# Structure of Atmospheric Turbulence
###### Abstract  
Turbulence is a phenomenon observed in the motions of fluids and gases. This phenomenon occurs in different mediums and conditions. In a turbulent state, the motions of various spatial scales are excited (from the largest scales associated with the boundary conditions of flow to the smallest fluctuations corresponding to the viscous dissipation. In spite of a number of achievements in the study of turbulent flows, a full theory of turbulence has not been developed. The full theory of turbulence is still a challenge for modern physics and mathematics. The importance of turbulence research is also determined by problems in aerodynamics, hydraulics, chemical production, geophysics, atmospheric physics, astronomy and other fields of science. The theory of atmospheric turbulence continues to develop rapidly. A lot of papers are devoted to studies of energy spectra of atmospheric turbulence under different thermal stratification of the atmosphere and over complex underlying surfaces. This Special Issue of _Atmosphere_ entitled \"Structure of Atmospheric Turbulence\" contains six papers. The paper \"Turbulence in Large-Scale Two Dimensional Balanced Hard Sphere Gas Flow\" is aimed at the study of turbulent motions as well as the transition from a laminar regime of flow to turbulence [1]. The author has studied the possibilities of the original model of a balanced compressible hard-sphere gas flow to describe the generation of turbulent motions for the two-dimensional case. In particular, features in the spectral structure of two-dimensional motions have been discussed. In an inertial jet, the energy spectrum of turbulence is shown to obey the \"\(-5/3\)\" power law in the intermediate range of scales and the \"\(-8/3\)\" power law for small scales. The power laws estimated in the paper are in good agreement with the previously obtained shapes of spectra. [PERSON]. [1] noted that in the two-dimensional cyclostrophic vortex, the \"\(-5/3\)\"slope of the energy spectrum is observed over the full spectral range. Usually, vortex structures are characterized by a spectrum slope close to \(-3\)[2, 3]. The paper \"Vertical Shear of the Horizontal Wind, Jet Streams, Symmetry Breaking, Scale Invariance and Gibbs Free Energy\" describes the study of turbulent atmosphere energetics [4]. The variations in the vertical scaling exponent of the horizontal wind with altitude are discussed. Dependencies of scaling exponent on the difference between the maximum and minimum of wind speeds as well as air temperatures are analyzed. The scaling exponent increases as these differences increase. It is also interesting to note that the scaling exponent tends to increase with the growth of the depth of the jet stream. In the paper, the results indicate that the persistence of molecular velocity after collision induces symmetry-breaking emergence of hydrodynamic flow. The paper \"A Survey of Structure of Atmospheric Turbulence in Atmosphere and Related Turbulent Effects\" is devoted to the study of the structure of atmospheric Kolmogorov and non-Kolmogorov turbulence [5]. In particular, the authors claim that atmospheric turbulence is Kolmogorov in the lower layers of the atmosphere. In higher layers of the atmosphere, turbulence is non-Kolmogorov. In the study, the authors analyze various dependencies of the spectral density of fluctuations on frequency in the troposphere and stratosphere. As applied to astronomy, the features of spectral variations of optical turbulence are considered in the paper \"Energy Spectra of Atmospheric Turbulence for Calculating \(C_{n}^{2}\) Parameter. I. Maidanak and Suffa Observatories in Uzbekistan\" [6]. Optical turbulence is a phenomenon associated with the fluctuations in air density at different altitudes in the atmosphere [7; 8; 9; 10]. These studies were carried out at the sites of astronomical observatories Maidanak and Suffa. These astronomical observatories are located at the best sites in Eurasia.