Fabled Northwest Passage begins to re-freeze

By: Dr. Jeff Masters , 2:29 PM GMT on October 12, 2007

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This summer's dramatic loss of Arctic sea ice peaked on September 15, and the polar ice cap is finally beginning to re-freeze, according to a press release issued by the National Snow and Ice Data Center on October 1. Extent of the September polar sea ice fell 39%, compared to the 1979-2000 average. To put this loss in perspective, in one year we lost as much ice as we lost during the previous 28 years. Summertime Arctic sea ice is now at 50% of what it was in the 1950s (Figure 1). One may look at at graph and wonder, but what about sea ice loss in other seasons? It hasn't been nearly so severe. True, but it is the summer ice we care most about, since summer is when the thick, multi-year ice melts, which can then precondition the Arctic for much greater ice loss in future years. As sea ice melts in response to rising temperatures, more of the dark ocean is exposed, allowing it to absorb more of the sun's energy. This further increases air temperatures, ocean temperatures, and ice melt in a process know as the "ice-albedo feedback" (albedo means how much sunlight a surface reflects). There is an excellent chance that the summer of 2007 will be remembered as the "tipping point" for Arctic sea ice, when an irreversible ice-albedo feedback process firmly established itself.



Figure 1. Arctic sea ice extent since 1900, as estimated from satellite and ship reports compiled by Walsh and Chapman (2001). Image credit: University of Illinois cryosphere group.

Northwest Passage opens for the first time in recorded history
Long before the Panama and Suez Canals made commercial trading between the Atlantic and Pacific Oceans economically feasible, ships made the long and perilous trip around the African and South America continents. Explorers, traders, and world leaders looking for faster and less dangerous shipping routes to far-away areas of the world have long eyed two routes through the ice-choked Arctic Ocean--the fabled Northwest Passage, through the cold Arctic waters north of Canada, and the Northeast Passage, extending along the northern coast of Russia. The first recorded attempt to find and sail the Northwest Passage was in 1497, and ended in failure. The thick ice choking the waterways thwarted all attempts at passage for the next four centuries. Finally, in 1905, Roald Amundsen completed the first successful navigation of the Northwest Passage. It took his ship two-and-a-half years to navigate through narrow passages of open water, and his ship spent two cold, dark winters locked in the ice during the feat. More recently, icebreakers and ice-strengthened ships have on occasion battered their way through the ice-blocked route.



Figure 2. The Northwest Passage shipping route (red line) and Northeast Passage (green line) superimposed on an ice coverage map from August 22, 2007. The Northwest Passage was ice-free and navigable for 36 days between August 14 and September 18, 2007. The Northeast Passage was blocked by a narrow strip of ice most of the summer. Image credit: National Snow and Ice Data Center.

Times are changing. In 2001, the Bering Strait, a key portion of both the Northwest and Northeast Passages, was completely ice free. This was followed in 2005 by record-breaking sea-ice melt in the Arctic, leading to the first ever recorded opening of the Northeast Passage. The fabled Northwest Passage remained closed in 2005. Arctic ice recovered a bit in 2006, and both passages remained closed. But the unprecedented melting during the summer of 2007 saw the Northwest Passage become ice-free and navigable along its entire length without the need for an icebreaker as of August 14, 2007. Remarkably, the Northwest Passage remained ice-free for 36 days, finally refreezing over a small section on September 19. The Northeast Passage was blocked by a narrow strip of ice all summer. However, this strip of ice thinned to just 30% coverage on September 25 and 26, making the Northeast Passage passable for ordinary ships on those days.

When is the last time the Northwest Passage was open?
We can be sure the Northwest Passage was never open from 1900 on, as we have detailed ice edge records from ships. It is very unlikely the Passage was open between 1497 and 1900, since this was a cold period in the northern latitudes known as "The Little Ice Age". Ships periodically attempted the Passage and were foiled during this period, and the native Inuit people have no historical tales of the Passage being navigable at any time in the past.

A good candidate for the last previous opening of the Northwest Passage was the period 5,000-7,000 years ago, when the Earth's orbital variations brought more sunlight to the Arctic in summer than at present. Prior to that, the Passage was probably open during the last inter-glacial period, 120,000 years ago. Temperatures then were 2-3 degrees Centigrade higher than present-day temperatures, and sea levels were 4-6 meters higher.

Final thoughts
If we have reached the tipping point for Arctic ice, what are the implications? I'll discuss this more in a future blog. Sea ice is very complicated, and it is not a sure thing that we have reached the tipping point. For more on the complexities of sea ice, read wunderblogger Dr. Ricky Rood's latest blog.

NASA has posted a beautiful satellite image of the Arctic ice cap at the September 15 2007 minimum, showing the open water of the Northwest Passage.

I thank Edalin Michael of the University of Michigan's School of Natural Resources and Robert Grumbine of NOAA's Sea Ice Group for their contributions to this blog.

References
Walsh, J.E and W.L.Chapman, 2001, "Twentieth-century sea ice variations from observational data", Annals of Glaciology, 33, Number 1, January 2001 , pp. 444-448.

Jeff Masters

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647. katadman
5:26 PM CDT on October 12, 2007
How's Patrap doing after surgery?
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646. nash28
10:25 PM GMT on October 12, 2007
Ya know, October is the time for W FL to be on guard. With the fronts coming down farther SWD, systems in the Gulf tend to get turned towards the FL coast.
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645. Hhunter
10:17 PM GMT on October 12, 2007
how many of you guys think computer models of climate 50 to 100 years out are right when they are not good 5 to 10 days out ..lol..go open a coolaide stand..and sell gw coolaide
Member Since: August 19, 2007 Posts: 0 Comments: 2974
644. Floodman
10:24 PM GMT on October 12, 2007
Well, they're certainly getting wet, but it looks as though their weather is trying to get up this way...
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643. nash28
10:24 PM GMT on October 12, 2007
Thanks man...

Been away from the tropics all week.
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642. beell
10:19 PM GMT on October 12, 2007
New Low done?
Enter smelly giant.
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641. katadman
5:23 PM CDT on October 12, 2007
Just hangin', trying to get a bead on what might or might not develop down there where my wife and son are traveling these days.
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640. Floodman
10:23 PM GMT on October 12, 2007
Yep nash...but I think they're not taking into account the early demise of shear in the GOM...
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639. nash28
10:22 PM GMT on October 12, 2007
Hey everyone....

Can't stay long, but I noticed the ECMWF has a little weak system coming ashore near Big Bend next week.
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638. Floodman
10:21 PM GMT on October 12, 2007
I read those too, katadman...I have to beat all those High School kiddies on the gaming servers, don't I? How are you, sir?
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637. katadman
10:15 PM GMT on October 12, 2007
And I thought all you read is gaming magazines, Flood.
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636. Floodman
10:11 PM GMT on October 12, 2007
634. seflagamma 10:07 PM GMT on October 12, 2007
so, do we have possible development out there are not????



The models are starting to line up on it...the 18Znam agrees with the CMC and GFS...I haven't looked at the GFDL...the Vorticity looks as though SOMETHING is going to form in the GOMEX and likely effect the Central to east gulf coast in the next 7 days, but what? TS? a Hurricane? Looks to be relatively weak, and that having been said, the next sets of model runs might build it in intensity. Again, with nothing really out there to measure, the models are showing was might be, maybe, if we squint at it just right...watch what the shear does, and whether the moisture builds back into the GOMEX
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635. aubiesgirl
10:12 PM GMT on October 12, 2007
LMAO..you guys crack me up
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634. seflagamma
6:06 PM AST on October 12, 2007
so, do we have possible development out there are not????

Member Since: August 29, 2005 Posts: 301 Comments: 40945
633. pablolopez26
10:04 PM GMT on October 12, 2007
It's an mp3 player produced by Microsoft to compete with the iPod...

You gotta hand it to M'Soft!!! I wouldnt want to be on their sites!! Wow...
632. Floodman
9:58 PM GMT on October 12, 2007
here you go, Ike:
Link one good tune deserves another...
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631. NRAamy
2:54 PM PDT on October 12, 2007
ah, thanks....I'm not up on my gadgets...

too much time spent with angry Good Humor bars I suppose....
Member Since: January 24, 2007 Posts: 317 Comments: 31946
630. Floodman
9:53 PM GMT on October 12, 2007
627. IKE 9:52 PM GMT on October 12, 2007
Thanks, Ike...I was listening to Mott the Hoople, but I'll break for the boys!

LOL.

All The Young Dudes!



Actually, All the Way to Memphis...
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629. Floodman
9:54 PM GMT on October 12, 2007
Oh, well, a touch of grey
Kind of suits you anyway...

Ooops...sorry, was that my outside voice?
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628. Floodman
9:52 PM GMT on October 12, 2007
625. ihave27windows 9:51 PM GMT on October 12, 2007
Domokun plays a Flying V



OMG! An angry, ambulatory poo/good humor bar playing a Gibson guitar!
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627. IKE
4:52 PM CDT on October 12, 2007
Thanks, Ike...I was listening to Mott the Hoople, but I'll break for the boys!

LOL.

All The Young Dudes!
Member Since: Posts: Comments:
626. Floodman
9:50 PM GMT on October 12, 2007
619. IKE 9:44 PM GMT on October 12, 2007
Floodman 4:41 PM CDT on October 12, 2007
IKE, three orbiting lows at 84 hours, center in the Yucatan, with a WNW drift? Looks like the CMC and GFS solutions from here...

Yup....here's one for U Flood-man.......




Thanks, Ike...I was listening to Mott the Hoople, but I'll break for the boys!
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625. ihave27windows
4:38 PM CDT on October 12, 2007
Domokun plays a Flying V
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624. Floodman
9:48 PM GMT on October 12, 2007
621. CosmicEvents 9:46 PM GMT on October 12, 2007
I'm a gambler...and a contrarian. I bet that now that it appears that so many have tired of discussing potential development in the tropics, this raises the chances greatly that something will indeed spin up. And it won't be naked. Of course, the notion that what we say on the blog affects Mother Nature is ridiculous. But those models are falling into place one after the other on something happening.



I was waiting for this! Heisenberg Uncertainty raises it's ugly head in the tropics blog!
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623. Floodman
9:47 PM GMT on October 12, 2007
618. NRAamy 9:42 PM GMT on October 12, 2007
Jerry Garcia, err...I mean Flood...what is a Zune?


It's an mp3 player produced by Microsoft to compete with the iPod...
Member Since: Posts: Comments:
622. Floodman
9:41 PM GMT on October 12, 2007
616. pottery2 9:40 PM GMT on October 12, 2007
Good Afternoon.
The NASA image of the Arctic sea ice is fearsome. In visual terms, we can see the amount of ice-loss, very clearly.
What exactly does this mean for climate generally, and for Tropical summer climate, in particular ?
This sea ice loss is the result of warming Northern temperatures ( obviously ), and this in turn must ultimately affect wind-flow from the poles to the Tropics, and vice versa. The loss of sea ice must obviously result in changes to the Gulf stream current, which depends on temperature variations to keep the flow going, and to regulate the depth of these flows. ( less ice, warmer water )
Until we have the research results to prove otherwise, it would seem prudent to attempt to reduce our heat emmissions into the atmosphere in the shortest possible time frame.

The long term consequences would seem pretty grim otherwise.



Hi, pottery2! It's about salinity as much as anything else...the flow stops if the salinity drops too low...if that happens, then the northern latitudes get colder, the warmer latitudes get warmer (to a point). Once the northern lats get to the tipping point, albedo takes over and the globe starts to cool...incoming solar radiation is reflected back into space and we have a new ice age. Confusing, yes, but thermodynamically it makes perfect sense...this theory posits that Global Warming (there, I said it!) can only go so far before the bounce back occurs, due to the actual DROP in polar temps spreading across the northern lats due to loss of the oceanic conveyor current...I read too much!
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621. CosmicEvents
9:41 PM GMT on October 12, 2007
I'm a gambler...and a contrarian. I bet that now that it appears that so many have tired of discussing potential development in the tropics, this raises the chances greatly that something will indeed spin up. And it won't be naked. Of course, the notion that what we say on the blog affects Mother Nature is ridiculous. But those models are falling into place one after the other on something happening.
Member Since: Posts: Comments:
620. CaneAddict
9:42 PM GMT on October 12, 2007
Good evening all!
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619. IKE
4:43 PM CDT on October 12, 2007
Floodman 4:41 PM CDT on October 12, 2007
IKE, three orbiting lows at 84 hours, center in the Yucatan, with a WNW drift? Looks like the CMC and GFS solutions from here...


Yup....here's one for U Flood-man.......

Link
Member Since: Posts: Comments:
618. NRAamy
2:41 PM PDT on October 12, 2007
Jerry Garcia, err...I mean Flood...what is a Zune?

Member Since: January 24, 2007 Posts: 317 Comments: 31946
617. Floodman
9:39 PM GMT on October 12, 2007
IKE, three orbiting lows at 84 hours, center in the Yucatan, with a WNW drift? Looks like the CMC and GFS solutions from here...
Member Since: Posts: Comments:
616. pottery2
5:18 PM AST on October 12, 2007
Good Afternoon.
The NASA image of the Arctic sea ice is fearsome. In visual terms, we can see the amount of ice-loss, very clearly.
What exactly does this mean for climate generally, and for Tropical summer climate, in particular ?
This sea ice loss is the result of warming Northern temperatures ( obviously ), and this in turn must ultimately affect wind-flow from the poles to the Tropics, and vice versa. The loss of sea ice must obviously result in changes to the Gulf stream current, which depends on temperature variations to keep the flow going, and to regulate the depth of these flows. ( less ice, warmer water )
Until we have the research results to prove otherwise, it would seem prudent to attempt to reduce our heat emmissions into the atmosphere in the shortest possible time frame.

The long term consequences would seem pretty grim otherwise.
Member Since: Posts: Comments:
615. Floodman
9:38 PM GMT on October 12, 2007
613. NRAamy 9:37 PM GMT on October 12, 2007
I like to think of him an as angry Good Humor Bar...

;)


Maybe a Zune with a 'tude?
Member Since: Posts: Comments:
614. Floodman
9:34 PM GMT on October 12, 2007
602. NRAamy 9:06 PM GMT on October 12, 2007
Pablo....Domokun is not poo....google him and find out...

:)



The Japanese are a very strange people...Domokun lives in a cave with an old couch potato rabbit and two bats, one a drunk...you have to admit that he sort of looks like poo...I mean really LOL
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613. NRAamy
2:37 PM PDT on October 12, 2007
I like to think of him an as angry Good Humor Bar...

;)
Member Since: January 24, 2007 Posts: 317 Comments: 31946
612. pablolopez26
9:26 PM GMT on October 12, 2007
Pablo....Domokun is not poo....google him and find out...

:)


Ha... I know... I was only messing...
611. Floodman
9:25 PM GMT on October 12, 2007
601. TampaSpin 9:06 PM GMT on October 12, 2007
Looks like ex94L is almost back in the carribean


Yep...the energy and spin are getting close...sometime in the overnight, certainly
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610. IKE
4:20 PM CDT on October 12, 2007
Statement as of 5:30 PM EDT on October 12, 2007

For the North Atlantic...Caribbean Sea and the Gulf of Mexico...

The National Hurricane Center has issued the last advisory on
Tropical Depression Fifteen located about 905 miles east of
Bermuda. Future information on this system can be found in high
seas forecasts issued by the National Weather Service...under AWIPS
header nfdhsfat1 and WMO header fznt01 kwbc.

A nearly stationary and large area of disturbed weather over
portions of Central America...the northwest Caribbean Sea...Cuba and
Jamaica is associated with a broad area of low pressure. Since
most of the system is now over land...tropical cyclone formation is
not expected. However...heavy rains will likely continue over this
area for the next few days...primarily over portions of the Pacific
coast of Central America.

Elsewhere...tropical cyclone formation is not expected during the
next 48 hours.

$$

Forecaster Blake
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609. catwomen
9:13 PM GMT on October 12, 2007
566. pablolopez26 8:38 PM GMT on October 12, 2007 Ladies ladies, please can we all stop with the whole rules thingie... Sometimes we will have off topic discussions, geez... Now this from Tahiti... Enjoy...





That's a nice picture Pablo. Now that's what I call vacation.
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608. amazinwxman
9:13 PM GMT on October 12, 2007
so is x-94L going to make it back into the water or not?
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607. kmanislander
9:10 PM GMT on October 12, 2007
Well I am out for now. Not a lot going on so will be on and off the blog from time to time.

Have a nice evening and a great weekend

Member Since: August 19, 2006 Posts: 0 Comments: 15948
606. NoNamePub
9:09 PM GMT on October 12, 2007
Have a good Weekend Folks...and try to behave!
: )
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605. IKE
4:09 PM CDT on October 12, 2007
All-important 18Z NAM model run is.........

Link
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604. latitude25
5:04 PM EDT on October 12, 2007
"computer models that project out 50 to 100 years when they are not even right 5 days out then you are drinking the cool aide my friend."

HHunter, I hate to get into GW debates, because I do study climate change.
So just the facts, no debate.

GW models are based on the "fact" that more heat creates more cirrus clouds, which trap more heat, which creats more cirrus clouds.
The main ingredient in the GW models and called a positive feedback loop.

It has just been shown that all the models for GW are wrong. More heat produces less cirrus clouds, which release more heat,...

...a negative feedback loop.

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603. NRAamy
2:06 PM PDT on October 12, 2007
kman...my only vacations will be to Miami for quite awhile...

:)

Member Since: January 24, 2007 Posts: 317 Comments: 31946
601. TampaSpin
9:06 PM GMT on October 12, 2007
Looks like ex94L is almost back in the carribean
Member Since: September 2, 2007 Posts: 179 Comments: 20448
600. kmanislander
9:03 PM GMT on October 12, 2007
Amy

I stand corrected ( but still give the Caymans a try AFTER Tahiti )!
Member Since: August 19, 2006 Posts: 0 Comments: 15948
599. pablolopez26
9:03 PM GMT on October 12, 2007
Hey NRA Amy is that little caricature thingie representative of poo... Ive seen it before... Its like Japanese or something... He has like songs and stuff... LOL
598. brazocane
9:03 PM GMT on October 12, 2007
hey Pablo did you know about a hundred years ago the water here was as clear as it is around Alabama. I think the jet stream moved and we now get all the sediment from the Mississippi delta.
Member Since: August 23, 2006 Posts: 0 Comments: 678
597. NRAamy
9:02 PM GMT on October 12, 2007
I live in Southern California...Tahiti is closer...


:)
Member Since: January 24, 2007 Posts: 317 Comments: 31946

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Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.

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