Bob Clauer's data analysis work has taken his team to the very edges of the planet.
Bob Clauer wants to understand how Earth's electromagnetic fields respond to solar activity. He explores the solar wind/magnetosphere interaction from the ground.
He describes the space environment as an electrodynamic system that involves plasma physics. "The solar wind interacts with Earth's magnetic field in a manner similar to a fluid, but an electrically conducting fluid."
A consequence of this interaction is that electric currents are generated and flow to the ionosphere. "It's a large, coupled system." Variations in the magnetic field and the energization of electrically charged particles are the items that comprise space weather.
The energy that is coupled to the magnetosphere from the solar wind and dissipated through electric currents in the upper atmosphere and the precipitation of energetic particles into the upper atmosphere (producing the aurora) — adds up to about 1012 W. "That's the same energy as a typical hurricane, but spread over a much larger area."
"It seems that if you drive the magnetosphere strongly, it goes into a periodic oscillation. Why does it do that"
Scientists and engineers study the space environment using magnetometers to look at electric currents, radar to measure the drift of plasma and infer the electric fields. Particle detectors, various radio remote sensing instruments and optical instruments are also used.
Clauer investigates the global type phenomena using global arrays of instruments. He has helped to establish an ionospheric HF radar at Virginia Tech, and also is principal investigator on a project to develop an array of magnetometer platforms in the southern hemisphere. The first platform was installed in Antarctica in January. The goal is to install a chain of seven to eight stations over the next three to four years.
Graduate student Lyndell Hockersmith near McMurdo, Antarctica
The chain is being installed along the 40 magnetic meridian — magnetically conjugate (reciprocal) to a chain of magnetometers on the west coast of Greenland. The chain reacts rapidly to changes in the solar wind. With the Greenland chain, researchers have been able to identify differences in the electrical coupling between the solar wind, magnetosphere and ionosphere during the summer and winter.
"We don't believe that it's changing due to time of year," Clauer says. "We think it's probably the difference in conductivity in the hemisphere." The research has been hampered by only having data from one pole. With the Antarctic chain, they will be able to study polar winter and polar summer simultaneously. The array will also be used to help understand a phenomenon first observed during magnetic storms only about 10 years ago. "It seems that if you drive the magnetosphere strongly, it goes into a periodic oscillation. Why does it do that"
Even with a single station at the South Pole, the team is getting data that helps the investigations, Clauer says. "I'm a data analyst. The art is in assembling data in ways that allow you to see things. I manipulate data to reveal different kinds of behaviors. We can't control things in this lab, so we do it by trying to control the various variables through a statistical analysis."
For more information, visit: www.space.vt.edu.