Jake Seeley '12 studies climate change models at the University of California, Berkeley.
While global climate models have been used to successfully study extreme weather such as hurricanes, droughts, and heat waves, they don't do as well with smaller-scale weather such as the severe thunderstorms that produce hail, powerful winds, and tornadoes.“This has been a tough nut to crack,” says Jake Seeley '12, a graduate student in the Department of Earth and Planetary Science at the University of California, Berkeley.
Because models can only reproduce weather down to scales of about 100 square kilometers, they can't simulate severe storms, which tend to be 25 kilometers wide. Some of the newest models can, however, predict certain atmospheric conditions that spawn them.
One condition is atmospheric instability, which can trigger vigorous convection, the mixing due to rising hot air. Add some strong horizontal winds, and you have a recipe for severe storms.
Seeley and his advisor, David Romps, analyzed 11 climate models to see how well their computed values of atmospheric instability and horizontal winds could reproduce the stormy conditions of the central Great Plains of the U.S., in what's known as Tornado Alley. By comparing the model data with real-world historical data, he identified three models that fit the bill.
Seeley then used the three models to determine whether conditions would be ripe for more storms 75 years into the future, under different scenarios of global warming. He found that if nothing is done to mitigate climate change, then severe storms would increase significantly. But if warming is slowed somewhat, then the heightened frequency can be reduced. And that would be a big deal, given that severe storms typically kill dozens of people each year—500 were killed by tornadoes alone in 2011— and do billions of dollars in damage.
Seeley presented these results at the meeting of the American Geophysical Union in San Francisco in December. For his Ph.D., he plans to work on smaller-scale models that simulate clouds and the atmosphere. Majoring in physics gave him a solid background for climate science, he says, and he encourages other physics majors to consider the field. After all, the climate will only become more important in the future, he adds.“It's only going to get weirder in the next 100 years.” —Marcus Y. Woo
