太空气象情况不容忽视

A massive ejection of material from the sun initially traveling at over 7 million miles per hour that narrowly missed Earth last year is an event solar scientists hope will open the eyes of policymakers regarding the impacts and mitigation（减轻，缓和） of severe space weather, says a University of Colorado Boulder professor. The coronal mass ejection, or CME, event was likely more powerful than the famous Carrington storm of 1859, when the sun blasted Earth's atmosphere hard enough twice to light up the sky from the North Pole to Central America and allowed New Englanders to read their newspapers at night by aurora light, said CU-Boulder Professor Daniel Baker. Had it hit Earth, the July 2012 event likely would have created a technological disaster by short-circuiting satellites, power grids, ground communication equipment and even threatening the health of astronauts and aircraft crews, he said.

CMEs are part of solar storms and can send billions of tons of solar particles in the form of gas bubbles and magnetic fields off the sun's surface and into space. The storm events essentially peel Earth's magnetic field like an onion, allowing energetic solar wind particles to stream down the field lines to hit the atmosphere over the poles.

Fortunately, the 2012 solar explosion occurred on the far side of the rotating sun just a week after that area was pointed toward Earth, said Baker, a solar scientist and the director of CU-Boulder's Laboratory for Atmospheric and Space Physics. But NASA's STEREO-A, satellite that was flying ahead of Earth as the planet orbited the sun, captured the event, including the intensity of the solar wind, the interplanetary magnetic field and a rain of solar energetic particles into space.

"My space weather colleagues believe that until we have an event that slams Earth and causes complete mayhem, policymakers are not going to pay attention," he said. "The message we are trying to convey is that we made direct measurements of the 2012 event and saw the full consequences without going through a direct hit on our planet."

Baker will give a presentation on the subject at the 46th Annual Fall Meeting of the American Geophysical Union held in San Francisco Dec. 9 to Dec. 13.