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Yang Wang is leading a unique study harnessing satellite data to study how solar activity affects a poorly understood region of Earth’s upper atmosphere.

Wang, a visiting faculty member in the Ann and H.J. Smead Department of Aerospace Engineering Sciences and a 2021 graduate of CU Boulder’s aerospace PhD program, has earned a $699,018, four-year

“I’m going to be studying the responses of the Earth’s ionosphere to solar activities, particularly in the polar regions,” Wang said. “They are very complicated, coupled processes and are not very well modeled or understood.”

The ionosphere stretches from 48-965 km (30-600 mi) above Earth’s surface. Conditions in it are influenced by space weather, including solar flares and other activity from the sun.

Wang is focused specifically on phenomena called “polar patches and tongues of ionization,” where plasma in the ionosphere stretches out thousands of miles beyond its normal locations. When this occurs, steep electron density gradients can cause disruptions in satellite navigation and communications systems.

A major obstacle in improving our understanding is the difficulty in collecting data. Many studies of space weather analyze how radio signals from global navigation satellite system (GNSS) satellites pass through the ionosphere before reaching ground-receiving stations. At Earth’s poles, however, it is very difficult to deploy and maintain GNSS receivers.

Wang has discovered a new way to collect the data. GNSS signals beamed to Earth’s surface also bounce back up after hitting the ground and reflect into space, where they can be received by other satellites.

A constellation of small satellites in low Earth orbits are already collecting this reflected signal information as part of unrelated research, and NASA makes data available to researchers.

“It’s really exciting to observe the ionosphere in this way,” Wang said. “The hardware systems aren’t designed to do this, so there are some limitations, but this could help us understand what’s going on at high latitudes.”

Wang is developing algorithms to conduct processing and analysis of that data to ferret out new useful information from noise.

“We want to better understand the physical processes in the space environment from the sun to the Earth and advance our understanding of how these polar patches form, evolve, and propagate,” he said.

The grant represents a special validation for Wang; it is the first proposal he submitted as a PhD graduate and will enable his research for the next four years.

“To have my proposal be reviewed by NASA and be recognized, I’m very happy,” Wang said.

*Polar Tongue of Ionization rendering by under��Creative Commons Attribution 4.0 License.