Electromagnetic fields of magnetospheric disturbances in conjugate ionospheres: Current/voltage dichotomy
Abstract
A circuit analogy for the magnetosphere-Ionosphere current systems has two extremes for drivers of ionospheric currents: the "voltage generator" (ionospheric electric fields/voltages are constant while current varies) and the "current generator" (current is constant while the electric field varies). Here we indicate another aspect of magnetosphere - ionosphere interaction which should be taken into account when considering the current/voltage dichotomy. We show that oscillatory FAC interact with the ionosphere in a different way depending on forced driving or excitation of resonant field line oscillations. A quasi-DC driving corresponds to a voltage generator, when the ground magnetic response is proportional to the ionospheric Hall conductance. The excitation of resonant field line oscillations corresponds to the current generator, when the ground magnetic response practically does not depend on the ionospheric conductance. According to the suggested conception such ULF phenomena as TCV, Pc5 waves, should be considered as resonant response of the magnetospheric field lines and they correspond to current generator. Quasi-DC non-resonant disturbances such as SC correspond to voltage generator. However, there quite a few factors that obscure the determination of the current/voltage dichotomy - occurrence of the auroral oval, ionospheric ihomogeneities, shielding of higher frequency ULF waves by the E-layer.
- Publication:
-
42nd COSPAR Scientific Assembly
- Pub Date:
- July 2018
- Bibcode:
- 2018cosp...42E2677P