The effect of the Region 2 currents location on the strength of the
auroral electrojet and global distribution of ionospheric currents
Abstract
In this study, we use a parametrized model of ionospheric
electrodynamics to investigate the effect of Region 2 currents’ location
on the development and dynamics of the auroral electrojet (AE), using
real cases data as input parameters for our simulations. We calculated
the maps of equivalent ionospheric currents reproducing the events of
interest, analyzed the results and compared with SuperMAG observations.
The simulations have shown that strong R2 currents provide a robust
closure for the ionospheric currents flowing from R1 via auroral zone
ionosphere. We found that the highest magnitude westward auroral
electrojet is in the day-to-dawn sector, while the equivalent
ionospheric currents on the night-side have much lower magnitude. We
suggest that the location of the R2 currents affects the entire
distribution of ionospheric currents, changing the MLT location and
magnitude of the maximum auroral electrojet. As the distance between the
location of the maxima for the R1 and R2 current systems increases, the
magnitude of the ionospheric currents decreases because the ionospheric
currents spread over larger regions at low latitudes. When R2 currents
cannot provide the proper closure, the ionospheric currents flow from
the dawn to dusk over the night-side ionosphere, leading to the westward
auroral electrojet development in the night region of the auroral zone.
We analyzed features and magnitude of these currents and compared with
observations.