标题：Classification of Days Using Locally GeneratedMagnetic Indices from Magnetic DataAcquisition System (Magdas) Ground BasedObservatories at Three (3) Nigerian Stations
期刊名称：Current Journal of Applied Science and Technology
印刷版ISSN：2457-1024
出版年度：2013
卷号：3
期号：4
页码：735-747
语种：English
出版社：Sciencedomain International
摘要：Investigation has been done concerning the mitigation of geomagnetic storm (a type of space weather that has the potential to cause damage across the globe with a single event) using locally generated magnetic Indices obtained from geomagnetic data from ground based Magdas magnetometers to classify the data into quiet and disturbed days thereby deducing the possible state of radio communications propagation over Nigeria. Physical mechanisms responsible for the characteristics of the ionosphere were identified. K (an index which measures the magnetic perturbations of the planetary field) and A (a linear measure of the Earth's field that provides a daily average level for geomagnetic activity) geomagnetic indices were generated locally using a simple algorithm and appropriate computer code, from MAGDAS magnetometers located at Abuja (9º 40’N, 7º 29’E), Ilorin (8º30’N, 4º33’E) and Lagos (6º27’N, 3º23’E) in Nigeria for the period 2006 – 2011 were used as the basis for the classification. Results showed that 31.85% of the days were found to be quiet while 39.36% of the days were found to be disturbed. The observed variations in the geomagnetic field responsible for the characteristics of the ionosphere over Nigeria comes probably from two principal sources, namely, transient variations - those generated by atmospheric processes such as ultraviolet radiation from the sun and partly by secular variations, which are due to internal disturbances within the Earth. Variations in the geomagnetic field are thus found to be responsible for the characteristics of the Ionosphere.
关键词：Geomagnetic indices;quiet and disturbed days;radio propagation andcommunications
