Sound Propagation Through and Scattering by Internal Gravity Waves in a Stably Strategified Atmosphere PDF Download
Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download Sound Propagation Through and Scattering by Internal Gravity Waves in a Stably Strategified Atmosphere PDF full book. Access full book title Sound Propagation Through and Scattering by Internal Gravity Waves in a Stably Strategified Atmosphere by . Download full books in PDF and EPUB format.
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 11
Get Book Here
Book Description
A stably stratified atmosphere supports propagation of internal gravity waves (IGW). These waves result in highly anisotropic fluctuations in temperature and wind velocity that are stretched in a horizontal direction. As a result, (IGW) can significantly affect propagation of sound waves in nighttime boundary layers and infrasound waves in the stratosphere. In this paper, a theory of sound propagation through, and scattering by, (IGW) is developed. First, 3D spectra of temperature and wind velocity fluctuations due to (IGW), which were recently derived in the literature for the case of large wave numbers, are generalized to account for small wave numbers. The generalized 3D spectra are then used to calculate the sound scattering cross section in an atmosphere with (IGW). The dependencies of the obtained scattering cross section on the sound frequency, scattering angle, and other parameters of the problem are qualitatively different from those for the case of sound scattering by isotropic turbulence with the von K rm n spectra of temperature and wind velocity fluctuations. Furthermore, the generalized 3D spectra are used to calculate the mean sound field and the transverse coherence function of a plane sound wave propagating through (IGW). The results obtained also significantly differ from those for the case of sound propagation through isotropic turbulence.
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 11
Get Book Here
Book Description
A stably stratified atmosphere supports propagation of internal gravity waves (IGW). These waves result in highly anisotropic fluctuations in temperature and wind velocity that are stretched in a horizontal direction. As a result, (IGW) can significantly affect propagation of sound waves in nighttime boundary layers and infrasound waves in the stratosphere. In this paper, a theory of sound propagation through, and scattering by, (IGW) is developed. First, 3D spectra of temperature and wind velocity fluctuations due to (IGW), which were recently derived in the literature for the case of large wave numbers, are generalized to account for small wave numbers. The generalized 3D spectra are then used to calculate the sound scattering cross section in an atmosphere with (IGW). The dependencies of the obtained scattering cross section on the sound frequency, scattering angle, and other parameters of the problem are qualitatively different from those for the case of sound scattering by isotropic turbulence with the von K rm n spectra of temperature and wind velocity fluctuations. Furthermore, the generalized 3D spectra are used to calculate the mean sound field and the transverse coherence function of a plane sound wave propagating through (IGW). The results obtained also significantly differ from those for the case of sound propagation through isotropic turbulence.
Author: Igor Chunchuzov
Publisher: Cambridge Scholars Publishing
ISBN: 1527547760
Category : Science
Languages : en
Pages : 355
Get Book Here
Book Description
This book presents the theory and results of experimental studies of the propagation of infrasound waves in a real atmosphere with its inherent fine-scale layered structure of wind speed and temperature. It is motivated by the fact that the statistical characteristics of anisotropic (or layered) fluctuations of meteorological fields, the horizontal scales of which significantly exceed their vertical scales, have been very poorly studied compared to those of locally isotropic turbulence in the inertial range of scales. This book addresses this lacuna by developing a theory of the formation of anisotropic inhomogeneities of the atmosphere in a random field of internal gravity waves and vortex structures. Using theory, it explains numerous experimental data depicting the influence of the fine structure of the atmosphere on the propagation of infrasound waves from pulsed sources. The text will appeal to specialists in the fields of acoustics and optics of the atmosphere, remote sensing of the atmosphere, the dynamics of internal waves, nonlinear acoustics, and infrasound monitoring of explosions and natural hazards.
Author: Alexis Le Pichon
Publisher: Springer
ISBN: 3319751409
Category : Science
Languages : en
Pages : 1168
Get Book Here
Book Description
Since the publication of the first volume “Infrasound monitoring for atmospheric studies” published in 2010, significant advances were achieved in the fields of engineering, propagation modelling, and atmospheric remote sensing methods. The global infrasound network, which consists of the International Monitoring Network (IMS) for nuclear test ban verification completed by an increasing number of regional cluster arrays deployed around the globe, has evidenced an unprecedented potential for detecting, locating and characterizing various natural and man-made sources. In recent years, infrasound has evolved into a broad interdisciplinary field encompassing academic disciplines of geophysics and innovative technical and scientific developments. The advances in innovative ground-based instruments, including infrasound inversions for continuous observations of the stratosphere and mesosphere, provide useful insights into the geophysical source phenomenology and atmospheric processes involved. Systematic investigations into low-frequency infrasound signals and the development of complementary observational platforms point out new insights into the dynamics of the middle atmosphere which play a significant role in both tropospheric weather and climate. This monitoring system also provides continuous relevant information about natural hazards with high societal benefits, like on-going volcanic eruptions, surface earthquakes, meteorites or severe weather. With this new edition, researchers and students benefit from a comprehensive content of both fundamental and applied inter-disciplinary topics.
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 10
Get Book Here
Book Description
In this project, we developed 3D models of temperature and wind velocity fluctuations in nighttime boundary layers (NBL) and, using these models, studied sound propagation and scattering. The 3D spectra of temperature and velocity fluctuations due to internal gravity waves in moderately and very stable NBL were obtained. The 3D spectra of turbulent temperature and wind velocity fluctuations in weakly stable, intermittent NBL were modeled with the use of the von Karman spectra. Quasi-wavelet models of turbulent temperature and velocity fluctuations were developed. The developed models of internal gravity waves, turbulence, and quasi-wavelets were then used for calculations of the statistical moments of plane and spherical sound waves propagating in the atmosphere. These calculations were done for three different problems: scattering of sound, line-of-sight sound propagation, and sound propagation in a refractive, turbulent atmosphere near an impedance ground. The coherence function of a sound field propagating in NBL was measured and compared with that predicted theoretically.
Author: Acoustical Society of America
Publisher:
ISBN:
Category : Acoustical engineering
Languages : en
Pages : 1384
Get Book Here
Book Description
Author: Vladimir E. Ostashev
Publisher: CRC Press
ISBN: 1482266652
Category : Technology & Engineering
Languages : en
Pages : 537
Get Book Here
Book Description
Introduces Systematic Formulations for Use in Acoustic ApplicationsAcoustics in Moving Inhomogeneous Media, Second Edition offers a uniquely complete and rigorous study of sound propagation and scattering in moving media with deterministic and random inhomogeneities. This study is of great importance in many fields including atmospheric and oceanic
Author: Nayar K. Balachandran
Publisher:
ISBN:
Category :
Languages : en
Pages :
Get Book Here
Book Description
Author: Nambath Krishnan Balachandran
Publisher:
ISBN:
Category :
Languages : en
Pages : 202
Get Book Here
Book Description
Author:
Publisher:
ISBN:
Category : Atmospheric physics
Languages : en
Pages : 412
Get Book Here
Book Description
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 46
Get Book Here
Book Description
A theory is presented which permits the study of the effects of horizontal winds on the dispersion and amplitudes of acoustic-gravity waves in the atmosphere. It is shown that the effective horizontal group velocity for a given frequency in a given normal mode depends on direction of propagation as well as on frequency and that it is not necessarily in the same direction as the horizontal wave number vector. A number of useful integral theorems are derived from a variational principle and one is subsequently applied to the development of a perturbation method for the computation of wind effects on dispersion. Application of the method to a realistic example indicates that winds can appreciably alter the dispersion of the normal modes and that they should be considered in any quantitative interpretation of experimental microbarograms.
