Harmonic analysis of geomagnetic indices Km
Abstract
The daily revolution of the earth's dipole axis about the axis of rotation requires the existence of a universal time variation of geomagnetic activity due to the varying inclination of the dipole axis toward the sun. In agreement with this idea, a harmonic analysis of the 3-hour geomagnetic indices Km (Mayaud, 1968) yields a 24-hour universal wave for the solstices and a smaller 12-hour universal wave for the equinoxes. The phase at each season corresponds to the expected time of maximum of the wave within the limits of statistical error.
- Publication:
-
Annales de Geophysique
- Pub Date:
- December 1974
- Bibcode:
- 1974AnG....30..503M
- Keywords:
-
- Earth Rotation;
- Geomagnetism;
- Harmonic Analysis;
- Indexes (Ratios);
- Magnetic Dipoles;
- Annual Variations;
- Diurnal Variations;
- Earth Axis;
- Equinoxes;
- Solar Wind;
- Solstices;
- Vector Analysis;
- Geophysics