Energy Spectra of Atmospheric Turbulence for Calculating Cn2 Parameter. I. Maidanak and Suffa Observatories in Uzbekistan

Artem Yu Shikhovtsev,Shuhrat A Ehgamberdiev,Pavel G Kovadlo,Yusufjon A Tillayev,Mansur A Ibrahimov,Evgeniy A Kopylov

doi:10.3390/atmos12121614

Abstract

Knowledge of the turbulence spectra is of interest for describing atmospheric conditions as applied to astronomical observations. This article discusses the deformations of the turbulence spectra with heights in a wide range of scales at the sites of the Maidanak and Suffa observatories. It is shown that the energy of baroclinic instability is high at the sites of these observatories and should be taken into account in the calculations of the refractive index structure constant Cn2.

Highlights

Atmosphere 2021, 12, 1614. https://Astroclimate imposes limitations upon astronomical observations [1,2,3,4]
The vortex-packet paradigm [6] assumes some kind of interaction between large and small vortex packets, with large packets moving at higher speeds and overtaking smaller packets
By processing the data of observations at astronomical telescopes, we developed a method to calculate Cn2 at different heights

Summary

Introduction

Astroclimate imposes limitations upon astronomical observations [1,2,3,4]. Turbulence is the key phenomenon in the Earth’s atmosphere that determines the quality of astronomical images. The key question is how large motions in the atmosphere influence small-scale turbulent structures. A large variety of atmospheric structures can occur due to complex interactions between winds and shears, internal gravity waves and convective motions. In order to describe the height structure of the optical turbulence at sites of such observatories, it is possible to use methods to estimate Cn2 (z) based on an analysis of meteorological parameters of the atmosphere [15,16]. Using dependencies of the power spectral density of meteorological parameter fluctuations on the period (frequency), the energy of small-scale turbulence may be estimated. We estimated the energy in the synoptic range in order to describe atmospheric characteristics at the sites of the astronomical observatories. We obtained and analyzed the mean values of the energy as well as the energy spectra of atmospheric turbulence in a wide range of scales for the Maidanak observatory (the height above sea level is 2650 m; latitude 38◦ 400 2400 N, longitude 66◦ 530 4700 E) and Suffa observatory (the height above sea level is 2324 m; latitude 39◦ 370 2700 N, longitude 68◦ 260 5200 E)

Full-Scale Turbulence Spectra

Methodology

Conclusions