Large‐Scale Wave‐Driven Interactions and Plasma‐Neutral Coupling in the Low‐Latitude Ionosphere‐Thermosphere

Abstract

AbstractThe plasma and neutral density variations, interactions and coupling processes within ±30° latitudes are examined concurrently by the DMSP‐F18 and Swarm‐C satellite during geomagnetically quiet years in 2020–2021. The wavenumber (WN) patterns are computed in the form of neutral and electron density for two altitudes and their latitudinal profiles are analyzed. We observe that the WN1 structure of the electron density has a significant seasonal dependence in the topside ionosphere and dominates all other structures but WN2 neutral density amplitude dominates all other structures in the middle thermosphere (∼440 km). Additionally, we analyze vertical‐temporal‐latitudinal tidal structures from the Climatological Tidal Model of the Thermosphere (CTMT) to find evidence for the modulation of the large‐scale waves (LSWs) neutral density structures. Through the examination of the in situ observational and modeling approaches, we show that the tidal contributors of WN structures obtained from CTMT can capture the influence of terrestrial sources on the WN structures of plasma‐neutral density and imprint the corresponding vertical coupling in the IT system. Correlation analysis reveals that the amplitudes of the WN1 and WN3 structures of electron density in topside ionosphere and those of neutral density in the middle thermosphere show intermittent but significant correlations with each other, unlike the WN2 and WN4 structures. This study provides new insights into the topside ionospheric response to wave driving in the lower atmosphere, which ultimately improves our capability to understand the interaction and vertical coupling of large‐scale structures, thereby advancing our predictive capabilities of space weather critical for satellite operations.