Climatology of the quasi-6-day wave in the mesopause region and its modulations on total electron content during 2003-2017

The westward quasi‐6‐day planetary wave (Q6DW) with zonal wave number 1 is a prominent oscillation in the mesosphere and lower thermosphere region, which causes significant variabilities in the ionosphere through E region wind dynamo. In this paper, the neutral wind observations from the Thermosphere Ionosphere and Mesosphere Electric Dynamics Doppler Imager experiment, the kinetic temperature observations from the Sounding of the Atmosphere using Broadband Emission Radiometry instrument, and the total electron content (TEC) maps from globally distributed Global Positioning System (GPS) receivers during 2003–2017 are utilized to statistically study the Q6DW in both the neutral atmosphere and the ionosphere. Our statistical results show that (1) the Q6DW is most likely to occur during May and September, exhibiting a quasi‐semiannual oscillation. (2) The periods of the Q6DW show two statistical crests at ~6 and ~7 days separately. (3) The ionospheric oscillations due to the Q6DW are positively related to both the 10.7‐cm solar flux index and the neutral wave amplitudes in the mesosphere and lower thermosphere region. The stronger oscillations in TEC under higher solar activity conditions are due to the larger ionization rate and thus larger background TEC. A stronger Q6DW results in stronger wind dynamos in the E region, which leads to stronger F region responses indirectly. (4) The interhemispheric asymmetries of the ionospheric responses to Q6DW show weak negative correlations with both solar activities and neutral wave perturbations, the mechanism of which needs our further investigation.