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From Science Daily:
A constant stream of particles and electromagnetic waves streams from the sun toward Earth, which is surrounded by a protective bubble called the magnetosphere. A scientist at NASA Goddard has recently devised, for the first time, a set of equations that can help describe waves in the solar wind known as Alfven waves. (Credit: European Space Agency)
Feb. 21, 2013 — Many areas of scientific research — Earth’s weather, ocean currents, the outpouring of magnetic energy from the sun — require mapping out the large scale features of a complex system and its intricate details simultaneously.
Describing such systems accurately, relies on numerous kinds of input, beginning with observations of the system, incorporating mathematical equations to approximate those observations, running computer simulations to attempt to replicate observations, and cycling back through all the steps to refine and improve the models until they jibe with what’s seen. Ultimately, the models successfully help scientists describe, and even predict, how the system works.
Understanding the sun and how the material and energy it sends out affects the solar system is crucial, since it creates a dynamic space weather system that can disrupt human technology in space such as communications and global positioning system (GPS) satellites.
However, the sun and its prodigious stream of solar particles, called the solar wind, can be particularly tricky to model since as the material streams to the outer reaches of the solar system it carries along its own magnetic fields. The magnetic forces add an extra set of laws to incorporate when trying to determine what’s governing the movement. Indeed, until now, equations for certain aspects of the solar wind have never been successfully devised to correlate to the observations seen by instruments in space. Now, for the first time, a scientist at NASA’s Goddard Space Flight Center in Greenbelt, Md., has created a set of the necessary equations, published in Physical Review Letters on Dec. 4, 2012.
“Since the 1970s, scientists have known that movement in the solar wind often has the characteristics of a kind of wave called an Alfvén wave,” says Aaron Roberts, a space scientist at Goddard. “Imagine you have a jump rope and you wiggle one end so that it sends waves down the rope. Alfvén waves are similar, but the moving rope is a magnetic field line itself.”
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h/t to oldbrew on Suggestions 3
2013-02-22 15:16:08
Source: http://tallbloke.wordpress.com/2013/02/22/nasa-deciphering-the-mysterious-math-of-the-solar-wind/