Altitude variation of ion composition in the midlatitude trough region: Evidence for upward plasma flow

摘要: Midday ion composition measurements made by the Explorer 32 mass spectrometer in midlatitude trough region (L = 5.0–10.5) are compared with within plasmasphere 1.8–2.2). In light (H+ and He+) concentrations observed to decrease altitude between 600 2500 km, a which O+ is major ion. Within plasmasphere, however, of ions, when minor, increase altitude. Model calculations indicate that behavior profiles consistent state stationary diffusive equilibrium, whereas dynamic plasma required account for distributions. Upward-directed H+ fluxes near sonic speeds above 2000 km reproduce measured variations. This ‘trough wind,’ consisting rapid upward flow H+, can be interpreted as evidence convection supersonic polar wind on closed field lines.