If you’ve spent any time in the White Mountains region of New Hampshire, you’ve no doubt seen the bumper sticker that reads “This Car Climbed Mt. Washington.”
Most of the vehicles bearing this point of pride belong to vacationers who drove up for the amazing views often found on the Northeast’s highest peak. But at least one pickup truck and its passengers were hard at work last summer when they ascended the world-famous Mt. Washington Auto Road. Equipped with a truck-mounted plastic tube and other equipment, they made several treks to collect and analyze water isotopes in the humidity hugging the mountain.
The moisture-catching exercise was part of a six-week pilot study on climate change to determine why Mount Washington’s summit is warming more slowly than lower elevations in the region, especially in certain seasons. For example, from 1935 to 2014, the summit saw an increase of 1.5 degrees Fahrenheit in average winter temperatures, while Pinkham Notch saw an increase of 2.5 degrees Fahrenheit over the same period.
Researchers used several tools to gauge atmospheric conditions at various elevations on the 6,288-foot mountain. Variants in the collected isotopes offer clues to water cycle history and can indicate what’s going on with climatic conditions. By screening water vapor for various isotopes, scientists expect to determine whether the air was within the planetary boundary layer—the lowest part of the atmosphere that is most influenced by the heating and cooling of Earth’s surface—or not. With the aid of weather balloons, researchers also measured temperature, relative humidity, and wind speed. These measurements collectively help identify changes in the boundary layer.
“The depth of the planetary boundary layer around Mount Washington changes daily and through the seasons, adding complexity to how it affects climate trends,” says Georgia Murray, an AMC staff scientist and one of the researchers who participated in the study. “When the summit is not within this layer, the weather can be different than at lower elevations, and, over time, that can result in different rates of climate change.”
The pilot study was funded by a grant from Plymouth State University, with participating partners including AMC’s Murray; Dr. Eric Kelsey, representing Plymouth State and the Mount Washington Observatory; and Adriana Bailey, who participated under the auspices of the University of Washington and is now a visiting scientist at Dartmouth College. If the group receives requested funding from the National Science Foundation in early 2017, the project—which Murray calls the tip of the iceberg in understanding climate change—will continue through 2020.