Intermittency of Gravity Wave Momentum Flux in the Mesopause Region Observed with an All-Sky Airglow Imager

Bing Cao, Alan Z Liu

Research output: Contribution to journalArticlepeer-review

Abstract

<p> The intermittency of gravity wave momentum flux (MF) near the OH airglow layer (&sim;87 km) in the mesopause region is investigated for the first time using observation of all-sky airglow imager over Maui, Hawaii (20.7&compfn;N, 156.3&compfn;W), and Cerro Pach&oacute;n, Chile (30.3&compfn;S, 70.7&compfn;W). At both sites, the probability density function (pdf) of gravity wave MF shows two distinct distributions depending on the magnitude of the MF. For MF smaller (larger) than &sim;16 m2 s&minus;2 (0.091 mPa), the pdf follows a lognormal (power law) distribution. The intermittency represented by the Bernoulli proxy and the percentile ratio shows that gravity waves have higher intermittency at Maui than at Cerro Pach&oacute;n, suggesting more intermittent background variation above Maui. It is found that most of the MF is contributed by waves that occur very infrequently. But waves that individually contribute little MF are also important because of their higher occurrence frequencies. The peak contribution is from waves with MF around &sim;2.2 m2 s&minus;2 at Cerro Pach&oacute;n and &sim;5.5 m2 s&minus;2 at Maui. Seasonal variations of the pdf and intermittency imply that the background atmosphere has larger influence on the observed intermittency in the mesopause region.</p>
Original languageAmerican English
JournalJournal of Geophysical Research: Atmospheres
Volume121
StatePublished - Jan 1 2016
Externally publishedYes

Disciplines

  • Atmospheric Sciences

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