Global observations of gravity wave intermittency and its impact on the observed momentum flux morphology
Article first published online: 11 OCT 2013
©2013. American Geophysical Union. All Rights Reserved.
Journal of Geophysical Research: Atmospheres
Volume 118, Issue 19, pages 10,980–10,993, 16 October 2013
How to Cite
2013), Global observations of gravity wave intermittency and its impact on the observed momentum flux morphology, J. Geophys. Res. Atmos., 118, 10,980–10,993, doi:10.1002/jgrd.50869., , and (
- Issue published online: 30 OCT 2013
- Article first published online: 11 OCT 2013
- Accepted manuscript online: 3 OCT 2013 09:31AM EST
- Manuscript Accepted: 27 SEP 2013
- Manuscript Revised: 20 SEP 2013
- Manuscript Received: 6 JUN 2013
- gravity waves;
 Three years of gravity wave observations from the High Resolution Dynamics Limb Sounder instrument on NASA's Aura satellite are examined. We produce estimates of the global distribution of gravity wave momentum flux as a function of individual observed wave packets. The observed distribution at the 25 km altitude level is dominated by the small proportion of wave packets with momentum fluxes greater than ∼0.5 mPa. Depending on latitude and season, these wave packets only comprise ∼7–25% of observations, but are shown to be almost entirely responsible for the morphology of the observed global momentum flux distribution. Large-amplitude wave packets are found to be more important over orographic regions than over flat ocean regions, and to be especially high in regions poleward of 40°S during austral winter. The momentum flux carried by the largest packets relative to the distribution mean is observed to decrease with height over orographic wave generation regions, but to increase with height at tropical latitudes; the mesospheric intermittency resulting is broadly equivalent in both cases. Consistent with previous studies, waves in the top 10% of the extratropical distribution are observed to carry momentum fluxes more than twice the mean and waves in the top 1% more than 10× the mean, and the Gini coefficient is found to characterize the observed distributions well. These results have significant implications for gravity wave modeling.