The escape of heavy ions from the Earth atmosphere is consequences of
energization and transport mechanisms, including photoionization,
electron precipitation, ion-electron-neutral chemistry and collisions.
Numerous studies considered the outflow of O ions only, but ignored the
observational record of outflowing N. In spite of 12% mass difference,
N and O ions have different ionization potentials, ionospheric
chemistry, and scale heights. We expanded the Polar Wind Outflow Model
(PWOM) to include N as well as key molecular ions in the polar wind. We
refer to this model expansion as the Seven Ion Polar Wind Outflow Model
(7iPWOM), which involves expanded schemes for suprathermal electron
impact and ion-electron-neutral chemistry and collisions. Numerical
experiments, designed to probe the influence of season, as well as that
of solar conditions, suggest that N is a significant ion species in the
polar ionosphere and its presence largely improves the polar wind
solution, as compared to observations.