Time Variations of the Earth's Magnetic Field: From Daily to Secular
Abstract
A detailed study of the earth's magnetic field is presented. The historical background of the topic and the instruments used in it are briefly reviewed. Present knowledge of the external and internal contributions to geomagnetic variations in the period range from less than one day to several hundred years are then examined in detail. Emphasis is placed on recent progress in the period range where these two types of variations are now known to overlap, particularly on the solar-cycle effects and on secular variation impulses. The use of the variations to probe the electrical conductivity of the earth's crust and mantle and to infer motions in the convecting fluid core is examined.
- Publication:
-
Annual Review of Earth and Planetary Sciences
- Pub Date:
- 1988
- DOI:
- Bibcode:
- 1988AREPS..16..389C
- Keywords:
-
- Earth Ionosphere;
- Earth Magnetosphere;
- Geomagnetism;
- Magnetic Anomalies;
- Magnetic Variations;
- Solar Cycles;
- Diurnal Variations;
- Earth Crust;
- Earth Mantle;
- Secular Variations