Potential Magnetospheric Effects of High-Power HF Heating

The high-latitude ionosphere forms a part of many magnetospheric current systems. To the extent that the ionospheric plasma provides feedback into the system rather than being purely passive, ionospheric perturbations due to high-power "heating" have the theoretical potential to impact magnetospheric phenomena. A number of effects have been theorized including substorm triggering, Alfven wave-induced particle precipitation, and mass loading of flux tubes via particle outflow. Experiments specifically designed to generate such effects have been formulated and attempted, although conclusive evidence of causality remains elusive, in part due to the extremely small number of samples and the random nature of the natural phenomena. We discuss experiments conducted to date and suggest experimental protocols to definitively determine any causal relationships between ionospheric heating and observable magnetospheric phenomena which can also occur naturally on a sporadic basis.