Resolution No.13 (1967): The Kn, Ks and Km indices

The IAGA considering the proposal of the Working Group on Magnetic Indices of Commission IV concerning the characterisation of the magnetic activity in each hemisphere and on a worldwide scale by the new indices Kn, Ks and Km, recommends that the determination of these new indices be started on a trial basis with data beginning 1 January 1964, and urges the fullest possible collaboration on the part of the observatories whose K indices will be required for this determination.