
%0 Journal Article
%A Hibberd, FH 
%T Day-to-Day Variability of the Sq Geomagnetic Field Variation
%J Australian Journal of Physics
%D 1981/02/01
%V 34
%N 1
%P 81-90
%K 
%R https://doi.org/10.1071/PH810081
%U https://www.publish.csiro.au/paper/PH810081 
%X Much apparent day-to-day variability in the H component of the Sq variation in low and middle latitudes is not due to a variability in ionospheric currents, but arises from contamination by often unrecognized disturbance field variations associated with distant agnetospheric currents. There appears to be little, if any, day-to-day variability in the shape, type or phase of the pure Sqvariation. There is, however, a substantial day-to-day variability in the daily range of Sq and this has a worldwide rather than a local cause. No conclusive evidence exists for motion of the Sq foci. In low and middle latitudes the Sq variation is essentially a daytime phenomenon. 
