Observation of Quasiperiodic Structures in the Hydroxyl Airglow on Scales Below 100 m

Abstract

Gravity waves are known to transport energy and momentum to the middle atmosphere. The breaking processes associated with divergence of fluxes of energy and momentum into the atmosphere occur on scales that cannot be resolved in models and therefore have to be parameterized. The question remains as to whether it is possible to use a turbulence model on scales below 100 m and what kind of turbulence model should that be. Here we use high spatial resolution observations of the OH nightglow located near 90‐km altitude from the Nordic Optical Telescope to observe quasiperiodic structures down to horizontal scales of 4.5 m. These results indicate that a Kolmogorov type of energy cascade model of turbulence with a −5/3 power law appears to be satisfied down to these short, 4.5‐m scales.