Abstract
The harmonic constituents of transient geomagnetic variations associated with the atmospheric tides M2 and O1 have frequencies which differ by an amount corresponding to only one cycle per year. Consequently, in subdivisions of data which do not cover a complete year, e. g. seasonal subdivisions, each such transient geomagnetic variation makes a contribution to the numerical estimate of the other. The necessary corrections required to adjust the results obtained for a typical seasonal subdivision are given here.
