ESL 75th Anniversary Feature: Alexandra Bringer
ElectroScience Laboratory (ESL) at The Ohio State University, Alexandra Bringer is helping to advance the technology behind climate science for future generations as an electrical and computer engineering (ECE) senior researcher associate.As part of the
“If we want to live longer on Earth, we have to know how to preserve it,” Bringer said. “You cannot just do nothing and see what happens. It is critical to think more about preserving it.”
Originally from France, Bringer came to Ohio State to get more involved in remote sensing research. She is part of a team led by ECE Professor and Chair Joel Johnson, currently assisting NASA on several projects in this realm.
For example, Bringer said, the “UWBRAD: Ultra-Wideband Software Defined Microwave Radiometer for Ice Sheet Subsurface Temperature Sensing” project is interesting because the physical temperature of the Greenland ice sheet can be directly retrieved from the multi-frequency measurements of its own thermal emissions.
She said knowing the physical temperatures inside the ice sheet is key for understanding its deformation and motion, as well as dynamics. Awareness of these forces is important for future prediction of ice coverage and rising sea levels. The UWBRAD radiometer provides real data on this front, she said. The tool was first deployed over Greenland in September 2016 and is scheduled for a second campaign deployment in September 2017 to back it up.
Meanwhile, the team is also looking for different applications for the instrument, such as detecting mountain snow thickness, or even mapping aquifers trapped “in firn,” a technical name for partially compacted snow leftover on the ice sheets from previous years.
“It’s like wet snow in firn instead of ‘just’ ice,” Bringer said about the aquifers, “but it does not freeze in winter nor throughout the year. The idea is to measure the thermal emission over an aquifer region with the radiometer and try to see if there is a particular signature of the brightness temperature to retrieve some physical information about the aquifer itself.”
Researchers hope to combine the satellite data with data from the second UWBRAD flyover deployment over Greenland, and use it to map the aquifers for further study.
Between the satellite data and the second UWBRAD flyover deployment over Greenland, she said they hope to combine data and map the aquifers.
“The wetness of the firn aquifer varies with the seasons, which causes a change in the brightness temperature and this signature is noticeable when looking at radiometer data in the course of a year,” Bringer said. “We’re trying to understand this signature and model that. Thermal emissions from the ice may line up to these.”
Remote sensing technology has many different scientific applications. Bringer’s research currently focuses on the cryosphere—or portions of the Earth’s surface where water is frozen solid.
“I was previously doing my PhD on remote sensing over the ocean,” Bringer said. “You can switch from different areas and use the same kind of skills.”
Moving forward, she feels grateful for being able to work under the guidance of Johnson and the people at ESL, especially on such high-level projects.
“Human activity is really impacting our environment. You can see that, for example, with global warming, which causes the rising sea level. It is really sad when you look at stuff like that and people get skeptical and say that it’s not happening, but it is. To be aware of that is really important,” Bringer said. “Working in fields like remote sensing, we can monitor climate changes over time and make people aware."
Learn more about the UWBRAD project: