There are a number of reasons why sea ice looks set to decrease dramatically over the next few weeks. On above image, extent for 2015 looks set to soon cross the lines for the years 2007 and 2011, while the sea ice today is in an even worse condition than one might conclude when looking at extent alone.
Thick sea ice is virtually absent compared to the situation in the year 2012 around this time of year, as illustrated by the image below that compares sea ice thickness on August 30, 2012 (left) with August 30, 2015 (right).
Furthermore, sea surface temperatures are very high. The North Pacific, on August 31, 2015, was about 1°C (1.8°F) warmer than it was compared to the period from 1971 to 2000, as illustrated by the Climate Reanalyzer image on the right.
As the image below shows, sea surface temperature anomalies are very high around North America, both in the Pacific Ocean and in the Atlantic Ocean.
The image below shows sea surface temperatures on August 30, 2015, indicating that a huge amount of ocean heat has accumulated in the Atlantic Ocean off the coast of North America.
The Gulf Stream is carrying much of this warm water toward the Arctic Ocean. Additionally, warm water from the Pacific Ocean is entering the Arctic Ocean through the Bering Strait.
There still are a few weeks to go before sea ice can be expected to reach its minimum, at around half September 2015, while sea currents will continue to carry warmer water into the Arctic Ocean for months to come.
There is a strengthening El NiƱo, while more open water increases the chance that storms will develop that will push the last remnants of the sea ice out of the Arctic Ocean, as discussed in earlier posts such as this one. Storms can also mix warm surface waters all the way down to the seafloor, as discussed in this earlier post. Typhoons increase this danger. The above image show three typhoons in the Pacific Ocean on 30 August, 2015, and the Climate Reanalyzer image on the right shows them on September 1, 2015.
These typhoons are headed in the direction of the Arctic. The Climate Reanalyzer forecast for September 8, 2015, below shows typhoons in the Pacific Ocean close to the Arctic Ocean, as well as strong wind over the Arctic Ocean.
Sam, once there is an ice-free Arctic (this year, next year...) is it possible to freeze up again and go back and forth for a while, or will it just get warmer and warmer?
ReplyDeleteIt may be possible to halt or - even better - reverse the decline of sea ice in the Arctic, but such efforts will be in vain without comprehensive and effective action that also includes dramatic cuts in emissions, removal of greenhouse gases from the atmosphere and oceans, etc, as discussed in the Climate Plan.
DeleteI was wondering what will likely happen without deliberate intervention...whether you see a zig-zaggy decline or a plummet. Since once the ice is melted the water will heat faster, no?
DeleteA BAU (business as usual) scenario will lead to an ice-free period that will increase each year in length. Even though air temperatures will be much lower in winter than in summer, rising ocean heat will make it ever harder for sea ice to form. Also see this page.
DeleteThanks Sam.
DeleteTell Gail about the tunnels Sam...
ReplyDelete... I find this rather terrifying.
ReplyDeleteTunnels?
ReplyDeleteYes, these tunnels
Deletehttp://arctic-news.blogspot.com/2015/02/multiple-benefits-of-ocean-tunnels.html
Enjoy
Thanks to Nick Breeze, I landed on this excellent article
ReplyDeleteAs 2015 smashes temperature records, it's hotter than you think
http://www.climatecodered.org/2015/08/as-2015-smashes-temperature-records-its.html
I have been wondering for a while how far away we were from that 0.85°C warming we keep hearing or reading about.
The answer is there, just don't fall off your armchair when you read it...
Yes, excellent post by David Spratt, reposted at the Arctic-news blog.
DeleteYes, it's really an excellent post, I'm want to try and get it into some French newspaper...
DeleteI'm trying to get a reply from David Spratt to have permission to translate and respost it on
http://leclimatoblogue.blogspot.ca/
I'm almost done wtih the translation and I can't find any other way to get to him except the comments...
Would appreciate eny help with that if possible.
Thank you and have a nice week-end :-)
David Spratt is on facebook at facebook.com/david.spratt.737
DeletePlease check out 2015 lectures by Peter Wadhams, John Nissen, David wasdell, jennifer Francis, and Paul Beckwith (on arctic sea ice) things look pretty gloomy.
ReplyDelete