Abstract
This paper is a brief summary of recent experimental studies conducted by the WPL staff in order to: (a) compare acoustic echo strengths with those predicted from measured turbulence intensities and scatter theory; (b) develop optimum experimental geometries for Doppler work, and (c) use the acoustic echo-sounder as a quantitative tool in studies of gravity wave dynamics in, and immediately above, the stable planetary boundary layer. We find that the observed acoustic echo strengths are roughly an order of magnitude greater than those predicted theoretically. This discrepancy might be in part due to partial reflection although the comparison is somewhat clouded by uncertainties in our knowledge of the equipment characteristics, propagation losses, etc. Comparisons between Doppler and in situ wind measurements give confidence in the Doppler results, but further experimentation and comparisons are needed. Preliminary use of acoustic Doppler data in a case study of gravity-wave dynamics in the planetary boundary layer has yielded boundary-layer wind speed and direction profiles which give insight into the mechanisms responsible for the wave generation. The Doppler data yield estimates of the wave associated momentum fluxes (∼a few dyn cm−2) as well. The results derived from the acoustic techniques are quite encouraging, but thus far remain unsubstantiated by independent wind and flux measurements.
Similar content being viewed by others
References
Atlas, D.: 1964, ‘Advances in Radar Meteorology’,Advan. Geophys. 10, 317.
Bean, B., Frisch, A. S., McAllister L. G., and Pollard, J. R.: 1973, ‘Planetary Boundary-Layer Turbulence Studies from Acoustic Echo Sounder and In-situ Measurements’,Boundary-Layer Meteorol., in this issue, p. 449.
Beran, D. W. and Clifford, S. F.: 1972, ‘Acoustic Doppler Measurements of the Total Wind Vector’,Proc. of AMS Second Symp. on Meterol. Obs. and Inst., San Diego, Calif., 100–109.
Beran, D. W., Little, C. G., and Willmarth, B. C.: 1971, ‘Acoustic Doppler Measurements of Vertical Velocities in the Atmosphere’,Nature 230, 160–162.
Cook, R. K.: 1962, ‘Strange Sounds in the Atmosphere. Part I’,Sound 1, 12–16.
Cook, R. K.: 1969, ‘Atmospheric Sound Propagation’, Final Report, Panel on Remote Atmospheric Probing of the Committee on Atm. Sc. NAS-NRC, 633–669.
Cook, R. K. and Young, J. M.: 1962, ‘Strange Sounds in the Atmosphere. Part II’,Sound 1, 25–33.
Deardorff, J. W.: 1969, ‘Numerical Study of Heat Transport by Internal Gravity Waves Above a Growing Unstable Layer’,Phys. Fluids, SupplementII, High Speed Computing in Fluid Dynamics, II 184-II 194.
Emmanuel, C. B.: 1973, ‘Richardson Number Profile Through Shear-Instability Wave Regions Observed in the Lower Planetary Boundary Layer’,Boundary-Layer Meteorol., in press.
Emmanuel, C. B., Bean, B. R., McAllister, L. G., and Pollard, J. R.: 1972, ‘Observations of Helmholtz Waves in the Lower Atmosphere With an Acoustic Sounder’,J. Atmospheric Sci. 29, 886–892.
Georges, T. M. and Clifford, S. F.: 1972, ‘Acoustic Sounding in a Refracting Atmosphere’,J. Acoust. Soc. Amer. (in press).
Gething, J. T. and Jenssen, D.: 1971, ‘Remote Measurement of Temperature and Humidity by Means of Acoustic Echo Sounding’,Nature,231, 198–200.
Gossard, E. E. and Munk, W.: 1954, ‘On Gravity Waves in Atmosphere’,J. Meterol. 11, 4, 246–269.
Gossard, E. E., Jensen, D. R., and Richter, J. H.: 1971, ‘An Analytical Study of Tropospheric Structure as Seen by High-Resolution Radar’,J. Atmospheric Sci. 28, 794–807.
Hall, F. F., Jr., J. W. Wescott, and W. R. Simmons: 1971, Acoustic Echo Sounding of Atmospheric Thermal and Wind Structure’,Proc. of 7th Int. Symp. on Remote Sensing of Environ., Univ. of Mich., 1715–1732.
Hooke, W. H., Young, J. M., and Beran, D. W.: 1972a, ‘Atmospheric Waves Observed in the Planetary Boundary Layer Using an Acoustic Sounder and Microbarograph Array’,Boundary-Layer Meteorol 2, 371–380.
Hooke, W. H., Hall, F. F., and Gossard, E. E.: 1973, ‘Observed Generation of an Atmospheric Gravity Wave by Shear Instability in the Mean Flow of the Planetary Boundary Layer’,Boundary-Layer Meteorol., in press.
Kallistratova, M. A.: 1961, ‘Experimental Investigation of Sound Wave Scattering in the Atmosphere’,Trudy Inst. Fiz. Atmos., Atmos. Turbulentnost 4, 203–256.
Little, C. G.: 1969, ‘Acoustic Methods for the Remote Probing of the Lower Atmosphere’,Proc. IEEE 57, 571–578.
McAllister, L. G., Pollard, J. R., Mahoney, A. R., and Shaw, P.J.R.: 1969, ‘Acoustic Sounding — A New Approach to the Study of Atmospheric Structure’,Proc. IEEE 57, 579–587.
Monin, A. S.: 1962, ‘Characteristics of the Scattering of Sound in a Turbulent Atmosphere’,Akust. Zh. 7, 457–461 (Sov. Phys. Acoust. 7, 370–373).
Ottersten, H.: 1970, ‘Radar Angles and Their Relationship to Meteorological Factors’,Final Report FOA, Res. Inst. of Nat. Def. Sweden 4, 1–33.
Tatarski, V. I.: 1971, ‘The Effects of the Turbulent Atmosphere on Wave Propagation’, (Israel Prog. for Sci. Trans].) NOAA TT 68-50464, 471 pp.
Townsend, A. A.: 1966, ‘Internal Waves Produced by a Convective Layer’,J. Fluid Mech. 24, 307–319.
Townsend, A. A.: 1968, ‘Excitation of Internal Waves in a Stably-Stratified Atmosphere With Considerable Wind Shear’,J. Fluid Mech. 32, 145–171.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Beran, D.W., Hooke, W.H. & Clifford, S.F. Acoustic echo-sounding techniques and their application to gravity-wave, turbulence, and stability studies. Boundary-Layer Meteorol 4, 133–153 (1973). https://doi.org/10.1007/BF02265228
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF02265228