Superstorm Sandy and Climate Change

Dumbo District  Flooded Oct 29, 2012

From Tom Zeller on HuffPo: "Hurricane Sandy's Storm Surge Wreaks Havoc As Its Energy And Trajectory Stun Experts":
"As Andrew Freeman at the website Climate Central noted last week -- even as Hurricane Sandy was still gathering strength in the Caribbean -- it is rather uncommon for hurricanes with Sandy's origins to move inland into the U.S. this late in the year. 'Normally, hurricanes that form in Sandy's location do head seaward, particularly in October, when strong cold fronts moving off the East Coast tend to sweep tropical weather systems away from the mainland,' Freeman said. 'In fact, there may only have been a couple of cases in the historical record dating back to the 19th century when a hurricane took a track in October similar to the one Sandy may ultimately follow.'
"Sandy followed the path it did in part because an unusual high pressure system has been parked over Greenland. That system is acting like a block, preventing anything from pushing northward through it, including Sandy, which instead took a devastating westward turn into New Jersey and onward into Pennsylvania.
"Meanwhile, the jet stream -- the steady, eastward-moving air current that undulates around the Northern Hemisphere, including across Canada and the U.S., and which would normally sweep storms along -- has been losing speed. In some areas, the drop-off has been as much as 14 percent, according to Jennifer Francis, a research professor at the Institute of Marine and Coastal Sciences at Rutgers University. That loss of speed, Francis recently noted, could lead to storms in the East appearing to get stuck, not unlike what is now happening to Sandy over Pennsylvania.
One theory for the drop-off in jet stream speed? The steady loss of Arctic sea ice as a result of global warming.
"'There is evidence that Arctic sea ice loss might be responsible for that sort of behavior of the jet stream,' Masters said. 'Whether it was the case for this particular block, we don't know. Our sea ice losses are a relatively new phenomenon, and we don't have a lot of years of data to study. But there certainly is a lot of potential for climate change to affect a storm like this.'" (full article here)

2012: Hottest Year Ever for the US, Arctic Sea-ice at Record Low

Some effects of sea-ice loss in the Arctic:

Heating of the arctic ocean and contiguous land masses:
-Release of methane and CO2 from permafrost areas
- Increased melt of the Greenland ice-cap. In terms of sea-level rise, this is the big one- the Greenland ice-cap, in some places 3 kilometers thick, is melting rapidly. If all that ice melts and drops into the ocean, sea-levels will rise by 7 meters.
- Reduced salinity in the North Atlantic is weakening  the Atlantic conveyor circulation at the northern end, destabilizing climate in Northern Europe
- Open seas in the arctic have oil and gas exploiters planning major drilling and extraction, the burning of this additional carbon will itself  increase atmospheric CO2 and global heating

-Reduced heat differential between Arctic and mid-latitudes: reduced strength of jet stream;
    - which allows arctic air to pour down into mid-latitudes and remain there for a longer time (extreme winter cold snaps, US and Europe 2010, 2011)
    - and allows very warm air to pour into arctic areas and remain for longer (2012 flash melt of greenland ice surface)

Update, Oct 26. One of those above-mentioned arctic outpourings is underway, with our local daytime temperatures dropping 30 degrees in 2 days. This arctic blast will collide in a few days with Hurricane Sandy,  a huge storm moving up the coast toward New York City. Sandy  is  blocked from a normal northeasterly trajectory by a high pressure mass sitting over Greenland, and is expected to lurch westward directly into the most heavily populated area of North America; the resulting hybrid storm could produce severe damages and flooding. The penetration of the arctic air mass, the late season hurricane, and the high pressure mass stuck over Greenland are examples of weather effects expected to accompany climate change, and here they may hybridize and produce a real mess on the East Coast.
At the same time, the last debates of the presidential campaign of 2012 are over, and for the first time since 1988, the subject of climate change was not even broached. Instead both candidates competed in promising more drilling and oil production. 

Designer Slugs- The Beautiful Nudibranch