Predicting hurricanes under goes a sea change
Climatologists say they have cracked the code for predicting hurricanes up to 10 years in the future.
And in what is certain to be controversial, they’ve done it by using a climate prediction model that factors in internal as well as external factors.
That means “external” factors such as greenhouse gases, volcanoes or aerosol sprays are part of the reason for the increase in one of nature’s most destructive forces.
“This is the first time this has been achieved,” lead researcher Doug Smith told the Star on Thursday. “And, yes, it is controversial. There is a lot of debate over external factors.”
What the study, published in the recent Nature Geoscience, has not done yet is pinpoint which of those largely man-made “external factors” are behind the hurricanes. Researchers will do that, said Smith, by taking them out “one at a time” and testing each.
A key feature of the study was also “hindcasting”: checking the models backwards from 2007 to 1960 to see if the theory holds up. Previous forecasts didn’t use as complex or long-ranging data.
Insurance companies are highly interested in such predictions, said Smith. While previous yearly forecasts started May 1 — the beginning of the hurricane season — Smith and his team backed that up to Nov. 1 — before annual insurance contracts are in place.
“There is increasing interest in what’s going to happen in the next few years,” said Smith, who works from the MetOffice in Exeter, England.
He and his team concentrated on North Atlantic hurricanes because “the Atlantic Ocean was the most predictable” in its sea surface temperatures.
As well, the number of North Atlantic hurricanes has been “increasing substantially since the 1970s,” he said.
What surprised researchers was the importance of the sea temperatures around Greenland on climate in the tropical Atlantic, he said.
“Normally, we though of it the other way around.”
The team expects to start making hurricane forecasts in the next few months, said Smith. And the prediction model can be extended to other vital climate information, such as rainfall in Africa and North America, he said.
-- Lesley Ciarula Taylor, Staff Reporter