Zone of Low Magnetic Intensity Causes Concern for NASA
(David A. Phillip/AP)
By Brian Trusdell | Tuesday, 18 August 2020 06:13 PM
An oval-shaped area of lower magnetic intensity in the atmosphere between South America and Africa is causing concern to NASA over the potential danger it poses to satellites and spacecraft that pass through it, the website ScienceAlert.com reported.
The South Atlantic Anomaly, first identified in 1958, appears to be dividing into two different cells, one over South America and the other off the coast of South Africa.
The concern is due to the fact the weakened magnetic field results in the closest approach of the Van Allen radiation belts to the Earth's surface. That leaves what some scientists refer to a "pothole" or "dent" in which charged solar particles can sail through the Earth's atmosphere and wreak havoc on electronic components, causing them to short-circuit and malfunction.
"The observed SAA can be also interpreted as a consequence of weakening dominance of the dipole field in the region," according to geophysicist and mathematician Weijia Kuang at NASA's Goddard Space Flight Center in Greenbelt, Maryland.
"More specifically, a localized field with reversed polarity grows strongly in the SAA region, thus making the field intensity very weak, weaker than that of the surrounding regions."
The consequences are that man-made satellites, such as the International Space Station, must take precautions when their orbits take it through the zone. Some satellite operators must routine shut down their equipment to avoid significant data loss or even permanent damage to key components.
Studies have indicated not only is the zone splitting, it appears to be moving to the northwest.
"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," Goddard geophysicist Terry Sabaka said.
"Because that's what helps us make models and predictions."