|Updated: 10:15 a.m. EDT -- 01 October 2002|
Michael W. Liemohn, assistant research scientist in the Space Physics Research Laboratory since 1998, is a leading expert on near-Earth atmospheric activity, particularly the study of geomagnetic storms.
Liemohn’s studies have significantly shifted understanding of storm-time ring current. This westward flowing current that encircles the Earth is greatly enhanced during major disturbances of Earth’s magnetosphere. Liemohn led a team of researchers who found that the ring current almost always has an asymmetrical shape, peaked on the side of the Earth that is in dusk. He was the first to show that energy flow out the dayside boundary is much greater than expected, indicating that the charged particles that make up the flow complete only a partial loop around the planet.
Other major studies that Liemohn has led have deepened the understanding of the decay and recovery of the ring current, which appears and disappears around Earth. As one colleague says, “He knows how to ask the important questions, and he has the creativity to see unanticipated answers.”
Liemohn’s research interests also include superthermal electron
transport—lower-energy electrons that are fast enough to travel
great distances in the magnetosphere before depositing their energy—and
data analysis from the Thermal Ion Dynamics Experiment onboard the
Polar Spacecraft, which made the first measurements of wind high
above the North Pole. His studies are not strictly Earth-bound;
recent projects have focused on data analysis from a surveying satellite
orbiting Mars. Liemohn’s research could have such practical
applications as extending the lifetime of satellites in the magnetosphere
by mitigating radiation effects and guiding the design of tethers
for orbital control and power generation.