A team led by University of Texas at Arlington physicists is studying the impact of space weather on Earth, particularly solar-induced phenomena on our electrical power grids.
Yue Deng, UTA distinguished professor of physics, is principal investigator for the project, titled "Advances in numerical simulations for resolving multi-scale geomagnetic disturbances." The work is being funded by a four-year, $652,409 grant from NASA through its Heliophysics Living With a Star (H-LWS) program. She is joined by Daniel Welling, assistant professor of physics, and Sheng Cheng, a research engineer scientist in Deng's lab.
The goal of the NASA H-LWS project is to use a system of numerical computer models to better understand how space weather affects changes in the Earth's magnetic field. A major focus is geomagnetically induced currents (GICs), which can result from geomagnetic storms—a type of space weather event in which the Earth's magnetic field is rattled by incoming magnetic solar material, creating geoelectric fields. Most GICs are caused by coronal mass ejections, which interact with the Earth's magnetic field and cause it to shake.
"In our study we hope to improve modeling of geomagnetic disturbances and the geoelectric field during disturbed periods and to improve our understanding of the roles of solar wind, the magnetosphere, the ionosphere and the thermosphere in driving geomagnetic variation and the geoelectric field," Deng said.
GICs can flow through any long metal structures, including railroad tracks, underground pipelines and power grids. While they are not likely to cause widespread permanent damage to power grids, GICs can cause blackouts over large areas in extreme cases.
"The power grid was never meant to handle such currents and can be knocked out of service under the right conditions," Welling said.
The hot topic in the field is small-scale geoelectric fields: very strong, short-lived fields that are only observed within a region of around 200 km, Welling said. These are difficult to predict because scientists don't yet have a good understanding of how they are generated. They could be the result of small-scale activity in near-Earth outer space, small-scale structures in the high-altitude atmosphere, structures in the ground conductivity profile, or some combination of these.
"Our project looks to explore all of these factors at once through a system of numerical computer models," Welling said. "We're taking new steps to develop our computer models to not only resolve small-scale activity, but include feedback processes between near-Earth space and the upper atmosphere. Many of these steps have never been taken before, so we're very excited at what we'll find."
The UTA team is collaborating with Los Alamos National Laboratory to better understand the role of the Earth's crust in its calculations.
"It is essential to understand the magnetospheric and ionospheric processes responsible for geomagnetic disturbances during space weather events in order to improve the preparedness of society to the impact of space weather," Deng said.
Alex Weiss, professor and chair of the Department of Physics, said Deng and her colleagues are playing a growing role in the space weather field. "This study will help to make important advances in our understanding of how space weather affects processes on Earth that can have a critical impact on our infrastructure," Weiss said.
Deng also recently secured an additional $1.5 million in funding to continue the Multidisciplinary University Research Initiative (MURI) project she is leading. The study, funded by the Air Force Office of Scientific Research, is titled "Next Generation Advances in Ionosphere Thermosphere Coupling at Multiple Scales for Environmental Specification and Prediction." The original five-year MURI grant of $7.3 million was made in 2016, and the latest round of funding brings the project's total to nearly $9 million.
The goal of the MURI project is to develop a next-generation space weather simulator capable of predicting how energy is distributed during events such as solar flares and magnetic storms. Deng is lead investigator of the study, which includes space physicists from the University of California at Los Angeles, Johns Hopkins University, Massachusetts Institute of Technology, University of Colorado at Boulder, University of New Mexico, University of Texas at Dallas and Penn State University.
-Written by Greg Pederson, College of Science
