Storm-induced sea level spikes expected to increase on the Gulf and Atlantic coasts

New NOAA model helps tease out differing reasons for storm surges

Using a new powerful NOAA global climate model, NOAA and partner researchers show that big storm-induced spikes in sea levels will increase in the future from the Gulf Coast to the Atlantic coast as warming progresses, but will be driven by differing forces.

Stronger hurricanes will be the primary driver for storm surge spikes along the Gulf Coast while overall rising sea levels will lead to more storm surges along the East Coast, according to new research appearing in the Journal of Climate.

“We are entering a period in numerical modeling where global models used to study climate are now able to make meaningful statements about the statistics of extreme weather events,” said Stephen Griffies, a physical scientist at NOAA’s Geophysical Fluid Dynamics Laboratory and co-author of the new research. “This study shows the importance of refined-resolution climate models for providing actionable information that is critical to coastal communities to adapt to life near the ocean in a warming world.”

Researchers studied the coastline from Halifax, Nova Scotia, to Houston, Texas. Using the NOAA model, they simulated how adding more carbon dioxide to the atmosphere at a rate of increase similar to that observed since the mid-20th century would affect sea level rise and storm surge. For both the Gulf and Atlantic coasts, the model showed storm surge heights increasing as future warming progresses.

Hurricanes will drive extreme storm surges in Gulf of Mexico

“For the Gulf of Mexico coast, the extreme sea level is highly sensitive to tropical cyclone characteristics like the storm winds,” said Jianjun Yin, an associate professor of geosciences at the University of Arizona, and lead author of the new study. “But for the East Coast of the U.S., especially the Northeast coast, the story is different -- the maximum storm surge is mainly influenced by the background sea level rise.”

Scientists were able to more accurately predict how the seas along the East Coast and Gulf Coast would rise during tropical cyclones, including hurricanes, and nor’easters using NOAA’s newest climate model, the Geophysical Fluid Dynamics Lab model CM4. The model combines information on weather, climate and sea level to produce high confidence predictions.

The climate model simulations that added carbon dioxide to the atmosphere year after year, as warming progresses, found there will be fewer -- but stronger -- tropical cyclones. The model also showed that increased carbon dioxide in the atmosphere would cause the Atlantic Meridional Overturning Circulation to slow down, increasing sea level rise and storm surge on the East Coast.

"The new GFDL climate model is a work in progress and with further enhancements to the resolution we’ll be able to simulate even more realistic storms that drive much of the extreme sea-level events,” said Griffies.

Co-authors of the research also included Michael Winton and Ming Zhao of NOAA GFDL, Laura Zanna of the University of Oxford and New York University. The research was funded in part by NOAA’s Climate Program Office Modeling, Analysis, Predictions and Projections Program

Please go online to read the research.

To read the University of Arizona press release please go online.

For more information, contact Monica Allen, NOAA Communications, at 301-734-1123 or monica.allen@noaa.gov