A recurrent neural network approach to quantitatively studying solar wind effects on TEC derived from GPS; preliminary results

Habarulema, John Bosco and McKinnell, Lee-Anne and Opperman, B. D. L. (2009) A recurrent neural network approach to quantitatively studying solar wind effects on TEC derived from GPS; preliminary results. Annales Geophysicae, 27 (5). pp. 2111-2125. ISSN 0992-7689

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Abstract

This paper attempts to describe the search for the parameter(s) to represent solar wind effects in Global Positioning System total electron content (GPS TEC) modelling using the technique of neural networks (NNs). A study is carried out by including solar wind velocity (Vsw), proton number density (Np) and the Bz component of the interplanetary magnetic field (IMF Bz) obtained from the Advanced Composition Explorer (ACE) satellite as separate inputs to the NN each along with day number of the year (DN), hour (HR), a 4-month running mean of the daily sunspot number (R4) and the running mean of the previous eight 3-hourly magnetic A index values (A8). Hourly GPS TEC values derived from a dual frequency receiver located at Sutherland (32.38° S, 20.81° E), South Africa for 8 years (2000–2007) have been used to train the Elman neural network (ENN) and the result has been used to predict TEC variations for a GPS station located at Cape Town (33.95° S, 18.47° E). Quantitative results indicate that each of the parameters considered may have some degree of influence on GPS TEC at certain periods although a decrease in prediction accuracy is also observed for some parameters for different days and seasons. It is also evident that there is still a difficulty in predicting TEC values during disturbed conditions. The improvements and degradation in prediction accuracies are both close to the benchmark values which lends weight to the belief that diurnal, seasonal, solar and magnetic variabilities may be the major determinants of TEC variability.

Item Type:Article
Additional Information:Annales Geophysicae (ANGEO) is the official open access journal of the European Geosciences Union (EGU) in the field of Solar Terrestrial Physics. Annales Geophysicae is an international, multi- and inter-disciplinary scientific journal for the publication of original articles and of short communications (Letters) for the sciences of the Sun-Earth system, including the science of Space Weather, the Solar-Terrestrial plasma physics, and the Earth's atmosphere
Uncontrolled Keywords:Ionosphere (Mid-latitude ionosphere; Modeling and forecasting; Instruments and techniques)
Subjects:Q Science > QC Physics
Divisions:Faculty > Faculty of Science > Physics & Electronics
ID Code:1746
Deposited By: Mrs Eileen Shepherd
Deposited On:07 Aug 2010 14:11
Last Modified:01 Aug 2012 10:01
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