On Aug. 21, 2017, darkness will fall for about three minutes as the moon passes between the sun and the Earth.
It will be a busy three minutes for scientists, including George Mason University researchers, as they scramble to gather as much information as possible about a layer of the Earth's upper atmosphere called the ionosphere.
Disturbances in the ionosphere, found 46 to 620 miles above the surface of the Earth, lead to radio wave problems and GPS glitches. Emergency communications also use the ionosphere when cell towers are down, in situations like hurricanes, and therefore might experience problems due to disturbances. A solar eclipse is a rare opportunity to learn more about the atmosphere.
"The aim of the project is to study how the solar eclipse affects the ionosphere by collecting information about low-frequency radio wave propagation," said Jill K. Nelson, an electrical and computer engineering professor in George Mason’s Volgenau School of Engineering.
Ionospheric disturbances cause unpredictable changes in low-frequence radio wave propagation that are poorly understood and often difficult to study, said Nelson, who is co-leading Mason’s team.
"Since a solar eclipse occurs much more quickly than the day-to-night transition, it offers the opportunity to study the behavior of ionospheric disturbances under predictable conditions and will offer new information about the ionization and recombination behavior of the D and E layers," she said.
The D and E layers are the lowermost layers of the ionosphere. The D layer is about 40 to 50 miles above the Earth's surface, while the E layer is approximately 60 to 70 miles above the Earth.
Nelson and fellow researchers will be joined in their exploration of this phenomenon by a network of citizen scientists, including amateur radio operators, STEM educators and high school students.
"My research is in signal processing and wireless communications, so my role is focused on designing low-cost receivers that can be used by [the] citizen participants to record data during the eclipse, as well as on studying the geographically distributed measurements we obtain through the project," Nelson said.
Laura Lukes, assistant director of Mason's Center for Teaching and Faculty Excellence and co-principal investigator on the project's National Science Foundation grant, said the project could lead to improved communication systems.
“While people don't directly interact with the ionosphere, they interact with communication systems that either use the ionosphere to send signals around the world, like radio waves, or signals that pass through the ionosphere, like GPS and satellite systems. In other words, the ionosphere impacts civilian and military communication and surveillance systems. Improving our understanding of how the ionosphere behaves and influences radio waves helps improve and secure our communication systems,” Lukes said.
“Mason is a great place to do interdisciplinary research,” Nelson added. “And this project has elements in electrical engineering, STEM education/outreach and physics. We’ve also made many connections outside of Mason [including University of Massachusetts Boston, the Space and Naval Warfare Systems Command, Georgia Tech and American Radio Relay League] to expand our research and outreach networks.”
Lukes agreed: “[This project] is a truly collaborative, grassroots effort fueled by the team's passion for STEM and engaging the broader world community.”