Ionospheric-origin ions modify the density, temperature and composition of the plasmasheet, the main reservoir of magnetospheric plasma. The presence of ionospheric-origin heavy ions influences the structure and dynamics of the current sheet, reconnection rates and the formation of Kelvin-Helmholtz instabilities, important drivers of global magnetospheric dynamics on which other systems (ring current, radiation belts) are dependent. The role of heavy ions in the plasma sheet dynamics and their acceleration are essential components in the study of magnetospheric processes and instabilities. This section provides the opportunity to report on the latest results from data analysis of terrestrial as well as of missions to other planets, theory and simulation dealing with the different aspects of influences of heavy ions on the magnetospheric processes.