# Influence of Atmospheric Flow Structure on Optical Turbulence Characteristics
## 1 Introduction  
The structure of small-scale turbulence significantly depends on the orography and energy of meso-scale and large-scale atmospheric flows. In particular, energy and enstrophy transfer in a spectrum of atmospheric flows determine the conditions of small-scale turbulence evolution [1; 2]. A number of numerical and experimental studies have focused on the influence of meso-scale and large-scale airflows on small-scale turbulence [3; 4; 5]. Over the years, meso-scale models have been used to obtain optical turbulence parameters above sites of interest for astronomy [6; 7]. A powerful means to simulate atmospheric processes is a Weather Research and Forecasting (WRF) model, including partial models to diagnose and forecast the weather [8; 9; 10; 11; 12; 13; 14]. In [15], the authors studied turbulence formed in jet streams. [PERSON] et al. identified the influence of residual turbulence from outside the jet on the intensity of turbulent fluctuations inside the jet. However, it can be difficult to unambiguously and reliably assess the relationship between turbulence inside and outsidethe jet through simulation. This is due to both the limitations that arise when matching the schemes of parameterization of meso-scale and micro-scale motions, and when motions in the central part of the jet has weakened interactions with motions outside the jet. Interesting studies on the origin and evolution of turbulence have been devoted to the phenomenon of coherent and structured optical turbulence. The phenomenon of coherent turbulence leads to a weakening of the turbulent phase fluctuations of a light wave propagating in the stratosphere-troposphere. The attenuation of phase fluctuations has been confirmed by a number of observations of image motion caused by fluctuations in the air refractive index along the line of sight of ground-based solar telescopes [16; 17]. [PERSON] et al. simulated meteorological conditions under which clear air turbulence was generated over northern India. The authors used the Weather Research and Forecasting model [18]. In the WRF model, a revised MM5 Monin-Obukhov scheme and Yonsei University scheme (YSU) were used to describe the surface and atmospheric boundary layers. Calculations were carried out for the two domains with a spatial resolution of 6 and 2 km, respectively. The authors showed that the WRF model could reproduce upward and downward airflows with high accuracy and describe the characteristics of clear air turbulence. Based on optical turbulence theory, we need to describe optical distortions using scales ranging from a few centimeters to so-called outer scales of turbulence (tens of meters). However, the WRF model does not reproduce such spatial scales. Eddy resolution models are also significantly limited, especially for long time intervals. Simulation complexity is associated with incorrect assessments of the influence of large-scale and meso-scale disturbances on small-scale turbulence. [PERSON] et al. pointed out the ability of the WRF model to reproduce weather and optical conditions, even with low-resolution input data [19]. [PERSON] et al. [20] state that spatial scales \(\sim\)3 km should be revealed in order to simulate atmospheric processes and evaluate their influence on small-scale turbulence. For example, mountain lee waves influencing small-scale turbulence may be detected in these simulations. Comparing the WRF and HARMONIE models (with a spatial resolution of 1 km), the authors showed that the turbulence generated in mountain lee wave events was reproduced in 86 and 55% of cases, respectively. We also note that the authors used the Yonsei University scheme to parameterize the atmospheric boundary layer. In addition to diagnosing atmospheric situations, the WRF model is beginning to be successfully used to forecast atmospheric characteristics, including parameters of surface and high-altitude turbulence. The strength of small-scale turbulence is usually estimated by \(C_{n}^{2}\).