講演情報
[PEM16-15]Imaging high-frequency atmospheric waves in the mesosphere–lower thermosphere using 1-s OH airglow observations
*Pierre-Yves Froissart1,2、Philippe Lognonné1、Pierre Simoneau2、Kiwamu Nishida3、Takao Ohminato3 (1.Université Paris Cité, Institut de Physique du Globe de Paris, CNRS、2.DOTA, ONERA, Université Paris-Saclay、3.Earthquake Research Institute, University of Tokyo)
キーワード：
upper atmosphere dynamics、airglow observations、ionospheric seismology、near-infrared
Atmospheric dynamics are characterized by the generation and propagation of a broad spectrum of waves, including gravity waves (GWs) and acoustic waves (AWs), which play a fundamental role in the vertical coupling of the atmosphere–ionosphere (A–I) system. As these waves propagate upward, the exponential decrease in atmospheric density leads to a strong amplification of their amplitudes, making the mesosphere and lower thermosphere (MLT) a particularly sensitive region for probing wave dynamics and energy transfer across atmospheric layers. In parallel, the upper atmosphere hosts natural airglow emissions, whose intensity and spatial structure respond directly to dynamical perturbations. Therefore, airglow observations are providing a unique means to image atmospheric wave propagation and investigate upper-atmospheric dynamics at high altitudes.
To investigate upper-atmospheric wave dynamics in the framework of ionospheric seismology, we deployed two permanent observatories monitoring the OH airglow layer (SWIR emission at ~87 km altitude) in Izu-Oshima (Japan) and on La Réunion Island (Indian Ocean). These observatories were initially designed to image the atmospheric signatures of seismic wave–induced perturbations propagating from the solid Earth into the upper atmosphere. The instruments operate continuously at 1 s cadence, enabling the observation of short-period waves that are typically unresolved by conventional airglow imaging systems. Over two years of measurements, we have built one of the most extensive ground-based OH airglow datasets to date (~40M images), allowing detailed characterization of small-scale atmospheric wave fields in the mesosphere and lower thermosphere (MLT) region.
This dataset provides new constraints on the generation, propagation, and dissipation of high-frequency atmospheric waves, and illustrates the sensitivity of airglow observations to a wide range of dynamical forcings, including seismic sources, as demonstrated by a dedicated modeling study. Beyond this specific application, our results highlight the potential of high-cadence airglow imaging as a powerful tool to study upper atmospheric dynamics bellow ionosphere levels with implications for future terrestrial and planetary atmospheric investigations.
To investigate upper-atmospheric wave dynamics in the framework of ionospheric seismology, we deployed two permanent observatories monitoring the OH airglow layer (SWIR emission at ~87 km altitude) in Izu-Oshima (Japan) and on La Réunion Island (Indian Ocean). These observatories were initially designed to image the atmospheric signatures of seismic wave–induced perturbations propagating from the solid Earth into the upper atmosphere. The instruments operate continuously at 1 s cadence, enabling the observation of short-period waves that are typically unresolved by conventional airglow imaging systems. Over two years of measurements, we have built one of the most extensive ground-based OH airglow datasets to date (~40M images), allowing detailed characterization of small-scale atmospheric wave fields in the mesosphere and lower thermosphere (MLT) region.
This dataset provides new constraints on the generation, propagation, and dissipation of high-frequency atmospheric waves, and illustrates the sensitivity of airglow observations to a wide range of dynamical forcings, including seismic sources, as demonstrated by a dedicated modeling study. Beyond this specific application, our results highlight the potential of high-cadence airglow imaging as a powerful tool to study upper atmospheric dynamics bellow ionosphere levels with implications for future terrestrial and planetary atmospheric investigations.