With crampons and laser beams, a PICS researcher sharpens the very-long-range forecast.
British Columbia’s iconic glaciers are shrinking. The province’s annual mean temperature has risen 1.9 degrees celsius since 1948, while winters have warmed by 3.7 degrees celsius.
This has impacted seasonal melt, with early rain and smaller snowpack.
Governments and stakeholders need to know what glacier freezing and thawing trends will look like over the long term, and rely on forecasting models to help fill in the picture. And better field data today sharpens the picture of tomorrow.
That’s why twice a year, the University of Northern British Columbia glaciology PhD student Ben Pelto has been visiting a half-dozen icefields in British Columbia’s Selkirk, Purcell, and Cariboo Mountains to dig snow pits, scrutinize ice cores, and drag around a ground-penetrating radar. He’s measuring accumulation and snow density as part of a multi-year PICS-supported project to improve our collective understanding of the degree to which glaciers contribute to seasonal streamflow levels.
The Pacific Climate Impacts Consortium—PICS’ sibling organisation—is feeding Pelto’s data into its hydrologic model, improving its reliability. Governments and stakeholders use the model to plan the impacts of hotter, drier summers and wetter and warmer winters on the province’s freshwater resources.
And there are many good reasons to do so.
The Role of the Ice
A wide range of solution seekers are looking for improved streamflow-model data.
For example, governments and non-governmental organizations such as the Columbia Basin Trust want to know what freshwater resources might look like in the coming decades, so they can make better investments and enact effective policies to protect economically, culturally, and ecologically important species, such as salmon. “The months when glaciers are producing the most runoff are the months when there are salmon runs, and salmon need an abundance of cold water,” Pelto says.
Then there’s BC Hydro. The province’s largest utility serves 1.8 million customers, and factoring in seasonal glacier melt along with changing precipitation patterns due to climate change, is part of the crown corporation’s long-term planning.
A Bird's Eye View
While much of Pelto’s field work involves getting up-close and personal with shovels and skis, he and his team also take to the skies in a small plane equipped with a light detection and ranging, or LIDAR, laser instrument.
As the aircraft cruises high above the glaciers, the LIDAR fires rapid pulses down to the ice about 6,000 feet below. The instrument can very precisely measure changes in the height of the ice above the bedrock, and captures an impressive two elevation data points per square meter.
“Physically in the field, we can only work on so many glaciers, but from the air, instead of just the six we work on... we end up measuring 100 per season, including those that are too dangerous, too steep, or too small.”
It’s no picnic up there in the Purcells when a storm blows in and brings data collection to a halt. But Pelto is right back out there as soon as the clouds clear, sharpening the picture one data point at a time.
“I’m really passionate about climate change science,” he says. “I’m trying to be a part of the solution, and I get to work on something that is meaningful, and contribute to society and the ecosystems that we benefit from and enjoy.”
PICS is working with the Columbia Basin Trust, BC Hydro, Environment and Climate Change Canada, and others to compile a public report on the state of the cryosphere in the Canadian Columbia River Basin. It’s expected in late 2019.
Pelto, B. M., Menounos, B., and Marshall, S. J.: Multi-year evaluation of airborne geodetic surveys to estimate seasonal mass balance, Columbia and Rocky Mountains, Canada, The Cryosphere, 13, 1709-1727, https://doi.org/10.5194/tc-13-1709-2019, 2019.