![]() ![]() 2000), to propose that core flux expulsion occurred preferentially at the edge of the LLSVP. ( 2015) used such local intensity and directional timeseries, together with observation of a Large Low Shear Velocity Province (LLSVP) in the lowermost mantle below Africa coincident with a historical African RFP on the CMB (e.g. In contrast, based on archeological materials, it was argued that the SAA has influenced the surface geomagnetic field for several millennia in Africa (Tarduno et al. However, the centennial forecast of Aubert ( 2015) is too short to determine with confidence the long-term behavior of the SAA. ![]() it may suggest a transient feature of the geodynamo. Based on a data assimilation scheme, Aubert ( 2015) predicted that the SAA will drift in the near future to the Pacific, i.e. It is under debate whether the current SAA location represents a persistent boundary-driven feature of Earth’s magnetic field or it is chaotically variable. 1989 Olson and Amit 2006) though this relation is not trivial (Terra-Nova et al. ![]() The current location of the SAA center in Brazil is related to the location of reversed geomagnetic flux patches (RFPs) at the core–mantle boundary (CMB) (Bloxham et al. Understanding the past and present locations and mobility as well as the future trajectory of the SAA is both a fundamental scientific challenge-it involves understanding the working of the geodynamo and the impact of core–mantle coupling on core dynamics, as well as an important societal issue-it has major consequences for the operation and protection of surface instruments and spacecrafts, from global positioning systems to the Hubble Space Telescope, which cannot obtain observations over the SAA region. 1999 Heirtzler 2002 Lean 2005 Auvergne et al. This leads to penetration of solar energetic particles deep into Earth’s atmosphere, posing severe problems for airplanes and ships positioning systems as well as spacecraft electronic systems (Konradi et al. NASA's satellite the Ionospheric Connection Explorer regularly travels through the region so the team is forced to keep track of the anomaly's position and strength.The South Atlantic Anomaly (SAA) is a region at Earth’s surface where the intensity of the magnetic field is particularly low. The anomaly is caused by processes inside of the Earth where the magnetic field originates, in the outer core where molten metal, rich in iron, churns 1,800 miles (2,900 km) below the surface.Īt the moment, to avoid satellites being hit by a high-energy proton, which can cause it to short circuit - or potentially worse if a key component is hit - operators shut down non-essential components in their satellites as they fly through the area. "Because that's what helps us make models and predictions." "Even though the SAA is slow-moving, it is going through some change in morphology, so it's also important that we keep observing it by having continued missions," Dr Sabaka said. Terry Sabaka and Wijia Kuang, geophysicists at NASA, are observing using the European Space Agency's SWARM satellites to investigate how the South Atlantic Anomaly is changing. Image: The South Atlantic Anomaly is growing, according to ESA ![]()
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