ABSTRACT
Currents are produced by charges in motion. Large-scale currents in space are produced by the charged particles of the solar wind, magnetospheres, and ionospheres. These currents are sources of magnetic fields in the distant regions of space. For example, the heliospheric current sheet produced by the dynamics of the solar wind is responsible for the IMF. Large-scale currents are also associated with planetary magnetospheres. A convenient way to discuss currents in planetary magnetospheres is to classify them as boundary currents, ring currents, ionospheric currents, field-aligned currents, and magnetotail currents. The main purpose of this chapter is to study how these currents are produced in planetary ionospheres and magnetospheres (Figure 7.1).
