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  • 1 Ogun State University Department of Physics Ago-Iwoye
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HF absorption enhancements following major geomagnetic storms are analysed, using the superposed epoch method, to examine the geomagnetic latitude limit of the after-effect phenomenon. The absorption data were obtained from one double hop and two single hop A3 transmission paths with ionospheric points at Fgeomag = 3:54oN and ~6. 40oN (15. 40 MHz), Fgeomag ~ 9N (4. 87 MHz), and Fgeomag ~ 11oN (6. 09 MHz) respectively. Presently, the results have shown that enhancement in absorption following major storms could be traced to the low latitude of 3. 54oN.

  • Gnanalingam S 1974: J. Atmos. Terr. Phys., 36, 1335-1354.

    () 36 J. Atmos. Terr. Phys. : 1335 -1354.

  • Legrand J P, Simon P A 1991: Solar. Phys., 131, 187-194.

    () 131 Solar. Phys. : 187 -194.

  • Glantz S A 1980: Circulation, 61 (1), 1-6.

    () 61 Circulation : 1 -6.

  • Oyinloye J O 1988: J. Atmos. Terr. Phys., 50(6), 519-522.

    () 50 J. Atmos. Terr. Phys. : 519 -522.

  • Maih M A 1989: J. Atmos. Terr. Phys., 51(6), 541-549.

    () 51 J. Atmos. Terr. Phys. : 541 -549.

  • Kane R P 1973: J. Atmos. Terr. Phys., 35, 1953-1960.

    () 35 J. Atmos. Terr. Phys. : 1953 -1960.

  • Lauter E A, Knuth R 1967: J. Atmos. Terr. Phys., 29, 411-417.

    () 29 J. Atmos. Terr. Phys : 411 -417.

  • Park C G, Meng C I 1976: J. Geophys. Res., 81 (25), 4571-4578.

    () 81 J. Geophys. Res. : 4571 -4578.

  • Märcz F 1976: J. Geophys. Res., 81 (25), 4566-4570.

    () 81 J. Geophys. Res. : 4566 -4570.

  • Märcz F 1983: J. Atmos. Terr. Phys., 45(5), 281-284.

    () 45 J. Atmos. Terr. Phys. : 281 -284.

  • Park C G 1974: J. Geophys. Res., 79 (19), 2821-2827.

    () 79 J. Geophys. Res. : 2821 -2827.

  • Chukwuma V U 1999: Indian J. Radio Space Phys., 28, 264-270.

    () 28 Indian J. Radio Space Phys. : 264 -270.

  • Chukwuma V U 2000: Indian J. Radio Space Phys., 29, 15-21.

    () 29 Indian J. Radio Space Phys. : 15 -21.

  • Chukwuma V U 2001: Acta Geod. Geoph. Hung., 36, 125-131.

    () 36 Acta Geod. Geoph. Hung. : 125 -131.

  • Chukwuma V U, Olatunji E O 1997: J. Sci. Res. Dev., 3, 213-218.

    () 3 J. Sci. Res. Dev. : 213 -218.

  • Forbes J M 2000: J. Atmos. Sol. Terr. Phys., 62, 685-693.

    () 62 J. Atmos. Sol. Terr. Phys. : 685 -693.

  • Piggott W R 1959: Radio Research Special. Report No. 27. H. M. Stationary Office, 1-37.

    Radio Research Special. Report No. 27 , () 1 -37.

  • Berger C, Barlier F, Ill M 1988: Phys. Scri., 37, 427-431.

    () 37 Phys. Scri. : 427 -431.

  • Beynon W J G, Williams E R 1974: J. Atmos. Terr. Phys., 36, 699-707.

    () 36 J. Atmos. Terr. Phys. : 699 -707.

  • Chandra S, Spencer N W 1976: J. Geophys. Res., 81 (28), 5018-5026.

    () 81 J. Geophys. Res. : 5018 -5026.

  • Chapman S 1968: In Solar Plasma Geomagnetism and Aurora, Gordon and Breach, New York, 95-108.

    In Solar Plasma Geomagnetism and Aurora , () 95 -108.

  • Whitehead J D 1956: J. Atmos. Terr. Phys., 9, 276-281.

    () 9 J. Atmos. Terr. Phys. : 276 -281.

  • Vats H O 1992: In: Geomagnetic Studies at Low Latitudes, Geological Society of India, Bangalore, India, 1992, 365-373.

    Geomagnetic Studies at Low Latitudes , () 365 -373.

  • Schwentek H 1966: Ann. Geophys., 22, 276-285.

    () 22 Ann. Geophys. : 276 -285.

  • Schwentek H 1976: In: Report UAG 57, World data Centre A, Boulder Colorado, USA, 122-146.

    Report UAG 57, World data Centre A , () 122 -146.

  • Schwentek H 1988: Private Communication