Irkutsk, Russian Federation
Irkutsk, Russian Federation
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
1. Arras C., Jacobi C., Wickert J. Semidiurnal tidal signature in sporadic E occurrence rates derived from GPS radio occultation measurements at higher midlatitudes. Ann. Geophys. 2009, vol. 27, no. 6, pp. 2555–2563. DOI:https://doi.org/10.5194/angeo-27-2555-2009.
2. Baggaley W.J. Ionospheric Es in southern hemisphere temperate zone. Seasonal characteristics for foEs, Aus. J. Phys. 1989, vol. 42, no. 4, pp. 451–464. DOI:https://doi.org/10.1071/PH890451.
3. Belinskaya A.Yu., Kovalev A.A., Karlin V.E. Variations of the Es layer over Novosibirsk in solar cycles 23 and 24. Dinamicheskie protsessy v geosferakh [Dynamic processes in the geospheres]. 2022, vol. 14, no. 1, pp. 93–100. (In Russian).
4. Chavdarov S.S., Chasovitin Yu.K., Chernysheva S.P., Sheftel V.M. Sredneshirotnyi sporadicheskii sloi E ionosfery [Mid-latitude sporadic E layer of the ionosphere]. Moscow, Nauka Publ., 1975, 148 p. (In Russian).
5. Christakis N., Haldoupis C., Zhou Q., Meek C. Seasonal variability and descent of mid-latitude sporadic E layers at Arecibo. Ann. Geophys. 2009, vol. 27, iss. 3, pp. 923–931. DOI:https://doi.org/10.5194/angeo-27-923-2009.
6. Forbes J.M., Makarov N.A., Portnyagin Yu.I. First results from the meteor radar at South Pole: A large 12-hour oscillation with zonal wavenumber one. Geophys. Res. Lett. 1995, vol. 22, no. 23, pp. 3247–3250. DOI:https://doi.org/10.1029/95GL03370.
7. Fytterer T., Arras C., Jacobi C. Terdiurnal signatures in sporadic E layers at midlatitudes. Adv. Radio Sci. 2013, vol. 11, pp. 333–339. DOI:https://doi.org/10.5194/ars-11-333-2013.
8. Gershman B.N., Ignatiev Yu.A., Kamenetskaya G.Kh. Mekhanizmy obrazovaniya ionosfernogo sporadicheskogo sloya Es na razlichnykh shirotakh [Formation mechanisms of ionospheric sporadic Es layer at different latitudes]. Moscow, Nauka Publ., 1976, 108 p. (In Russian).
9. Haldoupis C. A Tutorial Review on Sporadic E Layers. Aeronomy of the Earth’s Atmosphere and Ionosphere. New York, Springer, 2011, pp. 381–389.
10. Haldoupis C., Meek C., Christakis N., Pancheva D., Bourdillon A. Ionogram height time intensity observations of descending sporadic E layers at mid-latitude. J. Atmos. Solar-Terr. Phys. 2006, vol. 68, no. 3-5, pp. 539–557. DOI:https://doi.org/10.1016/j. jastp.2005.03.020.
11. Haldoupis C., Haralambous H., Meek C., Mathews J.D. Understanding the diurnal cycle of midlatitude sporadic E. The role of metal atoms. J. Geophys. Res.: Space Phys. 2023, vol. 128, no. 4, e2023JA031336. DOI:https://doi.org/10.1029/2023JA031336.
12. Jo E., Kim Y.H., Moon S., Kwak Y.S. Seasonal and local time variations of sporadic E layer over South Korea. J. Astron. Space Sci. 2019, vol. 36, no. 2, pp. 61–68.DOI:https://doi.org/10.5140/JASS. 2019.36.2.61.
13. Kokourov V.D., Petrukhin V.F., Ponomarev E.A., Sutyrin N.A. Climatic features of the ionosphere E region. Solnechno-zemnaya fizika [Solar-Terrestrial Physics]. 2003, iss. 3, pp. 24–27. (In Russian).
14. Lee C.-C., Liu J.-Y., Pan C.-J., Hsu H.-H. The intermediate layers and associated tidal motions observed by a digisonde in the equatorial anomaly region. Ann. Geophys. 2003, vol. 21, no. 4, pp. 1039–1045. DOI:https://doi.org/10.5194/angeo-21-1039-2003.
15. Maeda J., Heki K. Morphology and dynamics of daytime midlatitude sporadic-E patches revealed by GPS total electron content observations in Japan. Earth, Planets and Space. 2015, vol. 67, no. 89. DOI:https://doi.org/10.1186/s40623-015-0257-4.
16. Mathews J.D. Sporadic E: Current views and recent progress. J. Atmos. Solar-Terr. Phys. 1998, vol. 60, no. 4, pp. 413–435. DOI:https://doi.org/10.1016/S1364-6826(97)00043-6.
17. Oikonomou C., Haralambous H., Haldoupis C., Meek C. Sporadic E tidal variabilities and characteristics observed with the Cyprus digisonde. J. Atmos. Solar-Terr. Phys. 2014, vol. 119, pp. 173–183. DOI:https://doi.org/10.1016/j.jastp.2014.07.014.
18. Pignalberi A., Pezzopane M., Zuccheretti E. Sporadic E layer at mid-latitudes: Average properties and influence of atmospheric tides. Ann. Geophys. 2014, vol. 32, no. 11, pp. 1427–1440. DOI:https://doi.org/10.5194/angeo-32-1427-2014.
19. Wang W., Jiang C., Wei L., Tang Q., Huang W., Shen H., et al. Comparative study of the Es layer between the plateau and plain regions in China. Remote Sens. 2022, vol. 14, no. 12, id. 2871. DOI:https://doi.org/10.3390/rs14122871.
20. Zalizovski A.V. The role of tropospheric processes in the formation of sporadic layers of the E-region of the ionosphere over the Antarctic Peninsula. Radiofizika i radioastronomiya [Radiophysics and radio astronomy]. 2008, vol. 13, no. 1, pp. 26–38. (In Russian).
21. URL: http://ckp-rf.ru/ckp/3056/ (accessed November 5, 2024).
