http://sanfrancisco.cbslocal.com/2014/07/08/massive-solar-x-ray-eruption-hits-earth-potentially-disrupts-gps-and-airplane-ship-communications-flare-m-class-space-weather-explosion/
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A solar flare is an explosion where twisted magnetic fields let loose their energy from the surface of the sun. These are often above sunspots large enough to swallow the entire Earth. The flares contain X-rays, gamma rays, and other electromagnetic radiation, capable of producing various effects on the skies and technology on earth.
http://www.livescience.com/46694-magnetic-field-weakens.html
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Earth's magnetic field acts like a giant invisible bubble that shields the planet from the dangerous cosmic radiation spewing from the sun in the form of solar winds. The field exists because Earth has a giant ball of iron at its core surrounded by an outer layer of molten metal. Changes in the core's temperature and Earth's rotation boil and swirl the liquid metal around in the outer core, creating magnetic field lines.
http://www.floridatoday.com/story/tech/science/satellites-planets/2014/07/10/bernie-badger-comes-sun/12493839/
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What is a flare? A solar flare is a sudden brightening of a small region on the sun. It is thought to be the result of the conversion of energy into heat when intense magnetic fields associated with sunspots collapse. The thin solar atmosphere is heated to such high temperatures that x-rays are produced. The detection of a strong flux of x-rays coming from the sun is the tell-tale sign of a flare.