Power spectra of internal gravity waves / E.M. Dewan.
The OH layer located in the region of 85 km altitude emits strong infrared radiation. Gravity waves can be modulate the brightness of this layer over a wide range of spatial scales. Such fluctuations constitute, in effect, a form of IR clutter which could potentially degrade surveillance systems in...
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| Format: | Government Document Book |
| Language: | English |
| Published: |
Hanscom AFB, MA :
Geophysics Laboratory, United States Air Force,
1990.
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| Series: | GL-TR ;
90-233. Special reports (U.S. Air Force Geophysics Laboratory) ; no. 265. |
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| Summary: | The OH layer located in the region of 85 km altitude emits strong infrared radiation. Gravity waves can be modulate the brightness of this layer over a wide range of spatial scales. Such fluctuations constitute, in effect, a form of IR clutter which could potentially degrade surveillance systems in certain situations. For this reason there is interest in the spatial and temporal variations of atmospheric internal gravity waves. A physical, similitude model of internal gravity waves assumes saturation of the waves and control by cascade processes of the temporal and horizontal scales of the waves. This model contains all the power spectral densities (PSD's) (sometimes merely called spectra) to be found in the formalism of Garrett and Munk. The latter is a purely empirical model for internal gravity waves applicable to the atmosphere and ocean. The main new predictions of the present model are that the dissipation rate controls the amplitudes of the frequency and horizontal wave number spectra. The validity of the proposed model is unknown at this time, and will depend upon the future experimental tests. It is shown, however, that based on 'typical' parametric values, results from the model are encouraging. |
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| Item Description: | "17 September 1990." ADA231596 (from http://www.dtic.mil) Optical Physics Division Project 2310. Research supported by the Geophysics Laboratory, United States Air Force, Hanscom AFB, Massachusetts. |
| Physical Description: | v, 42 pages ; 28 cm. |
| Bibliography: | Includes bibliographical references (pages 25-27) |