Currents can be driven in the polar ionosphere

The study of ionospheric heaters that induce controlled modifications in the ionosphere allows better understanding of effects driven naturally by solar activity in the ionosphere and the radiation belts. Previous ionospheric heaters at the Earth's poles have generated ultralow‐frequency, extremely low frequency, and very low frequency waves in the ionosphere's D andE regions by modulating the auroral electrojet, the strong horizontal currents that naturally flow in the D and E regions at high latitudes. Now Papadopoulos et al. present theoretical and computational results that indicate that using high‐frequency heating, low‐frequency ionospheric currents can also be generated at F region altitudes, independent of the presence or absence of electrojet currents. The new technique, whose validity has been confirmed tentatively in recent polar experiments, allows generation of low‐frequency waves by midlatitude heaters, such as the one under construction in Arecibo, Puerto Rico, and their subsequent injection in the inner radiation belt. It will permit for the first time the study of the interaction of artificially generated low‐frequency waves with multi‐MeV protons trapped in the inner belt and their precipitation rates in the South Atlantic anomaly region. (Geophysical Research Letters, doi:10.1029/2011GL047368, 2011)