| dc.description.abstract | The dynamics of the ionosphere depends largely on solar activity. The attenuation of
radio signals as they propagate through the ionosphere can be determined through a
parameter called the Total Electron Content (TEC),which is a measure of the number
of electrons along a line of sight. The variability of TEC is critical around the dip
equatorial region especially within 15° North and South where we experience
anomalously enhanced TEC in the ionosphere. This study focused on the
characterization of the variability of TECover Malindi, Kenya (03.03°N, 40.13°E), and
the variability studies were carried out using inter-quartile range as the parameter,
with goal of coming up with a morphological description of TECthat would be useful
in the understanding of the space weather conditions over Kenya. The objectives of
the study were to obtain plots of TECagainst time for each day of the four months,
January, April, July and October, representing four seasons, of the years 1999, 2000,
2001 and 2002 and to characterize the variability of the TEC during the period of
study. The diurnal variability was greatest during the early morning and late evening
hours of the local time and minimum during the midday and midnight. The seasonal
variability was greatest during the March equinox, moderate during the summer
equinox and least during the solstices. There was observed enhanced night-time
variability just before midnight, which could be attributed to neutral winds. Of the
four years studied, 2000 and 2001 experienced the highest level of TEC variability
and a TECvariability level of between 12 and 30 TECU was thought to be significant
enough to depict the occurrence of scintillations. The research findings would be
useful to aviation industry, the marine industry, the communication service
providers and other technological systems whose operations may be affected by the
space weather conditions. | en_US |
