als49, 130064792

BSc Physics with Planetary and Space Physics

Institute of Mathematics, Physics and Computer Science

Aberystwyth University

Mapping the Sq Current System

aleh

Abstract

A comparison was undertaken of a model Sq current system developed using the Biot-Savart law

and one derived from a set of real magnetic data. A literature review is conducted on the history of

the research on magnetic field variations. A description of the general magnetic environment is

given along with an explanation of the science behind the ionosphere, current systems and the link

between these and magnetic field variations. Data from 13 northern hemisphere magnetometer

stations were used to identify the latitudinal dependence of the diurnal variations in the magnetic

field caused by the Sq current system. An estimate of the equivalent current system averaged for

the j-month data is given, as well as a quantitative estimate of the position of the focus of the

current whorl. A discussion is had of the possible reasons for discrepancies between the model the

data. The most significant of these is that the model uses simple mathematics and does not account

for external influences on the current system, which are discussed.