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Earth Planets Space, Vol. 64 (No. 6), pp. 425-432, 2012
doi:10.5047/eps.2011.10.013

Annual and semi-annual Sq variations at 96° MM MAGDAS I and II stations in Africa

R. El Hawary1,2, K. Yumoto3,4, Y. Yamazaki4, A. Mahrous1,2, E. Ghamry2,5, A. Meloni6, K. Badi7, G. Kianji8, C. B. S. Uiso9, N. Mwiinga10, L. Joao11, Thomas Affluo12, P. R. Sutcliffe13, G. Mengistu14, P. Baki15, S. Abe3, A. Ikeda4, A. Fujimoto4, and T. Tokunaga4

1Department of Physics, Helwan University, 11795 HU Cairo, Egypt
2Space Weather Monitoring Center, Helwan University, 11795 HU Cairo, Egypt
3Space Environment Research Center, Kyushu University, Fukuoka, Japan
4Department of Earth and Planetary Science, Kyushu University, Fukuoka, Japan
5National Research Institute of Astronomy and Geophysics, 11421, Helwan, Egypt
6Director of research INGV, Italy, 00143 Roma, Italy
7Department of Engineering, Sudan University of Science and Technology, 407 Khartoum, Sudan
8Department of Physics, Nairobi University, Kenya
9Department of Physics, University of Dar Es Salaam, Tanzania, 35063 Dar Es Salaam, Tanzania
10Department of Physics, University of Zambia, 32379 Lusaka, Zambia
11Department of Physics, Eduardo Mondlane University, Mozambique, 257 Maputo, Mozambique
12Department of Electronic Engineering, University of Kwazulu-Natal, South Africa, private bag X54001, Durban 4000, South Africa
13Hermanus Magnetic Observatory, South Africa, 32 Hermanus, 7200, South Africa
14Department of Physics, Addis Ababa University Ethiopia, 1176 Addis Ababa, Ethiopia
15Department of Physics, University of Nairobi, Kenya, P.O Box 30197, 00100 Nairobi, Kenya

(Received April 13, 2010; Revised August 12, 2011; Accepted October 8, 2011; Online published July 27, 2012)

Abstract: The quiet daily variations of the geomagnetic field (Sq) have been studied by using the geomagnetic data of the 10 International Quietest Days. Geomagnetic data from MAGDAS I and II stations—ten stations were selected around the 96° magnetic meridian (MM)—over Africa have been analyzed from September 2008 to August 2009. The analysis of this unique data set clarifies the characteristics of the Sq variations over the African sector for the first time by observational geomagnetic data. In this paper, we found that Sq(H) and Sq(D) show a predominantly annual variation. The most interesting result, and a new finding in the African sector, is the appearance of two vortices in the day lit southern hemisphere during spring. Further data analysis also revealed many other interesting characteristics for the Sq over the African sector.
Key words: Sq, northward current, ionospheric currents, ground-based magnetometers.


Corresponding author E-mail: z4rf@yahoo.com


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