Canadian snowpack gets thinner every decade: Environment Canada study

Canadian snowpack gets thinner every decade: Environment Canada study

Much of what used to come down as snow now happens as rain

It may not feel like it the morning after a blizzard, but Canada gets less snow than it used to — a lot less.

That’s the conclusion of scientists at Environment Canada, who have just published what they say is the most precise estimate of global snowfall yet.

“It seems like it should be easy, right? You just stick a ruler in the snow,” said Chris Derksen, a co-author of the study published Wednesday in the journal Nature.

But no.

Unlike rain, snow depth can vary widely over just a few metres depending on factors such as wind. As well, some snow is heavy with moisture and some is dry powder.

And the world’s network for snow observation is sparse, Derksen said. Add to that the difficulty of trying to estimate snow depth from satellite observations and you’ve got the beginnings of what has been a 15-year project for Derksen’s team.

“Snow is a tricky thing to measure,” he said. “We had quite a few data sets that estimated snow mass, but they were based on different techniques and they didn’t agree with each other very well.”

Working with Finnish colleagues, the federal researchers combined satellite data and on-the-ground measurements.

READ MORE: Higher-than-normal snowpacks mean parts of B.C. at risk of flooding

On average, they conclude, the world gets about 3,000 billion tonnes of snow every year.

But that’s not a static number, at least not in North America. Snowfall hasn’t changed much over Eurasia since 1980, but it is declining in Canada and the United States.

Over the last 39 years, snowfall in the two countries has dropped by about 4.6 billion tonnes a year. The paper is silent on how many shovelfuls that is, but Derksen said it’s about enough to fill almost two million Olympic-sized swimming pools with snowmelt.

The steepest drops are in the eastern part of the continent. Parts of the west have actually seen slight increases.

Derksen said regions with less snow aren’t necessarily drying out. Climate change has been shortening the season for a while, and some of what used to fall as snow now comes down as rain.

“The amount of precipitation is not decreasing.”

But snow is a lot easier to manage, he said.

“When (snow) melts, we can manage our reservoir levels and trap that meltwater. As soon as it rains, it runs off in streams.”

That difference has important consequences for big-city water supplies as well as flood threat management. The 2013 Calgary flood is an example of what can happen when unexpected heavy rains come early in the season, said Derksen.

The paper does have its uncertainties. It is unable to say much about snowpack in the mountains, for example.

But Derksen said the work goes a long way to understanding that most Canadian of elements. And it should help managers plan as snowfall changes along with the rest of the climate.

“What this study has tried to do is narrow that uncertainty.”

This report by The Canadian Press was first published May 20, 2020

Bob Weber, The Canadian Press


Like us on Facebook and follow us on Twitter.

Want to support local journalism during the pandemic? Make a donation here.

Climate changeEnvironment Canada weatherNews and WeatherSnow

Just Posted

The orange parcel was bought by the CRD for $1.1 million to add to Mount Work Regional Park. (CRD map)
Capital Regional District expands Mount Work land for $1.1 million

Privately-owned 13.8 hectares in the Highlands is ecologcically valuable

North Saanich has received a report from the Urban Development Institute calling on the municipality to expand and densify its housing options in the face of demographic and environmental changes as the municipality continues its Official Community Plan review. (Black Press Media file photo)
North Saanich asked to create more affordable, diverse housing

Urban Development Institute says community faces demographic, environmental challenges

One woman has been arrested in connection with a drug trafficking investigation. (Black Press Media file photo)
Victoria woman arrested, car and drugs seized during trafficking investigation

Multiple units combine forces for investigation, arrest

Royal Bay Secondary School’s rainbow crosswalk was vandalized shortly after being painted but by Monday, coincidentally the International Day Against Homophobia, Transphobia and Biphobia, the crosswalk had been cleaned up and students had surrounded it with chalk messages of support and celebration. (Zoe Ducklow/News Staff)
Royal Bay pride crosswalk restored following graffiti attack

Hate terms, racial slur, phallic images spray-painted at Colwood high school

Vancouver Canucks’ Jake Virtanen (18) and Calgary Flames’ Josh Leivo, front right, vie for the puck as goalie Jacob Markstrom, back left, watches during the first period of an NHL hockey game in Vancouver, on Saturday, February 13, 2021. THE CANADIAN PRESS/Darryl Dyck
Vancouver Canucks forward Jake Virtanen sued over alleged sexual assault

Statement of claim says the woman, identified only by her initials, suffered physical and emotional damages

An avalanche near Highway 1 in Glacier National Park. Avalanche Canada will benefit from a $10 million grant from the B.C. government. (Photo by Parks Canada)
Avalanche Canada receives $10-million grant from B.C. government

Long sought-after funds to bolster organization’s important work

More “strings of lights” were seen on May 15, 2021, in night sky over Vancouver Island. (File photo)
Sicamous RCMP Sgt. Murray McNeil and Cpl. Wade Fisher present seven-year-old Cody Krabbendam of Ranchero with an award for bravery on July 22, 2020. (Contributed)
7-year old Shuswap boy receives medal of bravery for rescuing child at beach

Last summer Cody Krabbendam jumped into the lake to save another boy from drowning

B.C. Health Minister Adrian Dix and provincial health officer Dr. Bonnie Henry update the province’s COVID-19 vaccine program, May 10, 2021. (B.C. government)
B.C.’s COVID-19 infection rate stays below 500 a day over weekend

14 more deaths, down to 350 in hospital as of Monday

Royal Bay Secondary School’s rainbow crosswalk was vandalized shortly after being painted but by Monday, coincidentally the International Day Against Homophobia, Transphobia and Biphobia, the crosswalk had been cleaned up and students had surrounded it with chalk messages of support and celebration. (Zoe Ducklow/News Staff)
B.C. high’s school’s pride crosswalk restored following ‘hateful’ graffiti attack

Hate terms, racial slur, phallic images spray-painted at Greater Victoria high school

Terrance Mack would have celebrated his 34th birthday on May 13, 2021. Mack’s family has identified him as the victim of a homicide in an apartment on Third Avenue in Port Alberni sometime in April. (SUBMITTED PHOTO)
Family identifies Ucluelet man as victim of Vancouver Island homicide

Terrance Mack being remembered as ‘kind, gentle’ man

Nathan Zuk had left his mother’s residence in Whaletown on Cortes Island in mid-December 2020 in a 14’ skiff rowboat and headed to an unknown location near the Pryce Channel, Deer passage, or Toba Inlet. Photo courtesy RCMP
RCMP need help finding man who set off from Cortes Island in 14-foot rowboat

Nathan Zuk left in December, may have been last seen in Toba Inlet approximately three weeks ago

Emergency service workers at the collision scene along Highway 4 in Hilliers on Sunday, May 16. A motorcyclist was airlifted to hospital by BC Air Ambulance and later died. (Collin C photo)
UPDATE: Motorcyclist dies from injuries sustained in Mid-Island highway collision

BC Highway Patrol says impairment not a contributing factor in crash

An avalanche near Highway 1 in Glacier National Park. Avalanche Canada will benefit from a $10 million grant from the B.C. government. (Photo by Parks Canada)
Avalanche Canada receives $10-million grant from B.C. government

Long sought-after funds to bolster organization’s important work

Most Read