Full-wave modeling of small-scale gravity waves using Airborne Lidar and Observations of the Hawaiian Airglow (ALOHA-93) O(1 S) images and coincident Na wind/temperature lidar measurements
Article first published online: 21 SEP 2012
Copyright 1998 by the American Geophysical Union.
Journal of Geophysical Research: Atmospheres (1984–2012)
Volume 103, Issue D6, pages 6439–6453, 27 March 1998
How to Cite
1998), Full-wave modeling of small-scale gravity waves using Airborne Lidar and Observations of the Hawaiian Airglow (ALOHA-93) O(1 S) images and coincident Na wind/temperature lidar measurements, J. Geophys. Res., 103(D6), 6439–6453, doi:10.1029/97JD03373., , , and (
- Issue published online: 21 SEP 2012
- Article first published online: 21 SEP 2012
- Manuscript Accepted: 19 NOV 1997
- Manuscript Received: 22 JAN 1997
Measurements were made of mesospheric gravity waves in the OI (5577 Å) nightglow observed from Maui, Hawaii, during the Airborne Lidar and Observations of Hawaiian Airglow (ALOHA-93) campaign. Clear, monochromatic gravity waves were observed on several nights. By using a full-wave model that realistically includes the major physical processes in this region, we have simulated the propagation of four waves through the mesopause region and calculated the O(1S) nightglow response to the waves. Mean winds derived from Na wind/temperature lidar observations were employed in the computations. Wave amplitudes were calculated based on the requirement that the observed and simulated relative airglow fluctuation amplitudes be equal. Although the extrinsic (i.e., observed) characteristics of all four waves studied were quite similar (horizontal wavelengths ∼20 to 30 km; periods ∼9 min; horizontal phase speeds ∼35 to 50 m s−1), the propagation characteristics of the waves are all quite different due to the different background mean winds through which the waves propagate. Three of the waves encounter critical levels in the mesopause region. For two of these waves the upward propagation beyond the 97 km level is severely impeded by their critical levels because the local value of the Richardson number exceeds unity there. The third wave is not severely attenuated at its critical level because the Richardson number there is about 0.25. The fourth wave does not encounter a critical level although it is strongly Doppler shifted to low frequencies over a limited height range by the mean winds. It appears to be able to propagate at least to the 110 km level essentially unimpeded. This study demonstrates that an accurate description of the mean winds is an essential requirement for a complete interpretation of observed wave-driven airglow fluctuations. The study also emphasizes that although the measured extrinsic properties of waves may be similar, their propagation to higher altitudes depends very sensitively on the mean winds through which the waves propagate.