7932490
submission
elyons writes:
Another neat discovery from the lab of Larry Lyons at UCLA. As reported earlier on Slashdot, Lyons' group studies the dynamics of auroras. Their most recent discovery reveals for the first time the sequence of events leading to dramatic space-weather disturbances. Using a network of cameras deployed around the Arctic in support of NASA's THEMIS mission, they recorded over 200 instances of aurora's colliding, causing brillant displays of northern lights (See time 8:22 for such an example).
5858667
submission
elyons writes:
UCLA atmospheric scientists have discovered a previously unknown basic mode of energy transfer from the solar wind to the Earth's magnetosphere. The sun, in addition to emitting radiation, emits a stream of ionized particles called the solar wind that affects the Earth and other planets in the solar system. The solar wind, which carries the particles from the sun's magnetic field, known as the interplanetary magnetic field, takes about three or four days to reach the Earth. When the charged electrical particles approach the Earth, they carve out a highly magnetized region — the magnetosphere — which surrounds and protects the Earth. Charged particles carry currents, which cause significant modifications in the Earth's magnetosphere. This region is where communications spacecraft operate and where the energy releases in space known as substorms wreak havoc on satellites, power grids and communications systems.
"It's like something else is heating the atmosphere besides the sun. This discovery is like finding it got hotter when the sun went down," said Larry Lyons, UCLA professor of atmospheric and oceanic sciences. "We all have thought for our entire careers — I learned it as a graduate student — that this energy transfer rate is primarily controlled by the direction of the interplanetary magnetic field. The closer to southward-pointing the magnetic field is, the stronger the energy transfer rate is, and the stronger the magnetic field is in that direction. If it is both southward and big, the energy transfer rate is even bigger."
