Turning the Tide on Climate Change

This story was first published in the Georgia Tech Research Newsroom. Read the full feature here.

The entire ocean is connected. Species like coral can be similar in entirely different parts of the ocean because those waters share characteristics like salinity, temperature, and nutrients. But how did this shared DNA travel in the first place? Currents connect ecosystems, and understanding their flow could help to rebuild other ecosystems. That’s the focus of the research from School of Earth and Atmospheric Sciences Professor Annalisa Bracco.

“Corals spread through larvae, which are transported by ocean currents. This is something that naturally happens and is, in the case of corals, definitely quite beneficial,” Bracco said. “If the coral gets bleached and dies, other coral DNA can come in the form of larvae and recolonize the territory.”

Bracco’s research is about more than just following these currents. She also determines how they could be used to rejuvenate weakened or destroyed ecosystems. Marine protected areas in the Gulf of Mexico could be expanded to deliver more flora and fauna larvae to repopulate stressed or damaged areas.

“We need to preserve ecosystems that are diverse, but also well connected, so they can transfer that diversity if something happens in another place,” Bracco said. Read more.

Modeling the Future of Glaciers and Ice Sheets

Retreating glaciers and the animals who live on them have become highly visible symbols of climate change. They are also a key to predicting its future. Alex Robel, an assistant professor in the School of Earth and Atmospheric Sciences, uses computational modeling to better understand how ice reacts to climate change and how, in turn, that causes global sea level to rise. His research group creates equations to explain how ice not only responds to climate change, but also how it flows, fractures, and melts.

“Unlike other fields, we don't have the standard set of equations that describe how ice sheets and glaciers work,” Robel said. “We use high-performance computing to simulate real glaciers on Antarctica and Greenland and try to understand how they have changed in the past and predict how they will change in the future.”

Not all ice is created the same. While sea ice freezes over a few feet of the top of the ocean in wintertime, glaciers are formed by the accumulation and compression of snow on land over long periods of time to depths of hundreds, even thousands, of feet. When enough accumulates, ice can start to flow like honey under its own weight and then is considered an ice sheet.

Developing these equations must account for how glaciers and ice sheets are exposed to the volatile climate system — and measuring conditions at the bottom of a glacier is no easy task. The field comes with a lot of inherent uncertainty that Robel’s group must plan for. Read more.