El Nino and Nunavut: colder weather

DWANE WILKIN
Nunatsiaq News

IQALUIT – Nunavut residents won’t benefit from warmer temperatures caused by this year’s El Nino, Environment Canada says.

In fact, if weather conditions from previous El Nino years are any indication, northerners are in for one of the coldest winters in recent times.

Amir Shabbar, a climatologist with Environment Canada who has been studying the weather phenomenon for two decades, said Asrctic temperatures typically drop below normal during El Nino years.

“I’ve looked at the northeast Arctic and the high Arctic,” Shabbar said, “and I find that those regions are consistently below normal in El Nino winters.”

Shabbar predicts that average winter temperatures in the Baffin region, for example, could be 1.5 degrees lower this year.

El Nino is the term used to describe the combination of unusual wind flows and sea currents that raise Pacific Ocean temperatures off the the west coast of South Amercia every few years.

This cyclical disruption of the ocean-atmospheric system in the tropics has important consequences for weather around the globe, including Canada.

Experts foresee warmer-than-usual winters from British Columbia through Ontario and southern and central Quebec. In other parts of the world, the phenomenon has been blamed for droughts, monsoons, sweltering heat and severe crop failures.

But not all El Nino winters are created equally.

Shabbar predicts that the shift in wind-flow patterns that is bringing milder winters to most regions of southern Canada, will continue to keep northerners locked in a deep-freeze.

“I’m afraid it is just the opposite of what it is in the South,” Shabbar said.

Here’s what is believed to be happening.

In normal, non-El Nino winters, a global air current known as the Jet Stream flows across the Pacific Ocean toward western North America, reaching Vancouver Island first, then continuing across the Prairies, the Great Lakes and into the Maritimes.

The Jet Stream’s lower latitude permits arctic air to move south periodically, sharing the cold temperatures with southern Canadians.

In El Nino years, however, the jet stream shifts much further north, reaching the Yukon first, and sweeping across the Northwest Territories, Hudson Bay and Northern Quebec.

“This jet stream does not allow this cold air to come down as frequently as it would in a normal situation,” Shabbar said. “So the cold air remains in the North and consequently the temperatures are below normal.”

The most dramatic El Nino winter in recent memory occurred in 1982-83, when temperatures in the northeastern Arctic plummeted to minus-40 degrees for prolonged periods.

Average mean temperatures for the south Baffin region range from minus-21.8 degrees to minus-25.9 degrees between December and February.

The term El Nino is a Spanish phrase meaning “Christ Child,” coined by fishermen along the coast of Ecuador and Peru to describe the warm current that typically appeared around Christmas time.

In normal non-El Nino years the trade winds blow toward the west across the tropical Pacific Ocean, piling up warm surface water in the west Pacific. This brings cold sea water from deeper levels closer to the surface near the coast of equatorial South Amercia.

During El Nino years, the trade winds in the Pacific Ocean relax. This leads to significantly warmer water temperatures, which in turn, change global wind patterns.

According to a special Environment Canada bulletin, this year’s El Nino show signs of being the strongest since sea-surface temperatures began in the earlier half of the century.

Shabbar predicted that the El Nino would have little impact on snowfall in the North.