Net cross equatorial transport of magnetic flux as a function of time (left panels). The black curves show the total net flux transport, dF/dt averaged over 1 year (top panel), 2 years (middle panel), and 4 years (bottom panel). The red curves show the diffusive component of the flux transport , see Eq. (3). The right panels show F^NH, the magnetic flux in the northern hemisphere, and − F^SH, the negative of the magnetic flux in the southern hemisphere (dashed curves), as well as their mean (solid black curve). For comparison the time integral of the diffusive flux is shown in red (assuming a starting value of 4 × 10²² Mx in 1976) and green (assuming a starting value of 2 × 10²² Mx). The intervals outlined by the vertical lines indicate the periods affected by the three events shown in Figs. 2–4, respectively.