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

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/].

2018 ◽  
pp. 41-48 ◽  
Author(s):  
Владимир Губенко ◽  
Vladimir Gubenko ◽  
Иван Кириллович ◽  
Ivan Kirillovich

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 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/].


2014 ◽  
Vol 32 (2) ◽  
pp. 181-186 ◽  
Author(s):  
O. Onishchenko ◽  
O. Pokhotelov ◽  
W. Horton ◽  
A. Smolyakov ◽  
T. Kaladze ◽  
...  

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.


1998 ◽  
Vol 11 (2) ◽  
pp. 1022-1022
Author(s):  
P.B. Babadzhanov

Observations in Central Asia in 1965-1966 by both photographic and radar methods allowed a determination of the radiants and orbits of Leonids (Babadzhanov and Getman 1970). Photographs showed that meteoroids undergo quasi-continuous fragmentation (QCF) in the Earth’s atmosphere. Taking account of QCF, the density of the Leonid meteoroids were found to lie between 1 and Agcm-3 the average being 2gcm-3 (Babadzhanov 1994), in agreement with the density range of between 0.2 and 6gcm-3 given by Maas et al (1990) for dust grains from comet P/1 Halley, with values below 0.6 being rare. Further, the icy grains have a density of about 1gcm-3 while silicate grains have a mean density 2.5 times higher.


Author(s):  
Jack G. Calvert ◽  
John J. Orlando ◽  
William R. Stockwell ◽  
Timothy J. Wallington

Ozone, an important trace component, is critical to life on Earth and to atmospheric chemistry. The presence of ozone profoundly impacts the physical structure of the atmosphere and meteorology. Ozone is also an important photolytic source for HO radicals, the driving force for most of the chemistry that occurs in the lower atmosphere, is essential to shielding biota, and is the only molecule in the atmosphere that provides protection from UV radiation in the 250-300 nm region. However, recent concerns regarding environmental issues have inspired a need for a greater understanding of ozone, and the effects that it has on the Earth's atmosphere. The Mechanisms of Reactions Influencing Atmospheric Ozone provides an overview of the chemical processes associated with the formation and loss of ozone in the atmosphere, meeting the need for a greater body of knowledge regarding atmospheric chemistry. Renowned atmospheric researcher Jack Calvert and his coauthors discuss the various chemical and physical properties of the earth's atmosphere, the ways in which ozone is formed and destroyed, and the mechanisms of various ozone chemical reactions in the different spheres of the atmosphere. The volume is rich with valuable knowledge and useful descriptions, and will appeal to environmental scientists and engineers alike. A thorough analysis of the processes related to tropospheric ozone, The Mechanisms of Reactions Influencing Atmospheric Ozone is an essential resource for those hoping to combat the continuing and future environmental problems, particularly issues that require a deeper understanding of atmospheric chemistry.


2013 ◽  
Vol 31 (3) ◽  
pp. 459-462 ◽  
Author(s):  
O. Onishchenko ◽  
O. Pokhotelov ◽  
V. Fedun

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.


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