NASA THEMIS satellites change solar storm theory

William Atkins
Saturday, 25 April 2009 18:52

Science - Space

Dr. Øieroset states, "Twenty times more solar particles cross the Earth’s leaky magnetic shield when the sun’s magnetic field is aligned with that of the Earth compared to when the two magnetic fields are oppositely directed.” [NASA]

The discovery by THEMIS researchers were reported on Friday, April 24, 2009, at the “General Assembly 2009” meeting of the European Geophysical Union (EGU) in Vienna, Austria.

These magnetic holes are produced in the magnetotail, the region of the magnetosphere on the side of the Earth that faces away from the Sun. The holes are produced when the magnetotail is stretched past its breaking point, which creates a huge and sudden release of energy.

This gigantic release of energy produces two spiraling vortices that turn opposite of each other.

These “plasma tornadoes” (as they are being called), or spiraling vortices, were measured by THEMIS as being about 70,000 kilometers (43,500 miles) in length and about the same width as the Earth, about 12,800 kilometers (8,000 miles).

They have speeds of over 1.6 million kilometers per hour (1 million miles per hour).

In addition, according to the Fox News article Electricity measured inside space tornadoes, “THEMIS found that space tornadoes can produce electrical currents greater than 100,000 amperes (for comparison, a 60-watt light bulb draws about half an ampere).”

Joachim Raeder (University of New Hampshire), who also has published journal articles with respect to THEMIS and solar storms, states. "If the solar field has been aligned with the Earth's for a while, we now know Earth's field is heavily loaded with solar particles and primed for a strong storm. This discovery gives us a basic predictive capability for the severity of solar storms, similar to a hurricane forecaster's realization that warmer oceans set the stage for more intense hurricanes. In fact, we expect stronger storms in the upcoming solar cycle. The sun's magnetic field changes direction every cycle, and due to its new orientation in the upcoming cycle, we expect the clouds of particles ejected from the sun will have a field which is at first aligned with Earth, then becomes opposite as the cloud passes by." [NASA]

For additional information, along with a video and pictures, check out the New Scientist article “Giant space tornadoes create Earth's auroras.”

More information about the THEMIS mission is found at THEMIS/Berkeley and THEMIS/NASA.