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.

scholarly journals Convective cells of internal gravity waves in the earth's atmosphere with finite temperature gradient

2013 ◽  
Vol 31 (3) ◽  
pp. 459-462 ◽  
Author(s):  
O. Onishchenko ◽  
O. Pokhotelov ◽  
V. Fedun
Keyword(s):  
Temperature Gradient ◽  
Gravity Waves ◽  
Closed System ◽  
Internal Gravity Waves ◽  
System Of Nonlinear Equations ◽  
Vertical Temperature Gradient ◽  
Vertical Temperature ◽  
Earth’S Atmosphere ◽  
Earth's Atmosphere ◽  
Convective Cells

Abstract. In this paper, we have investigated vortex structures (e.g. convective cells) of internal gravity waves (IGWs) in the earth's atmosphere with a finite vertical temperature gradient. A closed system of nonlinear equations for these waves and the condition for existence of solitary convective cells are obtained. In the atmosphere layers where the temperature decreases with height, the presence of IGW convective cells is shown. The typical parameters of such structures in the earth's atmosphere are discussed.

scholarly journals Fluctuations of radio occultation signals in sounding the Earth's atmosphere

2018 ◽  
Vol 11 (2) ◽  
pp. 663-680 ◽  
Author(s):  
Valery Kan ◽  
Michael E. Gorbunov ◽  
Viktoria F. Sofieva
Keyword(s):  
Gravity Waves ◽  
Radio Occultation ◽  
Radio Signal ◽  
Internal Gravity Waves ◽  
Statistical Characteristics ◽  
Phase Fluctuations ◽  
Upper Troposphere ◽  
Earth’S Atmosphere ◽  
Kolmogorov Turbulence ◽  
Earth's Atmosphere

Abstract. We discuss the relationships that link the observed fluctuation spectra of the amplitude and phase of signals used for the radio occultation sounding of the Earth's atmosphere, with the spectra of atmospheric inhomogeneities. Our analysis employs the approximation of the phase screen and of weak fluctuations. We make our estimates for the following characteristic inhomogeneity types: (1) the isotropic Kolmogorov turbulence and (2) the anisotropic saturated internal gravity waves. We obtain the expressions for the variances of the amplitude and phase fluctuations of radio occultation signals as well as their estimates for the typical parameters of inhomogeneity models. From the GPS/MET observations, we evaluate the spectra of the amplitude and phase fluctuations in the altitude interval from 4 to 25 km in the middle and polar latitudes. As indicated by theoretical and experimental estimates, the main contribution into the radio signal fluctuations comes from the internal gravity waves. The influence of the Kolmogorov turbulence is negligible. We derive simple relationships that link the parameters of internal gravity waves and the statistical characteristics of the radio signal fluctuations. These results may serve as the basis for the global monitoring of the wave activity in the stratosphere and upper troposphere.

scholarly journals Fluctuations of radio occultation signals in sounding the Earth's atmosphere

2017 ◽  
Author(s):  
Valery Kan ◽  
Michael E. Gorbunov ◽  
Viktoria F. Sofieva
Keyword(s):  
Gravity Waves ◽  
Radio Occultation ◽  
Radio Signal ◽  
Internal Gravity Waves ◽  
Statistical Characteristics ◽  
Phase Fluctuations ◽  
Upper Troposphere ◽  
Earth’S Atmosphere ◽  
Kolmogorov Turbulence ◽  
Earth's Atmosphere

Abstract. We discuss the relationships that link the observed fluctuation spectra of the amplitude and phase of signals used for the radio occultation sounding of the Earth's atmosphere, with the spectra of atmospheric inhomogeneities. Our analysis employs the approximation of the phase screen and of weak fluctuations. We make our estimates for the following characteristic inhomogeneity types: 1) the isotropic Kolmogorov turbulence and 2) the anisotropic saturated internal gravity waves. We obtain the expressions for the variances of the amplitude and phase fluctuations of radio occultation signals, as well as their estimates for the typical parameters of inhomogeneity models. From the GPS/MET observations, we evaluate the spectra of the amplitude and phase fluctuations in the altitude interval from 4 to 25 km in the middle and polar latitudes. As indicated by theoretical and experimental estimates, the main contribution into the radio signal fluctuations comes from the internal gravity waves. The influence of the Kolmogorov turbulence is negligible. We derive simple relationships that link the parameters of internal gravity waves and the statistical characteristics of the radio signal fluctuations. These results may serve as the basis for the global monitoring of the wave activity in the stratosphere and upper troposphere.

Acoustic-gravity waves in the Earth’s atmosphere generated by surface sources

2015 ◽  
Vol 70 (6) ◽  
pp. 541-548 ◽  
Author(s):  
V. E. Kunitsyn ◽  
B. Yu. Krysanov ◽  
A. M. Vorontsov
Keyword(s):  
Gravity Waves ◽  
Acoustic Gravity Waves ◽  
Earth’S Atmosphere ◽  
Earth's Atmosphere

scholarly journals Numerical and the MU radar estimations of gravity wave enhancement and turbulent ozone fluxes near the tropopause

2004 ◽  
Vol 22 (11) ◽  
pp. 3889-3898 ◽  
Author(s):  
N. M. Gavrilov ◽  
S. Fukao
Keyword(s):  
Gravity Waves ◽  
Wave Breaking ◽  
Internal Gravity Waves ◽  
Vertical Temperature ◽  
Turbulent Diffusion Coefficient ◽  
Middle Latitudes ◽  
Mu Radar ◽  
Different Seasons ◽  
Ozone Fluxes ◽  
Vertical Ozone

Abstract. It is shown with a numerical simulation that a sharp increase in the vertical temperature gradient and Brunt-Väisälä frequency near the tropopause may produce an increase in the amplitudes of internal gravity waves (IGWs) propagating upward from the troposphere, wave breaking and generation of stronger turbulence. This may enhance the transport of admixtures between the troposphere and stratosphere in the middle latitudes. Turbulent diffusion coefficient calculated numerically and measured with the MU radar are of 1-10m2/s in different seasons in Shigaraki, Japan (35° N, 136° E). These values lead to the estimation of vertical ozone flux from the stratosphere to the troposphere of (1-10)x1014, which may substantially add to the usually supposed ozone downward transport with the general atmospheric circulation. Therefore, local enhancements of IGW intensity and turbulence at tropospheric altitudes over mountains due to their orographic excitation and due to other wave sources may lead to the changes in tropospheric and total ozone over different regions.

scholarly journals Diagnostics of internal atmospheric wave saturation and determination of their characteristics in Earth’s stratosphere from radiosonde measurements

2018 ◽  
Vol 4 (2) ◽  
pp. 76-85
Author(s):  
Владимир Губенко ◽  
Vladimir Gubenko ◽  
Иван Кириллович ◽  
Ivan Kirillovich
Keyword(s):  
Energy Dissipation ◽  
Wind Speed ◽  
Internal Wave ◽  
Wave Amplitude ◽  
Internal Gravity Waves ◽  
Lower Atmosphere ◽  
Earth’S Atmosphere ◽  
Earth's Atmosphere ◽  
Amplitude Growth

Internal gravity waves (IGW) significantly affect the structure and circulation of Earth’s atmosphere by transporting wave energy and momentum upward from the lower atmosphere. Since IGW can propagate freely through a stably stratified atmosphere, similar effects may occur in the atmospheres of Mars and Venus. Observations of temperature and wind speed fluctuations induced by internal waves in Earth’s atmosphere have shown that wave amplitudes increase with height, but not quickly enough to correspond to the amplitude increase due to an exponential decrease in the density without energy dissipation. The linear theory of IGW explains the wave amplitude growth rate as follows: any wave amplitude exceeding the threshold value leads to instability and produces turbulence, which hinders further amplitude growth (internal wave saturation). The mechanisms that contribute most to the energy dissipation and saturation of IGW in the atmosphere are thought to be the dynamical (shear) and convective instabilities. The assumption of internal wave saturation plays a key role in radio occultation (RO) monitoring of IGW in planetary atmospheres. A radiosonde study of wave saturation processes in Earth’s atmosphere is therefore actual and important task. We report the results of determination of actual and threshold amplitudes, saturation degree, and other characteristics for the identified IGW in Earth’s atmosphere obtained from the analysis of SPARC (Stratospheric Processes And their Role in Climate) radiosonde measurements of wind speed and temperature [http://www.sparc.sunysb.edu/].

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