Observations from the AMPTE/Charge Composition Explorer (AMPTE/CCE) indicate the presence of two distinct O+ populations in the dayside subsolar low latitude boundary layer during some periods of northward Interplanetary Magnetic Field (IMF). The first population is O+ convected into the boundary layer from the outer magnetosphere and has been reported previously. It is suggested here that the new, second, O+ population is injected into the dayside boundary layer directly from the high latitude ionosphere. This second population can have a significant density and distinct characteristics such as field-aligned flow relative to boundary layer H+ that modify both the plasma composition and dynamics in the low latitude boundary layer. ¿ American Geophysical Union 1989