Ionospheric electron heating due to structured electric fields is considered herein. In a survey of incoherent scatter (IS) radar data gathered with the Sondrestrom IS radar in Greenland (66.99 ¿N, 50.95 ¿W), we find that such heating takes place at F layer altitudes accompanying intense auroral events in the E layer. Because of competition with heating by precipitating particles this type of heated region can only be observed when it is shifted from the geomagnetic field line penetrating the associated E layer arc. We have detected regions of this sort in which we argue that the temperature is enhanced either by illumination of auroral ionospheric cavities by an Alfv¿n wave source or by collocation with turbulent electrostatic fields. We have developed a model that predicts the observed Te enhancement in the F layer. We also present a consistent physical picture of auroral activity involving coupling between the magnetosphere and the ionosphere via electrostatic and wave- or turbulence-induced field-aligned currents. Both can be generated by the region surrounding the electron acceleration zone. Applying our model to the observations allows us to separate electron heating due to structured fields (with a pronounced maximum in the F layer), static field-aligned currents (with the electron temperature smoothly increasing with altitude from the F layer up to the magnetosphere), and electron impact in the E layer. In turn, the temperature observations give us information on the Alfv¿n wave impinging on the auroral F layer and/or the turbulent electrostatic fields which map to the ionosphere. ¿ American Geophysical Union 1996