Ph.D. Student Ventures to Sweden to Study Space Weather

02/13/2025
By Ed Brennen

About 100 miles up in the sky, where the upper mesosphere and lower thermosphere meet, is a region of the Earth’s atmosphere dubbed the “ignorosphere.” Too high for weather balloons to reach and too low for satellites to consistently orbit, it’s one of the least studied — and least understood — layers of the atmosphere.

One person who is not ignoring the ignorosphere is physics Ph.D. student Charmi Patel ’24.

Patel recently visited northern Sweden, where she set up an instrument called HiT&MiS, or the High Throughput and Multi Slit Imaging Spectrograph. Built by the Lowell Center for Space Science and Technology (LoCSST), the instrument studies atmospheric changes caused by solar radiation, also known as space weather. 

Understanding the ignorosphere could help predict how space weather affects everything from climate and communications to power grids and GPS systems here on Earth.

“It’s critical for us to understand what’s happening up there, because all of our infrastructure pretty much relies on space weather at this point,” says Patel, a native of Champaign, Illinois, who came to UMass Lowell to pursue graduate studies in physics — and the opportunity to work at LoCSST.

HiT&MiS was first developed more than a decade ago by a team that includes LoCSST Director and Physics Prof. Supriya Chakrabarti and Assoc. Prof. of Physics Timothy Cook. It was funded by a grant from the National Science Foundation.

Optical spectrographs work by breaking light into its different colors (or wavelengths) and recording the resulting spectrum, allowing scientists to determine what elements or compounds are present. Most optical spectrographs use a single slit to capture light, but HiT&MiS has four individual slits for high-resolution spectral analysis — even in daylight conditions.

Patel uses HiT&MiS to study the aurora borealis, or northern lights, which are currently at the peak of an 11-year solar cycle and have recently been visible over large swaths of the United States, including Lowell. Last summer, she set up the instrument in an 18th-floor dorm room at Fox Hall to monitor the northern lights.

The opportunity to install HiT&MiS in Sweden came about through Chakrabarti’s ongoing collaboration with the Swedish Institute of Space Physics. The Swedish team needs to monitor atmospheric conditions before launching rockets from its Esrange Space Center, located outside of Kiruna (the northernmost city in Sweden), and HiT&MiS provided an ideal solution.

Before the instrument could be shipped to Sweden, it needed to be fine-tuned to detect hydroxyl radicals (OH), which result when a hydrogen atom is removed from a water molecule. Working with postdoctoral research associate Sunip Mukherjee ’24, Patel got experience reconfiguring an optical system and learned to use optical modeling software called Zemax.

“I didn’t have any instrumentation experience, so I kind of learned things as I went,” says Patel, who was encouraged to “just break things” so she could learn by fixing them.  

Mukherjee says the opportunity to work on projects like HiT&MiS is one of the reasons “why I’m still here” at UMass Lowell after earning a Ph.D. in physics and applied physics.

“I love being able to do this end-to-end work, where I’m writing my own software to control my own hardware,” says Mukherjee, who is from Kolkata, India. “That kind of experience is very hard to get almost anywhere in the world.”

Patel spent a week in Sweden in mid-January, mounting HiT&MiS at an observatory in Kiruna, which is located inside the Arctic Circle. It has already been used in support of a rocket launch and will remain at the observatory for at least the next year, helping with future launches while observing the northern lights around the clock.

“Now we’re on to the data analysis stage, using programming languages like Python and Rust, which is always fun,” says Patel, who last fall received a fellowship from the Massachusetts Space Grant Consortium to support her work.

Once enough data is collected and analyzed, Chakrabarti says the team will be able to go back to the National Science Foundation with proposals for new studies.

“These models are extremely complicated,” he says. “What we’re doing here is like the blind men trying to understand the elephant — we’re incorporating various techniques from the ground and from space, trying to learn as much as we can.” 

Chakrabarti, who was recently named a 2025 Optica fellow and Distinguished University Professor at UML, says HiT&MiS provides unparalleled experience for graduate students.

“Our colleagues in Sweden are quite impressed when we send a student with a state-of-the-art instrument to support their rocket program,” he says.

And Patel has quite an experience to highlight on her résumé. 

“I have never been part of a science collaboration at this level,” she says. “Now I've been to a different country, met with other people in the field and learned what science collaborations look like.”