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Spectral characteristics of scintillations producing ionospheric irregularities in the Indian region

Abstract

VHF amplitude scintillations were recorded at Tirunelveli (8.7°N, 77.7°E; 0.6°N dip Latitude), Pondicherry (12°N, 79.1°E; 4.4°N dip Latitude) and Mumbai, (19°N, 73°E; 13.5°N dip Latitude) for the years 1992–1996 using the 250 MHz radio beacon from the geostationary satellite FLEETSAT (73°E). The recorded digital scintillation data for few nights are analyzed to estimate scintillation index (S4), fade rates, auto-correlation functions and power spectral densities for every 2.5 minute sample during the period of the scintillation activity. The power spectral slopes are shallower for the scintillation at the generation phase and steeper towards the decay phase, which indicates the erosion of smaller scale sizes towards the decay phase.

References

  1. Aarons, J., Global morphology of ionospheric scintillations, Proc. IEEE, 70, 360–378, 1982.

    Article  Google Scholar 

  2. Abdu, M. A., R. T. De Medeiros, and J. H. A. Sobral, Equatorial spread- F instability conditions as determined from ionosonde observations, Geophys. Res. Lett., 9, 692–695, 1982.

    Article  Google Scholar 

  3. Abdu, M. A., R. T. De Medeiros, J. H. A. Sobral, and J. A. Bittencourt, Spread-F plasma bubble vertical rise velocities determined from spaced ionosonde observations, J. Geophys. Res., 88, 9197–9204, 1983.

    Article  Google Scholar 

  4. Anderson, D. N. and G. Haerendel, The motion of depleted plasma regions in the equatorial ionosphere, J. Geophys. Res., 84, 4251–4256, 1979.

    Article  Google Scholar 

  5. Balsley, B. B., G. Haerendal, and R. A. Greenwald, Equatorial Spread-F: recent observations and new interpretations, J. Geophy. Res., 77, 5625–5628, 1972.

    Article  Google Scholar 

  6. Banerjee, P. K., R. S. Dabas, and B. M. Reddy, C and L band transionospheric scintillation experiment: Some results for applications to Satellite Radio Systems, Radio Sci., 27(6), 955–969, 1992.

    Article  Google Scholar 

  7. Basu, Su. and S. Basu, Equatorial scintillations, Progress Science ISEA-6, J. Atmos. Terr. Phys., 47, 753–768, 1985.

    Article  Google Scholar 

  8. Basu, S. and H. E. Whitney, The temporal structure of intensity scintillation near the magnetic equator, Radio Sci., 18(2), 263–271, 1983.

    Article  Google Scholar 

  9. Basu, S., J. P. McClure, S. Basu, W. B. Hanson, and J. Aarons, Coordinated study of equatorial scintillation and in situ and radio observations of nighttime F region irregularities, J. Geophys. Res., 85, 5119–5130, 1980.

    Article  Google Scholar 

  10. Bhattacharyya, A. and R. G. Rastogi, Amplitude scintillation during early and late phases of evolution of irregularities in the nighttime equatorial ionosphere, Radio Sci., 20(4), 935–946, 1985.

    Article  Google Scholar 

  11. Bhattacharyya, A. and R. G. Rastogi, Structure of ionospheric irregularities from amplitude and phase scintillation observations, Radio Sci., 26(2), 439–449, 1991.

    Article  Google Scholar 

  12. Bramley, E. N. and R. Browning, Mid-latitude ionospheric scintillation of geostationary satellite signals at 137 MHz, J. Atmos. Terr. Phys., 40, 1247–1255, 1978.

    Article  Google Scholar 

  13. Briggs, B. H. and I. A. Parkin, On the variation of radio star and satellite scintillations with zenith angle, J. Atmos. Terr. Phys., 25, 339–366, 1963.

    Article  Google Scholar 

  14. Chandra, H., Equatorial spread-F—Recent developments, Ind. J. Radio Space Phys., 19, 215–224, 1990.

    Google Scholar 

  15. Chandra, H., Hari Om Vats, G. Sethia, M. R. Deshpande, R. G. Rastogi, J. H. Sastri, and B. S. Murthy, Ionospheric scintillations associated with features of equatorial ionosphere, Ann. Geophys., 35, 145–151, 1979.

    Google Scholar 

  16. Chandra, H., G. D. Vyas, H. S. S. Sinha, R. N. Mishra, and S. Prakash, Ionospheric scintillation observations from SHAR, J. Atmos. Terr. Phys., 54, 167–172, 1992.

    Article  Google Scholar 

  17. Chandra, H. et al., Co-ordinated multistation VHF scintillation observations in India during March-April 1991, Ind. J. Radio Space Phys., 22, 69–81, 1993.

    Google Scholar 

  18. Cole, K. D., Formation of field-aligned irregularities in the magnetosphere, J. Atmos. Terr. Phys., 33, 741–750, 1971.

    Article  Google Scholar 

  19. Dungey, J. W., Convective diffusion in the equatorial F region, J. Atmos. Terr. Phys., 9, 304–310, 1956.

    Article  Google Scholar 

  20. Dyson, P. L., J. P. McClure, and W. B. Hanson, In situ measurements of the spectral characteristics of F region ionospheric irregularities, J. Geophys. Res., 79, 1497–1502, 1974.

    Article  Google Scholar 

  21. Elkin, T. J. and M. D. Papagiannis, Measurement and interpretation of power spectrum of ionospheric scintillation at a sub-auroral location, J. Geophys. Res., 74, 4105–4115, 1969.

    Article  Google Scholar 

  22. Fejer, B. G and M. C. Kelley, Ionospheric irregularities, Rev. Geophys. Space Phys., 18, 401–454, 1980.

    Article  Google Scholar 

  23. Fremouw, E. J., R. L. Leadbrand, R. C. Livingston, M. D. Cousins, C. L. Rino, B. C. Fair, and R. A. Long, Early results from the DNA wide band satellite experiment-complex signal scintillation, Radio Sci., 13, 167–187, 1978.

    Article  Google Scholar 

  24. Haerendal, G., Report, Max Planck Institute fur Physik und Astrophysik, Garching, West Germany, 1973.

    Google Scholar 

  25. Kelley, M. C. and J. P. McClure, Equatorial Spread-F: A review of recent experimental results, J. Atmos. Ter. Phys., 43, 427–435, 1981.

    Article  Google Scholar 

  26. Kersley, L. and H. Chandra, Power spectra of VHF intensity scintillations from F2 and E region ionospheric irregularities, J. Atmos. Terr. Phys., 46(8), 667–672, 1984.

    Article  Google Scholar 

  27. Krishnamoorthy, K., C. R. Reddy, and B. V. Krishnamurthy, Nighttime ionospheric scintillations at the magnetic equator, J. Atmos. Terr. Phys., 41, 123–134, 1979.

    Article  Google Scholar 

  28. Ossakow, S. L., Spread-F theories—a review, J. Atmos. Terr. Phys., 43, 437–452, 1981.

    Article  Google Scholar 

  29. Pathak, K. N., R. D. Jivrajani, B. Mathew, H. P. Joshi, and K. N. Iyer, Study of ionospheric scintillations near the crest of equatorial anomaly in India using digital data base, Ind. J. Radio Space Phys., 24, 138–150, 1995.

    Google Scholar 

  30. Pathan, B. M., P. V. Koparkar, R. G. Rastogi, and D. R. K. Rao, Dynamics of ionospheric irregularities producing VHF radio wave scintillations at low latitudes, Ann. Geophys., 9, 126–132, 1991.

    Google Scholar 

  31. Prakash, S., S. Pal, and H. Chandra, In-situ studies of equatorial spread-F over SHAR-steep gradients in the bottomside F-region and transitional wavelength results, J. Atmos. Terr. Phys., 53(10), 977–986, 1991.

    Article  Google Scholar 

  32. Rastogi, R. G., Solar cycle effect in radio wave scintillations at Huancayo, Ind. J. Radio Space Phys., 11, 215–221, 1982.

    Google Scholar 

  33. Rastogi, R. G. and R. F. Woodman, VHF radiowave scattering due to range and frequency types of equatorial spread-F, J. Atmos. Terr. Phys., 40, 485–491, 1978.

    Article  Google Scholar 

  34. Rastogi, R. G., H. Chandra, and M. R. Deshpande, Equatorial radio scintillations of ATS-6 radio beacons: Phase II Ootacamund 1975-76, Ind. J. Radio Space Phys., 11, 240–246, 1982.

    Google Scholar 

  35. Rufenach, C. L., Power law wavenumber spectrum deduced from ionospheric scintillation observations, J. Geophys. Res., 77, 4761–4772, 1972.

    Article  Google Scholar 

  36. Singleton, D. G., Power spectra of ionospheric scintillations, J. Atmos. Terr. Phys., 36, 113–133, 1974.

    Article  Google Scholar 

  37. Somayajulu, Y. V., S. C. Garg, R. S. Dabas, Lakha Singh, T. R. Tyagi, B. Loknadhan, S. Ramkrishna, and G. Navneeth, Multistation study of nighttime scintillations in low latitudes: Evidence of control by equatorial F region irregularities, Radio Sci., 19, 707–718, 1984.

    Article  Google Scholar 

  38. Sushil Kumar, A. K. Gwal, P. V. S. Rama Rao et al., Co-ordinated observations of VHF scintillations in India during February-March 1993, Ind. J. Radio Space Phys., 29, 22–29, 2000.

    Google Scholar 

  39. Taur, R. R., Ionospheric scintillations at 4 to 6 GHz, COMSAT Tech. Rev., 3, 145–163, 1973.

    Google Scholar 

  40. Umeki, R., C. H. Liu, and C. K. Yeh, Multifrequency spectra of ionospheric amplitude scintillations, J. Geophys. Res., 82, 2752–2760, 1977.

    Article  Google Scholar 

  41. Vyas, G. D. and H. Chandra, VHF scintillation and spread-F in the anomaly crest region, Ind. J. Radio Space Phys., 23, 157–164, 1994.

    Google Scholar 

  42. Woodman, R. F. and S. Basu, Comparison between ‘in-situ’ spectral measurements of equatorial F region irregularities backscatter observations at 3 m wavelength, Geophys. Res. Lett., 5, 869–872, 1978.

    Article  Google Scholar 

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Correspondence to S. Banola.

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Banola, S., Pathan, B.M., Rao, D.R.K. et al. Spectral characteristics of scintillations producing ionospheric irregularities in the Indian region. Earth Planet Sp 57, 47–59 (2005). https://doi.org/10.1186/BF03351805

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Key words

  • Equatorial ionosphere
  • ionospheric irregularities
  • VHF Scintillation
  • fade rate