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IJRSP Vol.39 [2010] >
IJRSP Vol.39(4) [August 2010] >
| Title: | Diurnal and seasonal variation of fading rates of E- and F- region echoes during IGY and IQSY at the equatorial station of Ibadan |
| Authors: | Somoye, E O |
| Keywords: | Ionospheric irregularities
Radio echoes
Fading rate
Diurnal variation
Seasonal variation
Vertical drift
East-West drift |
| Issue Date: | Aug-2010 |
| Publisher: | CSIR |
| PACS No.: | 94.20.Vv; 94.20.dg; 94.20.dj |
| Abstract: |
Fading rates of E- and F-region echoes observed at Ibadan (7.4°N, 3.9°E, 6°S dip) during the
International Geophysical Year (IGY) 1958 and the International Quiet Year of
the Sun (IQSY) 1964 are investigated for diurnal and seasonal variations. The
fading rates of E- and F-region echoes are found to be of the same order of
magnitude during the IQSY. However, the same is not true during IGY indicating
that fading of F-region echoes is dependent on solar activity while that of
E-region echoes is not as fading rate of E-region echoes are about the same
during both epochs. The fading rate is found to be maximum at noon and minimum
at sunrise and sunset for E-region echoes during both epochs and for F-region
echoes during IQSY. During IGY, fading rate is maximum at noon; and minimum at
sunrise and 2000 hrs LT (i.e. post sunset) at both epochs and for the two
regions about same times of reversal of F-region East-West (EW) and E×B
vertical drift during solar maximum. The maximum at noon appears to be due to:
(i) continuous daytime rise in hmF2 which enhances irregularities and (ii)
spread F irregularities generated by sudden increase in E×B plasma uplift not
seen by the close-spaced antenna technique used in the present study. F-region
fading rate is maximum during December solstice while E-region fading rates
show no seasonal variation. |
| Page(s): | 194-202 |
| CC License: |  CC Attribution-Noncommercial-No Derivative Works 2.5 India |
| ISSN: | 0975-105X (Online); 0367-8393 (Print) |
| Source: | IJRSP Vol.39(4) [August 2010]
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