The diversity of ionospheric storm disturbances caused by strong perturbations in the solar wind

Perturbations in the solar wind and IMF, such as coronal mass ejections and co-rotating interaction regions, can give rise to significant perturbations in the ionosphere, usually referred to as ionospheric storms. The storm ionosphere storm perturbations can be manifold and can impact technical systems based in transmission of radiosignals in different ways. Usually, there occur enhancements as well as depletions of electron density over a large region (positive and negative storms respectively). In high latitudes, there occur strong plasma dynamics generating patches and gradients. Another prominent example are large scale travelling ionospheric disturbances, which often occur in mid-latitudes during storms. The occurrence of the different ionospheric perturbations depends on the storm onset time, local time, season and geomagnetic latitude. Although a general character of ionospheric storms is well known, there often occur large deviations from the mean behavior. Here, we present statistical character of ionospheric storms and TID occurrence and their relation to the energy input from the solar wind. In addition, we present in a case study for the September 2017 storm the ionosphere perturbations which occurred over Europe and how ionosphere indices can indicate the occurrence of the different ionospheric perturbations.