Growing up in the snowy winters of Michigan, Sebastian Harkema, a Ph.D. candidate student in 草榴社区鈥檚 (UAH) department of Atmospheric & Earth Science, still remembers the first time he heard the roar of thunder during a winter storm.
While it was a rare and exciting phenomenon to witness, Harkema would鈥檝e never guessed years later he鈥檇 be as a leader in thundersnow research while in graduate school at UAH, a part of The University of Alabama system.
鈥淚t鈥檚 quite an honor to be featured by National Geographic. Their yellow rectangle border is iconic. When you see it, you know you鈥檙e going to be reading about the latest advances in scientific research,鈥� says Harkema.
For decades, scientists believed electrification within snowstorms was caused by collisions between ice crystals and graupel, also known as a snow pellet, in the presence of supercooled liquid water.
The doctoral student鈥檚 research, funded by the Future Investigators in NASA Earth and Space Science and Technology (FINESST) program, found that graupel may not play as large a role in the electrification of wintertime stratiform events, such as nor鈥檈asters, as previously thought.
Harkema also found that when thundersnow occurs, the lightning associated with the wintertime event produces large, less frequent flashes.
鈥淭his is key to promoting lightning safety during thundersnow events. Large, less frequent flashes along with snow dampening the sound of thunder could pose a risk to society outdoors, who are unaware that thundersnow is occurring during a snowstorm,鈥� says Harkema.
Harkema has made significant contributions in thundersnow research during his graduate studies at UAH. He has written and co-authored a number of publications and presented his research at several conferences, winning various accolades in recognition of his work. Most recently, Harkema presented his research on the Inhibition of Large-Scale Electrification Within Wintertime Stratiform Regions at the 2023 American Meteorological Society Conference, receiving high praise from colleagues within his field.
With all his success, it鈥檚 hard to imagine that his initial plan for graduate school never involved researching thundersnow.
Harkema was originally interested in UAH鈥檚 Department of Atmospheric & Earth Sciences due to its strong focus in satellite and remote sensing. Shortly after applying to UAH, research opportunities became endless for him.
Harkema was first contacted for an opportunity to work on a winter weather project through UAH Earth System Science Center鈥檚 cooperative agreement with NASA鈥檚 Short-term Prediction and Transition Center (SPoRT) for his graduate studies.
Wanting to take advantage of other research opportunities for students in winter weather, Harkema was encouraged by his NASA SPoRT mentor Dr. Emily Berndt and NASA SPoRT鈥檚 Dr. Christopher Schultz to apply to NASA鈥檚 2020 Investigations of Microphysics and Precipitation for Atlantic Coast Threatening Snowstorms (IMPACTS) field campaign. It was there, where Harkema was given his first opportunity to study electrification with winter storms using aircraft observations.
After the field campaign, the doctoral candidate realized he wanted to research thundersnow for his Ph.D. dissertation. By taking UAH鈥檚 Department of Atmospheric & Earth Sciences Professional Development course, Harkema learned about NASA鈥檚 FINESST program. Guided by his UAH advisor, Dr. John Mecikalski, Harkema applied and received funding to fund his research to analyze how the electrification process works in stratiform wintertime storms.
Harkema is planning to defend his Ph.D. on thundersnow this spring. Post-graduation, he hopes to continue researching thundersnow and broaden his research to study electrification in summertime stratiform events.