Lunar Tidal Effect on Equatorial Ionization Anomaly Region in China Low Latitude

Abstract

The equatorial ionization anomaly (EIA) crest derived from GPS observations, F2‐layer peak height (hmF2), critical frequency (foF2), and equatorial electrojet (EEJ) in China low latitude are used to study the lunar tidal effect on EIA region for the years from 2006 to 2015. A predominant 14.76‐day periodic component in EIA crest, hmF2, and EEJ concurrently appears in some seasonal intervals, which coincides with the half of the lunar revolution period (29.53 days) and the lunar phase, indicating that the 14.76‐day periodic oscillation in EIA region is modulated by the lunar tide. This 14.76‐day periodic oscillation occurs in all Northern Hemisphere (NH) winter and corresponds to their respective sudden stratospheric warming (SSW) period from 2006 to 2015. In addition, this 14.76‐day periodic oscillation also occurs in other seasons for some years, for example, May and August, in which wave power is sometimes comparable to that in SSW period. The occurrence of the 14.76‐day periodic oscillation and its wave power during non‐SSW seasons in the solar maximum years (2012–2015) is more frequent and higher than that in the solar minimum years (2008–2010). Our results suggest that, besides the NH SSW condition, the solar activity and some other unclear factors are also responsible for the lunar tide enhancement in EIA region.

Ionospheric Semidiurnal Lunitidal Perturbations During the 2021 Sudden Stratospheric Warming Event: Latitudinal and Inter‐Hemispheric Variations in the American, Asian‐Australian, and African‐European Sectors

“…Meanwhile, the A M2 and A M2 ′ signatures before day −10 seem to correspond to the less clear pre‐SSW PSSD signatures. It is worth noting that, although numerous previous studies (and the current paper) demonstrated that the ionospheric M2 perturbations tend to enhance during SSW events and proposed possible explanations (e.g., Forbes & Zhang, 2012), the ionospheric M2 perturbations may also enhance during non‐SSW periods (e.g., Mo et al., 2021). In addition, the enhancement around days 25∼30 corresponds to the PSSD cycles around the same period shown in Figure 4.…”

“…(TEC) (Fagundes et al, 2015;Goncharenko et al, 2013), foF2 and hmF2 (Liu et al, 2021;Mo et al, 2021). Besides observation studies, the importance of M2 tide in ionospheric variations during the SSW was also supported by simulation studies (Forbes & Zhang, 2012;Pedatella, Fang et al, 2016;Pedatella et al, 2012).…”

“…Therefore, the PSSD perturbation is also referred as M2‐like perturbation or M2 tide. Enhanced M2 perturbations were also detected in other ionospheric parameters, such as total electron content (TEC) (Fagundes et al., 2015; Goncharenko et al., 2013), foF2 and hmF2 (Liu et al., 2021; Mo et al., 2021). Besides observation studies, the importance of M2 tide in ionospheric variations during the SSW was also supported by simulation studies (Forbes & Zhang, 2012; Pedatella, Fang et al., 2016; Pedatella et al., 2012).…”

Revisiting the Ionospheric Disturbances Over Low Latitude Region of China During Super Typhoon Hato

“…Nevertheless, besides the electrodynamic process, the photo-chemical process is also important factor for the variation of foF2. Mo et al (2021) studied the lunar tide effect on ionospheric EIA using TEC from GNSS, foF2 and hmF2, it is found that the dependence of the hmF2 and EIA location on lunar tide is more obvious than that of foF2 and TEC. They attribute these dependences to the different relationship among the hmF2, foF2, the electric field modulated by lunar tide in E dynamo region and the photo-chemical process.…”

Solar Tide‐like Signatures in the Ionospheric Total Electron Content During the 2018 Sudden Stratospheric Warming Event

“…Naturally, multiple studies have demonstrated SSW effects in various ionospheric parameters, such as equatorial electrojet (EEJ), the peak electon density of F2 layer ($${\mathrm{N}}_{\mathrm{m}}{\mathrm{F}}_{2}$$) and total electron content (TEC) (e.g., Chau et al., 2010; Goncharenko, Coster, et al., 2010, 2010b; Mo et al., 2021; Pedatella et al., 2014; Pedatella & Forbes, 2010; Yamazaki et al., 2012; Ye et al., 2021). Further, the simulations of sophisticated models (Lin et al., 2012; Pedatella et al., 2012a, 2012b) also demonstrated that the SW2 also underwent amplification and played an important role in the ionospheric response to SSWs (Jin et al., 2012; Pedatella & Liu, 2013).…”