On the Contribution of Global Scale Polar-originating Ionospheric Current Systems to Geomagnetic Disturbances in Middle and Low Latitudes
Tsunomura, S.
Abstract
 It is important to examine the characteristics of polar-originating ionospheric current systems for the study of geomagnetic disturbances in middle and low latitudes. The purpose of this paper is to quantitatively clarify the characteristics of polar-originating ionospheric current systems,which concern with geomagnetic disturbances observed in middle and low latitudes.
This paper is composed of two main parts. One is for numerical analyses for polar-originating ionospheric current systems including the equatorial enhancement of the ionospheric conductivity and the other is for investigations of the characteristics of geomagnetic sudden commencement (SC) in middle and low latitudes. The latter is aimed to clarify the contribution of the SC-associated polar-originating ionospheric current system for the magnetic variations in middle and low latitudes.