Variations in Diffusion Coefficients on Equinox Days at Specified Critical Heights of the Ionosphere at the Equator

Year 2024, Volume: 19 Issue: 2, 407 - 414, 30.09.2024

Kadri Kurt , Ali Yeşil

https://doi.org/10.55525/tjst.1459356

Abstract

This study investigates the local time diffusion coefficient for stable and unstable ( , ) states at the equator (00), "the geographical latitude where the first peak of the magnetic equatorial trough in the ionosphere occurs," during the spring and fall equinoxes (March 21 and September 23). The findings show that the diffusion tensor in a steady state is completely real and has a magnitude equal to the speed of light in a steady state. But in the unsteady state, the diffusion tensor consists of two parts, real and imaginary. The diagonal elements of the real part tensor are of the size of the conductivity in the ionosphere and the elements of the imaginary part are of the size of the speed of sound with about the same magnitude. Furthermore, for all assumed conditions, the diffusion elements form the first peak of the magnetic equatorial trough at 6.00 am local time.

Keywords

Diffusion Tensor, Ionospheric Plasma, Diffusion Coefficient

Ekvatorda Iyonosferin Bazı Kritik Yüksekliklerinde Difüzyon Katsayılarının Ekinoks Günlerinde Değişimi

Abstract

Bu çalışmada, ilkbahar ve sonbahar ekinoksları (21 Mart ve 23 Eylül) sırasında “iyonosferdeki manyetik ekvatoral çukurun ilk zirvesinin meydana geldiği coğrafi enlem” olan ekvatorda (00) kararlı ve kararsız ( , ) durumlar için yerel zaman zaman difüzyon katsayısı araştırılmıştır. Bulgulara göre, kararlı durumda difüzyon tensörünün tamamen gerçek olduğunu ve sabit bir durumda ışık hızına eşit bir büyüklüğe sahip olduğunu göstermektedir. Fakat kararsız durumda difüzyon tensörü; reel ve sanal olmak üzere iki kısımdan oluşmaktadır. Reel kısım tensörününün köşegen elemanları iyonosferdeki büyüklüğü iletkenlik boyutunda, sanal kısmının elamanları yaklaşık aynı büyüklükte ses hızı boyutundadır. Bunun yanı sıra bütün kabul edilen şartlarda difüzyon elemanları sabah 6.00’da yerel zamanda manyetik ekvator çukurun ilk tepesini oluşturmaktadır.

Keywords

Difüzyon tensörü, iyonosferik plazma, difüzyon katsayıları

References

• Sağır S, Yeşil A. The relation between the refractive index of the equatorial ionospheric F2 region and long-term solar indices. Wirel Pers Commun 2018;102: 31-40.
• Yeşil A, Sağır S, Kurt K. The behavior of the classical diffusion tensor for equatorial ionospheric plasma. Journal of Science, 2016; 13: 123.
• Rishbeth H. Physics and chemistry of the ionosphere. Contemp Phys 1973;14(3): 229-249.
• Rishbeth H, Garriot OK. Introduction to Ionospheric Physics. New York, USA: Academic Press, 1969.
• Timoçin E, Yeşil A, Ünal İ. The effect of the geomagnetic activity to the hourly variations of ionospheric foF2 values at low latitudes. Arab J Geosci 2014; 7: 4437-4442.
• Kurt K. The Seasonal Behavior of the Characteristic Wave in Low Latitudes. Int J Innovative Eng Appl 2021; 5(1): 36-39.
• Mungufeni P, Rabiu BA, Okoh D, Jurua E. Characterisation of Total Electron Content over African region using Radio Occultation observations of COSMIC satellites. Adv Space Res 2020; 65(1): 19-29.
• Yesil A, Sagir S, Kurt K. The Behaviour of the Classical Diffusion Tensor for Equatorial Ionospheric Plasma. J Sci 2016; 13:123-127.
• Denisenko VV, Rycroft MJ, Harrison RG. A Mathematical Model of the Global Ionospheric Electric Field Generated by Thunderstorms. Bull Russ Acad Sci: Phys 2023; 87(1): 118-123.
• Tabassum A, Park K, Shin J, Jin HG, Baik JJ. Long-term changes in temperature, specific humidity, and precipitation in Bangladesh revealed by ERA5 data. Theor Appl Climatol 2023; 1-11.
• Olsen RC, Shawhan SD, Gallagher DL, Green JL, Chappell CR, Anderson RR. Plasma observations at the Earth's magnetic equator. J Geophys Res Space Phys 1987;92(A3): 2385-2407.
• Razzhevaikin VN. Instability of stationary nonmonotone solutions of the reaction equation with diffusion depending on density. Differ Equ 2006; 42: 567-575.
• Kolesnikov AF. Tirskii GA. The Stefan-Maxwell equations for diffusion fluxes of plasma in a magnetic field. Fluid Dyn 1985;19(4): 643–649.
• Yesil A. Sagir S. Kurt K. The Behaviour of the Classical Diffusion Tensor for Equatorial Ionospheric Plasma, J. Sci 2016; 13:123-127.
• Timoçin E, Ünal İ, Yeşil A. The Effect of the midlatitude electron density trough on the ionospheric conductivities. Iran J Sci Technol Trans A: Sci 2019; 43: 297-307.
• Sağir S, Yaşar M, Atici R. The Relationship between Dst, IMF-Bz and collision parameters for O++ N2→ NO++ N reactive scattering in the ionosphere. Geomagnetism and Aeronomy, 2019; 59: 1003-1008.
• Mendonça JT. Diffusion of magnetic field lines in a toroidal geometry. Phys Fluid Plasma Phys 1991; 3(1): 87-94.
• Kurt K, Yeşil MB. The Comparison of the Group and Phase Velocity of the Polarized Wave and the Equatorial Anomaly of the Ionosphere. Eur J Res Dev 2022; 2(2): 466-474.
• Katlamudi MR, Bulusu J. Low latitude Pi2 pulsations at Desalpar, Gujarat, India: A statistical analysis of the influences of magnetic storms/substorms, seasons, and solar cycles. J Atmos Sol Terr Phys 2023; 252: 106145.
• Yeşil A, Sağır S. The New Diffusion Tensor and the Equatorial Anomaly Altitudes of F-Region. Celal Bayar Univ J. Sci 2017; 13(3): 717-723.
• Yasar M. The solar eclipse effect on diffusion processes of O++ O2→ O2++ O reaction for the upper ionosphere over Kharkov. Therm Sci, 2021; 25(1): 57-63.
• Ünal İ, Karatay S, Yeşil A, Hançerlioğulları A. Seasonal variations of impedance in the ionospheric plasma. 2020; J Polytech.
• Yasar M. The change of diffusion processes for O++ N2→ NO++ N reaction in the ionospheric F region during the solar eclipse over Kharkov. Therm Sci 2021; 25(1): 51-56.