Surf's up: Catch an atmospheric wave as ASU research team launches Gravity Wave Zoo

For decades, scientists have studied the seasonal dynamics of upper-atmosphere weather that causes atmospheric waves using imagery and radar data. How and why the waves form and what causes them may provide clues on the conditions that support the wave events. 

The atmosphere is full of waves. Sound waves, for example, are easy for our ears to detect, especially if you’ve ever visited an amusement park with roller coasters. However, some of the most powerful waves in the atmosphere are silent and much harder to detect. These atmospheric waves are known as gravity waves. 

Jessica Berkheimer, an astrophysics PhD student at Arizona State University’s School of Earth and Space Exploration, and Assistant Professor Katrina Bossert, a space physicist in the School of Earth and Space Exploration, are among a team of scientists who have set out to learn more about gravity waves with the help of volunteers — or citizen scientists. 

The project, Gravity Wave Zoo, asks citizen scientists to identify gravity waves, instabilities and aurora using images and short video clips.

Based at the Poker Flat Observatory, just north of Fairbanks, Alaska, the project and the images are taken using an OH (hydroxyl) airglow imager that views the near-infrared at an altitude of 86 kilometers (53.5 miles above the Earth's surface) — that’s approaching the near-space environment where satellites orbit.  

“We wanted to create something that invites the public to participate in scientific thinking and data collection: a project that contributes to learning, scientific understanding, science awareness and enjoyment. Most importantly, Gravity Wave Zoo is designed to be fun,” Berkheimer said. “To help people get started, the project offers easily accessible tutorials and a field guide with example videos, pictures and demonstration classifications. Using Gravity Wave Zoo, citizen scientists engage in real scientific data while helping us evaluate large data sets. Ideally, it’s a win-win situation.”

The three main science aims for Gravity Wave Zoo are to:

• Identify gravity waves, instabilities and breaking.

• Learn what conditions are needed for these different events to take place.

• Compile observations over multiple years to study seasonal variations in gravity wave events. 

Gravity waves have become of great interest to scientists because of their essential role in energy and momentum transport throughout the atmosphere and their huge impacts on weather and climate. 

Citizen scientist contributions to the Gravity Wave Zoo project will help the research team provide valuable data to weather and climate models and provide helpful training data for machine learning algorithms.

Thousands of images from the hydroxyl airglow imager in central Alaska will be used to classify events of instabilities and waves in the lower thermosphere. The project will engage a broad range of people including K–12 students, college students and any interested person from the general public.  

“We want to know if there are certain times of the year or seasons where there are more instabilities and waves present in this region known as the 'edge of space,'" Bossert said. "Just as ships sailing in the ocean may encounter rougher waters or seasons with more storms, spacecraft orbiting Earth can also be impacted by weather both from Earth’s atmosphere and the sun. Citizen scientists will be able to help us answer the question of whether there are seasonal aspects of this polar region of the lower thermosphere that can potentially impact spacecraft in low Earth orbit.”

Gravity Wave Zoo is part of Zooniverse, the world’s largest and most popular platform for people-powered research. This research is made possible by volunteers — more than a million people around the world who come together to assist professional researchers. Their goal is to enable research that would not be possible, or practical, otherwise. Zooniverse research results in new discoveries, data sets useful to the wider research community, and many publications. 

Additional scientists on the Gravity Wave Zoo team are Jessica Norrell and Sophie Phillips of ASU, and Denise Thorsen, Richard Collins and Jintai Li at Alaska State University.

This project is supported by the National Science Foundation (NSF) Under the CAREER awards NSF AGS 1944027 and NSF FDSS 1936373.