Extreme Winters: When Jet Streams go Whonky

If this is global warming, why are so many people wading through more snow than ever before! Remember the snowfalls in New York and Washington DC.  And the roofs caving in Ontario & Quebec...?? Frozen fountains in Rome!? People trying to escape winter are getting hit with unusual snowstorms!

If you've attended my lecture on Ocean Currents, Changing Climates & Extreme Storms you might remember that I prefer the term Climatic Instability to Global Warming.  There's growing evidence of instability in the polar jet stream. The deterioration of the Polar Vortex could be leading to some of these extreme winter weather events.

The NOAA has an excellent website to explain the Warm Arctic, Cold Continents pattern. 

The graphic below shows the historic, relatively-stable polar vortex of 1968-96 compared to the destabilized vortex pattern we're experiencing lately in December (e.g., Dec 2009). 

The low Arctic pressure field is shown by purple colors in the figure for December 1968–1996. Strong Polar Vortex winds circle this pressure field, trapping cold air in the Arctic regions. In December 2009, this pattern broke down, Polar Vortex winds weakened (green colors) and cold Arctic air (which parallels the color contours) flowed southward.  Graphic credit NOAA

"This change in wind directions is called the Warm Arctic-Cold Continents climate pattern,” writes James Overland of the U.S. National Oceanic and Atmospheric Administration (NOAA). “The jet-stream breakdown last winter was the most extreme in 145 years of record. Loss of sea ice is certainly not the whole story behind cold mid-latitude winters, but it’s a constant push in that direction.”

“When the Polar Vortex — a ring of winds circling the Arctic — breaks down, this allows cold air to spill south, affecting the eastern United States and other regions,” says Dr. Overland. “This can result in a warmer-than-average Arctic region and colder temperatures that may include severe winter weather events on the North American and European continents.”

California Regional Weather Server provides up-to-date Jet Stream analyses, charts and archives.  Excellent resource!! Here's a current shot:

 

Thomas Homer-Dixon has done a great job of explaining the changing climatic pattern in an article in the Globe & Mail: And now the weather: nasty and brutish.   

Tail of the Dragon (True Story!)

Lizards come in all colors, shapes, and sizes – but the biggest lizard of all is truly a Dragon!  Imagine a creature that can bring down water buffalo, deer and wild pig on a regular basis.  You might think I’m kidding – but there is such a creature on a few select islands in Indonesia.  Have you heard of the Komodo Dragon (Varanus komodoensis)??

I was fortunate enough to visit Komodo Island in March on Holland America’s 2012 World Cruise as a lecturer onboard the ms Amsterdam.  Steamy tropical forests, palms, cockatoos screeching... and real live Dragons!  This would be the ultimate island for a season of Survivor!

Courtesy of Bill & Sandi Solyan

 Komodo Dragons can weigh 300 lbs and reach 10 ft in length.  They are immensely powerful and can kill an animal with one bite!  They have teeth very much like those of a shark – with a knife-sharp serrated-edge meant for tearing, not chewing.  But one bite...!?  “Give me a break,” might be a suitable response.

A Dragon wouldn’t give you a break, but I will.  Dragon saliva is crawling with so many varieties of bacteria that one bite is enough to cause septicaemia and death by blood-poisoning.  It has only recently been discovered that dragons also have venom (see Dr. Bryan Fry www.venomdoc.com), which may help speed the prey’s demise.  Once they take a good bite - causing maximum bleeding and tissue damage - the Dragon typically takes a “jaws-off” approach.  They wait for the animal to collapse from blood loss or infection and move in for the kill.  A Dragon can swallow a whole pig in 20 minutes (see video).  A Dragon can eat up to 80% of its body weight in one sitting!!  A Dragon can sack and destroy an entire medieval village in 1 hour – hey, that’s not true!!  But you get the point.  These giant lizards are a force to contend with.

Courtesy of Bill & Sandi Solyan

Search for the Dragon

After our arrival at Komodo National Park, we were given a brief overview of the route for our 1 hour trek.  Our group of approximately 20 people was accompanied by a ranger and his assistant, both armed with sticks approx. 6 ft long with forked ends.  We soon learned that the sticks are helpful when faced with an overly-eager Dragon.  The first Dragon was asleep on the trail... he was only about 7 or 8 ft long.  We were asked to go around him so as not to disturb his nap.  Ordinarily I don’t like to hike off-trail, but something in my genetic makeup kept urging me to let a sleeping dragon lie.  

Our next Dragon was about 10 ft long and built like a reptilian 300 lb bulldog.  His two foot long forked tongue flicked the air to get a good sniff of us well-fed cruise ship passengers.  His friends did the same and we found ourselves in the midst of a small pack of Dragons... five in fact.  Lucky for us they were all busy digesting a previous meal of pig or deer and thought we looked too agile and alert.  A previous group had a bit of excitement when a dragon rushed toward them for a closer look.  One ranger actually grabbed the Dragon by the tail to stop it!  And see what I mean about those forked sticks!

 Courtesy of Barbara Heywood-Chasey

Photo: George Sranko

Turns out the big ten footers aren’t the most dangerous; the 7-8 footers are the real hunters because they are lithe and quick on their feet.  (Dragons under 5-6 feet long hang out in the trees because mom and dad don’t mind snacking on youngsters when they can catch one.)  Dragons can smell blood up to 5 miles away... consequently the big ones just hang around until they catch a whiff of blood and guts and mosey on over to take over the situation.  Of course, offal isn't too awful -- it's mighty nice when it can be discovered!!