Convection effect in the atmospheric surface layer in the course of solar eclipses of 20 March 2015 and 10 June 2021
| 1Chernogor, LF 1V.N. Karazin Kharkiv National University, Kharkiv, Ukraine |
| Kinemat. fiz. nebesnyh tel (Online) 2021, 37(6):19-33 |
| https://doi.org/10.15407/kfnt2021.06.019 |
| Start Page: Dynamics and Physics of Solar System Bodies |
| Language: Ukrainian |
Abstract: The parameters of geophysical fields and numerous parameters of the Earth — atmosphere — ionosphere — magnetosphere system undergo significant changes in the course of a solar eclipse (SE). In particular, the planet surface temperature decreases, the convection and turbulent processes slow down, and the atmospheric temperature near the ground reduces during an eclipse. The inhomogeneous structure of the atmospheric surface layer notably changes, the role of temperature fluctuations in this layer reduces, and consequently, the role of fluctuations in the atmospheric refractive index diminishes. The purpose of this work is to present the analysis of observational data about solar limb flickering during the two last partial SE that took place near the city of Kharkiv on 20 March 2015 and 10 June 2021 and to analyze the estimates of the statistical parameters governing air convection. The SE effects in the atmospheric surface layer were observed via the optical AFR-2 chromospheric-photospheric telescope at the V. N. Karazin National University Kharkiv Astronomkal Observatory 70 km from the city of Kharkiv in the southeast direction. The flickering of the solar limb was measured on the days of the SE of 20 March 2015 and of10 June 2021, as well as on the reference days in order to determine the basic parameters of the atmospheric convection. The variations in the convection parameters are qualitatively similar to variations in illumination of the Earth’s surface and in the air temperature in the atmospheric surface layer. In the summertime, all parameters concerning convection are a factor of approximately 2 greater than those in the springtime. The influence of the SE of 10 June 2021 on atmospheric convection was considerably smaller than the influence of the 20 March 2015 eclipse, which is explained by an insignificant magnitude of SE (0.11 vs. 0.54), and by a cloudy sky screening the solar disk, which appreciably suppressed atmospheric convection. The comparative study of convection during seven SE that took place during 1999—2021 has shown that the magnitude of the effect significantly de t pended on season, local time, the state of tropospheric weather, the magnitude of a solar eclipse, and the thickness of the cloud cover. |
| Keywords: air temperature variations, atmospheric convection, solar eclipse, solar eclipse magnitude, statistical parameters of turbulence |
References:
1. Akimov A. L., Akimov L. A., Chernogor L. F. (2007). Turbulence Parameters in the Atmosphere Associated with Solar Eclipses. Radio Phys. and Radio Astron. 12(2). 117—135 (In Russian).
2. Akimov A. L., Chernogor L. F. (2010). Effects of the solar eclipse of August 1, 2008 on the Earth’s lower atmosphere. Kinematics and Phys. Celestial Bodies. 26 (3). 135—145.
https://doi.org/10.3103/S0884591310030050
3. Akimov L. A., Bogovskii V. K., Grigorenko E. I., Taran V. I., Chernogor L. F. (2005). Atmospheric — Ionospheric Effects of the Solar Eclipse of May 31, 2003, in Kharkov. Geomagnetism and Aeronomy. 45 (4). 494—518.
4. Akimov L. A., Grigorenko E. I., Taran V. I., Tyrnov O. F., Chernogor L. F. (2002). The complex radio physical and optical studies of dynamic processes in the atmosphere and geospace caused by a solar eclipse August 11, 1999. Zarubezhnaya radioelektronika. Uspekhi sovremennoy radioelektroniki. 2. 25—63 (in Russian).
5. Akimov L. A., Grigorenko E. I., Taran V. I., Chernogor L. F. (2005). Features atmospheric-ionospheric effects of the solar eclipse of May 31, 2003: The results of the optical and radio physical observations in Kharkov. Uspekhi sovremennoi radioelektroniki. (3). 55—70 (in Russian).
6. Klifford S. F. (1981). The classical theory of wave propagation in a turbulent medium. In.: Laser Beam Propagation in the Atmosphere. Berlin, Heidelberg: Springer, 9—43.
https://doi.org/10.1007/3540088121_16
7. Kolchinskii I. G. (1967). Optical Instability of the Earth’s Atmosphere from Observations of Stars. Kiev: Naukova Dumka. [in Russian].
8. Lukin V. P. (1980). Correction of random angular displacements of optical beams. Soviet J. Quantum Electronics. 10 (6). 727—732.
https://doi.org/10.1070/QE1980v010n06ABEH010279
9. Monin A. S., Yaglom A. M. (1971—2013). Statistical Fluid Mechanics. The Mechanics of Turbulence. Vol. I. 1971. Cambridge, MA: MIT Press. 769; Vol. II. 2013. Dover Publications. 896.
10. Tatarski V. I. (1961). Wave Propagation in a Turbulent Medium. New-York: McGraw-Hill. 285 p.
11. Chernogor L. F. (2008). Effects of solar eclipses in the surface atmosphere. Izvestiya, Atmos. and Oceanic Phys. 44 (4). 432—447.
https://doi.org/10.1134/S000143380804004X
12. Chernogor L. F. (2011). Dynamic processes in the near-ground atmosphere during the solar eclipse of August 1, 2008. Izvestiya. Atmos. and Oceanic Phys. 47 (1). 77—86.
https://doi.org/10.1134/S000143381101004X
13. Chernogor L. F. (2013). Physical effects of solar eclipses in atmosphere and geospace: monograph. Kharkiv. V. N. Karazin Kharkiv National University Publ. 480 p. (in Russian).
14. Chernogor L. F. (2016). Atmosphere — Ionosphere response to solar eclipse over Kharkiv on March 20, 2015. Geomagnetism and Aeronomy. 56 (5). 592—603.
https://doi.org/10.1134/S0016793216050030