B.Eng, M.Sc. (Physics),
Ph.D. student (Climatology)
and Part-time Professor,
University of Ottawa
Frankenstorm Sandy is a scary beast. A hybridization between a tropical hurricane and a mid-latitude cyclone, her behavior is not natural at all. Moving northward off the east coast, Sandy is turning left toward land instead of right toward the sea. Sandy’s being blocked from moving north by a high pressure area of enormous magnitude, and being sucked west by a low pressure region of very exceptional (and highly unusual) strength.
Thus the designation “Frankenstorm”.
So why is Sandy turning left towards the U.S. east coast? That’s where meteorology comes in - and the meteorology is now a lot different thanks to climate change. How so?
As I wrote in my last blog, push something and it moves a little … push it a little more and it moves a little more. This is called a “linearity” response. But sometimes a little push can lead to something totally unexpected! This is called “nonlinearity” and, contrary to what one might think, nonlinearities are inherent in most systems - like our atmosphere. Until recently, our atmosphere and oceans behaved like linear systems: incremental dumping of greenhouse gases into the atmosphere caused incremental changes, like rising temperatures and predictable rates of ice melt. But things are now changing unexpectedly fast – nonlinearity is kicking in! Make no mistake about it, Frankenstorm Sandy IS a nonlinearity event; totally unpredicted and totally unprecedented - the latest example of global weirding.
|NASA image with data from the U.S. Defense Meteorological Satellite Program’s Special Sensor Microwave/Imager. |
The line on the image shows the average minimum extent from the period covering 1979-2010, as measured by satellites.
If you think this storm is bad, get used to it. Frakenstorms like Sandy will become commonplace, the new norm, as it were.
As I write this blog for Sierra Club Canada, Frankenstorm Sandy maintains (and may even be gaining) strength as she approaches the U.S. coast. She’s expanded in size so much that gale force winds are now covering an area over 1500 km in diameter.
Sandy is now the largest hurricane ever recorded in the Atlantic basin. Her winds have reached 150 kilometers per hour and her barometric pressure has dropped to 940 millibars (among the lowest pressure ever measured anywhere in the continental United States).
As I’ve been predicting in my blog since August, hold on folks… the times they are a-changin’.
Originally posted October 29, 2012, at Sierra Club Canada; posted here with author's permission