  During periods of strong geomagnetic activity, intense currents flow from the
magnetosphere into the high-latitude E-region ionosphere along geomagnetic
field lines, B. In this region, collisions between the plasma and neutral
molecules allow currents to flow across B, enabling the entire
magnetosphere-ionosphere current system to close. These same currents cause
strong DC electric fields in the E-region ionosphere where they drive plasma
instabilities, including the Farley-Buneman instability (FBI). These
instabilities give rise to small-scale plasma turbulence that modifies the
large-scale ionospheric conductance that, in turn, affects the evolution of the
entire near-Earth plasma environment. Also, during geomagnetic storms,
precipitating electrons of high energies, $\gtrsim$ 5 keV, frequently penetrate
down to the same regions where intense currents and E fields develop. This
research examines the effects of precipitating electrons on the generation of
the FBI and shows that, under many common conditions, it can easily suppress
the instability in a predictable manner. Therefore, we expect precipitation to
exert a significant feedback on the magnetosphere by preventing the elevated
conductivity caused by FBI driven turbulence. This suppression should be taken
into account in global modeling of the magnetosphere-ionosphere coupling.
