SAN FRANCISCO---Thanks to ultra-high speed, custom written software, researchers from the University of Michigan have simulated the effect of solar surface eruptions on the Earth's magnetosphere. The simulations not only capture for the first time a three dimensional model of so-called coronal mass ejections, but do it far faster than real time---meaning, the researchers said, that the simulation might some day find work predicting the effects of space weather phenomena on the Earth in ample time to prepare for them.
Led by Tamas Gombosi, professor of atmospheric, oceanic and space sciences, as well as aerospace engineering, associate research scientists Darren De Zeeuw, Clinton Groth, and Hal Marshall wrote software to model coronal mass ejections (CMEs), sudden and unpredictable burps of ionized hydrogen and electrons that stream from the sun's surface and deep into the solar system.
Groth and De Zeeuw then coupled that model with another simulation of the Earth's magnetic field, to see how it changes as the CME passes this planet. Although scientists have observed changes in the magnetosphere as a result of these solar wind disturbances, no one had been able to simulate those events until now.
"Our goal is to model what happens in the heliosphere from the surface of the sun to the Earth," said Groth, who is presenting the CME simulation work in San Francisco at the fall meeting of the American Geophysical Union.
De Zeeuw, who is presenting the magnetosphere modeling this week at the San Francisco conference, said the key to the research was developing software capable of such massive calculations---as many as 80 billion floating point operations a second (80 Gflops), he said. The simulations were run on a 512-processor CRAY T3E supercomputer at NASA/Goddard Space Flight Center in Greenbelt, Md. By minimizing the complexity of communication between the microprocessors, the team was able to maximize the speed and efficiency of the machine.
As a result, said Gombosi, we can produce a fully developed model of a solar wind event 17 times faster than it would actually occur. That's significant, he said, because CMEs can alter the Earth's own magnetic field, which in turn can affect the ionosphere. Dramatic changes in the ionosphere can be trouble for electrical power grids, especially in Northern cities, and have been linked to outages. Knowing that a major disturbance was on its way could help municipalities better deal with such electrical fluxes, Gombosi said.
The U-M is one of nine Grand Challenge Investigations funded by the NASA High Performance Computing and Communication Program's Earth and Space Sciences Project. Additional funding comes from NASA's Office of Space Science, the National Science Foundation, and the Air Force Office of Scientific Research.
# # # # # #