Wednesday, July 03, 2013

The Jet Stream, The Calgary Floods, And Global Warming

One day I want to do an in-depth post on gradually changing attitudes among climate scientists re attributing individual events to global warming.  This is not that post.  Instead I've just ripped some text from Dr. Jeff Masters at Wunderground that talks about how unusual patterns in the jet stream brought Alberta its great flood:

...June 18 - 22, when a ridge of high pressure over Alaska broke all-time heat records in the state, with unofficial readings as high as 98°F. A low pressure system became trapped over Alberta, Canada, bringing the city of Calgary a $3 billion flood disaster. This was the most expensive flood in Canadian history, and third most expensive natural disaster of any kind for the country. The only more expensive disasters were a 1989 wildfire ($4.2 billion) and a 1977 drought ($3 billion.)


When the jet stream goes into one of these extreme configurations, it freezes in its tracks for weeks, resulting in an extended period of extreme heat or flooding, depending upon where the high-amplitude part of the jet stream lies. The scientists found that because human-caused global warming is causing the Arctic to heat up more than twice as rapidly as the rest of the planet, a unique resonance pattern capable of causing this behavior was resulting. According to an email I received from German climate scientist Stefan Rahmstorf, one of the co-authors of the study, unusually extreme jet stream amplitudes likely played a role in the May - June Central European flooding event.

So there you have it.  For now.


MgS said...

To put it in perspective, the flooding in YYC was far worse than the 2005 flooding, and possibly worse than a major flood that happened in the first half of the 20th century.

There was minor flooding in 2011 as well, although it didn't make the headlines.

If 2005 was a "once in a century" event, then you have to start asking why a flood that is over double the magnitude of that flood happened less than a decade later.

The Mound of Sound said...

There are many questions that are going unasked, MgS. When will the next flood hit? How severe will it be? How badly degraded has Calgary's infrastructure been from past severe events and how vulnerable will it be to future, potentially more severe events?

It's like betting on a prize fight. It's not so much whether your guy can take a punch but just how many punches can he take before he's out for the count. That's a discussion nobody wants to have.

Paul Kuster said...

This back when it was global cooling we should've been freaked out about.
Fool me twice........

bigcitylib said...

I thought Paul was just an anti-wind guy but he's actually gone the full crazy.

Paul Kuster said...

Crazy? Coming from you, I'll take that as a compliment, thank-you. Just keep posting desperately overreaching linkages to "global warming". It provides great amusement to those of us who are significantly more scientifically literate.

Steve Bloom said...

More scientifically literate, and yet nearly all scientists qualified to speak on the subject disagree? Sorry, Paul, no cigar.

Paul Kuster said...

You guys remind me of those WWII Japanese soldiers on those remote Pacific islands who thought the war was still on years after it was over.


Smoke'em if you got'em