Solar wind connects to the Earth's magnetosphere

Sep 11, 2009 22:41 GMT  ·  By
The rate at which the solar wind transfers energy to the magnetosphere can vary widely, but what determines the rate of energy transfer is unclear
   The rate at which the solar wind transfers energy to the magnetosphere can vary widely, but what determines the rate of energy transfer is unclear

Experts at the University of California in Los Angeles (UCLA) have recently uncovered a previously unknown mode of energy transfer in the planet's upper atmosphere, between solar winds and the Earth's magnetosphere shield. According to the team, the find may have vast implications in the field of designing and constructing safer spacecraft, for operations at high altitudes, at the limits between the atmosphere and outer space.

“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,” UCLA Professor of Atmospheric and Oceanic Sciences Larry Lyons explains. He is also a co-author of two new papers detailing the finds, published as companion papers in the respected Journal of Geophysical Research. Solar winds and radiation are the two main things emanating from the Sun. The winds are made up of streams of ionized particles, which create a highly magnetized region known as the magnetosphere as they approach the Earth.

The magnetosphere is, arguably, the biggest asset this planet has, in that it is the only thing standing between us and deadly cosmic radiation. These emissions are kept at bay by the action of this atmospheric layer, which takes up much of their energy, and converts dangerous and highly energetic particles into their basic, more harmless components, such as muons. These elementary particles then rain down on and through the ground, but have little to no adverse effects on simple or complex life.

Astronomers and physicists have known for a long time that the rate at which the solar wind transfers energy to the magnetosphere varies considerably at a given time, but exactly what the mechanisms behind this phenomenon were remained a mystery until recently. “We thought it was known, but we came up with a major surprise. This is where everything gets started. Any important variations in the magnetosphere occur because there is a transfer of energy from the solar wind to the particles in the magnetosphere. The first critical step is to understand how the energy gets transferred from the solar wind to the magnetosphere,” Lyons says.

“So rather than the picture of the connection between the magnetic field of the sun and the Earth controlling the transfer of energy by the solar wind to the Earth's magnetosphere, something else is happening that is equally interesting. The next question is discovering what that is. We have some ideas of what that may be, which we will test,” he concludes.