PSU's Climate Science Lab gets NASA grant to better simulate extreme precipitation

How well can a climate model simulate an extreme precipitation event and what causes it? Researchers from Portland State's Climate Science Lab have been awarded an $843,000 grant from NASA to evaluate just that. 

Paul Loikith and Andrew Martin, both with PSU's Geography Department, say better understanding the processes that drive extreme precipitation — whether that's a cold front, hurricane or atmospheric river — is critical as climate change is projected to impact the frequency, severity and seasonality of extreme precipitation across the U.S. 

"When thinking about how extreme precipitation may change under global warming, the way it will change will be in part because of its driving mechanism," Loikith said. "Extreme precipitation caused by hurricanes will be affected in different ways by global warming than extreme precipitation caused by atmospheric rivers."

The four-year project, funded through NASA's Modeling, Analysis and Prediction (MAP) program, involves evaluating a suite of climate models against actual observations for their ability to accurately simulate precipitation extremes with the proper driving meteorological mechanisms.

"For example, in the real world, most extreme precipitation events in Portland are caused by atmospheric rivers," Loikith said. "We therefore want to make sure that extreme precipitation events over Portland in climate models are also caused by atmospheric rivers."

Martin says an increase in extreme precipitation increases the risk of flooding, which can impact roads, dams, buildings, agriculture and water quality. He expects their findings will help water managers better interpret climate models and better anticipate future infrastructure investment needs.

Loikith and Martin say the project will also help advance the software tools used in climate model evaluation and enable better research about climate change.