Abstract：
:A large number of high-accuracy vector measurements of the Earth's magnetic field have recently become available from the satellite Oersted, complementing previous vector data from the satellite Magsat, which operated in 1979/80. These data can be used to infer the morphology of the magnetic field at the surface of the fluid core, approximately 2,900 km below the Earth's surface. Here I apply a new methodology to these data to calculate maps of the magnetic field at the core surface which show intense flux spots in equatorial regions. The intensity of these features is unusually large--some have intensities comparable to high-latitude flux patches near the poles, previously identified as the major component of the dynamo field. The tendency for pairing of some of these spots to the north and south of the geographical equator suggests they might be associated with the tops of equatorially symmetric columnar structures in the fluid, or their antisymmetric equivalents. The drift of the equatorial features may represent material flow or could represent wave motion; discrimination of these two effects based on future data could provide new information on the strength of the hidden toroidal magnetic field of the Earth.
journal_name
Naturejournal_title
Natureauthors
Jackson Adoi
10.1038/nature01879keywords:
subject
Has Abstractpub_date
2003-08-14 00:00:00pages
760-3issue
6950eissn
0028-0836issn
1476-4687pii
nature01879journal_volume
424pub_type
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