Variability Of Plasma Bubble In The Equatorial Ionosphere At Midnight

There are various types of ionospheric irregularities. Among these is the plasma bubble occurrence. They are most prominent at night time in the equatorial ionosphere. Many of the bubbles drift with approximately the velocity of the background plasma, but it is possible to infer that most bubbles have moved upward at some time in their recent history through the ion composition signals obtained from the Atmospheric Explorer magnetic ion mass spectrometer. The variation of plasma bubble occurrence at midnight round the globe was investigated. The data used covers the period of January to December 1978 which was obtained by observations of the Atmosphere Explorer satellite which passes through the Ionosphere. The total number of satellite passes (trips) during the midnight (i.e. 0000LT) were taken, whether or not they contain bubbles and denote the total number of trips by Tt,, then a count of the number of passes (trips) with bubbles also at midnight (Tb) for each station were taken, and finally a count of the total number of bubbles (B) in all these passes. The regions were divided into three zones namely the Africa sector, the Afro-Asia sector and the Pacific region. The results obtained shows that the number of passes with bubbles (Tb) and the number of bubble occurrence (B) are proportional to each other. It was also observed that the plasma bubble occurrence varies from one region of the world to another at midnight. The highest activity of plasma bubble occurrence (B) was recorded in the African sector; and so also for the number of trips with bubbles (Tb). and followed by the Pacific region. This shows that the Africa sector that was close to the equator has the highest activity of plasma bubble occurrence. Keywords: plasma bubble, equatorial ionosphere, ion density, ionospheric irregularities, magnetic ions. Journal of Environmental Extension Vol. 7 2008: pp. 10-1

Variability In The F1 And F2 Region Electron Density During A Geomagnetic Activity At Mid – Latitude

This paper investigated the variation in the F1 and F2 region electron density during a geomagnetic activity at East Asian mid-latitude stations. In this analysis, D(foF1) and D(foF2) representing deviation of the critical frequency for the F1 and F2 ionospheric regions respectively were employed. The F1 region appears to be much more stable than the F2 layer during the stormy event, as there was no significant effect on the F1 layer in most of the ionospheric stations under investigation. It was also observed that independent of the sign of the storm effect on NmF2, the electron density, if any, in the F1 region is always negative. Moreover, no F1 ionospheric response was observed at midnight (0000UT) throughout the storm event in all the stations; but recorded its maximum effects between 0600UT-1800UT during the day. Conclusively, there is a considerable intra-hour variability of F2 electron density NmF2 during ionospheric disturbances. Keywords: Electron density, Geomagnetic storm, Critical frequency, Ionospheric response Journal of Environmental Extension Vol. 7 2008: pp. 48-5

Moderate storms: a class of rarely investigated geomagnetic storms

No Abstract.International Journal of Natural and Applied Sciences Vol. 3 (4) 2007: pp. 537-54

Geomagnetic Storm And Its Effects On The Ionospheric Environment: A Case Study

Study and prediction of magnetic storms are becoming increasingly important as they have profound influence on human and societal life. Intense solar flares release very high energy particles that can be as injurious to human as the low energy radiation from nuclear blasts. Ionospheric storms can affect radio communications at all latitudes – some radio frequencies are absorbed and others are reflected, leading to rapidly fluctuating signals and unexpected propagation paths. Other areas affected by geomagnetic storm include: · Disruption of defense communication such as early warning radio system · Erratic behaviour of air and marine navigation instrument · Current surges in power lines, causing flickering lights and blackouts that result in damage that attracts colossal amount of money. Seeing that our environment is vulnerable to magnetic storm this paper presents the interplanetary origin of an intense storm and the response of our ionosphere to it. Keywords: magnetic storms, solar flares, current surges, ionosphere Journal of Environmental Extension Vol. 7 2008: pp. 31-3