The geomagnetic field is generated by convection motions of an electrically conducting fluid at Earth's outer core. The field is measured directly at Earth's surface by observatories and at space by dedicated satellites. For periods preceding direct magnetic measurements, analysis of archeological material provides vital information about the field. Though complete self-consistent 3D solutions to all relevant fields inside the core, i.e. velocity, magnetic field and temperature (or co-density) can be only obtained with numerical dynamo simulations. Here in this project we explore geomagnetic observation, field models and numerical dynamo simulations to study the persistence of the South Atlantic Anomaly, which is the region of weakest intensity field at Earth's surface presently located on inland Brazil. The anomaly persistent in Brazil can have several societal impacts. This region is less shielded by the Earth's magnetic field and thus bombarded by energetic particle that degrade electronics , optics, solar panels , and other critical systems by braking chemical bonds and disrupting crystalline structures. Our key questions are: the dynamical origin on the core of low field intensity registered in archeomagnetic field series, how old are the South Atlantic Anomaly, is it the South Atlantic Anomaly mantle controlled, how does the heterogeneous CMB heat flux prescribe preferential convection and weak surface field and how does the amplitude of tomographic heterogeneous CMB heat flux determine dynamo regimes (dipolar or reversing) and properties.
News published in Agência FAPESP Newsletter about the scholarship: