The presence of heavy ions in the near-Earth environment has a profound impact on the global magnetosphere-ionosphere (M-I) structure and dynamics. Knowledge of the ion composition and their sources and sinks throughout the M-I system is essential to study their role in regulating various magnetospheric processes. This session solicits observational, theoretical and modeling studies that have the potential to advance our understanding of the circulation of heavy ions based on separating the ionospheric and solar wind sources of lower (He⁺, N⁺, O⁺, He⁺² and O⁺²) and higher (C⁺ⁿ, N⁺ⁿ, O⁺ⁿand Fe⁺ⁿ) charge states, and the molecular ions (NO⁺, N₂⁺, and O₂⁺). This session seeks to engage scientists from the fields of solar, ionospheric, and magnetospheric physics to determine the spatial distribution of heavy ions in response to the different solar and geomagnetic conditions, and study their effects on waves properties and associated particle loss and energization mechanisms.