Impact of the interaction between the quasi‐2 day wave and tides on the ionosphere and thermosphere

Abstract The quasi‐2 day wave (QTDW) can effectively interact with atmospheric tides in the mesosphere and lower thermosphere. We study the effect of this QTDW‐tidal interaction on the ionosphere and thermosphere using the thermosphere‐ionosphere‐mesosphere electrodynamics general circulation model. This interaction reduces the amplitude of the migrating diurnal tide in the lower thermosphere by ~10 m/s in neutral winds and also generates sum and difference secondary waves in the lower thermosphere and E region ionosphere. As a result of the changed migrating diurnal tide and sum/difference secondary wave, vertical ion drift varies with local time at different longitudes by ~5 m/s. In addition, the changed migrating diurnal tide also modulates the thermospheric composition (O/N 2 ). During a QTDW event, the ionosphere F 2 region peak electron density ( N m F 2 ) is reduced due to the mixing effect of the QTDW dissipation; N m F 2 also shows changes in local time variation due to the QTDW‐tidal interaction. The sum and difference secondary waves can cause additional oscillations in vertical ion drift and ionospheric electron densities. The QTDW‐tidal interaction is another mechanism by which the QTDW impacts the ionosphere and thermosphere, along with other mechanisms: QTDW modulation of the E region wind dynamo with a period of quasi‐2 days and QTDW dissipation induced mixing in the thermosphere.