Numerical Study of Heat Transport by Internal Gravity Waves above a Growing Unstable Layer

1969 ◽  
Vol 12 (12) ◽  
pp. II-184 ◽  
Author(s):  
James W. Deardorff
Keyword(s):  
Heat Transport ◽  
Gravity Waves ◽  
Numerical Study ◽  
Internal Gravity Waves ◽  
Unstable Layer

Reflexion and stability of waves in stably stratified fluids with shear flow: a numerical study

1968 ◽  
Vol 34 (3) ◽  
pp. 609-624 ◽  
Author(s):  
Walter L. Jones
Keyword(s):  
Gravity Waves ◽  
Richardson Number ◽  
Numerical Study ◽  
Internal Gravity Waves ◽  
Three Dimensions ◽  
Stratified Fluids ◽  
Reflected Wave ◽  
Horizontal Wave ◽  
Numerical Examination ◽  
Stability Of Waves

A numerical examination has been made of the reflectivity of critical levels with low Richardson number to internal gravity waves propagating in stratified fluids with shear. At sufficiently low positive Richardson numbers the reflected wave may actually be stronger than the incident.The normal mode instabilities of three simple models have also been computed. The results are presented in three dimensions: Richardson number, horizontal wave scale and real wave frequency.

Study of Propagation of Acoustic-Gravity Waves Generated by Tropospheric Heat Source

2021 ◽  
Author(s):  
Yuliya Kurdyaeva ◽  
Sergey Kshevetskii
Keyword(s):  
Heat Source ◽  
Gravity Waves ◽  
Numerical Study ◽  
Pressure Fluctuations ◽  
Boundary Surface ◽  
Internal Gravity Waves ◽  
Problem Model ◽  
Acoustic Gravity Waves ◽  
Infrasonic Waves ◽  
Comparison Results

<p>     The use of experimental data on pressure variations on the Earth's surface makes possible to study the propagation of acoustic-gravity waves from the lower to the upper atmosphere. However, a question arises: how the pressure on the Earth's surface is related to meteorological processes and how significant inaccuracy is allowed when replacing tropospheric meteorological sources instead experimentally observed pressure fluctuations on the Earth's surface.</p><p>     The problem of wave propagation from a tropospheric heat source was analytically studied to resolve this issue. Based on general assumptions about the tropospheric source and its parameters, an estimate of the waves that could be generated by such source was made. The study showed that the generation of internal gravity waves by a heat source cannot occur without the generation of infrasonic waves by this source. Therefore, infrasonic waves must also be taken into account. The source of infrasonic waves was defined and it was shown that in terms of power it is approximately equal to the source of internal gravity waves. Despite this, the amplitude of the generated infrasonic waves is less than the amplitude of the gravity ones, due to the fact that the source frequency is less than the acoustic cutoff frequency.</p><p>     In the numerical study of this problem, model local thermal small-sized tropospheric sources of waves operating at different frequencies were studied. Pressure fluctuations at the Earth's surface from the studied model source are recorded and then used at the boundary surface to calculate the propagation of waves upward from pressure fluctuations. Comparison results of calculations directly from a tropospheric source operating at infrasonic frequencies and from recorded pressure fluctuations on the Earth's surface showed that the wave pattern above the source, created directly by the tropospheric source, and from pressure variations recorded on the Earth's surface, practically coincide. In the case when the tropospheric source operates at the frequencies of internal gravity waves, the general coincidence of the two wave patterns also takes place. However, the quality of this match is lower. This happens due both to the typical features of the propagation of the internal gravity waves themselves, and to the fact that during the operation of such a source, infrasonic waves are additionally generated.</p><p>     The reported study was funded by RFBR and Kaliningrad region according to the research project № 19-45-390005.</p>

Model of the internal gravity waves excited by lithospheric greenhouse effect gases

2001 ◽  
Vol 7 (2s) ◽  
pp. 26-33 ◽  
Author(s):  
O.E. Gotynyan ◽  
◽  
V.N. Ivchenko ◽  
Yu.G. Rapoport ◽  
◽  
...  
Keyword(s):  
Gravity Waves ◽  
Greenhouse Effect ◽  
Internal Gravity Waves

scholarly journals Shear-induced breaking of internal gravity waves

2021 ◽  
Vol 921 ◽  
Author(s):  
Christopher J. Howland ◽  
John R. Taylor ◽  
C.P. Caulfield
Keyword(s):  
Gravity Waves ◽  
Internal Gravity Waves

Abstract

scholarly journals Rolls of the internal gravity waves in the Earth's atmosphere

2014 ◽  
Vol 32 (2) ◽  
pp. 181-186 ◽  
Author(s):  
O. Onishchenko ◽  
O. Pokhotelov ◽  
W. Horton ◽  
A. Smolyakov ◽  
T. Kaladze ◽  
...  
Keyword(s):  
Nonlinear Dynamics ◽  
Gravity Waves ◽  
Closed System ◽  
Wind Shear ◽  
Internal Gravity Waves ◽  
Temperature Gradients ◽  
System Of Equations ◽  
Vertical Temperature ◽  
Earth’S Atmosphere ◽  
Earth's Atmosphere

Abstract. The effect of the wind shear on the roll structures of nonlinear internal gravity waves (IGWs) in the Earth's atmosphere with the finite vertical temperature gradients is investigated. A closed system of equations is derived for the nonlinear dynamics of the IGWs in the presence of temperature gradients and sheared wind. The solution in the form of rolls has been obtained. The new condition for the existence of such structures was found by taking into account the roll spatial scale, the horizontal speed and wind shear parameters. We have shown that the roll structures can exist in a dynamically unstable atmosphere.

Sign in / Sign up

Export Citation Format

Share Document