University of Iowa News Release
June 14, 2005
UI Researchers Receive $423,000 NASA Grant For Aurora Study
Craig Kletzing, professor in the University of Iowa College of Liberal Arts and Sciences, Department of Physics and Astronomy, has received a $423,000, three-year NASA grant to provide instrumentation to study the role that certain waves play in generating the northern lights and other phenomena.
The project, called CHARM (Correlations of High-frequencies and Auroral Roar Measurements) is being led by James LaBelle of Dartmouth College and includes the UI as a co-investigator. During the winter of 2006-2007, a sub-orbital sounding rocket will be launched from Poker Flat, Alaska to explore the important role played by Langmuir and upper hybrid waves in the Earth's auroral ionosphere as well as in other systems throughout the solar system and in astrophysics.
In addition to mediating the transfer of energy between particle populations, these waves generate radiation that propagates over long distances, providing remote sensing of plasma processes. Understanding the dynamical role of Langmuir and upper hybrid waves and the mechanisms and characteristics of resulting electromagnetic radiation is a high priority in space physics, Kletzing says.
"We will conduct a rocket experiment to answer several of the most outstanding questions about the physics of high-frequency waves in the Earth's aurora. By including sophisticated measurements of correlations between Langmuir waves and auroral electrons, this experiment will directly test theoretical predictions of wave growth, electron bunching and resulting wave evolution," he says. "These measurements will be combined with a sophisticated all-digital receiver with dedicated high frequency probes and preamplifiers, allowing, for the first time from a sounding rocket, detection of the relatively weak electromagnetic 'auroral roar' signals emitted by auroral upper hybrid waves."
He adds that he and his colleague, UI assistant research scientist Scott Bounds, will provide Langmuir probes and particle detectors to measure the ionospheric plasma temperature and density as well as particle distribution functions. The work will significantly advance knowledge of high-frequency emissions in the Earth's aurora as well as in beam-plasma systems elsewhere in the solar system and beyond. Langmuir waves are waves that occur in plasmas (thin, electrically charged gases) in both space and laboratory environments.
In related work, Kletzing in 2004 received a $475,000, three-year NASA grant to study reconnection, a phenomenon related to the sun's interaction with the Earth's magnetic field and creating effects including the northern lights. That grant is part of a larger $1.6 million NASA project led by Kletzing and including co-investigators from Dartmouth College, West Virginia University, Goddard Space Flight Center and The Aerospace Corporation, a private, non-profit corporation with headquarters in El Segundo, Calif.
In 2003, Kletzing and his colleagues received a $450,000, three-year National Science Foundation (NSF) grant for laboratory studies of Alfven waves occurring in plasmas. Also, in 2003 and 2002 he traveled to Alaska to launch sounding rockets to study the northern lights. The UI rocket launches, in turn, were part of a long line of distinguished University of Iowa research into the nature of the northern lights. In 2001, Kletzing and a research team, led by UI researchers Robert Mutel and Donald Gurnett, reported finding a novel way to remotely pinpoint the source of Earth's most intense, naturally occurring radio noise. They showed that the radio noise, called auroral kilometric radiation (AKR), is being emitted along magnetic field lines about 3,000 miles above bright regions in the Earth's northern lights.
In 2000, UI researcher Jack Scudder and an international team of physicists made the first direct observations of the switch that permits energy to be transferred between the solar wind and Earth. Additionally, in 1986, UI researcher Louis Frank and his colleagues used NASA's Dynamics Explorer 1 spacecraft to capture the first images of the complete ring of the northern lights.
STORY SOURCE: University of Iowa News Services, 300 Plaza Centre One, Suite 371, Iowa City, Iowa 52242-2500.