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Overview of Radiation Transport Physics and Space Environments
Published in John D. Cressler, H. Alan Mantooth, Extreme Environment Electronics, 2017
Another modification to the simple toroidal model results from the fact that Earth’s magnetic field is multipolar in nature, causing the magnetic field strength contours to sink toward the earth. This multipolar field causes the South Atlantic Anomaly (SAA)—a dip toward the Earth in proton and inner electron flux contours over the South Atlantic. For equal altitudes, the particle flux will be higher for locations in the SAA than for those outside of it.
Localised thermal convection in rotating spheres that undergo weak precession
Published in Geophysical & Astrophysical Fluid Dynamics, 2021
Kameng Lam, Dali Kong, Keke Zhang
The localised convective wave with its localised heat flux represents an unusual nonlinear phenomenon in rotating spherical convection. This is because the problem is characterised by the uniform velocity and temperature boundary condition, by a spherically symmetric buoyancy force and by an azimuthally periodic Poincaré force. Consequently, the localisation of the convective wave and the corresponding localised heat flux is solely caused by the nonlinear interaction of various waves. This is the first time that localised convective waves with localised convective heat flux have been found in the problem of non-magnetic convection in rapidly rotating fluid spheres. It may be speculated that localised heat flux (and radial flow) in the Earth's core convection affected by the Earth's precession might be associated with hot spots and plumes at the core-mantle boundary or with the localised up-welling radial flow near the core-mantle boundary responsible for the unusual localised morphology of the observed geomagnetic field such as the South Atlantic Anomaly (Gubbins and Bloxham 1987). However, the real dynamics of the Earth's liquid core, where the magnetic Lorentz force certainly plays a vital role, would be highly complicated: how the localised convective flow is affected by the Lorentz force remains to be an open question.