Observation of Gravity Wave Vertical Propagation through a Mesospheric Inversion Layer
Résumé
The impact of a mesospheric temperature inversion on the vertical propagation of gravity
waves has been investigated using OH airglow images and ground-based Rayleigh lidar measure-
ments carried out in December 2017 at the Haute-Provence Observatory (OHP, France, 44N). These
measurements provide complementary information that allows the vertical propagation of gravity
waves to be followed. An intense mesospheric inversion layer (MIL) observed near 60 km of altitude
with the lidar disappeared in the middle of the night, offering a unique opportunity to evaluate
its impact on gravity wave (GW) propagation observed above the inversion with airglow cameras.
With these two instruments, a wave with a 150 min period was observed and was also identified
in meteorological analyses. The gravity waves’ potential energy vertical profile clearly shows the
GW energy lost below the inversion altitude and a large increase of gravity wave energy above
the inversion in OH airglow images with waves exhibiting higher frequency. MILs are known to
cause instabilities at its top part, and this is probably the reason for the enhanced gravity waves
observed above.
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