1. Infrasound propagation in the atmosphere
with mesoscale fluctuations induced by internal gravity waves
Igor Chunchuzov, Sergey Kulichkov, Oleg Popov, Vitaly Perepelkin
Obukhov Institute of Atmospheric Physics,
Moscow, 3 Pyzhevskii Per., Russia
Presented at Acoustics’17, June 25-29, 2017, Boston

3. ABSTRACT
The influence of the mesoscale wind velocity and temperature fluctuations induced by internal gravity waves(IGWs) on infrasound propagation in the atmosphere is studied. The statistical characteristics of the fluctuations in the parameters of infrasonic signals (such as variances and temporal spectra of the fluctuations in travel time and angle of arrival, amplitude and time duration) caused by gravity wave-associated fluctuations are studied based on the nonlinear model of shaping of the 3-D spatial spectrum of the fluctuations. The nonlinear shaping mechanism for the 3-D spectrum is associated with both the non-resonance interactions between IGWs and wave breaking processes caused by the wave-induced shear or convective instabilities. The 1-D wave number spectra (vertical and horizontal) of the mesoscale fluctuations obtained from the 3-D model are compared with the observed spectra derived from the radar,lidar and airplane temperature and wind measurements in the middle atmosphere. The results of theory and numerical modeling of infrasound scattering from gravity wave-associated fluctuations are presented. The vertical profiles of the wind velocity fluctuations in the stratosphere and lower thermosphere up to the altitudes of 130 km are retrieved from the infrasound scattered from the mesoscale wind velocity and temperature fluctuations. The results of acoustic probing of the stably stratified atmospheric boundary layer using detonation source of acoustic pulses are discussed.

4. Mesoscale wind velocity and temperature fluctuations induced by internal gravity waves (IGWs) in the atmosphere. 3-D spectrum.
Effect of IGWs on the parameters of infrasound signals ( travel time, azimuth of propagation, wave form and coherence )
Infrasound probing of the fine-scale layered structure in the stratosphere, mesosphere and lower thermosphere.
Probing of the atmospheric boundary layer using acoustic pulse sources
Areas of using real time wind data.
C O N T E N T

5. Parameterization of the 3-D IGW spectrum [Chunchuzov I. , 2002: J. Atm
Parameterization of the 3-D IGW spectrum [Chunchuzov I., 2002: J. Atm. Sci., 59, ]
is parameter of anisotropy,
is Coriolis parameter
is variance of gravity wave-induced wind velocity fluctuations,
is BV-frequency,
is the vertical scale of IGW sources,
is parameter of nonlinearity
of IGW wave field,
is characteristic vertical wavenumber,
horizontal -to –vertical
scale ratio for IGW
sources,
- critical vertical wavenumber at which
wave-induced (shear or convective) instability switches on and generates small-scale turbulence.

6. Vertical wavenumber (1D) spectra
-for relative
temperature fluctuations
Vertical wavenumber (1D) spectra
for wind
velocity
fluctuations
for vertical displacements,
for the relative temperature fluctuations

7. Travel time fluctuations  induced by a random
internal gravity wave field
[Chunchuzov, I.P. “Influence of internal gravity waves on sound propagation in the lower atmosphere.” Meteorol. and Atm. Phys., 34, 1-16, 2003]
< 2>= 2 n R0 0 [(2<T2>+<2>)/kZ*]/(3c02) (0)
<2>= 41/2 r 0 (2 <T2>+ <2>)/(3k0c02) (0),
0 =
n-number of total reflections, R0 =z(x0)-1 is the radius of curvature of the ray path z=z(x) taken at a ray turning point (x0, z(x0)), r is horizontal distance.
<T2 >= <T‘ 2/(4T02)>, <2> = <Vx 2/c02>, where T'’/T0 and Vx are the fluctuations of the relative temperature and horizontal wind velocity component , respectively.
kz*= N/(2<Vх2>)1/2-characteristic vertical wavenumber, N is BV-frequency,
k0-characteristic horizontal wavenumber of the 3D spectrum.

8. Fluctuations of the azimuth of arrival
is the sound travel time between two receivers separated by distance
is the temporal fluctuation of
For the stratospheric arrival at r=200km from a source:
For
in the range ( ),
is in the range ( ) deg
This is the estimate of the IGW-associated error in determining of the azimuth of arrival, which is consistent with the observed azimuth fluctuations from surface explosions [Kulichkov et al., InfraMatics, 18, June 2007]

9. Transverse coherence function of a plane sound wave
is extinction coefficient
Ostashev V.E., I.P. Chunchuzov
D.K. Wilson.
JASA, 2005, V.118 (6)

10. V. Zhupanovsky, KAMCHATKA

11. Recordings of infrasound signals at 110km (IS44) and 91 km (PRT) from v. Zhupanovsky

12. Trace velocity vs time in the shadow zone

14. Acoustic field (IS44) for the unperturbed atmosphere, f=0
Acoustic field (IS44) for the unperturbed atmosphere, f=0.2 Hz, Oct
Acoustic field for the unperturbed atmosphere,
f=0.2 Hz, Oct

16. Effect of the N-wave reflection from fine-scale layered
Effect of the N-wave reflection from fine-scale layered wind velocity and temperature fluctuations
Analytic solution for the reflected wave field is a convolution of the vertical profile of the gradient of relative effective sound speed fluctuations with the wave form of the incident N-wave.
Time duration of the
reflected signal
Vertical sound speed fluctuations obtained from the model by I.P. Chunchuzov. “On the nonlinear shaping mechanism for gravity wave spectrum in the atmosphere.” Ann. Geophys., 27, , 2009
Calculated reflected signal
for the incident N-wave with

17. Retrieval method (Chunchuzov et al. , Izvestiya, Atm
Retrieval method (Chunchuzov et al., Izvestiya, Atm. Ocean Physics, 2015, V.51(1), p.69-87)
Waveform of the reflected signal
Relation between reflected signal
and profile of fluctuations , N-wave
( i=1,2,…,n) m
is number of discrete values of t within a time duration of N-wave
Finding approximate solution X by a least
square method

19. Acoustic field (IS44) for the retrieved profile, f=0.2 Hz, Oct 11 2014

21. COMMON STRUCTURE OF THE INFRASOUND ARRIVALS

22. Retrieved profiles from 3 successive signals with the 15-min time interval, v. Tungurahia, July 15, 2006

23. RETRIEVED PROFILES OF THE FLUCTUATIONS Ceff(z) [Chunchuzov, I. , S
RETRIEVED PROFILES OF THE FLUCTUATIONS Ceff(z) [Chunchuzov, I., S. Kulichkov, V. Perepelkin, O. Popov, P. Firstov, J.D. Assink, E. Marchetti, , J. Geophys. Res., 120, doi: /2015JD023276, 2015]
Chunchuzov, I., S. Kulichkov, V. Perepelkin, O. Popov, P. Firstov, J.D. Assink, E. Marchetti, “Study of the wind velocity- layered structure in the stratosphere, mesosphere and lower thermosphere by using infrasound probing of the atmosphere”, J. Geophys. Res., 120, doi: /2015JD023276, 2015

24. The comparison of the vertical profiles of wind velocity fluctuations obtained by a) MU radar (reproduced from Tsuda T., 2014, Proc. Jpn. Acad., Ser. B 90, V. 90: 12-27) and infrasound sounding (Chuchuzov et al., 2015, J. Geophys. Res., 120: , doi: /2015JD )

25. Vertical wave number spectra of the retrieved Ceff-fluctuations

27. How could we use retrieved wind profiles in the upper atmosphere
How could we use retrieved wind profiles in the upper atmosphere? 1)For monitoring temporal variability of the wind field in the lower thermosphere ( km) . This layer is not studied by other remote sensing methods (radars, lidars and satellites). Wind data in the upper atmosphere are necessary for - climate change modeling, -modeling the transport of atmospheric aerosol, particularly, ash from volcano eruptions, -modeling infrasound propagation through atmosphere with real-time retrieved IGW perturbations. 2) For studying the statistical characteristics of the IGW perturbations (variances, vertical wavenumber spectra and structure functions) to parameterize the effect of IGWs on infrasound signal parameters and wave drag in general circulation models of the atmosphere. What are the main statistical parameters of random IGW perturbations that affect parameters of infrasound signals?

28. Acoustic pulse generator in Armenia
Chunchuzov I.P., Perepelkin V.G., Popov O.E., Kulichkov S.N.,Vardanyan A.A. , Ivazyan G.E., Khachikyan Kh.Z.. Study of the characteristics of the fine-scale layered structure of the lower troposphere by using acoustic pulse remote sensing . Izvestiya Atmospheric and Oceanic Physics, 2016 , Vol. 53, No. 3, pp. 279–293.
Chunchuzov I.P., Perepelkin V.G., Popov O.E., Kulichkov S.N.,Vardanyan A.A. , Ivazyan G.E., Khachikyan Kh.Z.. Study the characteristics of the fine-scale layered structure of the lower troposphere by using acoustic pulse remote sensing . Izvestiya Atmospheric and Oceanic Physics, 2016 (in Press)
Generator with 3 acoustic cannons. 1- аcoustic cannons; 2 – control panel 3- gas cylinders with an explosive mixture (propane)

29. Рис. 5. Вверху: Один из сигналов , зарегистрированный в Армении (г
Рис.5. Вверху: Один из сигналов , зарегистрированный в Армении (г. Талин) в 19:38:48 мест. вр. на расстоянии r=2.25 км от источника. На верхней панели указаны волноводный приход сигнала (waveguide) (а), и приходы 1,2 и 3, обнаруженные на “хвосте” сигнала с помощью корреляционного анализа сигналов на приемниках треугольной антенны. На панелях б)-д) , показаны, соответственно: зависимости от текущего времени (горизонтальная ось) спектра всего сигнала (единицы справа в Па2/Гц) в зависимости от частоты (вертикальная ось слева); средней когерентности сигналов между приемниками антенны в зависимости от частоты; азимута прихода сигнала (в град) и его фазовой скорости (единицы в м/c, указаны справа). Внизу: Спектры начального сигнала (20м), его приходов 1,2, 3 (2.25км) и шума перед приходом всего сигнала (е).

30. (middle panel) by parabolic equation method
Upper panels: Vertical profiles of the effective sound speed fluctuations retrieved from the 3
arrivals 1,2 and 3. Lower panel: Calculation of the signal and its spectrum as a function of time
(middle panel) by parabolic equation method
Upper panels: Vertical profiles of the effective sound speed fluctuations retrieved from the 3 arrivals 1,2 and 3. Lower panel: Calculation of the signal P’ and its spectrum as a function of time (middle panel) by parabolic equation method

31. Retrieved profiles DСeff(z) obtained from the arrivals 1 and 2 of the signal (middle and right panels) superimposed on the mean profile (left) obtained from sodar and temperature profiler data on Aug near Moscow (ZNS)
Retrieved profiles DСeff(z) obtained from the arrivals 1 and 2 of the signal (middle and right panels) superimposed on the mean profile (left) obtained from sodar and temperature profiler data on Aug near Moscow (ZNS)

32. Calculated signal (Parabolic Equation) P’ in the range Hz for the profile Сeff(z) in two cases: а) using sodar profile b) using sodar profile+ retrieved fluctuations in the layers 1 ( m) and 2 ( m). The retrievals 1 and 2 are predicted only in the case b.
Calculated signal (Parabolic Equation) P’ in the range Hz for the profile Сeff(z) in two cases: а) using sodar profile б) using sodar profile+ retrieved fluctuations in the layers 1 ( m) and 2 ( m). The arrivals 1 and 2 are predicted only in the case (б). Recorded arrivals 1 and 2 (в)

33. CONCLUSIONS
The recently developed infrasound probing method allowed us to retrieve vertical profiles of
the wind velocity fluctuations in the stratosphere (30-55 km) and MLT ( km).
Till present these layers have not been studied well by other remote sensing methods (radars, lidars, satellites).
Despite the difference in the locations and time periods for the retrieved wind velocity
profiles all of them show common features such as similar power law decays for the vertical
wave number spectra in the upper stratosphere in the range of vertical scales from a few
kilometers to about 100 m.
3. The obtained vertical wave number spectra show a capability of the infrasound method in
studying statistical characteristics of the mesoscale wind velocity fluctuations in the middle
and upper atmosphere. These characteristics are necessary for the parameterization of the
gravity wave drag in climate change and weather prediction models
4. The incorporation of the real-time wind vertical structure into the infrasound propagation
models can significantly improve the localization of the infrasound sources.