The Mackinac Bridge crosses the Straits of Mackinac, which connects Lake Michigan and Lake Huron.

More detailed climate model aids Great Lakes resilience planning

Numerous studies detail how climate change affects the Great Lakes, but little is known about how the lakes themselves affect the region’s weather patterns. A digital modeling pilot project strives to improve understanding of the topic, including lake effect snow, to help the region’s climate resilience planning.

The $20 million Department of Energy-funded Coastal Observations, Mechanisms, and Predictions Across Systems and Scales, or COMPASS, program launched in early 2020 with two main projects: the Great Lakes modeling pilot and a related one in the Mid-Atlantic. Researchers from Argonne National Laboratory in Illinois and Michigan Technological University are on the Great Lakes team, and others from Argonne and the University of Toledo are on the Mid-Atlantic team.

Taking their temperature

The Great Lakes team used precise water surface temperature measurements to design experiments and simulations. The models provide a more granular look: They zoom into a 2-mile area compared with other models’ resolution of a few hundred miles. 

Argonne’s supercomputers allow the team to quickly test large, complex datasets and scale the science. Jiali Wang, an atmospheric scientist at Argonne, said the simulations would not have been possible without supercomputers, and the calculations would have taken years to complete on a conventional laptop. She said speed is key for climate science.

“We can’t wait. We need reliable data right now to prepare to meet tomorrow’s challenges,” Wang said in a news release.

What they found

The high-resolution models showed that just a small amount of warming in the lakes’ surface temperatures, 1.4 degrees Celsius, can significantly affect regional summer climate, such as:

  • Higher near-surface air temperature
  • More water evaporation over the lakes
  • Fewer big thunderstorms upstream from the lakes region
  • Smaller, more frequent thunderstorms downstream of the region

The researchers concluded that rising Great Lakes surface temperatures have the potential to destabilize the region’s climate conditions and increase extreme weather events. 

Better understanding the risks of the Great Lakes warming helps with developing resilience strategies, Wang said. The team’s more accurate climate models will aid long-term projections for the next 20 to 30 years. 

What’s next

The COMPASS teams will continue to enhance their predictive models and understanding of coastal regions and climate change.

The Great Lakes team will use their tools for an upcoming study in the Chicago area that examines how lake breezes influence urban heat stress, convective storms, rainfall, and flooding. They’ll use the technologies to predict urban flooding caused by strong convective storms and possible land use changes.

Another study will use high-resolution modeling of Ohio’s Portage River watershed to examine above- and below-ground water flow. They aim to better understand agricultural impacts on waterways and the importance of nutrient removal systems as the hydrological cycle — water’s continuous circulation between ground and atmosphere — intensifies with climate change.