Table of Contents
RETRACTED

This article has been retracted as it was found to contain a substantial amount of material from the article by Yermolaev, Y. I., and M. Y. Yermolaev (2008), Comment on β€œInterplanetary origin of intense geomagnetic storms (Dst < -100 nT) during solar cycle 23” by W. D. Gonzalez et al. Geophys. Res. Lett., 35, L01101, doi:10.1029/2007GL030281.

ISRN Astronomy and Astrophysics
Volume 2011 (2011), Article ID 961757, 13 pages
http://dx.doi.org/10.5402/2011/961757
Research Article

On the Geoeffectiveness Structure of Solar Wind-Magnetosphere Coupling Functions during Intense Storms

Space Weather Research Group, Department of Industrial Physics, College of Science & Engineering, Landmark University, PMB 1001, Omu Aran, Kwara State, Nigeria

Received 28 September 2011; Accepted 10 November 2011

Academic Editors: G. Chernov and M. Ding

Copyright © 2011 B. Olufemi Adebesin et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

The geoeffectiveness of some coupling functions for the Solar Wind-Magnetosphere Interaction had been studied. 58 storms with peak Dst < −100 nT were used. The result showed that the interplanetary magnetic field 𝐡 𝑧 appeared to be more relevant with the magnetic field 𝐡 (which agreed with previous results). However, both the 𝑉 (solar wind flow speed) and 𝐡 𝑧 factors in the interplanetary dawn-dusk electric field ( 𝑉 Γ— 𝐡 𝑧 ) are effective in the generation of very intense storms (peak Dst < −250 nT) while “intense” storms (−250 nT ≤ peak Dst < −100 nT) are mostly enhanced by the 𝐡 𝑧 factor alone (in most cases). The southward 𝐡 𝑧 duration 𝐡 𝑇 seems to be more relevant for Dst < −250 nT class of storms and invariably determines the recovery phase duration. Most of the storms were observed to occur at midnight hours (i.e., 2100–0400 UT), having a 41.2% incidence rate, with high frequency between 2300 UT and 0000 UT. 62% of the events were generated as a result of Magnetic Cloud (MC), while 38% were generated by complex ejecta. The 𝐡 - 𝐡 𝑧 relation for the magnetic cloud attained a correlation coefficient of 0.8922, while it is 0.7608 for the latter. Conclusively, 𝐡 𝑧 appears to be the most geoeffective factor, and geoeffectiveness should be a factor that depends on methods of event identification and classification as well as the direction of event correlation.