Sun, moon and balloons
UND scientists, students launch weather balloons in Colorado to track atmospheric changes caused by solar eclipse
Eleven UND students hit the road for a 22-hour car ride with atmospheric science professors Jared Marquis and Montana Etten-Bohm in October. Along for the ride were 30 balloons, radio equipment, cloth gloves and several canisters of helium.
Their destination: Cortez, Colo., a small municipality nestled in the southwest corner of the state near New Mexico. Cortez and nearby Mesa Verde National Park fell in the thin strip stretching from Oregon to Panama where the annular solar eclipse (when the sun is partially covered, creating a “ring of fire” around the moon) was visible on Oct. 14.
The students and faculty traveled there to collect data as part of the Nationwide Eclipse Balloon Project, a NASA- and National Science Foundation-sponsored program started in 2017 at Montana State University. The project teaches students from 75 schools around the country about atmospheric sciences and engineering by launching weather balloons during annular and total solar eclipses.
Jared Marquis, assistant professor of atmospheric sciences at UND, said the department started preparing for the event last fall, when plans for the trip fell into place. Last summer, Marquis and his colleague in atmospheric sciences, assistant professor Montana Etten-Bohm, traveled to Kentucky to learn about the process of launching weather balloons. Then, they went about relaying this information to students.
Marquis used his experience in Kentucky to create a semester-long course which would explain the data they were trying to collect and walk students through the launch process. The course culminated in a launch in Clifford Hall’s parking lot a month before the eclipse.
“We started launching them at nine in the evening, after it was dark outside,” said Marquis. “We wanted to practice launching in semi-adverse conditions, so we were working in the dark using headlamps to see what we were doing.”
Test balloons were provided by NEBP, and Marquis and Etten-Bohm worked with the North Dakota Space Grant Consortium to buy helium for their test launches. The consortium also helped pay for student meals on the trip to Colorado.
The process can be delicate, said Marquis. Students have to wear cloth gloves when handling the balloons to protect them from oil on their skin, which can affect the elasticity of the balloon and cause the balloon to burst too soon.
The filling of balloons requires an equal amount of care. The balloons ascend more than 100,000 feet, Marquis said. That means too much helium could cause a balloon to burst too soon as the gas expands, but an underfilled balloon could drift off course as it rises too slowly.
“In Colorado, one of our balloons floated 160 miles downrange. We were out in the middle of nowhere when I got a call from the sheriff saying they found it in a powerline,” Marquis said with a laugh.
The balloons must reach high altitudes in order to work well above the tropopause, the thin layer of atmosphere between the stratosphere and troposphere. The tropopause contains the jet stream, a powerful river of wind and an interesting location for measuring changes in the atmosphere at the time of a solar eclipse.
Several large canisters of helium were on site to fill the balloons to a specific pressure. Each balloon had to be filled just before its launch, as team members didn’t want to leave the balloons filled for too long, Marquis said.
Sondes – small transmitters that signal changes in the atmosphere to a station on the ground – were attached to each balloon. Using these tools, the students collected data to see if the annular eclipse affected air pressure, temperature and wind speed.
Marquis said that the information collected as a part of NEBP is helpful for several reasons.
“Understanding what’s happening in the atmosphere during eclipses can be useful for figuring out whether our existing models are working,” Marquis said. “It’s also helpful for our understanding of how the atmosphere is functioning. We can look at how things work when the sun is ‘turned off’ in this relatively small area to see how that might change things on the ground and throughout the atmosphere.”
In total, the three groups launched a balloon an hour for 30 hours. Marquis said they started the launches 24 hours before the eclipse to establish a baseline to compare to the data collected during the annular eclipse.
The groups worked out of an unfinished lab space offered to them by Pueblo Community College, not far from Mesa Verde National Park, where the balloons were launched.
After 30 hours, UND’s crew successfully launched 28 of the 30 balloons, losing one after its GPS signal was lost and another after a balloon popped miles before the tropopause.
However, Marquis said these mishaps can provide good data points and, most importantly, are valuable for student learning. He emphasized that courses and experiences like this offer experiential learning opportunities that will help them in their careers.
“These balloons are launched twice a day, every day, at roughly 100 sites around the country for analyzing data and initializing weather models,” he said. “This training is useful for students who might want to do this at weather service offices, but it’s also good for aviation students who want to understand where this data is coming from. It’s a perfect learning experience, and it’s also fun.”
Further, Marquis said that the hands-on experience of launching weather balloons and learning how data is collected makes the practice of analyzing that data less abstract for students..
“They get a lot of auditory and visual explanations in our lectures, and then they get hands-on experience out in the field for some experiential learning. It really taps into all of the ways students learn,” he said. “Going out and collecting your own data is also, I think, much more exciting than looking at data from 30 years ago.”
Right now, the students who participated in the launches are working on projects using the experiences and data they amassed in Cortez to benefit future students of atmospheric sciences. Marquis said that class groups were free to choose the focus of their projects, but the data would help future students.
“We can use this data for future semesters, so even students who didn’t collect the data themselves will be able to hear about the project and use research from their own department to study the eclipse’s effects,” he said.
Some students focused on what Marquis describes as “hardcore science,” analyzing the eclipse’s effects on weather and atmosphere. Other groups used their experience to develop learning modules to share the process with students in introductory courses.
Marquis said UND will launch balloons as a part of the NEBP in April 2024, this time for a total solar eclipse. The team is considering Illinois and Indiana as possible destinations and anticipates many of the students will return for the spring launches.