The earth's field departs from its dipole shape substantially at large distance (greater than about 30,000 km) What agencies may be responsible for this distortion ?

Question

$\begin{array}{1 1} \text{The motion of ions in the earth's ionosphere } \\ \text{The magnetic field around the earth } \\ \text{The electromagnetic radiations in the atmosphere } \\ \text{ All\;the \;above } \end{array}$