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ISSN 2415-3400 (Online)
ISSN 1028-821X (Print)

Polarisation of night-time ELF–VLF atmospherics as statistically approached

Gorishnya, YV
Organization: 

O. Ya. Usikov Institute for Radiophysics and Electronics of the National Academy of Sciences of Ukraine
12, Proskura st., Kharkov, 61085, Ukraine

E-mail:
 yugorishnya@gmail.com

https://doi.org/10.15407/rej2019.04.020
Language: russian
Abstract: 

 

Subject and Purpose. Tweek-atmospherics (night-time low-frequency atmospherics), along with radio transmission by VLF radio stations, are used to study the lower ionosphere. The predictions of the available analytical theory regarding the polarization of such atmospherics and the previously accumulated experimental material describe the left elliptical polarization as a characteristic feature of the tweek-atmospherics in their tail section. The horizontal geomagnetic field’s component in reflection layer of the lower ionosphere should lead, within the theory framework, to non-reciprocity of the “east–west” and “west – east” propagation of tweeks. The study aim was to determine the polarization of tweek-atmospherics using three-component records and to statistically evaluate the null hypothesis regarding to two polarization parameters of tweek-atmospherics.

Methods and Methodology. By the ensemble of experimental tweek-atmospheric records of about 300 examples, that is large enough for statistical processing, the polarization was studied along the atmospherics’ waveforms.

Results. For the first (fundamental) harmonic, two characteristics of the polarization of the tweek-atmospherics (the polarization ratio and the phase difference) were calculated and analyzed, depending on the parameter identical to an incidence angle. The difference in the polarization ratio values has found between tweek-atmospherics with near-equatorial paths and atmospherics outside the geomagnetic equator area, where the condition of quasi-longitudinal wave propagation along the geomagnetic field is satisfied.

Conclusions. Study has shown that the non-reciprocity of the propagation of tweek-atmospherics in the “east–west” and “west–east” directions regarding the geomagnetic field is observed as statistically significant differences in the phase difference at an incidence angle about 40...60˚ that correspond to an ending of head area of atmospheric waveforms.

Keywords: ELF–VLF radio waves, extra low frequencies, lightning location, lower ionosphere diagnostic, tweek-atmospherics, very low frequencies

Manuscript submitted 18.01.2019
Radiofiz. elektron. 2019, 24(4): 20-29
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References: 
1. Gorishnya, Y.V., 2014. Electron density and lower ionosphere height estimations by results of analysis of multimodal tweek-atmospherics. Radiofiz. Electron., 5(19)(1), pp. 20-28 (in Russian).
2. Gorishnya, Yu.V., 2017. Plasma Density Evaluation in the Sharply-bounded Ionosphere Model by Tweeks. In: IEEE First Ukraine Conf. Electrical and Computer Engineering (UKRCON). Conf. Proc. Kyiv, Ukraine, May 29 - June 2. Kyiv: KPI Publ., pp. 94-97. DOI: https://doi.org/10.1109/UKRCON.2017.8100367
3. Shvets, A.V., Gorishnya, Yu.V., 2011. Lightning location and estimation of the lower ionosphere effective height using dispersion properties of tweek-atmospherics. Radiofiz. Electron., 16(4), pp. 53-59 (in Russian).
4. Gorishnya, Y.V., Shvets, A.V., 2010. Statistical study of multimodal tweek-atmospherics. In: 13th Int. Conf. on Mathematіcal Methods іn Electromagnetіc Theory (MMET 2010). Proc. Kyіv, Ukraіne, 6-8 Sept. Kyiv: ІEEE, pp. 98-101. DOI: https://doi.org/10.1109/MMET.2010.5611445
5. Shvets, A.V., Gorishnya, Y.V., 2012. The Method for Estimating of Parameters of Lower Atmosphere through Broadcast Sygnals of Tweek-Atmospherics. In: Electromagnetіc Methods of Envіronmental Studіes (EMES'2012). Proc. Kharkiv, Ukraine, 25-27 Sept. Kharkiv: RI NANU Publ., pp. 289-291 (in Russian).
6. Yamashita, M., 1978. Propagation of tweek atmospherics. J. Atmos. Terr. Phys. 40(2), pp. 151-156. DOI: https://doi.org/10.1016/0021-9169(78)90019-3
7. Shvets, A.V., Hayakawa, M., 1998. Polarization effects for tweek propagation. J. Atmos. Solar-Terr. Phys. 60(4), pp. 461-469. DOI: https://doi.org/10.1016/S1364-6826(97)00131-4
8. Shvets, A.V., 1997. On the polarization properties of tweeks. In: V.M. Yakovenko, ed. 1997. Radiofizika i elektronika. Kharkov: IRE NAS of Ukraine Publ. 2(2), pp. 101-106 (in Russian).
9. Shvets, A.V., Gorіshnya, Y.V., 2007. Polarіzatіon of atmospherіcs propagatіng under nіght-tіme іonosphere. In: The 6th Іnt. Kharkov Symp. on Phys. and Eng. of Mіcrowaves, Mіllіmeter and Submіllіmeter Waves and Workshop on Teraherz Techn. Symp. (MSMW'07). Proc. Kharkov, Ukraіne, 25-30 June 2007. Kharkiv, IRE NAS of Ukraine Publ. Vol. 2, pp. 763-765.
10. Ryabov, B.S., 1994. Tweek formation peculiarities. Geomagn. Aeronomy, 34(1), pp. 60-66.
11. Wait, J.R., 1962. Electromagnetic Waves in Stratified Media. Oxford, New York: Pergamon Press.
12. Reeve, C.D., Rycroft, M.J., 1972. The eclipsed lower ionosphere as investigated by natural very low frequency radio signals. J. Atmos. Terr. Phys. 34(4), pp. 667-672. DOI: https://doi.org/10.1016/0021-9169(72)90154-7