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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Non-monotonic growth and motion of the South Atlantic Anomaly

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Amit, Hagay [1] ; Terra-Nova, Filipe [2] ; Lezin, Maxime [1] ; Trindade, Ricardo I. [2]
Total Authors: 4
[1] Univ Nantes, CNRS, Lab Planetol & Geodynam, UMR 6112, 2 Rue Houssiniere, F-44000 Nantes - France
[2] Univ Sao Paulo, Dept Geofis, Inst Astron Geofis & Ciencias Atmosfer, Cidade Univ, Rua Matao 1226, BR-05508090 Sao Paulo - Brazil
Total Affiliations: 2
Document type: Journal article
Source: EARTH PLANETS AND SPACE; v. 73, n. 1 DEC 8 2021.
Web of Science Citations: 0

The South Atlantic Anomaly (SAA) is a region at Earth's surface where the intensity of the magnetic field is particularly low. Accurate characterization of the SAA is important for both fundamental understanding of core dynamics and the geodynamo as well as societal issues such as the erosion of instruments at surface observatories and onboard spacecrafts. Here, we propose new measures to better characterize the SAA area and center, accounting for surface intensity changes outside the SAA region and shape anisotropy. Applying our characterization to a geomagnetic field model covering the historical era, we find that the SAA area and center are more time dependent, including episodes of steady area, eastward drift and rapid southward drift. We interpret these special events in terms of the secular variation of relevant large-scale geomagnetic flux patches on the core-mantle boundary. Our characterization may be used as a constraint on Earth-like numerical dynamo models. (AU)

FAPESP's process: 18/07410-3 - Persistence of the South Atlantic Anomaly in geomagnetic observations, field models and numerical dynamos
Grantee:Filipe Terra Nova dos Santos
Support Opportunities: Scholarships in Brazil - Post-Doctoral