We investigated the relationship between convective activity and F‐region short‐period ionospheric disturbances at middle latitudes from 2018 to 2020. The ionospheric variations were extracted from the total electron content (TEC) data obtained by the BeiDou geostationary orbit receiver in Wuhan, China, while the convective activities were represented by precipitation data from the fifth generation European Center for Medium‐Range Weather Forecasts Reanalysis (ERA5). Additionally, an ionosonde located in Wuhan, China, was used to study the variation in the sporadic E (Es)‐layer. Seasonal variations in the convective activity and TEC disturbances were studied. It was found that short‐period ionospheric disturbances occurred mainly around summer midnight and around the June solstice. In addition, the correlations between convective activity and the ionosphere have also been studied. A positive correlation between precipitation and short‐period ionospheric disturbances was found. Similarly, precipitation and also had a positive correlation. By analyzing the precipitation azimuth and upward propagation of convective gravity waves, we proposed a possible coupling mechanism between the ionosphere and the troposphere, through which convective gravity waves could indirectly affect F‐region short‐period ionospheric disturbances by modulating the Es‐layer.

The anomalous strengthening of the stratospheric Aleutian High during the early boreal winter of 2016/2017 led to a rare Canadian stratospheric warming (CSW) event, during which the extent of the wind reversal in the Arctic region is the strongest among CSWs since 2001. Unlike sudden stratospheric warmings, the polar vortex during this CSW is merely distorted, not displaced off the pole or split into two pieces, and the polar mean temperature only has a modest increase of a few kelvins. Using the Aura satellite Microwave Limb Sounder measurements, an exceptionally strong 12‐day wave (12DW) with westward zonal wavenumber 1 is captured in the mesospheric water vapor mixing ratio during the recovery phase of this CSW. Further diagnostic analysis suggests that the baroclinic/barotropic instability related to this CSW triggers the 12DW in the Arctic stratosphere, and meridional advection plays a leading role in the modulation of 12DW on mesospheric water vapor.

This research studies the medium timescale (6–30 days) ionospheric response over the Wuhan area to solar radiative, recurrent geomagnetic, and lower atmospheric forcing. The ionospheric response is examined by wavelet analysis of the total electron content (TEC) over the Wuhan area from 2001 to 2020. Ionospheric oscillations with periods centering at the harmonic oscillations of the 27-day solar rotation (e.g., 27 days, 13.5 days, 9 days, and 6.75 days) are focused upon. The results show that the quasi-27-day TEC oscillations at the middle latitude have a better overall correlation with solar radiation than recurrent geomagnetic activity, but the correlation between TEC and recurrent geomagnetic activity has a significant increase at the solar minimum stage. As for ionospheric oscillations with periods shorter than 15 days, these oscillations correlate better with recurrent geomagnetic activity. Moreover, a quasi-27-day TEC oscillation event at the middle latitude caused by convective activity from the lower atmosphere was studied. This suggests that lower atmospheric forcing is also an important factor causing ionospheric oscillations. In addition, the ionospheric oscillations over the Wuhan area also show unique regional characteristics, as the regional ionosphere does not respond well to the Kp oscillation with periods shorter than 20 days, particularly, 13.5 days.

We studied the characteristics of quasi-two-day wave (QTDW) using the meridional wind in the mesosphere and lower thermosphere (MLT) obtained from a meteor radar over Kototabang (KB, 0.2$°$S, 100.3$°$E) from 2003 to 2012. Atmospheric oscillations have a crucial impact on atmospheric dynamics, which contributes to more accurate space weather forecasting, thus providing a more secure space environment for human space exploration activities such as remote sensing and satellite navigation. QTDWs are typical atmospheric oscillations in the upper stratosphere, mesosphere and lower thermosphere. The occurrence time, amplitudes, periods and vertical wavelengths of QTDW events are analyzed statistically. Data obtained from the TIMED Doppler Interferometer (TIDI), which can measure wind and temperature and is onboard the Thermosphere, Ionosphere, Mesosphere Energetics and Dynamics (TIMED) satellite, are used to analyze the global distribution and spatial structure of QTDWs with different zonal wavenumbers. The characteristics of the QTDWs over KB are compared with the QTDWs at the middle latitudes using the meridional wind data from a meteor radar over Wuhan (114.4$°$E, 30.6$°$N), Beijing (116.5$°$E, 39.9$°$N) and Mohe (121.1$°$E, 50.1$°$N). The amplitudes of the QTDW and spectral analysis are calculated by the least squares fitting method. Our results demonstrate that QTDWs are present almost all year around over KB. The occurrence time, amplitudes, periods and vertical wavelengths of QTDW events with different zonal wavenumbers are determined in this study. We also find that the statistical characteristics of the QTDWs in KB are different from those at middle latitudes. The westward zonal wavenumber −4 (W4) events gradually increase with increasing latitude, whereas westward zonal wavenumbers −1, −2, and −3 (W1, W2 and W3, respectively) events all decrease with increasing latitude.