At high-latitudes, the interaction of the solar wind and the Earth’s magnetic field causes a dawn-dusk cross-polar potential difference. The resulting electric fields cause the ionosphere plasma to drift in a two cell-convection pattern. However, at and below the E region, collisions between ionosphere plasma and neutral particles affect the plasma drift. The ionospheric dynamo region marks the transition from a completely collisional plasma below about 80 km to a collision-less plasma above about 120 km altitude. Since this transition occurs at different altitudes for ions and electrons, electric currents can flow perpendicular to the magnetic field lines. These Pedersen and Hall currents cause important space weather processes like Joule heating and geomagnetic disturbances. Incoherent scatter radars (ISRs) allow to infer various ionosphere and neutral atmosphere parameters, hence making them a valuable tool for studying space weather processes in the dynamo region. In this seminar, I will present the application of ISRs to study space weather processes like traveling ionospheric disturbances and Joule heating. The evaluation of thermosphere-ionosphere models with ISR measurements is an important step towards space weather forecasts. The potential use of ISR measurements for data assimilation will be discussed.