A Giant Breach in Earth’s Magnetic Field

by Tony Marsden

I found this interesting article from NASA dated December 16, 2008. My comment(Is it possible this could be what is causing the upsurge in earthquake and volcanic activity)?

NASA’s five THEMIS spacecraft have discovered a breach in Earth’s magnetic field ten times larger than anything previously thought to exist. Solar wind can flow in through the opening to “load up” the magnetosphere for powerful geomagnetic storms.

But the breach itself is not the biggest surprise. Researchers are even more amazed at the strange and unexpected way it forms, overturning long-held ideas of space physics.

“At first I didn’t believe it,” says THEMIS project scientist David Sibeck of the Goddard Space Flight Center. “This finding fundamentally alters our understanding of the solar wind-magnetosphere interaction.”"

“”The opening was huge-four times wider than Earth itself,” says Wenhui Li, a space physicist at the University of New Hampshire who has been analyzing the data. Li’s colleague Jimmy Raeder, also of New Hampshire, says “1027 particles per second were flowing into the magnetosphere-that’s a 1 followed by 27 zeros.

This kind of influx is an order of magnitude greater than what we thought was possible.”

The event began with little warning when a gentle gust of solar wind delivered a bundle of magnetic fields from the Sun to Earth. Like an octopus wrapping its tentacles around a big clam, solar magnetic fields draped themselves around the magnetosphere and cracked it open.

The cracking was accomplished by means of a process called “magnetic reconnection.” High above Earth’s poles, solar and terrestrial magnetic fields linked up (reconnected) to form conduits for solar wind.

Conduits over the Arctic and Antarctic quickly expanded; within minutes they overlapped over Earth’s equator to create the biggest magnetic breach ever recorded by Earth-orbiting spacecraft.” “The size of the breach took researchers by surprise. “We’ve seen things like this
before,” says Raeder, “but never on such a large scale. The entire day-side of the magnetosphere was open to the solar wind.”

The circumstances were even more surprising. Space physicists have long believed that holes in Earth’s magnetosphere open only in response to solar magnetic fields that point south. The great breach of June 2007, however, opened in response to a solar magnetic field that pointed north.

“To the lay person, this may sound like a quibble, but to a space physicist, it is almost seismic,” says Sibeck. “When I tell my colleagues, most react with skepticism, as if I’m trying to convince them that the sun rises in the west.”"

“The years ahead could be especially lively. Raeder explains: “We’re entering Solar Cycle 24. For reasons not fully understood, CMEs in even-numbered solar cycles(like 24) tend to hit Earth with a leading edge that is magnetized north. Such a CME should open a breach and load the magnetosphere with plasma just before the
storm gets underway. It’s the perfect sequence for a really big event

Credit: Science@NASA

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