Quantifying Nighttime Gravity Wave‐Driven Mesosphere‐Ionosphere Coupling Over CONUS Using NASA AWE Radiance and GNSS TEC Observations

Abstract We present the first coordinated study of nighttime mesosphere‐ionosphere coupling over the continental United States (CONUS) from January through November 2024 using NASA Atmospheric Waves Experiment (AWE) airglow measurements near 87 km and GNSS Total Electron Content observations near 300 km. Coherent wave structures observed at both altitudes and high spatial correlations between their variances are used to identify strongly coupled events. Among 273 AWE swaths, ∼65% exhibit strong coupling during quiet geomagnetic conditions, compared to ∼23% during active times. The occurrence of strong coupling is negatively correlated with Kp and AE and positively correlated with Dst, indicating systematic modulation by geomagnetic activity. For strongly coupled events, GNSS‐observed TIDs preferentially propagate northward, whereas only ∼14% exhibit the classic southwestward propagation associated with Perkins instability. This northward preference is consistent with nighttime thermospheric wind filtering that favors poleward‐propagating gravity waves. Our findings establish a quantitative baseline for nighttime mesosphere‐ionosphere coupling.