When Alex and Zoe Kugler, high school students from Monarch High School in Louisville, Colorado, embarked on their year-long senior research project, they were eager to find mentors who could help them blend their love for engineering and science. The students found a perfect match with CIRES Fellow Xinzhao Chu’s research group — and the partnership sparked exploration into the relationship between aurora activity and metal layers high in the atmosphere above Antarctica.

The students’ work revealed an unexpected mismatch between records of solar indices, which measure the sun's activity and the disturbances to Earth’s magnetic field, and aurora activity at McMurdo Station in Antarctica. The project earned Alex and Zoe Kugler first-place wins in the senior division for Earth and environmental sciences at the Boulder Valley School District Regional Science Fair and Colorado Science and Engineering Fair.

“It was really cool to experience what the research process is like with people who do it all the time,” Alex Kugler said. “We were able to learn a lot of stuff and then do it on our own, but our mentors were always there to help us.”

The students’ year-long project was part of a science research seminar at Monarch High School. In the class, participants find a mentor or a group of research mentors from their community and work with them to dig into a specific science topic.

“When we were researching potential people to reach out to, we were interested in [the Chu] lab because we're both interested in engineering and science,” Zoe Kugler said. “It seemed like a fun marriage of the two because they're doing all this stuff with the lidar, and they're using it to research the upper atmosphere.”

The Chu group uses lidar, a remote sensing method, to explore interactions between space and the atmosphere. Chu and her colleagues were the first to identify iron layers in the upper atmosphere over Antarctica.

Earth’s magnetic field redirects energized particles from the sun toward the poles, which is why auroras are more commonly seen at high latitudes. At Earth’s poles, the magnetic field can also influence the ionosphere, a part of the upper atmosphere where atoms and molecules are ionized or electrically charged by solar radiation. This is the same part of the upper atmosphere where Chu and her colleagues identified layers of iron, which means Earth’s magnetic field could potentially impact how and when these layers appear.

Comparing aurora activity to solar indices

“We started our work based on this 2020 paper that Dr. Chu led,” Alex Kugler said. “They found that the iron layers in that paper had a strong correlation—almost one to one — with the aurora, whereas the sodium didn't. Dr. Chu thought this would be interesting to explore more.”

The students used images of auroras from the National Institute of Polar Research’s sky camera to create keograms, which show a change in light intensity through time, and calculate average aurora intensity. They then compared the aurora intensity data to various solar indices.

They and their mentors expected to see an increase in aurora strength when solar activity went up, but that’s not what they found. Instead, the students found there wasn’t a strong correlation between aurora strength and solar activity.

The students suggest the mismatch could be because of McMurdo Station’s location: McMurdo is situated outside the auroral oval where auroras are most commonly seen, and it is in the Southern Hemisphere, while many of the solar indices are based on observations in the Northern Hemisphere.

“I think what made Alex and Zoe’s work more interesting is that they didn't find what they expected to see,” said Jackson Jandreau, a PhD candidate in CU Boulder’s Department of Aerospace Engineering Sciences and CIRES who mentored the students. “It was probably a better experience for them because it's usually what happens in science.”

In February, the students won first place in the senior division for Earth and environmental sciences at the Boulder Valley School District Regional Science Fair. In April, they presented their work at the Colorado Science and Engineering Fair — they won again in the same category.

Patterns between aurora activity and atmospheric metals

Following their science fair wins, Alex and Zoe Kugler took the research to the next level. They developed code to analyze the correlations between aurora activity and the spikes in atmospheric metals previously observed by the Chu group.

They discovered a correlation between iron layers and aurora activity only occurred a few times in their 101-night record — the majority of the time, their initial analysis showed no statistically significant link. The Chu research group will explore these correlations further using more detailed analysis techniques. The students also uncovered another pattern: nights when the spikes in iron and sodium layers correlated with each other but not the aurora.

Their work suggests the transport and processes that form atmospheric metal layers are complex and likely influenced by more than just aurora activity.

Alex and Zoe Kugler presented these results at the International Science and Engineering Fair (ISEF) in Columbus, Ohio, in May.

"The experience was amazing, we got to meet people from all over the world who were really passionate about all different types of science,” Zoe Kugler said. “It was incredible to see the work and dedication that went into these projects."