Accession Number:

ADA231596

Title:

Power Spectra of Internal Gravity Waves

Descriptive Note:

Special rept.

Corporate Author:

AIR FORCE SYSTEMS COMMAND HANSCOM AFB MA GEOPHYSICS LAB

Personal Author(s):

Report Date:

1990-09-17

Pagination or Media Count:

46.0

Abstract:

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 PSDs 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.

Subject Categories:

  • Atmospheric Physics
  • Optics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE