The discovery is featured in the March 29 issue of the journal Science. McWilliams, from the U of S Institute of Space and Atmospheric Studies (ISAS), is a contributor on the article with lead author Q.H. Zhang from the Polar Research Institute of China and collaborators from Norway, the U.S., and the United Kingdom.
Plasma is the same phase of matter that makes up the sun. Atmospheric plasma, including the "islands," is created when high-energy particles from the sun interact with the Earth's magnetic field and slam into the ionosphere, the electrically-charged layer of atmosphere about 300 kilometres up. There, they skitter across the planet at a kilometre a second, making a complete lap around the Earth in about three hours.
McWilliams explained the timing of the finding is particularly good, since the sun is entering the peak of its regular 11-year cycle of activity known as the solar maximum. This is expected to make for spectacular aurora displays in the high latitudes on Earth, but also has more serious implications.
"These islands are more common during very disturbed times, such as during magnetic storms driven by events on the sun," she explained. "These are times when you would most want accurate communications and navigation, particularly if the storm caused problems with infrastructure such as power grids."
The most famous Canadian example of this came in March, 1989 when a massive solar storm caused a power blackout over much of Quebec.
Solar storms routinely disrupt high-frequency radio waves used by airlines and in remote areas such as the Arctic where satellite communications are not possible. GPS systems are similarly vulnerable. Even hobbyists who race homing pigeons keep a wary eye on magnetic storms, as they can cause their prized birds to become confused and lost, McWilliams said.
Governments of countries around the world, particularly those from high latitudes, are beginning to recognize the hazard of solar storms, and are including it in their risk assessments. For example, the U.K. formally considers it along with threats such as disease, volcanic eruptions and war.
By its very nature, space science is a global endeavor, and McWilliams explained that Canada, and the U of S in particular, play a key role. ISAS is the home of the International SuperDARN Data Copy and Distribution Facility, the central point that gathers data from the world-wide network (Super Dual Aurora Radar Network) and distributes it to research partners around the world. Several SuperDARN radars in Canada are operated by ISAS as well.
McWilliams was brought in as a SuperDARN expert on the research team, providing analysis and interpretation of global-scale maps of plasma circulation in the high atmosphere.
"All international SuperDARN partners synchronize our radars so they operate together," McWilliams said. "They are programmed so they can all perform a full scan together, to within a fraction of a second. Every minute, 24-7, we get full scans from all radars in the north and in the south."
The article is called "Direct Observations of the Evolution of Polar Cap Ionization Patches," by Q.H. Zhang et al in the March 29, 2013 issue of Science.
For more information, contact:
Research Communications Specialist