South Atlantic Anomaly: 2015 through 2025

  • Released Monday, August 17, 2020
  • ID: 4840

The bulk of Earth’s magnetic field originates deep within its core, at the boundary between the molten outer core and the solid mantle. The magnetic field extends past the surface into space and acts like a protective shield around the planet, repelling and trapping charged particles from the Sun. But over South America and the southern Atlantic ocean, an unusually weak spot in the field, called the South Atlantic Anomaly (SAA), allows these particles to dip much closer to the surface. Particle radiation in the SAA can knock out onboard computers and interfere with the data collection of satellites that pass through it.

The SAA creates no visible impacts on daily life on the surface, and its weakening magnetic intensity is still within the bounds of what scientists consider normal variation. However, recent observations and forecasts show that the region is expanding westward and continuing to weaken in intensity. Observational data from 2015-2020 found that the SAA has recently started to split from a single valley, or region of minimum field strength, into two cells; and models out to the year 2025 show the split continuing in the future, creating additional challenges for satellite missions.

NASA’s geomagnetic and geophysical research groups are using observations and models to monitor and predict future changes in the SAA and the rest of Earth’s geomagnetic field – helping prepare for future challenges to satellites and humans in space.
Geomagnetic intensity color bar with colors range from purple to gray to orange labeled low to high instead of using nanoteslas

Geomagnetic intensity color bar with colors range from purple to gray to orange labeled low to high instead of using nanoteslas

Geomagnetic intensity color bar for the Earth's surface. Colors range from purple to gray to orange with a data range of 27300 to 82500 nanoteslas (nT)

Geomagnetic intensity color bar for the Earth's surface. Colors range from purple to gray to orange with a data range of 27300 to 82500 nanoteslas (nT)

Geomagnetic intensity color bar for the core-mantle boundary. Colors range from purple to gray to orange with a data range of 0 to 1000000 nanoteslas (nT)

Geomagnetic intensity color bar for the core-mantle boundary. Colors range from purple to gray to orange with a data range of 0 to 1000000 nanoteslas (nT)

Isoline bars that are mapped with the colorbar

Isoline bars that are mapped with the colorbar



Credits

Please give credit for this item to:
NASA's Scientific Visualization Studio


Datasets used in this visualization

Terra and Aqua BMNG (A.K.A. Blue Marble: Next Generation) (Collected with the MODIS sensor)

Credit: The Blue Marble data is courtesy of Reto Stockli (NASA/GSFC).

Dataset can be found at: http://earthobservatory.nasa.gov/Newsroom/BlueMarble/

See more visualizations using this data set
CM6 geomagnetic field model and GEMS assimilation system
ModelNASA/GSFC2015-2025

2015-2019: global geomagnetic field made by CM6 from satellite and observatory magnetic data; 2020-2025: geomagnetic forecasts made by GEMS (Geomagnetic Ensemble Modeling System)

See more visualizations using this data set
GTOPO30 Topography and Bathymetry
Data CompilationUSGS

Note: While we identify the data sets used in these visualizations, we do not store any further details nor the data sets themselves on our site.



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