Investigation of acoustic gravity waves in the upper atmosphere by the artificial periodic inhomogeneities method at Nizhny Novgorod

1996 ◽  
Vol 39 (3) ◽  
pp. 224-228
Author(s):  
N. V. Bakhmet'eva ◽  
V. V. Belikovich ◽  
E. A. Benediktov ◽  
V. N. Bubukina ◽  
N. P. Goncharov ◽  
...  
Keyword(s):  
Gravity Waves ◽  
Upper Atmosphere ◽  
Acoustic Gravity Waves ◽  
Periodic Inhomogeneities

Vertical Propagation of Acoustic-Gravity Waves from Atmospheric Fronts into the Upper Atmosphere

2019 ◽  
Vol 55 (4) ◽  
pp. 303-311
Author(s):  
Y. A. Kurdyaeva ◽  
S. N. Kulichkov ◽  
S. P. Kshevetskii ◽  
O. P. Borchevkina ◽  
E. V. Golikova
Keyword(s):  
Gravity Waves ◽  
Upper Atmosphere ◽  
Acoustic Gravity Waves ◽  
Atmospheric Fronts ◽  
Vertical Propagation

Simulation of Propagation of Acoustic-Gravity Waves Generated by Tropospheric Front Instabilities into the Upper Atmosphere

2020 ◽  
Vol 177 (11) ◽  
pp. 5567-5584
Author(s):  
S. Kshevetskii ◽  
Yu. Kurdyaeva ◽  
S. Kulichkov ◽  
E. Golikova ◽  
O. Borchevkina ◽  
...  
Keyword(s):  
Gravity Waves ◽  
Upper Atmosphere ◽  
Acoustic Gravity Waves

Numerical Modeling of Nonlinear Interactions of Spectral Components of Acoustic-Gravity Waves in the Middle and Upper Atmosphere

2020 ◽  
Author(s):  
Nikolai M. Gavrilov ◽  
Sergej P. Kshevetskii
Keyword(s):  
Gravity Waves ◽  
Upper Atmosphere ◽  
Jet Flows ◽  
Small Scale ◽  
Nonlinear Interactions ◽  
Mean Flow ◽  
Wave Source ◽  
Acoustic Gravity Waves ◽  
The Mean ◽  
Wave Modes

<p>Acoustic-gravity waves (AGWs) measuring at big heights may be generated in the troposphere and propagate upwards. A high-resolution three-dimensional numerical model was developed for simulating nonlinear AGWs propagating from the ground to the upper atmosphere. The model algorithms are based on the finite-difference analogues of the main conservation laws. This methodology let us obtaining the physically correct generalized wave solutions of the nonlinear equations. Horizontally moving sinusoidal structures of vertical velocity on the ground are used for the AGW excitation in the model. Numerical simulations were made in an atmospheric region having horizontal dimensions up to several thousand kilometers and the height extention up to 500 km. Vertical distributions of the mean temperature, density, molecular viscosity and thermal conductivity are specified using standard models of the atmosphere.</p><p>Simulations were made for different horizontal wavelengths, amplitudes and speeds of the wave sources at the ground. After “switch on” the tropospheric wave source, an initial AGW pulse very quickly (for several minutes) could propagate to heights up to 100 km and above. AGW amplitudes increase with height and waves may break down in the middle and upper atmosphere. Wave instability and dissipation may lead to formations of wave accelerations of the mean flow and to producing wave-induced jet flows in the middle and upper atmosphere. Nonlinear interactions may lead to instabilities of the initial wave and to the creation of smaller-scale perturbations. These perturbations may increase temperature and wind gradients and could enhance the wave energy dissipation.</p><p>In this study, the wave sources contain a superposition of two AGW modes with different periods, wavelengths and phase speeds. Longer-period AGW modes served as the background conditions for the shorter-period wave modes. Thus, the larger-scale AGWs can modulate amplitudes of small-scale waves. In particular, interactions of two wave modes could sharp vertical temperature gradients and make easier the wave breaking and generating  turbulence. On the other hand, small-wave wave modes might increase dissipation and modify the larger-scale modes.This study was partially supported by the Russian Basic Research Foundation (# 17-05-00458).</p>

scholarly journals Propagation to the upper atmosphere of acoustic-gravity waves from atmospheric fronts in the Moscow region

2019 ◽  
Vol 37 (3) ◽  
pp. 447-454 ◽  
Author(s):  
Yuliya Kurdyaeva ◽  
Sergey Kulichkov ◽  
Sergey Kshevetskii ◽  
Olga Borchevkina ◽  
Elena Golikova
Keyword(s):  
Experimental Data ◽  
Gravity Waves ◽  
Pressure Fluctuations ◽  
Lower Boundary ◽  
Lower Troposphere ◽  
Upper Atmosphere ◽  
Moscow Region ◽  
Atmospheric Front ◽  
Lower Boundary Condition ◽  
Acoustic Gravity Waves

Abstract. The paper uses experimental data of pressure variations on the Earth's surface during the passage of an atmospheric front recorded by a network of four microbarographs in the Moscow region. Applying these experimental data, empirical approximations of atmospheric pressure field oscillations are suggested. The obtained approximating surface pressure functions are used as the lower boundary condition for simulating the vertical propagation of acoustic-gravity waves from a source in the lower troposphere. Estimates of the amplitude of temperature disturbances in the upper atmosphere caused by acoustic-gravity waves from a propagating atmospheric front are obtained. For the amplitude of wave temperature disturbances, values of about 200 K are obtained. The amplitude of temperature disturbances in the upper atmosphere caused by background pressure fluctuations on the Earth's surface is estimated at 4–5 K.

Acoustic-gravity waves in the upper atmosphere

1974 ◽  
Vol 12 (2) ◽  
pp. 193 ◽  
Author(s):  
K. C. Yeh ◽  
C. H. Liu
Keyword(s):  
Gravity Waves ◽  
Upper Atmosphere ◽  
Acoustic Gravity Waves

scholarly journals Electromagnetic oscillations of the Earth's upper atmosphere (review)

2010 ◽  
Vol 28 (7) ◽  
pp. 1387-1399 ◽  
Author(s):  
A. G. Khantadze ◽  
G. V. Jandieri ◽  
A. Ishimaru ◽  
T. D. Kaladze ◽  
Zh. M. Diasamidze
Keyword(s):  
Gravity Waves ◽  
Geomagnetic Field ◽  
Large Scale ◽  
Low Frequency ◽  
Planetary Waves ◽  
Upper Atmosphere ◽  
Acoustic Gravity Waves ◽  
Weakly Ionized ◽  
General Dispersion ◽  
Electromagnetic Oscillations

Abstract. A complete theory of low-frequency MHD oscillations of the Earth's weakly ionized ionosphere is formulated. Peculiarities of excitation and propagation of electromagnetic acoustic-gravity, MHD and planetary waves are considered in the Earth's ionosphere. The general dispersion equation is derived for the magneto-acoustic, magneto-gravity and electromagnetic planetary waves in the ionospheric E- and F-regions. The action of the geomagnetic field on the propagation of acoustic-gravity waves is elucidated. The nature of the existence of the comparatively new large-scale electromagnetic planetary branches is emphasized.

scholarly journals Vertical propagation acoustic-gravity waves from atmospheric fronts into the upper atmosphere

2019 ◽  
Vol 55 (4) ◽  
pp. 3-12
Author(s):  
Y. A. Kurdyaeva ◽  
S. N. Kulichkov ◽  
S. P. Kshevetskii ◽  
O. P. Borchevkina ◽  
E. V. Golikova
Keyword(s):  
Gravity Waves ◽  
Atmospheric Pressure ◽  
Lower Boundary ◽  
Lower Troposphere ◽  
Upper Atmosphere ◽  
Atmospheric Front ◽  
Lower Boundary Condition ◽  
Acoustic Gravity Waves ◽  
Temperature Disturbance ◽  
Atmospheric Fronts

Using experimental observations of atmospheric pressure variations on the Earth’s surface recorded with a network of 4 microbarographs located in the Moscow region during the passage of an atmospheric front, empirical approximations of oscillations of atmospheric pressure field were constructed. The obtained approximating functions were used as the lower boundary condition for the numerical simulation of acoustic-gravity wave propagation to the upper atmosphere from the source in the lower troposphere. Estimates of the amplitude of temperature disturbances in the upper atmosphere caused by iacoustic gravity waves from the atmospheric front are given. The obtained estimates for the temperature disturbance amplitude take values around 170 K. The amplitude of temperature disturbances in the upper atmosphere, caused by background variations of pressure on the Earth's surface, is estimated at 4-5 K.

Nonlinear Acoustic‐Gravity Waves in the Upper Atmosphere

1973 ◽  
Vol 54 (1) ◽  
pp. 326-326
Author(s):  
C. H. Liu
Keyword(s):  
Gravity Waves ◽  
Upper Atmosphere ◽  
Acoustic Gravity Waves ◽  
Nonlinear Acoustic
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