By Edwin L. Aguirre
Two faculty researchers in the Department of Environmental, Earth and Atmospheric Sciences will study the cause of heat waves and droughts in the Northeast region of the U.S. and how they interact with each other under a three-year, $478,000 grant from the National Oceanic and Atmospheric Administration (NOAA).
“Our goal is to better understand the physical factors and weather patterns that cause hot and dry weather, and how much hotter can it get when it’s dry, and how much drier can it get when it’s hot,” says Prof. Mathew Barlow, who is the principal investigator on the project, with Asst. Prof. Christopher Skinner as co-principal investigator.
“We hope to answer some important questions such as how well can we predict this kind of weather and how much more often will we get this kind of weather in the future,” says Barlow.
According to NOAA and NASA, 2019 was the second-hottest year on record for Earth, with the average temperature across the globe 1.71 degrees Fahrenheit (0.95 degree Celsius) above the 20th-century average. The hottest year, 2016, exceeded that average by 1.78 degrees Fahrenheit (0.99 degree Celsius).
Barlow and Skinner cannot say for certain exactly how climate change would affect regional droughts and heat waves and their interactions; that is, if climate change would accelerate both processes and make them more frequent or intense.
“We’ll have to do the project to see. Although broadly, we have a high degree of confidence that heat waves will increase in both number and intensity,” Barlow says. “Droughts are trickier, although we think it’s likely that the intensity of droughts will increase.”
He says it’s the first time this type of research is being done for the Northeast.
“Technically, there are climate projections already available for heat waves and droughts for the Northeast,” says Barlow. “What we’re adding is a much more detailed look at the projections and emphasizing a process-based view rather than just a statistical analysis.”
Using machine learning and moisture-tracking techniques, the researchers will assess the current climate model’s ability to simulate and predict these weather phenomena and their interactions. “We expect the techniques developed in our project to be directly applicable to other regions of the country,” says Barlow.
Historically, heat waves have not been that frequent for the Northeast and so people are not very well-equipped to handle them, Barlow notes.
“Many houses don't have central air-conditioning and have to make do, if at all, with inefficient and less-effective window units. This causes a range of impacts – health stress for people who don’t have good AC, extra cost for people who have window units, and overall strain on the electric grid,” he explains. “In terms of droughts, they get less attention in states like Massachusetts that aren’t as agriculturally oriented, but still have important impacts in terms of water quality, recreation, ecosystem health and some agricultural crops.”
Skinner says one of the complicating factors with predicting and projecting droughts in the Northeast is that the region’s rainfall comes from a lot of different places.
“Some of it comes from water that evaporated from the ground in the Midwest, some from the Mid-Atlantic states, some from the Atlantic Ocean and some comes all the way from the Gulf of Mexico,” explains Skinner.
“In this project, we are going to study which of these regions is most important for rainfall and droughts in the Northeast and examine whether climate change may alter the relative importance of those regions. For example, can a drought in the Midwest increase the likelihood of dry, hot conditions in the Northeast? Will a warmer world make the Northeast more or less dependent on certain geographical regions for rainfall? These are questions we hope to answer,” he says.
Assisting Barlow and Skinner in the project are graduate students Allison Hannigan and Tyler Harrington and postdoctoral researcher Laurie Agel of the department’s Climate System Dynamics group.
Barlow is currently finishing up a four-year, $454,000 project that started in 2016 and is funded by the National Science Foundation (NSF) to study extreme rainfall in the Northeast.
“Our NOAA project is a natural extension of that NSF award, to look at the opposite extreme of weather phenomena,” he says.