Quiet Time Correlation Between Geomagnetic Field Variations and the Dynamics of the East African Equatorial Ionosphere
International Journal of Astrophysics and Space Science
Volume 5, Issue 1, February 2017, Pages: 6-18
Received: Feb. 22, 2017; Accepted: Mar. 8, 2017; Published: Mar. 17, 2017
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Omondi George Erick, Department of Physics and Materials Science, Maseno University, Maseno, Kenya
Baki Paul, Department of Physics and Space Science, Technical University of Kenya, Nairobi, Kenya
Ndinya Boniface, Department of Physics, Masinde Muliro University of Science and Technology, Kakamega, Kenya
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The equatorial ionosphere is highly dynamic and consequently poses serious threats to communication and navigation systems. As a result, proper understanding of ionospheric dynamics is important. The present paper presents the results of an investigation of the correlation between quiet time vertical total electron content (VTEC) and solar quiet variation in the horizontal component of geomagnetic field (Sq(H)) from low solar activity year (2009) to the high solar activity year (2014) within the equatorial East African sector using statistical analysis method. Values of Sq(H) were observed to increase steadily from around 0700LT attaining maximum values around 1100-1200LT, then descending towards zero level and beyond. The magnitudes of (VTEC) increase uniformly from around 0600-1000LT, then gradually, attaining maximum values around 1300-1500LT. The time instants of occurrence of these peaks are mainly controlled by drifts and photo-ionization. The correlation coefficients (ccs) between (VTEC) and Sq(H) were found to be strongest during the ascending phase (0600-1200LT), ranging from 0.69 to 0.98 at Addis Ababa and 0.61 to 0.97 at Nairobi. During the descending phase (1300-1800LT), ccs range from -0.28 to 0.89 at Addis Ababa and-0.06 to 0.76 at Nairobi. A high level of significance (99.98%) of ccs was obtained. The good linear relationship is attributed to the independent increase of the eastward electric field and photo-ionization on (VTEC) while poor relationship is possibly due to domination of photo-ionization over equatorial ionization anomaly (EIA) development. The annual ccs between (VTEC) and Sq(H) exhibit a general dependence on solar activity at Addis Ababa, closer to the dip equator, rather than at Nairobi during the ascending phase of the daytime. This observation suggests that the EEJ changes linearly with change in solar activity, thus streamlining the variations in TEC, through drifts, and Sq(H) by intensifying the eastward equatorial electric field.
Equatorial Electrojet, Equatorial Ionization Anomaly, Solar Quiet, Total Electron Content, Correlation
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Omondi George Erick, Baki Paul, Ndinya Boniface, Quiet Time Correlation Between Geomagnetic Field Variations and the Dynamics of the East African Equatorial Ionosphere, International Journal of Astrophysics and Space Science. Vol. 5, No. 1, 2017, pp. 6-18. doi: 10.11648/j.ijass.20170501.12
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Abbas, M., Zaharadeen, Y. J., Joshua, B. and Mohammed, S. (2013). Geomagnetic Field Variations at Low Latitudes along 96 degrees Magnetic Meridian. International Journal of Marine, Atmospheric & Earth Sciences, 1 (2): 96-109.
Alken, P. and Maus, S. (2009). Electric fields in the equatorial ionosphere derived from CHAMP satellite magnetic field measurements. Journal of Atmospheric and Solar-Terrestrial Physics, http://dx.doi.org/10.1016/j.jastp.2009.02.006.
Anderson, A., Anghel, A., Yumoto, K., Ishitsuka, M. and Kudeki, E., (2002). Estimating daytime vertical drift velocities in the equatorial F-region using groundbased magnetometer observations. GeophysicalResearchLetters, 29 (12), 1596, http://dx.doi.org/10.1029/2001GL014562
Ayorinde, T. T., Rabiu, A. B., Amory-Mazaudier, C. (2016). Inter-hourly variability of total electron content during quiet condition over Nigeria, within the equatorial ionization anomaly region. Journal of Atmospheric and Solar-Terrestrial Physics, http://dx.doi.org/10.1016/j.jastp.2016.04.005.
Basu, S. and Gupta, A. D. (1967). Latitude Variation of Total Electron Content in the Equatorial Region. Journal of Geophysical Research, 72 (21), 5555-5558.
Baumjohann, W. and Treumann, R. A. (1996). Basic Space Plasma Physics. London: Imperial College Press.
Bolaji O. S., Adeniyi, J. O., Adimula, I. A., Radicella, S. M., Doherty P. H. (2013). Total electron content and magnetic field intensity over Ilorin, Nigeria. Journal of Atmospheric and Solar-Terrestrial Physics, 98, 1-11.
Campbell, W. (2003). Introduction to geomagnetic fields (2nd ed.). New York: Cambridge University Press.
Chakraborty, S. K. and Hajra, R., (2008). Solar control of ambient ionization of the ionosphere near the crest of the equatorial anomaly in the Indian zone. Annales Geophysicae, 26, 47–57.
El Hawary et al. (2012). Annual and semi-annual Sq variations at 96◦ MM MAGDAS I and II stations in Africa. Earth Planets Space, 64, 425–432.
Goodman, J. M. (2005). Space Weather and Telecommunications. Radio Propagation Services, Inc. (RPSI), Alexandria, VA 22308-1943 USA, ISBN 0-387-23670-8.
Gopi, S. (2014). Gopi Seemala Rinex GPS-TEC program version 2.9.2. Retrieved February 29, 2016, from http://seemala.blogspot.com
Kumar, S.(2016). Performance of IRI-2012 model during a deep solar minimum and maximum year over global equatorial regions. Journal of Geophysical Research: Space Physics, 121, doi: 10.1002/2015JA022269.
Lanyi, G. E. and Roth, T. (1988). A comparison of mapped and measured total ionospheric electron content using global positioning system and beacon satellite observations. Radio Science, 23 (4), 4 83-492.
Mala, S. B., Joshi, H. P., Iyer, K. N., Aggarwal, M., Ravindran, S. and Pathan, B. M., (2009). TEC variations during low solar activity period (2005–2007) near the equatorial ionospheric anomaly crest region in India. Annales Geophysicae, 27, 1049–1057.
Matsushita, S. and Maeda, H. (1965). On the Geomagnetic Solar Quiet Daily Variation Field during the IGY. Journal of Geophysical Research, 70 (11), 2535-2558.
Olwendo, O. J., Baki, P., Cilliers, P. J., Mito, C.& Doherty, P. (2012). Comparison of GPS TEC measurements with IRI-2007 TEC Comparison of GPS TEC measurements with IRI-2007 TEC phase of solar cycle 23. Advances in Space Research, 49, 914–921.
Oron, S., D'ujanga, F. M.& Ssenyonga, T. (2013). Ionospheric TEC variations during the ascending solar activity phase at an equatorial station, Uganda. Indian Journal Of Radio & Space Physics, 42, 7-17.
Rabiu, A. (2001). Seasonal variability of Solar quiet at middle latitudes. Ghana Journal of Science, 41, 15-22.
Rabiu, A. B., Mamukuyomi, A. I. and Joshua, E. O. (2007). Variability of equatorial ionosphere inferred from geomagnetic field measurements. Bull. Astr. Soc. India, 35, 607-618.
Rabiu, A. B., Yumoto, K., Falayi, E. O., Bello, O. R.& MAGDAS/CPMN Group. (2011). Ionosphere over Africa: Results from Geomagnetic Field Measurements During International Heliophysical Year IHY. Sun and Geosphere, 6 (2), 63 - 66.
Rastogi, R. G. and Iyer, K. N. (1976). Quiet day variation of geomagnetic H-field at low latitudes. Journal of Geomagnetism and Geoelectricity, 28, 461.
Rastogi, R. G., Kitamura, T. and Kitamura, K. (2004). Geomagnetic field variations at the equatorial electrojet station in Sri Lanka, Peredinia. Annales Geophysicae, 22, 2729-2739.
Sharma, K., Dabas, R. S. and Sudha, R. (2012). Study of total electron content variations over equatorial and low latitude ionosphere during extreme solar minimum. Astrophysics and Space Science, doi 10.1007/s10509-012-1133-3.
Stolle, C., Manoj, C., Luhr, H., Maus, S. and Alken, P., (2008). Estimating the daytime equatorial ionization anomaly strength from electric field proxies. Journal of Geophysical Research, 113, A09310, http://dx.doi.org/10.1029/2007JA012781.
Veenadhari, B. and Alex, S. (2006). Space weather effects on low latitude geomagnetic field and ionospheric plasma response. ILWS Workshop, February 19-24. GOA.
Viljanen, A., Pulkkinen, A., Pirjola, R., Pajunpa¨a¨, K., Posio, P. & Koistinen, A. (2006). Recordings of geomagnetically induced currents and a nowcasting service of the Finnish natural gas pipeline system. Space Weather, 4 (S10004), doi: 10.1029/2006SW000234.
World Data Center for Geomagnetism, Kyoto. (2016). Geomagnetic Data Service. Retrieved January 04, 2016, from http://wdc.kugi.Kyoto-u.ac.jp/cgi-bin/Kp-cgi
Yamazaki, Y. and Kosch, M. J. (2015). The equatorial electrojet during geomagnetic storms and substorms. Journal of Geophysical Research: Space Physics, 120, 2276-2287, doi: 10.1002/2014JA020773.
Yamazaki, Y., Yumoto, K., Cardinal, M. G., Fraser, B. J., Hattori, P., Kakinami, Y., Liu, J. Y, Lynn, K. J. W., Marshall, R., McNamara, D., Nagatsuma, T., Nikiforov, V. M., Otadoy, R. E, Ruhimat, M., Shevtsov, B. M., Shiokawa, K., Abe, S., Uozumi, T.&Yoshikawa, A. (2011). An empirical model of the quiet daily geomagnetic field variation. Journal of Geophysical Research, 116 (A10312), doi: 10.1029/2011JA016487
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