Thirty-Year Period in Secular Variation of the Main Geomagnetic Field
Geophysics
2022-09-15 v1
Abstract
During the centennial period from 1900 to 2000, the globally averaged unsigned annual rate of the main geomagnetic field experienced a three-episode variation. The maximum annual rates occurred respectively around 1910-1920, 1940-1950, and 1970-1980, showing a 30-year period. In addition, the rising phase in each episode is much shorter than declining phase. The governing factor of this periodic variation is non-dipole field, instead of the dipole field, although the secular variation of the magnetic energy concerned with the dipole is dominative over all other multiples.
Keywords
Cite
@article{arxiv.2209.06486,
title = {Thirty-Year Period in Secular Variation of the Main Geomagnetic Field},
author = {Wen-Yao Xu and Henri-Claude Nataf and Zi-Gang Wei and Ai-Min Du},
journal= {arXiv preprint arXiv:2209.06486},
year = {2022}
}