Simulated longitudinal variations in the E-region plasma density induced by non-migrating tides

Based on the GCITEM-IGGCAS model and tides from TIMED/SABER observations, the longitudinal variations of the E-region plasma densities, which is induced by non-migrating tides, are investigated. We simulated the intra-annual variation of the E-region plasma density, and found that equinoctial E-region plasma density shows an obvious wavenumber-4 longitudinal structure both in Equinox and in June Solstice, and a wavenumber-3 longitudinal structure in December Solstice. Our simulations suggest that DE3 tide can drive the wavenumber-4 structure in E-region plasma density, and DE2 tide can drive the wavenumber-3 structure. O2+ controls the longitudinal variations of total ions density at lower E-region, and NO+ mainly controls that at higher E-region. We also noticed that the longitudinal variations of O2+ and of NO+ show obvious phase differences.

► E-region plasma density shows a wave-4 structure both in Equinox and June Solstice.
► E-region plasma density shows a wave-3 structure in December Solstice.
► DE3 tide can drive wave-4 structure, and DE2 can drive wave-4.
► O2+ control lower E-region longitudinal variation, and NO+ control higher E-region.
► The longitudinal variations of O2+ and of NO+ show obviously phase differences.