Statistical correlation of spectral broadening in VLF transmitter signal and low-frequency ionospheric turbulence from observation on DEMETER satellite
In our earlier papers we have found the effect of VLF transmitter signal depression over epicenters of the large earthquakes from observation on the French DEMETER satellite that can be considered as new method of global diagnostics of seismic influence on the ionosphere. At present paper we investi...
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2008-10-01
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| Series: | Natural Hazards and Earth System Sciences |
| Online Access: | http://www.nat-hazards-earth-syst-sci.net/8/1105/2008/nhess-8-1105-2008.pdf |
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| author | A. Rozhnoi M. Solovieva O. Molchanov O. Akentieva J. J. Berthelier M. Parrot P. F. Biagi M. Hayakawa |
| author_facet | A. Rozhnoi M. Solovieva O. Molchanov O. Akentieva J. J. Berthelier M. Parrot P. F. Biagi M. Hayakawa |
| author_sort | A. Rozhnoi |
| collection | DOAJ |
| description | In our earlier papers we have found the effect of VLF transmitter signal depression over epicenters of the large earthquakes from observation on the French DEMETER satellite that can be considered as new method of global diagnostics of seismic influence on the ionosphere. At present paper we investigate a possibility VLF signal-ionospheric turbulence interaction using additional characteristic of VLF signal-spectrum broadening. This characteristic is important for estimation of the interaction type: linear or nonlinear scattering. Our main results are the following: <br> &ndash; There are two zones of increased spectrum broadening, which are centered near magnetic latitudes Φ=&plusmn;10&deg; and Φ=&plusmn;40&deg;. Basing on the previous case study research and ground ionosonde registrations, probably it is evidence of nonlinear (active) scattering of VLF signal on the ionospheric turbulence. However occurrence rate of spectrum broadening in the middle-latitude area is higher than in the near-equatorial zone (~15–20% in comparison with ~100% in former area) that is probably coincides with the rate of ionospheric turbulence. <br> &ndash; From two years statistics of observation in the selected 3 low-latitude regions and 1 middle-latitude region inside reception area of VLF signal from NWC transmitter we find a correlation of spectrum broadening neither with ion-cyclotron noise (<I>f</I>=150–500 Hz), which possibly means poor representation of the turbulence by the noise due to its mixture with natural ELF emission (which correlates with whistler), nor with magnetic storm activity. <br> &ndash; We find rather evident correlation of ion-cyclotron frequency noise, VLF signal depression and weak correlation of spectrum broadening with seismicity in the middle-latitude region over Japan. But in the low-latitude regions we do not find such a correlation. Statistical decrease of VLF signal supports our previous case study results. However rather weak spectrum broadening-seismicity statistical correlation means probably that passive scattering prevails upon nonlinear (active) one. |
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| id | doaj.art-63bb4845a6644b3e922132376ea678ad |
| institution | Directory Open Access Journal |
| issn | 1561-8633 1684-9981 |
| language | English |
| last_indexed | 2024-12-12T11:53:20Z |
| publishDate | 2008-10-01 |
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| series | Natural Hazards and Earth System Sciences |
| spelling | doaj.art-63bb4845a6644b3e922132376ea678ad2022-12-22T00:25:16ZengCopernicus PublicationsNatural Hazards and Earth System Sciences1561-86331684-99812008-10-018511051111Statistical correlation of spectral broadening in VLF transmitter signal and low-frequency ionospheric turbulence from observation on DEMETER satelliteA. RozhnoiM. SolovievaO. MolchanovO. AkentievaJ. J. BerthelierM. ParrotP. F. BiagiM. HayakawaIn our earlier papers we have found the effect of VLF transmitter signal depression over epicenters of the large earthquakes from observation on the French DEMETER satellite that can be considered as new method of global diagnostics of seismic influence on the ionosphere. At present paper we investigate a possibility VLF signal-ionospheric turbulence interaction using additional characteristic of VLF signal-spectrum broadening. This characteristic is important for estimation of the interaction type: linear or nonlinear scattering. Our main results are the following: <br> &ndash; There are two zones of increased spectrum broadening, which are centered near magnetic latitudes Φ=&plusmn;10&deg; and Φ=&plusmn;40&deg;. Basing on the previous case study research and ground ionosonde registrations, probably it is evidence of nonlinear (active) scattering of VLF signal on the ionospheric turbulence. However occurrence rate of spectrum broadening in the middle-latitude area is higher than in the near-equatorial zone (~15–20% in comparison with ~100% in former area) that is probably coincides with the rate of ionospheric turbulence. <br> &ndash; From two years statistics of observation in the selected 3 low-latitude regions and 1 middle-latitude region inside reception area of VLF signal from NWC transmitter we find a correlation of spectrum broadening neither with ion-cyclotron noise (<I>f</I>=150–500 Hz), which possibly means poor representation of the turbulence by the noise due to its mixture with natural ELF emission (which correlates with whistler), nor with magnetic storm activity. <br> &ndash; We find rather evident correlation of ion-cyclotron frequency noise, VLF signal depression and weak correlation of spectrum broadening with seismicity in the middle-latitude region over Japan. But in the low-latitude regions we do not find such a correlation. Statistical decrease of VLF signal supports our previous case study results. However rather weak spectrum broadening-seismicity statistical correlation means probably that passive scattering prevails upon nonlinear (active) one.http://www.nat-hazards-earth-syst-sci.net/8/1105/2008/nhess-8-1105-2008.pdf |
| spellingShingle | A. Rozhnoi M. Solovieva O. Molchanov O. Akentieva J. J. Berthelier M. Parrot P. F. Biagi M. Hayakawa Statistical correlation of spectral broadening in VLF transmitter signal and low-frequency ionospheric turbulence from observation on DEMETER satellite Natural Hazards and Earth System Sciences |
| title | Statistical correlation of spectral broadening in VLF transmitter signal and low-frequency ionospheric turbulence from observation on DEMETER satellite |
| title_full | Statistical correlation of spectral broadening in VLF transmitter signal and low-frequency ionospheric turbulence from observation on DEMETER satellite |
| title_fullStr | Statistical correlation of spectral broadening in VLF transmitter signal and low-frequency ionospheric turbulence from observation on DEMETER satellite |
| title_full_unstemmed | Statistical correlation of spectral broadening in VLF transmitter signal and low-frequency ionospheric turbulence from observation on DEMETER satellite |
| title_short | Statistical correlation of spectral broadening in VLF transmitter signal and low-frequency ionospheric turbulence from observation on DEMETER satellite |
| title_sort | statistical correlation of spectral broadening in vlf transmitter signal and low frequency ionospheric turbulence from observation on demeter satellite |
| url | http://www.nat-hazards-earth-syst-sci.net/8/1105/2008/nhess-8-1105-2008.pdf |
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