Solar-Terrestrial Physics Solar-Terrestrial Physics Solar-Terrestrial Physics 2500-0535 86525 10.12737/stp-111202507 Results of current research Results of current research Results of current research Diurnal variations in characteristics of sporadic layer Eₛ over Irkutsk Diurnal variations in characteristics of sporadic layer Eₛ over Irkutsk Воронова Екатерина Андреевна Voronova Ekaterina Yurevna https://orcid.org/0000-0002-0847-3553 Ратовский Константин Геннадьевич Ratovsky Konstantin Gennadyevich ratovsky@iszf.irk.ru

кандидат физико-математических наук;

candidate of physical and mathematical sciences;

 Институт солнечно-земной физики СО РАН Иркутск Россия Institute of Solar Terrestrial Physics SB RAS Irkutsk Russian Federation Институт солнечно-земной физики СО РАН Иркутск Россия Institute of Solar-Terrestrial Physics SB RAS Irkutsk Russian Federation 26 03 2025 26 03 2025 11 1 56 62 15 08 2024 02 12 2024 https://naukaru.ru/en/nauka/article/86525/view

We have studied the morphological features of semidiurnal variations in the occurrence of the sporadic Es layer (PEs) and height of the layer (hEs), using data from the Irkutsk DPS-4 ionosonde (52.3° N, 104.3° E) for 2003–2021. By averaging over all the years, we calculate diurnal variations in PEs and hEs for each month. It is observed that the maximum of occurrence PEs is achieved when the height hEs decreases; and there is an asymmetry in the maximum of occurrence PEs: morning maxima are larger than evening ones. These features are interpreted based on the concept of the optimal height for Es formation and the role of photoionization in forming the sporadic layer.

We have studied the morphological features of semidiurnal variations in the occurrence of the sporadic Es layer (PEs) and height of the layer (hEs), using data from the Irkutsk DPS-4 ionosonde (52.3° N, 104.3° E) for 2003–2021. By averaging over all the years, we calculate diurnal variations in PEs and hEs for each month. It is observed that the maximum of occurrence PEs is achieved when the height hEs decreases; and there is an asymmetry in the maximum of occurrence PEs: morning maxima are larger than evening ones. These features are interpreted based on the concept of the optimal height for Es formation and the role of photoionization in forming the sporadic layer.

 sporadic layer diurnal variations occurrence frequency height semidiurnal tides sporadic layer diurnal variations occurrence frequency height semidiurnal tides The work was financially supported by the Ministry of Science and Higher Education of the Russian Federation (Subsidy No. 075-GZ/C3569/278) The work was financially supported by the Ministry of Science and Higher Education of the Russian Federation (Subsidy No. 075-GZ/C3569/278)

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