Research groups of heliophysics, geophysics, and geomagnetic NASA scientists are tracking the evolving dent in the Earth's magnetic field that might cause huge problems for satellites.
The Earth's magnetic field serves as its shield from the harmful radiation particles from the Sun. However, the scientists found a dent over South America and the southern Atlantic Ocean. They named it the South Atlantic Anomaly (SAA).
NASA has been tracking and studying this area as it allows radiation particles to dip closer to the Earth's surface and could knock out the computers onboard the low orbit satellite passing through that area, interfering with their data collection.
Additionally, they are also interested if the SAA might cause changes to the magnetic field strength on the surface, how could these changes affect the Earth's atmosphere, and as an indicator of what is happening to the magnetic field deep within the planet.
As of now, there are no visible impacts by the SAA recorded daily. Recent observations suggest that it is slowly expanding westward and weakening. They also observed that it is splitting into two lobes, which creates another problem for satellite missions.
What's happening inside the Earth?
SAA arises from the Earth's tilt of the magnetic axis and the flow of molten metals in its core. The core magnetic field originates from the Earth's outer core, wherein the churning metals act as a massive generator, called the geodynamo, which creates electric currents that produce the unstable magnetic field of the planet.
Due to the complex geodynamo in the core and within its boundary with the mantle, the core motion changes over time, and the magnetic field also fluctuate in space and time. These processes ripple outward to the magnetic field surrounding and protecting the Earth that generates the SAA, and the tilt and drift of the magnetic poles that are moving over time.
In short, the dynamic geoprocesses in the core and the tilt of the magnetic axis produce the SAA. It allows the Sun's radiation particles through solar wind and vast clouds of hot plasma to be trapped in the Earth's magnetic field to dip closer into the surface.
Geophysicist and mathematician Weijia Kuang from the Goddard's Geodesy and Geophysics Laboratory said that SAA could also be interpreted as the weakening dominance of the dipole field.
Hazardous for Low-Earth Orbits
Although SAA happens due to the geoprocess within Earth, its effects reach far beyond its surface, affecting those low-Earth orbit satellites that pass through it. If the satellite is hit with high radiation levels, it can cause a single event upset (SEU) that causes the systems to glitch temporarily, or if it hits a key component, it could create permanent damage.
Satellites usually shut down non-essential components to avoid losing instruments as they pass through the SAA. NASA's Ionosphere Connection Explorer keeps a tab on SAA's location as it regularly passes through the area.
Moreover, the ISS also passes through the SAA. The low-Earth orbit satellite carries the Global Ecosystem Dynamics Investigation (GEDI) mission, which collects data from outside of the ISS and could be affected by the high radiation in the SAA region.
The scientists also measured the particle radiation in SAA and found that it is slowly moving northwesterly. The results confirmed the models generated from the geomagnetic measurements, showing how SAA's location changes over time as the geomagnetic field develops.
It also provided the scientists with a clear picture of the amount of radiation that satellites receive as they pass through radiation, which emphasizes the need for further and continuing and monitoring of SAA.
Check out more news and information on Space on Science Times.
