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fork(2) [soylentnews.org] writes:

      Science [sciencemag.org] reports:

For years, scientists have noticed rapidly varying electric fields inside dust storms and dust devils, the dirty whirlwinds that skitter across many desert areas. Some even wondered how those fields might alter the size of the storms, but no one had made any measurements. Now, first-of-their-kind field tests in the western Sahara reveal that the fields -- generated when windblown sand grains rub together -- loft desert dust much more effectively than previously recognized, creating larger and longer lasting storms than wind alone.

      When wind begins to blow across a sandy, dusty surface, the lightest particles aren't the first to move. That's because much of the dust is either stuck to larger particles or tucked between them. But when sand grains start to bounce across the surface, they strike other grains and shake loose the dust, which then rises into the air just above the ground. All that bouncing and jostling also generates static electricity -- the geological version of shuffling your feet across the carpet.

      When this happens, the larger sand grains typically lose electrons to the lighter dust particles, giving the dust a negative charge. The dust particles are blown higher into the air more readily, whereas the now positively charged sand grains usually remain closer to ground level. That separation of charges creates an electric field that may help electrify some of the dust still bound to sand grains, thus boosting even more of it into the air.

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