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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997. guygee
8:34 AM GMT on October 13, 2007
For anyone who thinks that real climate scientists have not already extensively studied the "heat island effect", please see the United States Historical Climatology Network site. In particular, see the Quality Control, Homogeneity Testing, and Adjustment Procedures link for details. Online documentation describing the UNITED STATES HISTORICAL CLIMATOLOGY NETWORK MONTHLY TEMPERATURE AND PRECIPITATION DATA set is available, and the data, metadata and documentation can be downloaded here.

The "heat island effect" is a tired old argument that may have been once valid, but the dataset above is detrended to account for this effect as well as other errors in the historical record.

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996. UYA
8:37 AM GMT on October 13, 2007
If you want to argue that global warming is not a reality than you should move on past this tired old debunked argument.

I can argue this point till you cry my friend.
You will actually break down and be reduced to tears.
Simply because you have not presented the most important fact.
You espouse scientific extrapolations. You put forth a vehicle that is supposed to transport us all from here to wherever there is.
Weak scientific consensus is not the ride I choose to hitch.
The fact is......science is using faulted data.
Until that is closer to reality....there is no CONUS warming.
That is all believed due to faulty input data.
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995. UYA
8:33 AM GMT on October 13, 2007
They wouldn't accept my answers.
I failed the test I guess. Whoopah!
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994. guygee
8:06 AM GMT on October 13, 2007
UYA - Complete accuracy is a physical impossibility. Consider: there is a "true value" for any physical parameter, but the measurement device inevitably introduces error via limited precision, device imperfections that affect repeatability (variations of the measured value given a constant true value) and through other device-dependent processes that we may lump together simplistically under the heading of "random errors".

What is important is whether we can put an absolute upper and lower limit on the errors in all of the measurements that are inputs into our model. It is also very useful if we can statistically analyze the errors in terms of the underlying distributions and any potential biases. Given we can do this, than we can perform "Worst case analysis" of the error in our model, and assign probabilities to the output in our models.

This aspect of modeling has been developed and well-known by scientists for decades or longer...the "heat island" effect can be studied by measuring the potential biases and varying the inputs to the models to account for differing initial conditions and "post-prediction" matching of past conditions. This issue has been extensively studied and well-addressed by the scientific community. If you want to argue that global warming is not a reality than you should move on past this tired old debunked argument.
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993. moonlightcowboy
8:26 AM GMT on October 13, 2007


I only scored 50 percent correct. But, I found it interesting, and obviously, maybe should do more reading on the subject. Just CLICK on the above picture to take the test. It's brief, 10 questions and explanations are given.
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992. UYA
8:25 AM GMT on October 13, 2007
All information is much appreciated Cowboy. Thanks.
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991. moonlightcowboy
8:13 AM GMT on October 13, 2007
Just doing some reading on another site and found this. Personally, not jumping in with an opinion of the GW issue, but I will say that, I'm skeptical over issues proclaimed that don't support equally observed and recorded data through the eons of time that the planet has been around.

This is what I found:

Orbiting satellites provide the most accurate global temperature readings -- accurate to 0.1 degree C. Interestingly, in the 18 years that satellites have been recording temperature they have actually showed a slight decrease in average global temperatures.

Ground-based thermometers that were originally in rural areas have been reading increasingly hotter temperatures with time due to urban encroachment. The asphalt and concrete structures replacing green leafy plants makes for hotter local ground temperatures. This phenomenon is known as the "urban heat-island effect" and has been well-documented by climatologist Dr. Patrick Michaels, professor of environmental sciences, University of Virginia.

In a November 1997 press release Vice President Al Gore proclaimed that 1997 was the hottest year on record. Ground-based temperature readings were the basis for this announcement. Had the data from orbiting satellites been cited the report would have been much different: no net increase in global temperatures in 1997.

--the Heartland Institute
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990. UYA
8:08 AM GMT on October 13, 2007
Heat island is not even in this discussion. I'm talking about your average "official" reporting station in average city USA!
Most are poorly located and are now obsolete and completely inaccurate due to lack of maintenance and the fact that nobody monitors the situation.
So, if you tell me the average US temp has risen by 2 or 5 degrees....I just explained it!
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989. UYA
7:58 AM GMT on October 13, 2007
Well...no I am not the first.
But I trust climatologists just as much as I do the CMC model.
They are all modeling....without accurate input...there is no possibility of getting even close to accurate.
So, if the climate modelers are using this land-based data.....which they are........I say they are full of Bunk!
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988. guygee
7:46 AM GMT on October 13, 2007
UYA - There is no doubt a heat island effect and there is a large body of scientific literature on studies of this effect and the removal of the bias due to this effect from present-day temperature records for the purpose of climatological analysis and modeling. It is common knowledge among most any competent scientist who has done any sort of measurements for scientific research that the issue of proper calibration is paramount. Do you think that you are the first person to think about this issue, or that this topic has been inadequately addressed?
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987. UYA
7:51 AM GMT on October 13, 2007
It's a well known fact that rural temperature readings have decreased.....while the city readings hav increased.
What is your temp right now? Assuming you live rurally.....then check the temp in your nearest metro area.
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986. UYA
7:40 AM GMT on October 13, 2007
What I do know to be true is that the area surrounding most sensors has become mostly asphalt areas and corrupted readings via exhaust as well as emissions....yes.
So, I invite you to visit your local "official" station and snap a photo.
While many are still as they should be....there is a 50/50 reason to distrust most readings.
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985. guygee
7:34 AM GMT on October 13, 2007
UYA - So you believe most MMTS sensors are located near air-conditioning exhausts, and so by inference this is the cause of perceived global warming? Just reading your post above, trying to understand your serious point.
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984. UYA
7:35 AM GMT on October 13, 2007
You sound like you have a thought or two.......
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983. UYA
7:26 AM GMT on October 13, 2007
That's interesting guygee.....Never thought of that "paid" writing thing....LOL
Nahh...just working on a serious point, that's all.
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982. guygee
7:06 AM GMT on October 13, 2007
UYA - Are you getting paid for blogging here, or do you actually believe what you write?
Just curious...
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981. UYA
6:53 AM GMT on October 13, 2007
I don't think his billion dollar TV ad campaign has as much effect as really hitting the trenches......Know what I mean?
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980. UYA
6:47 AM GMT on October 13, 2007
So, maybe if Al Gore is really part of the GW solution he should commit his Nobel money towards upgrading and making local reporting stations at least close to accurate??
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979. silverstripes
11:46 PM PDT on October 12, 2007
UYA,

I only said some because there are quite a few that are properly sited.
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978. UYA
6:42 AM GMT on October 13, 2007
What a shame that some of these stations data are even being used to compute the mean global data set.

They are all part of the data.
Pretty silly when you honestly see the facts.
I invite you all to visit your local reporting station and see for yourselves.
It will open your eyes for sure.
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977. silverstripes
11:33 PM PDT on October 12, 2007
I checked out quite a few pics myself and was shocked to see where some of those were placed. No wonder we are warming up. HAHA. Structures (concrete, buildings, roofs, etc.) will hold and emit heat through the night biasing your low temps on the high side as well thus bringing your mean temp even higher. What a shame that some of these stations data are even being used to compute the mean global data set.

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975. UYA
6:28 AM GMT on October 13, 2007
silverstripes....Yes Sir!
This is the largest part of the understanding process regarding warming temps.
It's pretty amazing .....there are hundreds of photos of improperly positioned sensors.
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974. silverstripes
11:21 PM PDT on October 12, 2007
UYA,

I believe you are correct. The high temps when your station is incorrectly sited will only be in that immediate area. Move the station a couple of hundred feet away in the proper siting zone and you suddenly have a normal temp and no more GW. That site rocks.


I have dealt with this in my own PWS siting. Put it too near a fence, your house, near concrete, etc.. your high temps are too high. I can not believe these stations used for "scientific" analysis are so horribly sited.
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973. UYA
6:23 AM GMT on October 13, 2007
Your basic "official" temperature sensor:



Photobucket - Video and Image Hosting



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972. stormybil
6:14 AM GMT on October 13, 2007
new model run are out most now agree with the gfs and the bahammas storm over fla . but they do form it pretty fast .
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971. UYA
6:15 AM GMT on October 13, 2007
Along with inaccurate temperature reports....there are also in-accurate rainfall reports as well.
Many reporting stations get covered by lawn irrigation and report rainfall which is not true!
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970. UYA
6:06 AM GMT on October 13, 2007
Y'all gotta deal with the fact that recorded temperatures at your so-called"official" stations are totally whacked!
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969. UYA
6:03 AM GMT on October 13, 2007
Temp is the measure of the heat in the area regaurdless it's source.-


No ....you don't believe that heat from an AC exhaust is real natural heat? LMAO!
How about Jet Wash from the airports?
Wake-up!
Temperatures are false and not correct as being recorded in most places.
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968. stormybil
6:04 AM GMT on October 13, 2007
you too mlc latters
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967. moonlightcowboy
6:00 AM GMT on October 13, 2007
"Hold down the fort and keep the gates closed!"

MLCgoodnight4.gif

Have a good sleep, stormybill, UYA, Skye and all.

MLC<---------------out for some shut-eye!
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966. Skyepony (Mod)
5:50 AM GMT on October 13, 2007
I've seen it. Proving every 10th of a degree measured in N America maynot be correct doesn't prove that the NW Passage didn't melt. It's warmer, it melted, it's gonna melt more next summer, deal with it. My point is people/countries/companies are probibly gonna fight over this gold mine that was formerly worth nothing more than ice & a home for the innuit.

Also your link~ Temp is the measure of the heat in the area regaurdless it's source.
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965. UYA
5:48 AM GMT on October 13, 2007
Aahh....Skye, don't leave now! I just posted the most important link for factual information about US temps you could ever want......
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964. Skyepony (Mod)
5:38 AM GMT on October 13, 2007
UYA~ Yeah freezing is what is expected in fall. So You don't think it will melt again? I was thinking about the implications, things that Dr Masters may bring up in the next blog he mentioned he was planning to do on the subject. But it's late & can wait.
Nite ya'll.
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963. stormybil
5:40 AM GMT on October 13, 2007
maybe the blob in the sw car. we seeing now will be a new invest

and the intelicast puts a low by west tip of cuba as the trof breaks down could this be the gfs fla strom developing on the 14th

Link
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961. moonlightcowboy
5:34 AM GMT on October 13, 2007
Have a good sleep, beell!
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960. beell
5:30 AM GMT on October 13, 2007
good way to end the evening for me mlc...in good company. breeze on ahead.
Nite all
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959. moonlightcowboy
5:26 AM GMT on October 13, 2007
Agreed, beell. We seem to be on the same page. (be careful! lol) Yes, these next 12-24 hrs should be really interesting.
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958. UYA
5:26 AM GMT on October 13, 2007
UYA~ I do believe a large past of today's topic was the Northwest Passage. But if you don't care to discuss it..

Yeah, but the Doctor said it was actually re-freezing....so what is the point?
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957. beell
5:19 AM GMT on October 13, 2007
GN flaboyinga.
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956. beell
5:04 AM GMT on October 13, 2007
Season still on for me friend. Enjoying every twist, wisp, turn and wobble. Might even learn something. Not dealing w/total doom here so what the heck. Could be collapsed in a doorway somewhere dead-drunk. No wait...that was earlier.
Liked your w-wnw talk. Gotta get out over water soon or it will have to go overland w/the easterlies. Intensification would complicate things and is a point well taken.
you know, jmho



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955. Skyepony (Mod)
5:08 AM GMT on October 13, 2007
UYA~ I do believe a large past of today's topic was the Northwest Passage. But if you don't care to discuss it..

Guess your hay farmers weren't waiting in muddied fields like the ones in NEFL for this dry air. If ya'll are so dry your in red flag already without something tropical your way soon, area isn't gonna yeild the rest of the state much hay for winter.
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953. flaboyinga
1:08 AM EDT on October 13, 2007
MLC, there are a lot of ex's floating around lately. Fortunately most remain unmentioned.lol
Later.
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952. Skyepony (Mod)
4:58 AM GMT on October 13, 2007
Malcolm Brinded, Shell's chief executive of exploration and production, told, "There has been drilling there, there has been exploration there, but this is a return to make a new charge at it. Link
It's certainly in the works.

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951. moonlightcowboy
5:06 AM GMT on October 13, 2007
I did find it a bit odd that the discussion had no mention of x94.
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950. flaboyinga
1:02 AM EDT on October 13, 2007
I believe it is time to watch the loops on the insides of my eyelids. A good night and a better tomorrow to one and all.
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949. moonlightcowboy
4:53 AM GMT on October 13, 2007
The ne'ly flow and shear in the GOM is forecast to move out to the ne as the trough over Jamaica lifts out and parks southernmost over the Bahamas and could leave FL under the same type of low pressure there.

As the ne'ly flow moves out of the GOM, the easterlies move back in shifting the wind pattern. When that happens, if x94 has moved into the wCarib, the steering pattern could change to w, wnw. That possibly reflects what the the GFS is seeing. However, if shear relaxes as is forecast, intensification over the Carib/GOM waters is more likely than what seems to be indicated imo.

Interestingly, the broad area of low pressure is also forecast to spawn another spinner llc in the Pacific just south of Acalpulco.

The high over the CONUS pushes the cold front further out to sea and then lifts to the ne itself. IMO, that leaves the nGOM vulnerable. Interestingly, that GFS run also shows a something developing in the Bahamas, passing thru the straits, hitting the swest FL coast and crossing over to the Atlantic.

Whhhhheeeeeeww, "season over" --- sure doesn't look like it! Dang, my fingers are tired! Sorry, lol.
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948. UYA
4:59 AM GMT on October 13, 2007
Take the Algore nonsense and take it to the correct blog. This one is still tropical I think!
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947. Skyepony (Mod)
4:57 AM GMT on October 13, 2007
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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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