South atlantic anomaly7/6/2023 ![]() The Earth’s magnetic field protects our atmosphere from solar wind, which is a stream of charged particles coming from the sun. The area is one of debate between scientists, some of whom question where it comes from, and if it could signal the total weakening of the field, and even an upcoming pole reversal. ![]() The perplexing behavior in the South Atlantic region causes technical disturbances in satellites and spacecraft orbiting Earth, which has left experts puzzled. The study was detailed in the May online edition of thejournal Nature Geoscience.Earth's roaming magnetic poles create longer periods of instability, study says Mandea and Olsen hope to continue refining their model withupdated observations, and perhaps to eventually help predict future changes inthe Earth's magnetic field. The Earth's overall magnetic field has weakened at least 10percent over the past 150 years, which could also point to an upcoming fieldreversal. Astronauts on the International Space Station retreated to aprotected area as a precaution to avoid unnecessary radiation exposure. The constant radiation bombardment from the sun blows withthe solar wind to Earth, where it flows against and around the magnetic field.The effect creates the tear-drop shaped magnetosphere bubble, but even thepowerful field cannot keep out all the high-energy particles.Ī large sunspot set off a majorradiation storm in 2006 that temporarily blinded some sun-watchingsatellites. "If there are magnetic storms and high-energyparticles coming from the sun, the satellites could be affected and theirconnections could be lost." "For satellites, this could be a problem," Mandeatold. Radiationstorms from the sun could fry electronicequipment on satellites that suddenly lacked the protective cover of arapidly changing magnetic field. However, the rapid weakening of the magnetic field in theSouth Atlantic Anomaly region could signalfuture troubles for such satellites. Mandea worked with Nils Olsen, a geophysicist at theUniversity of Copenhagen in Denmark, to create a model of the fluid core thatfits with the magnetic field changes detected by the satellites. ![]() Measuring interactions between the magnetic field and themolten iron core 1,864 miles (3,000 km) down has proven difficult in the past,but the constant observations of satellites such as CHAMP and Orsted have begunto bring the picture into focus. ![]() ![]() Some studies in recent years have suggested the nextreversal might be imminent, but the jury is out on that question. A flip in the north and south poles typically involves aweakening in the magnetic field, followed by a period of rapid recovery andreorganization of opposite polarity. The last major change in the field took place some 780,000years ago during a magnetic reversal, although such reversals seem to occurmore often on average. The field creates a tear-dropshaped bubble that has constantly shielded life on Earth against much of the high-energy radiation flowing from the sun. The Earth's magnetic field extends about 36,000 miles(58,000 km) into space, generated from the spinning effect of theelectrically-conductive core that acts something like a giant electromagnet. ![]()
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