Иркутск, Россия
The study presents the results of comparative analysis of features of a short-period (with periods of internal gravity waves) variability of total electron content (TEC) in the ionosphere at middle (Novosibirsk) and high (Norilsk) latitudes over a long period of time (2003–2020). The period analyzed makes it possible to estimate not only diurnal and seasonal variations in the variability, but also its changes within the solar activity cycle. The level of TEC variability is shown to experience pronounced seasonal variations with maxima in winter months. The difference between the level of variability in winter and summer is about two times for Novosibirsk and up to seven times for Norilsk. The variability features a distinct diurnal variation; however, the diurnal dependence at the mid- and high-latitude stations differs significantly. At high latitudes, the level of variability in the winter period strictly depends on solar activity. For the mid-latitude station, there is no clear dependence of variability level on solar activity; in the years of solar maximum, on the contrary, a slight decrease in the variability is observed. In summer, the level of variability at both middle and high latitudes remains practically unchanged and does not depend on solar activity. The main features in the dynamics of variability are shown to be similar at stations located at other longitudes, except for the East American sector. The result obtained suggests that the short-period TEC variability at high latitudes is primarily related to changes in solar activity, but regular variations in the variability at midlatitudes are probably not associated with heliophysical activity. The observed increase in the level of short-period variability in the winter mid-latitude ionosphere is assumed to be related to an increase in wave activity in the stratosphere.
ionosphere; total electron content; GPS; ionospheric variability
1. Afraimovich E.L., Edemskiy I.K., Leonovich A.S., Leonovich L.A., Voeykov S.V., Yasyukevich Y.V. MHD nature of night-time MSTIDs excited by the solar terminator. Geophys. Res. Lett. 2009a, vol. 36, L15106. DOI: 10.1029/ 2009GL039803.
2. Afraimovich E.L., Edemskiy I.K., Voeykov S.V., Yasukevich Yu.V., Zhivetiev I.V. Spatio-temporal structure of the wave packets generated by the solar terminator. Adv. Space Res. 2009b, vol. 44, pp. 824–835. DOI: 10.1016/j.asr.2009.05.017.
3. Altadill D. Time/altitude electron density variability above Ebro, Spain. Adv. Space Res. 2007, vol. 39, pp. 962–969. DOI: 10.1016/j.asr.2006.05.031.
4. Araujo-Pradere E.A., Fuller-Rowell T.J., Codrescu M.V., Bilitza D. Characteristics of the ionospheric variability as a function of season latitude local time and geomagnetic activity. Radio Sci. 2005, vol. 40, RS5009. DOI: 10.1029/2004RS003179.
5. Chernigovskaya M.A., Shpynev B.G., Ratovsky K.G, et al. Ionospheric response to winter stratosphere/lower mesosphere jet stream in the Northern Hemisphere as derived from vertical radio sounding data. J. Atmos. Solar-Terr. Phys. 2018, vol. 180, pp. 126–136. DOI: 10.1016/j.jastp.2017.08.033.
6. Edemskiy I.K., Yasyukevich Y.V. Duration of wave disturbances generated by solar terminator in magneto-conjugate areas. Proc. XXXth URSI General Assembly and Scientific Symposium. Istanbul, Turkey, 2011, pp. 1–4. DOI: 10.1109/ URSIGASS.2011.6051003.
7. Forbes J.M., Palo S.E., Zhang, X. Variability of the ionosphere. J. Atmos. Solar-Terr. Phys. 2000, vol. 62, iss. 8, pp. 685–693. DOI: 10.1016/S1364-6826(00)00029-8.
8. Francis S.H. A theory of medium-scale traveling ionospheric disturbances. J. Geophys. Res. 1974, vol. 79, iss. 34, pp. 5245–5260. DOI: 10.1029/JA079i034p05245.
9. Frissell N.A., Baker J.B.H., Ruohoniemi J.M., Greenwald R.A., Gerrard A.J., Miller E.S., West M.L. Sources and characteristics of medium-scale traveling ionospheric disturbances observed by high-frequency radars in the North American sector. J. Geophys. Res. 2016, vol. 121, pp. 3722–3739. DOI: 10.1002/2015JA022168.
10. Hocke K., Schlegel K. A review of atmospheric gravity waves and travelling ionospheric disturbances: 1982–1995. Ann. Geophys. 1996, vol. 14, pp. 917–940. DOI: 10.1007/ s00585-996-0917-6.
11. Lastovicka J. Forcing of the ionosphere by waves from below. J. Atmos. Solar-Terr. Phys. 2006, vol. 68, pp. 479–497. DOI: 10.1016/j.jastp.2005.01.018.
12. Liu H.-L., Yudin V.A., Roble R.G. Day-to-day ionospheric variability due to lower atmosphere perturbations. Geophys. Res. Lett. 2013, vol. 40, pp. 665–670. DOI: 10.1002/grl.50125.
13. Medvedev A.V., Ratovsky K.G., Tolstikov M.V., Alsatkin S.S., Scherbakov A.A. Studying of the spatial–temporal structure of wavelike ionospheric disturbances on the base of Irkutsk incoherent scatter radar and digisonde data. J. Atmos. Solar-Terr. Phys. 2013, vol. 105, pp. 350–357. DOI: 10.1016/j.jastp.2013.09.001.
14. Mendillo M., Rishbeth H., Roble R.G., Wroten J. Modelling F2-layer seasonal trends and day-to-day variability driven by coupling with the lower atmosphere. J. Atmos. Solar-Terr. Phys. 2002, vol. 64, pp. 1911–1931. DOI: 10.1016/ S1364-6826(02)00193-1.
15. Nesterov I.A., Andreeva E.S., Padokhin A.M., Tumanova Yu.S., Nazarenko M.O. Ionospheric perturbation indices based on the low- and high-orbiting satellite radio tomography data. GPS Solut. 2017, vol. 21, pp. 1679–1694. DOI: 10.1007/s10291-017-0646-1.
16. Ratovsky K.G., Medvedev A.V., Tolstikov M.V. Diurnal, seasonal and solar activity pattern of ionospheric variability from Irkutsk Digisonde data. Adv. Space Res. 2015, vol. 55, pp. 2041–2047. DOI: 10.1016/j.asr.2014.08.001.
17. Rishbeth H., Mendillo M. Patterns of F2-layer variability. J. Atmos. Solar-Terr. Phys. 2001, vol. 63, pp. 1661–1680. DOI: 10.1016/S1364-6826(01)00036-0.
18. Shpynev B.G., Churilov, S.M., Chernigovskaya M.A. Generation of waves by jet-stream instabilities in winter polar stratosphere/mesosphere. J. Atmos. Solar-Terr. Phys. 2015, vol. 136(B), pp. 201–215. DOI: 10.1016/j.jastp.2015.07.005.
19. Shpynev B.G., Khabituev D.S., Chernigovskaya M.A., Zorkal’tseva O.S. Role of winter jet stream in the middle atmosphere energy balance. J. Atmos. Solar-Terr. Phys. 2019, vol. 188, pp. 1–10. DOI: 10.1016/j.jastp.2019.03.008.
20. Whiteway J.A., Duck T.J., Donovan D.P., Bird J.C., Pal S.R., Carswell A.I. Measurements of gravity wave activity within and around the Arctic stratospheric vortex. Geophys. Res. Lett. 1997, vol. 24, iss. 11, pp. 1387–1390. DOI: 10.1029/97GL01322.
21. Wu D.L., Waters J.W. Satellite observations of atmospheric variances: A possible indication of gravity waves. Geophys. Res. Lett. 1996, vol. 23, iss. 11, 24, pp. 3631–3634. DOI: 10.1029/96GL02907.
22. Yasyukevich A., Medvedeva I., Sivtseva V., Chernigovskaya M., Ammosov P., Gavrilyeva G. Strong Interrelation between the Short-Term Variability in the Ionosphere, Upper Mesosphere, and Winter Polar Stratosphere. Remote Sens. 2020a, vol. 12, 1588. DOI: 10.3390/rs12101588.
23. Yasyukevich Yu., Mylnikova A., Vesnin A. GNSS-Based Non-Negative Absolute Ionosphere Total Electron Content, its Spatial Gradients, Time Derivatives and Differential Code Biases: Bounded-Variable Least-Squares and Taylor Series. Sensors. 2020b, vol. 20, 5702. DOI: 10.3390/s20195702.
24. URL: https://omniweb.gsfc.nasa.gov/vitmo/cgm.html (accessed May 1, 2021).
