Fires could go 'pyro'

NASA field campaign gives scientists up-close look at Sask. fires

Margaret Munro, Canwest News Service
Published: Friday, July 04, 2008
 
Scientists say wildfires in northern Saskatchewan could go "pyro" this weekend, sending ash, smoke and gases soaring more than 10 kilometres up into Earth's upper atmosphere.
 
It is one of the more spectacular ways nature regenerates the northern boreal forest -- and one with such far-ranging implications that NASA has two research planes and 120 scientists in Cold Lake, Alta., tracking the blazes.
 
"It's the same as having a volcano go off," said Canadian fire expert Brian Stocks of the "pyro-convection" that could occur as early as today.

A cool front moving in over the fires is setting up the kind of explosive conditions that can send smoke billowing into the stratosphere, which starts at about 10 kilometres.
 
Pyro-convection is also associated with "blow-out" fire conditions on the ground, fuelling the fires and speed they travel at, says Stocks. "Basically the fire accelerates the convection and the convection accelerates the fire."
 
He is sympathetic to the northern communities evacuated because of the fires, which have burned more than 4,000 square kilometres.
 
But the blazes are giving researchers an unprecedented close-up look at boreal fires, which are expected to grow more common as the climate changes.
 
"We've been lucky. The most active fires in Canada are right next door," says atmospheric chemist Daniel Jacob of Harvard University, a lead scientist on the three-week NASA field campaign being run out of a hangar at the Canadian military base in Cold Lake.
 
There are about 120 scientists from around the world at the command post, two planes based in Cold Lake and a third, a B-200 King Air, in Yellowknife.