Old and New Tech Meet in the Snow
Complementary techniques combine to give scientists a clear look at British Columbia’s changing snowpack.
Scientists marvel at new technology that allows them to do their work in ways they previously could’ve only imagined. But new tech doesn’t mean old fieldwork techniques are entirely obsolete. Far from it. Old and new science approaches complement each other—even when one way involves considerably more sweat and elbow grease. An airplane still needs guidance from people on the ground, especially when that airplane’s mission is to measure snow.
In mid-March, a team of three hearty researchers and bags of heavy gear are dropped by helicopter into the wintry backcountry of Mount Arrowsmith, the highest mountain on southern Vancouver Island in British Columbia. It’s the first of five visits for the scientists scheduled over the next few months. After setting up camp at an elevation of 1,450 meters, the team begins looking for places to probe and core. They want to see how deep the snow is in that exact spot.
“It’s all about measuring snow depth to figure out how much water we have stored,” says Hakai researcher Will McInnes, part of the team on Mount Arrowsmith.
Calculating snow depth is key to understanding how much water the snowpack holds, and how that amount fluctuates as the climate changes. But snow isn’t an even blanket across the landscape. They’ll have to sample a whole bunch of spots to get a precise estimate for the entire area.
Once a suitable sample spot is found, one of the three team members—McInnes, Bill Floyd, or Alison Bishop—sends the long, tent pole–like probe as deep as it will go. That’s the relatively easy part.
Then they assemble the series of hollow aluminum tubes. The bottom tube has a serrated stainless steel cutting bit at the tip, while the top has a bar to crank and dig the core down through the snow and ice layers until it hits solid ground. The core is brought back to the surface and weighed using a modified fish scale. From that weight and depth, scientists calculate the snow’s density and how much water is trapped in the snowpack.
“I was surprised how deep the snow was,” says McInnes. “Drilling down the core by hand, sometimes the deepest was over four meters. It’s an extreme ab[dominal] workout.”
The coring core aerobics are especially grueling in 2021—this winter was the deepest snow measured at the Mount Arrowsmith weather station since they began sampling the site.
“We only have five years of data at this site, so the record is pretty short,” says Bill Floyd, an adjunct professor at Vancouver Island University and research hydrologist with the Province of British Columbia. “But that’s over a meter more snow than the lowest snow year in 2018.”
At the same time, three other teams are conducting the same work on other peaks on the south coast: 80 kilometers to the northwest near Mount Washington, near Mount Cain on northern Vancouver Island, and on Mount Seymour across the Salish Sea in North Vancouver. And over all of them, an airplane buzzes overhead—the Airborne Coastal Observatory, or ACO.
“With traditional coring methods, we can get a couple hundred measurements over four days,” says McInnes. “With the plane you can get millions of measurements at all four sites in one or two days, depending on the weather.”
The ACO plane is outfitted with an impressive array of equipment, including LiDAR, which uses lasers to map the surface of the landscape. By flying at the same time the teams work on the ground, the snowpack data from the plane is literally ground-truthed.
The advantage of the plane is that it can measure everything, including snow-covered cliffs, crags, and cornices where the ground team can’t safely work. So why not just fly the plane and leave the cores at home? It isn’t just because the scientists like to get out for an end-of-season ski.
Snow and ice can accumulate at different densities depending on the conditions and where they settle on the landscape. To determine how much water is trapped in the snowpack, scientists need to know the density in various spots. The more precise measurements on the ground are also key to validate the LiDAR data, which is more prone to sources of error.
It’s not all bluebird skies and fresh powder, either. Ground-truthing the snowpack is hard, chilly work. “Getting out of bed in the morning is tough,” says McInnes. “Frozen boots. Frozen water bottle. Ice-crusted tent.”
Even if the technology on the plane seems like a replacement, we still need the ski team to crank a core-too.