By IANS,
Washington : Solar storm particles are relentlessly bombarding the earth, through two gaping breaches in the earth’s magnetic field, which shields it from such particles, according to researchers.
“The discovery overturns a long-standing belief about how and when most of the solar particles penetrate earth’s magnetic field, and could be used to predict when solar storms will be severe. Based on these results, we expect more severe storms during the upcoming solar cycle,” said Vassilis Angelopoulos.
Angelopoulos of University of California, Los Angeles (UCLA) is the principal investigator for NASA’s THEMIS mission (Time History of Events and Macroscale Interactions during Substorms). THEMIS helped discover the size of the leak.
As solar particles (ions and electrons) are electrically charged, most of them are deflected by the planet’s magnetic field. However, the number of particles breaching this shield when it develops leaks depends on the orientation of the sun’s magnetic field.
It had been thought that when the sun’s magnetic field is aligned with that of the earth, the door is shut and that few if any solar particles enter earth’s magnetic shield, said an UCLA release.
Surprisingly, recent observations by THEMIS spacecraft fleet demonstrate that the opposite is true. “Twenty times more solar particles cross the earth’s leaky magnetic shield when the sun’s magnetic field is aligned with that of the earth compared to when the two magnetic fields are oppositely directed,” said Marit Oieroset of University of California, Berkeley, co-author of a paper on this study, published in May 2008.
Researchers have long suspected that this “closed door” entry mechanism might exist, but didn’t know how important it was. “It’s as if people knew there was a crack in a levee, but they did not know how much flooding it caused,” said Oieroset.
These findings were published in Geophysical Research Letters.