
%0 Journal Article
%A Hopgood, P.A. 
%T On the determination of K-indices by computer
%J Exploration Geophysics
%D 1986/03/01
%V 17
%N 1
%P 6-7
%K 
%R https://doi.org/10.1071/EG986006
%U https://www.publish.csiro.au/paper/EG986006 
%X At a magnetic observatory, a 'K-index' is assigned to each 3 h interval of recording to be a measure of whether conditions were quiet or active during this time. A K-index measures the maximum amplitude or disturbance variations, independent of the regular daily (or solar diurnal) variation. The numbers used for K-indices are the digits from 0 to 9, with higher numbers corresponding to greater magnetic activity. The K-index scale is quasi-logarithmic, and may be thought of as being like the magnitude scale for earthquakes in seismology. Thus K = 0 means very quiet magnetic conditions and K = 9 means a very strong magnetic storm. More information on K-index scales is given in Parkinson (1983). 
