Propagation of Internal Gravity Waves in a Thermally Stratified Atmosphere
Published Online: 17 MAR 2013
Copyright © 1974 by the American Geophysical Union.
The Upper Atmosphere in Motion
How to Cite
Hines, C. O. (1974) Propagation of Internal Gravity Waves in a Thermally Stratified Atmosphere, in The Upper Atmosphere in Motion, American Geophysical Union, Washington, D. C.. doi: 10.1029/GM018p0533
- Published Online: 17 MAR 2013
- Published Print: 1 JAN 1974
Print ISBN: 9780875900186
Online ISBN: 9781118663578
- Atmosphere, Upper—Addresses, essays, lectures;
- Dynamic meteorology—Addresses, essays, lectures
The reflection of internal gravity waves in a thermally stratified atmosphere may result in the formation of a wave duct between a strongly reflecting region and the ground. In some cases total reflection occurs and wave energy propagates horizontally in the duct without loss. In other cases, however, the reflection is not total but is nevertheless strong; in these latter cases the duct is ‘imperfect’ and wave energy is carried to great distances with only minor loss in the form of a leakage into the overlying regions. In this paper the imperfect ducting of internal gravity waves in thermally stratified atmospheres is analyzed numerically, temperature profiles generally representative of summer and winter conditions being studied in detail. Modal solutions relating the frequencies, wavelengths, propagation speeds, and attenuation indices to one another are obtained. An evaluation of the role in the ducting process of the atmospheric temperature profile is made using computed patterns of energy flow and vertical distributions of energy density. The results show the existence of propagation modes which are strongly ducted by the atmosphere and which have properties that are in general agreement with traveling ionospheric disturbances in the F region.