Ice Dancing

Steve, when I look at the 250m MODIS data I clearly see melt ponds on the ice…;)

There is an interactive map of DMI: http://ocean.dmi.dk/satellite/index.uk.php
Please run it for one month as it is possible to set maximum span of one month only.
What wonders me is how quickly SST has risen for several degs over ONE month!
Could more knowledgeable explain this phenomena to me?
With regards

Run anomalies, of course, I forget to add.

IPCC “Consensus” on Solar Influence was Only One Solar Physicist who Agreed with Her Own Paper
Judith Lean´s concoction, IPCC´s “witch”
http://climaterealists.com/?id=5910

AndyW
Winds create low pressure on the leeward side of an obstruction. That is why sailboats sail, and why ice is being pulled away from the western sides of Arctic Islands.

I haven’t said anything about Julienne’s thoughts on the minima, what I am saying is that increased temps mean the ice is more mobile and so wind patterns play a part at this part of the season, not that it is just wind or just temps on these areas. It’s a combination of factors. Julienne said as much when you asked before if it was down to wind a few weeks ago.
I don’t even agree with wind being the critical factor for summer minima, the summer of 2007 was not just wind and ice being blown out of the Nares/Fram straight, it was mainly due to the high and low pressures meaning warm southerly winds melted and concentrated the ice from the Siberian side. Yes, it was the winds, but it was warm winds, also the temperatures were high due to lots of clear skies as well.
It’s painful for both sides not having it down to just temps or wind I know, but unfortunately that is the way it is.
Andy
PS Good post, enjoyed the graphics.

TomRude, Yes we have. Have you seen this:
http://eureferendum.blogspot.com/2010/06/corporate-cowardice.html
“Had the WWF sought direct confrontation with myself, or Booker in The Sunday Telegraph, it would have received a robust response, but the complaint was directed at the weakest link, The Sunday Times, which had made some errors in attribution.
Although these errors did not affect the substance of the case, the paper has chosen to go far beyond that needed, and conceded that “the IPCC’s Amazon statement is supported by peer-reviewed scientific evidence.” This simply is not true.
However, the central falsehood having been endorsed now by The Sunday Times, this has been sufficient for the WWF to declare a victory and cut and run, thus displaying the corporate cowardice and mendacity that one would expect of this odious organisation.”
or this?
http://eureferendum.blogspot.com/2010/06/moonbat-too-far.html

Phil,
You must have X-Ray vision – like Superman.

Second thought which is probably more to the point:
What the “heck” is going on up there? El Nino is officially asleep, the temp up there is below normal, and the sun is sound asleep.
What in the world (within the physics no one seems to be able to clearly state) accounts for:
http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/seaice.recent.arctic.png
Either our “tools for measurement” are cave age or something is afoot the models or understanding fails to reflect logically?
I’m probably missing the obvious – thanks in advance for the help with surface winds and currents.
Regards,
John from CA

stevengoddard says:
June 25, 2010 at 12:26 pm
Unless some “dark matter ice” over there…☺

Not to further stir the pot, but so far this June has shown the fastest ice loss rate during the satellite era currently at 83,000 sq-km per day. This past May was also the fastest rate of ice loss from 1979-present.
So I am keenly interested in what is driving this rate of loss this year. If you look at the air temperature anomalies, you find that temperatures are anomalously warm, but not as warm as say in 2007 that showed 925 mbar air temperature anomalies that were 7oC above normal in the E. Siberian Seas (1-23 June). You have the Arctic Dipole anomaly this month resulting in winds pushing ice away from the Siberian coast in the Laptev Sea towards the pole (in 2007 it was more in the E. Siberian and Chukchi seas). I haven’t looked at SSTs yet. Cloud cover (or rather more clear skies) looks like it might be about the same this year as in 2007. I don’t know if the PIOMAS volume estimates are correct for this year or not, but the way the ice is responding at the moment would lead me to believe it is on the thin side.

The ice extent graph is running parallel to 2006 and is offset downwards due to deficiencies in regions which are normally ice free in September. There is little reason to pay attention to the ice extent graphs until at least July.

John from CA says:
June 25, 2010 at 12:22 pm
SST anomalies show warmer water appearing out of nowhere into the gap between Greenland and Canada, as well as on the other side. I take that as upwelling, because the waters to the south of those places is well below normal.
As for the rest of the Arctic, nothing doing except the winds.

Julienne,
The WRF forecast for Barrow calls for much less sun than 2007 over the next two weeks.
http://seaice.alaska.edu/gi/observatories/barrow_breakup

Steve,
Nice graphics, clearly showing ice shearing and flow ice moving along the Barrows edge of the ice sheet. Took me a minute to realize that the polar graphic has the Bering Strait clocked at 8:30 location and the video has it clocked at roughly 12:00 position, though!
Question: How do we know the ice shear and flow is primarily from Beaufort gyre wind effects and not ocean current effects…. or both? Which way are the primary currents running through the Bering Strait now and how does that create eddy and feeder currents off Barrow? What does the sea bottom structure look like along Barrows and how does it amplify or negate ocean currents? How do tidal effects add to/subtract from the primary currents and cyclicly reinforce or mute the currents near Barrow?
Anecdote: I grew up on a large lake in Wisconsin. During spring melt, if the warming spring winds stayed relatively low velocity, we would see significant degrees of ice thinning down to maybe 4 inches of rotten ice and a relatively quiet departure of the remaining ice before whatever breeze was running. If the initial ice thickness was great (3 feet), that could take a long time! Other years, we might see enough melting to open up small leads and start honeycombing the ice, followed by high winds. That would drive the still relatively thick ice from the lake surface, leaving huge heaps of ice 20 feet and more high in the far reach bays and up on their shorelines. Shoreline trees, large boulders, and even occasionally lake shore houses were “bulldozed” by the wind driven ice sheets! It is a sight to behold and the grinding and tinkling noises of the crushing ice sheet cannot be adequately described with words. That occurred with a maximum wind fetch of only 11 miles, providing a study of wind/ice/melt dynamics in microcosm, compared to the macro scale Arctic ice pack dynamics!
Thanks again – Good Stuff!

stevengoddard says:
June 25, 2010 at 1:11 pm
The ice extent graph is running parallel to 2006 and is offset downwards due to deficiencies in regions which are normally ice free in September. There is little reason to pay attention to the ice extent graphs until at least July.
____________________
Except for the fact that you haven’t.
Will Arctic Sea Ice Update #11 rear it’s ugly head before July?

You all have no idea how much I don’t care about arctic sea ice. We know the northwest passage was open as recently as the 1940s and that it has been open at other times in recorded history. We also know that the earth is relatively warm now after its entirely “precedented” warm up following the LIA. The only reason we don’t know if it has been ice free in the recent past is because we have only had the technology in place to look for the last 30 years or so. In light of this, if the arctic is “ice free” sometime in the next ten years, why do we care?

kwik says: wrote
June 25, 2010 at 1:15 pm
I think its the Sun.
“Hot Tip; Sun-Gate coming up?;”
Thanks Kwik. I love this kind of news. Let me post a bit of the article;
“New global warming data fraud scandal seems to show a faked ‘consensus’ of the impact of solar forcing on Earth’s climate based on one finding.
A staggering new finding seems to mire the Intergovernmental Panel on Climate Change (IPCC) in global warming scandal every bit as devastating as Climategate.
The news broke June 24, 2010 on a Czech climate skeptic blog, Klimaskeptik.cz, that calls the latest global warming scandal, “Judithgate.”
Roughly translated into English the site reveals that the The IPCC relied on evidence supplied by just only one Solar Physicist, Judith Lean, to create their “consensus that solar influence upon the climate was minimal.
Judithgate Scandal Goes Viral
The story has going viral on climate skeptic websites and is reported on a leading blog, ‘Climate Realists’ as ,’IPCC “Consensus” on Solar Influence was Only One Solar Physicist who Agreed with Her Own Paper.”
http://www.climatechangefraud.com/behind-the-science/7220-new-global-warming-scandal-consensus-on-sun-is-one-expert

Here is what I see:
I see NOAA talking about temperature anomaly records being broken:
http://www.ncdc.noaa.gov/sotc/?report=global
The combined global land and ocean average surface temperature for May 2010 was 0.69°C (1.24°F) above the 20th century average of 14.8°C (58.6°F). This is the warmest such value on record since 1880.
For March–May 2010, the combined global land and ocean surface temperature was 14.4°C (58.0°F) — the warmest March-May on record. This value is 0.73°C (1.31°F) above the 20th century average.
The combined global land and ocean average surface temperature for January–May 2010 was the warmest on record. The year-to-date period was 0.68°C (1.22°F) warmer than the 20th century average.
The global land surface temperatures for May and the March–May period were the warmest on record, at 1.04°C (1.87°F) and 1.22°C (2.20°F) above the 20th century average, respectively.
In the Northern Hemisphere, both the May 2010 average temperature for land areas, and the hemisphere as a whole (land and ocean surface combined), represented the warmest May on record. The average combined land and ocean surface temperature for the Northern Hemisphere was also record warmest for the March–May period.
I see Arctic ice area dropping like a rock:
http://www.ijis.iarc.uaf.edu/seaice/extent/AMSRE_Sea_Ice_Area.png
along with ice volume:
http://psc.apl.washington.edu/ArcticSeaiceVolume/images/BPIOMASIceVolumeAnomalyCurrent.png
I see the lowest Arctic sea ice extent for this date since satellites began measuring the entire Arctic:
http://iup.physik.uni-bremen.de:8084/amsr/ice_ext_n.png
I see large sections of the Western Arctic being softened up for 3 more months of melting:
ftp://ftp-projects.zmaw.de/seaice/NEAR_REAL_TIME/Arc_latest_large.png
I see melt ponds north of 88° N:
http://www.arctic.noaa.gov/latest/noaa1.jpg
I see Steven Goddard desperately trying to play down the connection between “warming” and “Arctic sea ice melting”.
What do you see ?

I think this chart from Cryosphere Today is relevant.
http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/sea.ice.anomaly.timeseries.jpg
This year is like no previous year in terms of ice growth and recession so predicting the September outcome is difficult. If the rate stays constant as it is at the moment, there will be a record year.

Anu,
The sad thing is that, for a while, you were trying to make intelligent posts.

Dave Springer says:
June 25, 2010 at 2:15 pm
“If you are keenly interested in knowing what’s driving the record ice melt given air temperatures are not as warm as this time in 2007 I have conducted an experiment which provides the answer. Maybe you can duplicate it to confirm.”
” There’s the answer to the mystery which keenly interests you.”
Dave, another experiment is done every day by nature itself.
A big icecube in water/air: Arctic.
A big icecube on land/air: Antarctic.
The answer is there for everyone to see. Its the ocean.
And what heats the ocean? The sun.
And whats in between? Clouds.

Normally at this time of year there is a sort of a hold-up in the melt rate – a kink in the graph as the melt kind of slows and hesitates before plunging on down. The `fastest melt rate between blah-de-blah … ‘ that we have seen this year isn’t really because the ice is melting all that fast in absolute terms. It is mostly due to a complete absence of the usual kink. So what usually causes the kink and why is it missing this year?
Another unusual feature of the melt this year has been the early opening up of gaps arising from shear due to the Beaufort gyre. Could the two be related?
The kink usually occurs at the time during the melt when ice has most melted away outside the arctic basin and before it starts to melt much inside the arctic basin.
So why the pause? Perhaps the melt has to hold up and wait for ice to break free at the edges of the arctic basin before it can proceed.
This suggests an explanation for what we are seeing. Perhaps what has happened this year is that the ice broke free at the edges of the arctic basin much much earlier than usual – before the melt even got anywhere near the edges of the arctic basin. Consequently the usual hold-up to wait for the ice to break free isn’t happening this year.
So why did the arctic ice pack break free at the edges so early? Two hypotheses no doubt will be suggested.
1. Perhaps the ice is rotten.
2. Perhaps stronger than usual winds broke it free.
To check the first hypothesis we should look at ice thickness data. However the ice in the arctic basin seems reasonably thick. What does `rotten’ mean anyway? Perhaps those using the term would like to explain what they mean. If the suggestion is that the ice is not as dense or mechanically strong as usual, then is there any core sample data to bear this out?
To check the second hypothesis we should look at the speed of the Beaufort gyre and at wind conditions over the arctic. Does anyone have useful data that would suggest the winds driving the gyre are pushing the pack harder than usual this year?

____
Julienne says:
June 25, 2010 at 12:52 pm
Not to further stir the pot, but so far this June has shown the fastest ice loss rate during the satellite era currently at 83,000 sq-km per day. This past May was also the fastest rate of ice loss from 1979-present.
So I am keenly interested in what is driving this rate of loss this year. If you look at the air temperature anomalies, you find that temperatures are anomalously warm, but not as warm as say in 2007 that showed 925 mbar air temperature anomalies that were 7oC above normal in the E. Siberian Seas (1-23 June).
______
But didn’t 2007 have as much of a negative AO going into the year ? So temps were warmer come spring this year at high lattitudes than 2007 and all the ice around the edges was very late developed when the AO righted itself come Feb, so they crumbled quickly just after that and are still doing so.
Will it continue? I now think the AO has less of an effect from this time on and it will be due just to weather, clear skies and the temperatures in general.
Did you have a guess on the sea extent minima by the way? What was it?
Andy

another big story for the AGW coffin. THis ones quite devastating although go ol Leif won’t like it LOL
http://co2insanity.com/2010/06/25/judithgate-ipcc-thinks-one-person-is-a-consensus/

@Ian H.
That “gyre” affect on the ice definitely crossed my two brain cells. I have seen these gyre vortices cut the most perfect hole in river ice. It makes one wonder if it is a heat transfer mechanism at the very edge of the gyre (Faster velocity = faster heat removal).
At least it will keep Steve out of 30 year trendlines 😉 Ouch!
(Just playing Steve, we all enjoy your investigations, just sometimes the opinion of “fair” are landmines.)

Ian H says:
What does `rotten’ mean anyway? Perhaps those using the term would like to explain what they mean. If the suggestion is that the ice is not as dense or mechanically strong as usual, then is there any core sample data to bear this out?
_________
Essentially that is correct, “rotten” ice is that is a mixture of older multi-year ice that has partially melted both from above and below, combined with newer less dense ice, that often has a “top glaze” on it, so from a satellite image, you might think you have continuous solid piece of ice that is all the same density and volume, when it fact you’ve got a weakened mixture of ice. A good and very recent video presentation on this, right from the team that studied this “rotten ice” over the past winter can be found here:
http://video.hint.no/mmt201v10/osc/?vid=55
I think at least some of the mystery of how supposedly this years 40% greater volume (according to Steve’s analysis, but other models such as PIOMAS strongly disagree) ice could be melting so fast this year can be found in the “rotten ice” scenario. There may be other factors as well, such as increased heat flux from the West Spitzbergen Current or just the warm temps the Arctic saw during the extreme negative AO from this past winter.
Also, in looking back at the sea ice extent charts (that Steve says we ought not look at until July), but let’s look at them anyway, we see that during this past winter, the sea ice extent was actually running very close to 2007’s level until the “bump up” in March/April. This bump up, which happened rapidly and was primarily concentrated in the Bering Sea and Sea of Okhotsk, was new and thin ice, which physics would tell us, because it came late in the season and was thin and not very dense, was bound to melt very fast. The March/April bump up led the sea ice extent to approach almost back to the long term average (and Steve made much of this and used sea ice extent graphs at the time to do so, though now we are told by him to ignore the extent graphs until next week), it was clear that what inflated so fast was bound to melt fast, and sure enough, we had the rapid melt of May and June, and here we are, getting ready to see what July brings.
Who is more correct? PIPS 2.0 or PIOMAS? How will the “rotten ice” respond, or is it really rotten anyway? What about the heat flux coming in from both the Atlantic and the Pacific side? How much is the ice being melted from below? And finally, how will those fickle winds and currents move the ice?
This is a such a wonderful time to be a cryo-nut! No matter what happens, it will be an interesting July-Sept period!
and yes, some direct “on the ice” data gathering last winter found much of the Arctic basin full

stevengoddard,
As far as I can see, you are still yet to respond to my questions regarding the graphs that you posted on ice thickness and ice volume – you know, the graphs that indicate that current ice area is over 20 million square kilometres, something that is not possible. I had thought that you or I had made a simple error that could easily be corrected. If so, can you let me know what it is. Thanks. 🙂

Ian,
You asked “What does ‘rotten ice’ mean…?”. Where I grew up (Wisconsin), the term referred to the result of spring surface melt water on top of solid lake ice permeating the ice thickness along small fractures and flaws, resulting in an ice layer that is riddled with small through thickness melt holes. ‘Rotten ice’ or ‘honeycombed ice’ has little resistance to shear, bending, or compression loads and is easily fractured into slender icicles that make a wonderful glass-like tinkling sound when the wind and currents are giving it the Oster blender treatment!
When the lake ice started showing significant surface melting and the first indications of rotten ice (honeycombing) started to appear, ice fishing, ice boating, and skating were done!

It seems to me to be paradoxal to try to read anything into this week long clip. I looked up a map of Arctic SST’s and found this:
http://polar.ncep.noaa.gov/sst/ophi/color_sst_NPS_ophi0.png
The current temps are at or below freezing, for fresh water, but probably above for the salt content. Then it dawned on me that where there is water it will of course be above freezing and where there ice it will be below. I know, Duh…. during the week of the clip I see ice moving out of the picture and ice moving into the picture, leaving the overall area about the same. The ice volume this year may indeed be below average, but so what? The “average” temperatures are really quite average, we’re coming off of an El Niño, and the ice is really active. I get a little perplexed when someone says “see, it’s proof of global warming”, when there just isn’t significant warming. Personally, I think that no matter what this year holds, we’re on our way to colder temps for the next couple of decades, but I can’t be sure…

R. Gates says:
June 25, 2010 at 4:26 pm
That’s a lot of fuss just to prop up the idea that the Earth is headed for par-broiling, when the big picture is the switcheroo of climactic zones in the N. Hemisphere.
I’ll lend you a nickle so you can lay it on the table to see how much the oceans rose last year from catastrophic global warming.

Tom
The surface of sea ice is freshwater, because of snowfall and because the saltier ice tends to melt first.

Anu
I ‘m fine with NOAA, I just don’t trust you.

@kwik
Good point comparing arctic (floating) and antarctic (grounded) ice. One could also use Greenland in the latter or one could use the Antarctic Western Penninsula ice shelf for the former. It would end up the same.
Keep in mind the average temperature of the ocean isn’t much above ice water at about 40F. Only a relatively shallow surface layer is much warmer than that.
I wonder what the average ocean temperature was near the end of the last ice age when it had presumably been losing heat for 100,000 years. Another oddity in the ice age/interglacial oscillation is the slope of the ramps leading up and down. The warm-up period in the interglacial is pretty fast compared to the cool-down period. Morever, the glaciers rule for 100,000 years and the interglacial only lasts about 10-20,000 years.
One thing that can’t be denied (although the warmists appear to deny it) is that for the past many millions of years the “arctic ice cap” covers everything north of Virginia and stays that way year round with rather brief interludes where it retreats to where it is today. The conclusion is the earth is a planet struggling to become a giant snowball every 100,000 years and not quite getting there. Talking about purposely doing things to help it get colder is ignorant. Spending a significant fraction of global GDP to do isn’t ignorant it’s insane.

Phil. says:
June 25, 2010 at 11:04 am
“The disintegration of that “large chunk of ice” shows how ‘rotten’ it really is.”
It seems to me that the breakup of the “large chunk of ice” was not caused, as Steve surmises, by crashing into the main mass of ice, but because it hit something stationary, perhaps a sandbar or an island. Still, that does not provide any clue about “how rotten” the ice floe was when it broke up. What do you use as a measuring standard for that?

Phil,
Have you located the sea ice west of Barrow yet, or do you still believe that the University of Alaska is running an elaborate hoax?

I see a lot of cool water in the tropics…
http://www.drroyspencer.com/wp-content/uploads/AMSRE-SST-Global-and-Nino34-thru-June-17-2010.gif
I suspect the lack of OHC will outplay the arctic “open skies”… and you will be disappointed.

This is what happens when the POTUS starts apologizing to everybody.
http://www.abc.net.au/news/stories/2010/06/24/2936414.htm

Arno Arrak says:
June 25, 2010 at 6:55 pm
Warmists just don’t get the concept: If your tropical warm water heads too far North, it’s no different that leaving your front door open in winter. The heat escapes and your house freezes.

Personal observation in SW Florida.
Since the contrails stopped happening because of the Gulf oil spill, I notice it cools down a lot faster in the evening. It is now a comfortable 79 degrees in Cape Coral. Florida is like a desert, hot during the day and cooler at night because of the lack of cloud cover from the lack contrails. Last year wasn’t so nice at night.
I look forward to the death count this coming winter from freezing conditions in the northern hemisphere. I wonder how the death count is going to turn out from freezing conditions in the southern hemisphere this year.

stevengoddard,
You stated that volume equal area * thickness.
Your charts say that the current average thickness is 2.5 metres.
Your charts also say that the current average volume is 55,000 cubic kilometres.
This means (using the equation that you outlined) that you are using an area of over 20 million square kilometres in your calculations.
Can you please clarify if this is indeed the area that you are using in your calculations. It would be a very simple thing just to tell me, and everyone here, what the precise numbers in your calculations are. There are only three of the, after all, and one of them – volume – is derived from the other two.
What is your current average calculated thickness? Is it 2.5 metres?
What is your current calculated volume? Is it 55,000 cubic kilometres?
What is the area that you are using in the equation? Is it 20 million square kilometres?
It would be very simple of you to confirm the figures that you are using. I am wondering why you are refusing to do so … If it is because you do not want to admit making an arithmetic error, do not worry about that – everyone makes them from time to time. If it is because you are aware that I have made an arithmetic error and want to spare my feelings, don’t worry about that, either – I have made too many arithmetic errors in my time to be overly concerned about another one.
Oh, and I have read all your sea ice posts. There is nothing in them about the area value that you are using in your volume calculations that I have seen. I may have missed it. But you can simply cut and paste in in a response here if you have already posted it, or just point me to the direct link.

Gneiss says:
June 25, 2010 at 7:34 pm
That’s what happens when you stare too long at lifeless masses of ice.
Try reading Jack London’s story about the two who decided to stay all winter in the Arctic Night.
What a lovely place. Beachfront sales, anyone?

David Gould
I have never produced any chart using cubic kilometres, and had you actually read my posts (as you claim) you would know that my measured units of volume are pixel-metres.
You are too anxious to speak, and not bothering to listen.

stevengoddard,
Excellent – thank you. I did ask the question confirming what units these were in, as it was not on the chart. See: very simple to answer. 🙂

Phil. says:
June 25, 2010 at 8:03 pm
“When it disintegrates like that piece did it’s pretty rotten.”
June 25, 2010 at 11:04 am you stated: “The disintegration of that “large chunk of ice” shows how ‘rotten’ it really is.”
Neither of those statements tells me anything about what measuring standard you applied in determining the two values for the extent off “rottenness”: “pretty rotten” and “how rotten it really is.”
That is insufficiently concrete to base a scientific observation on, but I grant you that it is good enough for an unsubstantiated opinion.
All I see is that the ice floe broke up when it hit something stationary. The broken pieces of the ice floe then drifted around that obstacle and merged with the ice sheet.
What is that stationary obstacle? Is it perhaps an area of ice that is frozen to the ocean floor, or is it maybe an artificial island that was constructed for a drilling rig?
As to the depth of the water in the area, Google Earth does not provide a good resolution for determining that very precisely, nor does it seem to indicate any of the many drilling islands that have been constructed during the last few years.
Regardless of what Google Earth shows, the series of photos provided by Steven does show a stationary object. It seems to me that stationary objects are likely to cause ice floes that hit them to break up, even if the ice floes are comprised of solid, “healthy” ice.

stevengoddard says:
June 25, 2010 at 6:10 pm

Tom
The surface of sea ice is freshwater, because of snowfall and because the saltier ice tends to melt first.

I have to add that ice in the icebergs is also mainly salt free.
Ice is the crystal form of H2O and these crystals by the forces that form them are pure H2O. Now brine can be trapped in bubbles within large crystals, but there seems to be a process where even brine is squeezed out over time from the ice.

AndyW says:
June 25, 2010 at 3:08 pm
Andy, actually in 2007 there was a positive AO during winter, and negative during summer.
According to Wang et al. (2009) (and note DA refers to the Dipole Anomaly)
It was also found that the 2007 summer falls into state 3: −AO+DA, with the AO and DA indices being −1.5 and +2.2, respectively, both higher than 0.6 standard deviation as shown in Figure 2f (the AO/DA indices in 2007 winter, spring, summer, and autumn are 0.58/0.53, 1.35/0.15, −1.5/2.22, and 0.34/0.03, respectively). The resulting SLP anomaly was a DA-dominated two-center structure, and the wind anomaly was meridional, blowing from the western to the eastern Arctic (Figure 4a). This DA-induced wind anomaly was dynamically responsible for the 2007 summer minimum (Figure 1). The positive AO during the 2007 winter (AO index = 0.5, see Figure 2e) and spring (AO index = 1.35) also contributed warming to the Arctic, further thinning sea ice. To illustrate that the +DA and +AO are the key factors for the past ice minima, we construct the climate states to identify the latest five ice minimum summers against summer DA and AO indices, as shown in Table 2. Except for year 2002 (climate state 1) during which +AO played an important role in the Arctic ice minimum, in all four cases, +DA played a leading role for the summer ice minima, although the −AO tends to converge the sea ice inside the Arctic Ocean.
Definitely as the summer progresses the AO has less of an impact and the DA becomes more important. The negative winter AO this year was different than a classic negative AO pattern. Really and AO index is just a small part of the story, the location of the sea level pressure anomalies and how much spatial area they coverage is more telling. So despite a very strong negative AO this winter, the ice export out of Fram Strait was actually normal (not reduced as you might expect during a negative AO phase). In addition, there was large transport of ice from the Canadian Archipelago into the Beaufort and Chukchi seas that didn’t turn northwards as you would expect under a stronger Beaufort Gyre, but instead transported that ice into the E. Siberian Sea.
My estimate based on typical survival rates of ice of different ages was 5.5 million sq-km. But I’m not convinced that will be accurate because we have seen that survival rates are changing. If survival rates of 2007 are more appropriate then this September is estimated at 4.3 million sq-km. So I think this DA will be important to watch, since if it persists all summer like it did in 2007, then the extent will most likely end up very close to that in 2007.

R. Gates says:
June 25, 2010 at 2:58 pm
Yes it’s important to find out what the SSTs and currents are doing this year. The Dipole Anomaly of 2007 did strengthen inflow of the warm Pacific water which no doubt played an important role that year. I haven’t looked at any of that for this year yet. It’s true air temperatures were anomalously warm all winter in response to the negative AO, but basically since about 2000, air temperature anomalies have been positive during all months. Guess it would be worth looking at the monthly air temperature anomalies for 2007 and 2010 and see how they compare. I do believe the ice is thin, and this is key to the fast pace of decline we’ve seen in May and June (and why June is now a new record low during the satellite era).
One way to look at it is if you have thick ice (> 3m), you could have anomalously warm conditions (SSTs, air temperatures) that would translate into large ice volume loss, but it would have little impact on the ice extent since the ice remains thick enough to survive. But when the ice is thin, you can have the same anomalously warm conditions that would cause the same ice volume loss, but now it also translates into ice extent loss because the ice has melted out entirely.

What do you see?
Is this a Rorschach test?

In my previous comment (June 25, 2010 at 9:17 pm), I mentioned drilling islands.
I came across something that relates to that, “Marine Geological Research in the Canadian Beaufort Sea”, at http://www.bsstrpa.ca/NaturalResources.htm
That web page shows fairly detailed sonar scans of various geological features that fall into a couple of subject areas that were covered at wattsupwiththat.com. One of those is methane bubbling from the sea floor. The other is geological features that could account for stationary obstacles to drifting ice floes: pingo-like mud-volcanoes, drilling islands and something that may be surprising, keels of ice pressure ridges that drag on the ocean floor and cause a proliferation of deep furrows in the ocean floor (mostly 50cm deep, with some up to more than 2m deep).
“The mud volcanoes range from a few meters to more than 20m high and have diameters that can be 50 to 300m across.”
As to the mud-volcanoes, one sonar scan illustrating one was taken in water at a depth of 60m. Moreover, that scan clearly shows a number of gauges that appear to have been left by ice keels.
I imagine that the marine-geological conditions in similar water depths in the American Beaufort Sea do not have any national distinctions.
The area of the Arctic Ocean that contains the stationary object against which the solitary large ice floe shown by Steven smashed itself appears to have a depth of about 36 to 38m (according to Google Earth).

Rbateman:
“Warmists just don’t get the concept: If your tropical warm water heads too far North, it’s no different that leaving your front door open in winter. The heat escapes and your house freezes.”
How far north is too far north and how are you privy this this limit? What are the natural and unnatural drivers that could put warm water “too far north”?

Phil. says:
June 25, 2010 at 11:04 am
The disintegration of that “large chunk of ice” shows how ‘rotten’ it really is.
Gosh Phil, you must be right! Because, after all, how could ice break up in summer!? You got us there man. You’re good, really good.
(yes, ‘sarc off’ now)

stevengoddard,
Now that my confusion regarding the units/area issue has been resolved, perhaps we can get to my main question.
According to your graphs, average ice depth today is 2.5 metres. Average ice depth last year was 2.1 metres. Volume, however, is about the same. This implies a decline in ice area of 15 per cent. That seems unlikely to me. As I pointed out, if we are just looking at the Arctic Basin that would imply an ice area this year some 750,000 square kilometres lower than at the same time last year.
Can you clarify whether you could the same result? I may be making another error, and would like to be sure of what it is that your analysis shows.

Dave Springer says:
June 25, 2010 at 6:18 pm
Yes, its odd how the IPCC looks for CO2 and denies everything else. And the big research organisations do the same. Otherwise there will be no grants. Its a big Hoax.
Turns out there are many cycles superimposed pluss delay effects from ocean currents, and dips from vulcanoes. And pluss-minus feedback-loops from clouds.
These are the things that needs to be studied to fully understand.
Not that silly little trace-gas.
Here is a large cycle; Denied by IPCC CAGW crowd, as allways.
But clear for everyone else to see;
How much influence of it do we see from it today?
http://www.phys.huji.ac.il/~shaviv/Ice-ages/GSAToday.pdf

Phil,
I was wondering if you could be any relation to the groundhog ?
Fred

So I think this DA will be important to watch,

Julienne, how can a layman keep an eye on that Arctic Dipole Pattern? Do you have any links?

If your pixels-metrea volume numbers are based on the original pixel sized images, than your volume numbers are indeed wrong.
If not, than have the original images been resampled to a different higher resolution?

EFS_Junior
What part of “You would also know that I zoom the ROI before counting.” wasn’t clear?

Julienne says:
June 25, 2010 at 10:26 pm
R. Gates says:
June 25, 2010 at 2:58 pm
Yes it’s important to find out what the SSTs and currents are doing this year. The Dipole Anomaly of 2007 did strengthen inflow of the warm Pacific water which no doubt played an important role that year.
_________________
Thanks for your response. I know that funding is always difficult, but considering the impact on melt in the Arctic, it would seem to me that a series of permanent bouys that monitor the WSC and Bering Strait heat flux inflows would be an excellent investment, or perhaps these already exist, but I don’t know where to find the data? Recent studies done by Weslawski et. al. on the WSC would seem to have been done via ship board measurements, rather than permanent bouys. Also, in terms of the sea ice volume, I would love to see some data that shows how smooth the ice is underneath and across the central Arctic basin. Though I’m not an expert such as yourself, I thought I had read somwhere that a great deal of the mass/volume of sea ice can be found in the fins from pressure ridges. If the “rotten” ice is overall smoother on the bottom or has less deep fins from pressure ridging, than this might account for a great deal of the volume loss, and might lead to quicker melting. I would presume this has never been studied, but perhaps you know differently?

Yes, I figured it out, Region Of Interest, which doesn’t mean a whole heck of a lot without an actual boundary definition.
My ROI is the entire Arctic at the point of maximum sea ice extent (plus a few % for any sea ice movement ambiguities in the early part of the melt season) for the entire melt season.

stevengoddard,
I was hoping that you could address this:
“According to your graphs, average ice depth today is 2.5 metres. Average ice depth last year was 2.1 metres. Volume, however, is about the same. This implies a decline in ice area of 15 per cent. That seems unlikely to me. As I pointed out, if we are just looking at the Arctic Basin that would imply an ice area this year some 750,000 square kilometres lower than at the same time last year.
Can you clarify whether you could the same result? I may be making another error, and would like to be sure of what it is that your analysis shows.”
Now, Arctic Basin area has, according to this: http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/recent365.anom.region.1.html
plummeted in recent days, and is now close to being 15 per cent below last year’s value at the same time. But at the time that you posted your analysis, this precipitous decline had only just begun. So can you tell me whether your analysis shows a 15 per cent decline in area in the Arctic Basin when this year is compared to last year?
As I said, I may well have made another error. These are intended to be genuine questions – I want to understand what it is that you are doing.