field obtained with Helioseismic Magnetic Imager onboard the Solar Dynamics Observatory (Schou et al., 2012; Scherrer et al., 2012; Pesnell et al., 2012). This map was recorded on July 16, 2011. The dark- and light-shaded regions are the south (negative) and north (positive) polarities of the field, respectively. The extended patches of concentrated positive and negative magnetic polarities are the active regions that host sunspots and plages. As the active region evolves and decays, its field is more diffused and scattered. Far away from the active regions are quiet regions and magnetic networks, structured by the convection near the surface. The line of sight component of the magnetic field is saturated at ±300 G.