The Van Allen radiation belts and the point of the South Atlantic Anomaly.

The South Atlantic Anomaly (or SAA) is the region where Earth's inner van Allen radiation belt makes its closest approach to the planet's surface. The result is that, for a given altitude, the radiation intensity is higher over this region than elsewhere. The SAA is produced by a "dip" in the Earth's magnetic field at that location, caused by the fact that the center of Earth's magnetic field is offset from its geographic center by 450 kilometers (280 miles). Some believe that the anomaly is a side effect of Geomagnetic reversal. Image File history File links This is a lossless scalable vector image. ... Image File history File links This is a lossless scalable vector image. ... Adjectives: Terrestrial, Terran, Telluric, Tellurian, Earthly Atmosphere Surface pressure: 101. ... Van Allen radiation belts The Van Allen Radiation Belt is a torus of energetic charged particles (plasma) around Earth, held in place by Earths magnetic field. ... The magnetosphere shields the surface of the Earth from the charged particles of the solar wind. ... This template is misplaced. ... Recent geomagnetic reversals. ...

The South Atlantic Anomaly is of great significance to satellites and other spacecraft that orbit at several hundred kilometers altitude and at orbital inclinations between 35° and 60°; these orbits take satellites through the Anomaly periodically, exposing them to several minutes of strong radiation each time. The International Space Station, orbiting with an inclination of 51.6°, required extra shielding to deal with this problem. The Hubble Space Telescope does not take observations while passing through the SAA. An Earth observation satellite, ERS 2 For other uses, see Satellite (disambiguation). ... The Space Shuttle Discovery as seen from the International Space Station. ... Two bodies with a slight difference in mass orbiting around a common barycenter. ... International Space Station insignia ISS Statistics Crew: 3 As of June 20, 2007 Perigee: 319. ... The Hubble Space Telescope (HST) is a telescope in orbit around the Earth, named after astronomer Edwin Hubble. ...

An illustration of the SAA^[1] is shown in the image below. The figures show the maps of proton flux (number of protons registered by solid state detector with geometry factor 9.5×10^-3 cm² sr every second) at 850 km altitude. The maps are shown in geographic coordinates. In physics, the proton (Greek proton = first) is a subatomic particle with an electric charge of one positive fundamental unit (1. ...

This image depicts:

1. the outer radiation belt - two red bands in top and bottom boundaries of images,
2. SAA - inner radiation belt - large red spot in the right part of images,
3. near-equatorial protons - band of proton flux enhancement near geomagnetic equator.

The SAA drifts to the west at a speed of about 0.3 degrees per year, and is noticeable in the figures below. The drift rate of the SAA is very close to the rotation differential between the Earth's core and its surface, estimated to be between 0.3 and 0.5 degrees per year. Adjectives: Terrestrial, Terran, Telluric, Tellurian, Earthly Atmosphere Surface pressure: 101. ...

Image File history File links Download high resolution version (583x610, 87 KB) This image is a work of the National Oceanic and Atmospheric Administration, taken or made during the course of an employees official duties. ...

See also

• Operation Argus

Operation Argus was secretly conducted during August and September of 1958, in the South Atlantic (see: South Atlantic Anomaly), by the US Atomic Energy Commission, in conjunction with the Explorer IV mission. ...

References

1. ^ (for 1978 and 2005 years, NOAA satellites data