[P-EM12] Coupling Processes in the Atmosphere-Ionosphere System

[PEM12-41] Response of ionospheric F2-peak height and sea levels to the lunar gravitational force

*Tsung-Yu Wu¹、Jann-Yenq LIU¹ (1.National Central University)

キーワード：Ionospheric height, Sea level, Lunar gravitational force

The semidiurnal lunar tide (M2) is a well-known phenomenon in the ocean and upper atmosphere. This study utilizes the ionospheric electron density sounded by global navigation satellite system (GNSS) radio occultation (RO) measurements and sea levels (SLs) recorded by NOAA (National Oceanic and Atmospheric Administration) tide gauges to examine the M2 signatures in both the ocean and ionosphere. The F2-peak height (hmF2) and SL yield the M2 amplitude in a range of 0.3–198 cm and 0.7–7.3 km, respectively. The M2 high tide in hmF2 typically leads the sublunar point by about 3 lunar hours. By contrast, the high tide in M2 of SLs at various locations can occur almost anytime, which suggests that the geographic topography plays an important role. Statistical analysis reveals no significant correlation between the M2 amplitude or phase of SL and hmF2, which indicates that SL variations are unlikely to modulate hmF2 under the M2 mode.