F-layer critical frequency determination from ionospheric Alfven resonance observations
- resonance,
- ionosphere,
- Alfven,
- critical frequency
Abstract
The parameters of the ionospheric Alfven (IAR) and Schumann (SR) resonances are determined by the intensity of their source (global thunderstorm activity) and properties of the propagation medium (the ionosphere and magnetosphere of the Earth). Our observations and results of other authors show that the SR depends primarily on the global parameters of the source and propagation medium. Otherwise the IAR features are mainly determined by local characteristics of the near-earth plasma. The latter circumstance was the basis for the authors to analyze the possibility of diagnostics of the local ionosphere using the IAR data. ELF recordings, obtained at the Ukrainian Antarctic Station (UAS) and low-frequency observatory IRA NAS Ukraine (LFO) were used for the analysis. The presence of long-term data sets obtained at the points with a spatial spacing of about 15 thousand kilometers, allowed us to study the basic seasonal and diurnal behavior of the eigenfrequencies and “observability”of IAR, as well as to investigate the dependence of these parameters from the site position. IAR characteristics were compared with synchronous data of the ionospheric sounding and the total electron content (TEC) over the observation points. A joint analysis of data showed that plasma parameters at the height of the ionosphere F-region have a major impact on the variation of eigenfrequencies of IAR. The article describes a phenomenological model and proposes the technique of estimation of the magnitude of the critical frequency of F layer - F2f0 based on the calculation of frequency interval between the IAR peaks -Δf. The reliability of this technique is confirmed comparing the reconstructed values F2f0 with the vertical sounding data obtained at UAS.
References
- Belyaev, P.P., Polyakov, S.V., Rapoport, V.O. et al. (1989). E`ksperimental`ny`e issledovaniya rezonansnoj struktury` spektra atmosfernogo e`lektromagnitnogo shumovogo fona v diapazone korotkoperiodny`x geomagnitny`x pul`sacij [Experimental research of the resonance structure of the spectrum of the atmospheric electromagnetic noise background in the range of short-periodic geomagnetic pulsations]. Izvestiya vy`sshix uchebny`x zavedenij, 32(6), 663–672.
- Belyaev, P.P., Polyakov, S.V., Rapoport, V.O. et al. (1989). Teoriya formirovaniya rezonansnoj struktury` spektra atmosfernogo e`lektromagnitnogo shumovogo fona v diapazone korotkoperiodny`x geomagnitny`x pul`sacij [The theory of the formation of the structure of the range of atmospheric noise background in the range of short-periodic geomagnetic pulsations]. Izvestiya vy`sshix uchebny`x zavedenij, 32(7), 802–810.
- Koloskov, A.V., Sinicyn, V.G., Gerasimova, N.N., & Yampol`skij, Yu.M. (2008). Okolozemny`e rezonatory` SNCh-voln kak indikatory` kosmicheskoj pogody` [Near-Earth resonators of ULF waves as indicators of space weather]. Kosmіchna nauka і texnologіya, 4(5), 49–64.
- Ostapenko, A.A., & Polyakov, S.V. (1990). Dinamika koe`fficienta otrazheniya al`fvenovskix voln diapazona Pc1 ot ionosfery` pri variaciyax e`lektronnoj koncentracii nizhnej ionosfery` [The dynamics of the reflection coefficient of the Alfven waves in the Pc1 range from the ionosphere under variations of electronic concentration of the lower ionosphere]. Geomagnetizm i Ae`ronomiya, 30(1), 50–56.
- Polyakov, S.V., & Rapoport, V.O. (1981). Ionosferny`j Al`fvenovskij Rezonator. Geomagnetizm i Ae`ronomiya, 21, 816–822.
- Sinicyn, V.G., & Yampol`skij, Yu. M. (2006). UNCh-SNCh-rezonansy` v geokosmose kak indikatory` kosmicheskoj pogody` [ULF-SLF resonances in geospace as indicators of space weather]. Lekcii BShFF-2006. pp. 54–57.
- Belyaev, P.P., Bosinger, T., Isaev, S.V. et al. (1999). First evidence at high latitudes for the ionospheric Alfven resonator. Journal of geophysical research, 104(#A3), 4305–4317.
- Belyaev, P.P., Polyakov, S.V., Ermakova, E.N. et al. (2000). Solar cycle variations in the ionospheric Alfvén resonator 1985–1995. Journal of Atmospheric and Solar-Terrestrial Physics 62, 239–248.
- Bosinger, T., Haldoupis, C., Belyaev, P.P. et al. (2002). Spectral properties of the ionospheric Alfvén resonator observed at a low-latitude station (L = 1.3). Journal of geophysical research, 107(A10), 1281.
- Jayachandran, B., Krishnankutty, T.N., & Gulyaeva, T.L. (2004). Climatology of ionospheric slab thickness. Annales Geophysicae, 22, 25–33.
- Hebden, S.R., Robinson, T.R., Wright, D.M. et al. (2005). A quantitative analysis of the diurnal evolution of Ionospheric Alfven resonator magnetic resonance features and calculation of changing IAR parameters. Annales Geophysicae, 23, 1711–1721.
- Odzimek, A., Kułak, A., Michalec, A. et al. (2006). An automatic method to determine the frequency scale of the ionospheric Alfven resonator using data from Hylaty station, Poland. Annales Geophysicae, 24, 2151–2158.
- Parent, A., Mann, I.R., & Shiokawa, K. (2006). Observing the MLT and L-shell dependence of ground magnetic signatures of the ionospheric Alfven resonator. Int. Conf. Substorms-8, pp. 225–230.
- Pokhotelov, O.A., Feygin, F.Z., Khabazin, Yu.G. et al. (2003). Observations of IAR spectral resonance at a large triangle of geophysical observatories. Physics of Auroral Phenomena, Proc. XXVI Annual Seminar. Apatity, pp. 123–126.
- Yahnin, A.G., Semenova, N.V., Ostapenko, A.A. et al. (2003). Morphology of the spectral resonance structure of the electromagnetic background noise in the range of 0.1–4 Hz at L = 5.2. Annales Geophysicae, 21, 779–786.