
TY  - JOUR
A1  - Hopgood, P.A. 
T1  - On the determination of K-indices by computer
JF  - Exploration Geophysics
JO  - Explor. Geophys.
Y1  - 1986
VL  - 17
IS  - 1
SP  - 6
EP  - 7
KW  - 
UR  - https://doi.org/10.1071/EG986006 
N2  - 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). 
ER  -

