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Published:
Jan 7, 2009Keywords:
Equatorial electrojet Numerical models Optimisation
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The copyright of a submitted article is only transferred to the publishers if and when the article is accepted for publication. All rights reserved. No part of this publication may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, electrostatic, mechanical, photocopying, recording or otherwise without the prior written permission of the publishers.
Main Article Content
On The Estimation of Parameters of Thick Current Shell Model of Equatorial Electrojet Using Optimisation Method
Abstract
Equatorial electrojet, an intense current flowing eastward in the low latitude ionosphere within the narrow region flanking the dip equator, is a major phenomenon of interest in geomagnetic field studies. For the first time the five parameters required to fully describe the Onwumechili\'s composite thick current shell model format of equatorial electrojet have been evaluated from a single autonomous set of ground data at solar minimum. The non-linear model was applied to four data points, each with a pair of simultaneously measured horizontal H and vertical Z variation field components. The resultant system of eight non-linear equations with five unknown model parameters
were subjected to non-linear least square optimisation method taking advantage of the
robust Levenberg-Madquart optimisation subroutine of licensed MATLAB 6.0 version. The thick current shell format model parameters estimated for Indian sector are shown to be within the appropriate limits and in excellent agreement with literature and physical expectation.
Keywords: Equatorial electrojet; Numerical models; Optimisation
Journal of Science & Technology (Ghana) Vol. 28 (3) 2008: pp. 1-9
