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HenkL

Latest from research vessel Polarstern (Aug 20 - 18Z):

air temperature: +0.2°C
water temperature: +1.1°C
weather: recent drizzle
position: 88°54'N 59°54'E
ICE code: 58095
(ice concentration 9-10/10; medium-thick 1st yr ice with some old; no land ice; ship in ice; ice difficult to penetrate, no change)

Werther

In an attempt to focus on what’s important, I compared the sit 18 august 2011 to 2010. Why not 2007? Because I think 2007 isn’t relevant. It was, as a ‘threshold’, if we can’t agree whether 2007 decrease was a ‘tipping point’. But 2010 was way worse than 2007 in, FI, volume.
CAD shows me 2011 almost 700MK lower in extent than 2010(I saw CT accounts for 390MK, but I skipped some rests outside the pack). The loss of the ice-arm toward Taymir peninsula (northern Russia) counts for minus 315MK. Second, loss in the Beaufort/Chukchi region: minus 245MK. Third, minus 72MK in the East Siberian Sea and 58MK in the north Barentz Sea.
To wrap up this season preliminary, it’s getting worse from whatever point of view. This year showed us how the pack spreads out, thinning on the way. That hides ‘truth’ because we hold on to 15% in our grid counting. So extent, and to a lesser degree, area, seem to hold tight.
Hidden from our attention, volume is taking another beating. The Taymir/Severnaya Zemlya-arm and the Barentz losses were high concentration, thick ice in 2010. That alone stands for 300 km³ less volume.
Whether there’ll be an extent record or not around the third week of September, volume is already nearing or crossing the 4000 km³ mark.
I wonder what 2,8 million square km’s of icefree waters in the Barentz-Kara region are going to do to fall weather in Europe?

Neven

I wonder what 2,8 million square km’s of icefree waters in the Barentz-Kara region are going to do to fall weather in Europe?

Very good question, Werther, which - frankly - intrigues me more than the question whether we'll see new records. We've had two freak winters in a row on the Northern Hemisphere. This, of course, could be a coincidence, but another one this year...

Account Deleted

http://img535.imageshack.us/img535/231/20110820.jpg

Fragments of fresh fracture makes the ocean. Apparently this is the final collapse of the Ward Hunt Ice Shelf (largest ice shelf in the Arctic)

Janne Tuukkanen

If the climate of northern Europe will turn to more continental one, ie. freezing winters and torching summers, it will be very hard and expensive road.

First it was thought that mild winters would cause savings in diminished heating. And so that would had been several decades ago, but in modern western world savings are countered by air conditioning during summers. Now we might encounter both heating and cooling expenses rising.

OTOH there's some very smart district cooling projects, which will (and has) surpass inefficient electrical air conditioning at least in metropolitan areas.

Andrew Xnn

I agree with Werther about the relevance of 2007. Review recent volume measurements and it's clear enough that there is no going back to 2007 levels. The delta between now and 2007 is significant and gradually growing over time.

We seem to have entered a new mode for the arctic. Last year (2010 for now) is the best analog for now.

Noel Ward

I also tend to agree with Werther. 2007 was a big year for ice loss, but mostly because it was so dramatic. 2010 was impressive, but what I think of is how this year's slush puppy is showing us more about how the ice can act and what it can mean for future summers. OK, the slush can perhaps freeze up faster as the melt season winds down, but that "new" ice is likely to be pretty fragile stuff that can melt sooner next spring. Add that to the continued loss of MYI and things appear to be going consistently downhill. (More data and a longer trend line, perhaps, for the deniers to find an excuse for.)

Then there's the issue of NH weather. I'm in the U.S. and we've had some exceedingly bizarre weather the past 3 years, especially the past two. Cold in much of the nation, even where it usually isn't all that cold and all but one state had significant snow storms, which is not remotely normal. I live in New England and the number of really cold days and the amount of snow we had went into the record books. I know I burned more firewood and used more heating oil than ever last winter.

Then there's this summer where the heat has been persistently high over much of the U.S., weeks at a time over 37 C in several places. There is certainly a connection, but as usual more data is needed to truly quantify the trends. Another "hard winter" from 30 to 55 degrees North latitude would be no surprise to me.

Frivolousz21

UB final map out..I overlapped it...and it shows a good bit of compaction/melt Again though a lot of this in between areas of ice so I have no idea how much Jaxa will pick up on it..But 12.5km2 grid resolution is not that much more than 6.25 compared to 25km.

Right now things are definitely up in the air with the winds about to explode off Canada into the Pack.

Frivolousz21

-36K prelim.

Frivolousz21

00z GFS now takes the partial DA anomaly and makes it full blown by day 6-7.

Rlkittiwake

To throw more props in Werther's direction, in 2007 it looked like there was going to be a resilient ice core north of the CA. In the last few years, it looks like what would have once been the "core" is being transported by the Beaufort Gyre and is then becoming the slush puppy.

And a question: how is ice export through the Fram and Nares straits changing under the new regime? In 2007 it looked like there was a solid tongue coming down the east coast of Greenland, but this year it looks more like slush. Is more ice coming out now because the pack is broken up, or was more coming out then because the pack movement isn't dependent on concentration?

D

It looks like the two competing trends must be reconciled soon. The volume trend seems to show a virtually ice free arctic by 2015. The area trend is much slower, with the ice free date appearing to be around 2040.

Why is the area trailing the volume by so much?

Will the decline in volume eventually force the area to catch up?

Are there other factors that are going to slow the volume trend in the near future?

Is it reasonable to assume that the ice free date will be between 2015-2040, or are both trends going to be superseded by a well hidden third trend?

On the one hand, an ice free arctic in a few years might be the shocking event that the world needs to wake up to the reality of global warming.

On the other hand, I don't think we should be making strong predictions until we have good answers to those four questions. The skeptics have quite the propaganda machine. We can't afford to make any significant errors in predicting certain events too early.

Maybe the best approach would be just to publicize the obvious trend-lines along with a few potentially relevant factors, and tell the public that they should draw their own conclusions.
Let them think that they are figuring out what is going to happen rather than being told. The general public might never reach a correct conclusion about something as complicated as a proper forcing value, but
the arctic data seems simple enough that just handing them the raw data might get them to invest more into the idea of global warming.

Frivolousz21

D,


the ice sheet could be 1-3 feet thick but have an Area of 5,000,000km2 because it's spread out.

This year the ice fanned out when areas rapidly melted.

NSIDC noted this, it's very deceiving.


kind a weird how quite the Cryosat2 front is.

Neven

I have updated the Fram Strait animation, but as we all know thanks to Paul Klemencic's updates, there's not much happening there.

ECMWF also shows the beginning of a DA, but it's far off into the future (one week is far for weather forecasting).

kind a weird how quite the Cryosat2 front is.

They still need more time for calibration etc, Frivolousz21. But I think it'll be ready next year, and hopefully accessible to us amateurs.

crandles

Slight change on the dmi 30% extent plot. I also note NSIDC concentration map has updated to 19th from 16th. Are these linked?

Lord Soth

During a five day period between Aug 30 and Sept 3 2007, there was a total of 36K of ice lost or on average 7K a day.

I see this as the last chance for 2011 to wipeout 2007 lead.

I believe 2011 will at least secure second place. The melt season ended early for 2008 on September 9th.

With the slush puppy, I'm expecting the melt to last in the 20 something of September, and we may even see a record for the lastest melt.

Neven

Slight change on the dmi 30% extent plot.

Ah, so the flatlining wasn't an artifact. That answers Phil263's question.

Phil263

Ah, so the flatlining wasn't an artifact. That answers Phil263's question

Still odd that the flatlining was stuck right on 4 million!

Frivolousz21

the concentration on most of the Eastern Side of the Ice pack is decieving from the Kara to the Fram Straight it is wrecked. It is held together by some very thin ice. This season is almost out of time but that area is forecasted to under go more warm air and there is just a ton of warm water being pumped into it. I can see why it's crippling so fast. There is definitely no thickness left there.

And down the Fram it's in thin thin ice with that warm water still being pumped in.

http://www.wetterzentrale.de/pics/Rhavn1321.gif

It really starts around 84 hours...and gets going...by day 7-8 the flow is brutal from the Kara or even laptev to the Greenland sea right out..with thousands of miles of gusty winds.

ouch.

Tor Bejnar

I remain influenced by the low ice volume, poor state of ice (much slush puppy ice, possibly quite rotten as well) and warm (brrr - I've swum in cold water but…) water temperatures. Another week of significant export through Fram Strait in the next two or three weeks, and/or slush puppy ice blown toward Eurasia and I imagine minimum extent could occur as late as earliest October. Significant dispersal may get much slush puppy ice below the 15% extent threshold, too.

With these various IFs, I see extend approaching Lucia's 3.95MK min a possibility. If not this year, then next year ...

Frivolousz21

Jaxa was revised adding another 1500km2 to the loss.
Four days ago: 56K loss

three days:

77K prelim then a 80K final.

then two days ago had a 46K prelim and 38K final.

last night had a 36K prelim and 37.5K final.


Jaxa runs a two day average.


Todays will probably be a bit higher

Philiponfire

It has just occurred to me that there is a burning question that remains unanswered in my reading.

how thin can the ice get and still register as being ice? for example if there was slush puppy with a particle size of one cubic centimetre or less it would naturally keep spreading out until it was only at max one centimetre layer. if those particles were packed at over 15% of area then would they show up as ice or not?
so with this model. as slush melts it continues to spread with area and extent being dictated by the wind and tide. my thinking is that only time will tell how fragile all that blue is on the CT map. but bearing in mind the volume drop it has to be still possible for some big surprises.

Bob Wallace

A question-

Along the east edge of Greenland a lot of open water is showing between land and ice at the southern end of the ice pack. Further north the shoreline ice is starting to show 'gray', concentration is dropping.

Is it usual for the shore and ice to separate late in the year or might this be a freeing of the ice which could allow it to drift into warmer water?

http://www.iup.uni-bremen.de:8084/amsr/GreenlandSea_visual.png

Neven

Bob, it all depends on which way the winds are blowing. If they blow eastwards for a sufficiently long time you'll see the sea ice (and the fast ice too which tends to break off there around this time in the melting season) break away from the shores.

It's not abnormal, but not very common either, I surmise.

Frivolousz21

SIA dropped to 3.2694285.

-72.400km2 loss

Timothy Chase

Frivolousz21, I had been reading -72.400 km2 as a little less than 72 and 1/2 km2. Your thousands separator looks suspiciously like my decimal point. Then I remembered that in some countries a dot is used as the thousands separator. This was due to my working a few years back to make a software package conform to local conventions, depending upon the country. Other countries might use spaces as a thousands separator, if I remember correctly.

www.google.com/accounts/o8/id?id=AItOawkpUaD_uYjZAIrhpA6AA5KyEs-CSoL4zlM

is it just me or has that crack in the Petermann Glacier extended quite a bit lately?

FrankD

comparing last year at day 231 and this year at day 230 there is a little difference visible in the size and position of the crack:

Chris K

r w Langford

Philiponfire: You have skirted a topic that intrigues me. Why is there so much interest in sea ice extent and sea ice area when a critical factor is sea ice volume. Thick ice is critical for most mammals in the arctic and it is critical for future ability for transportation and resource extraction. On the other hand SIE and SIA are important factors for albedo and thereby ocean warming and likely global weather. Perhaps we discuss extent simply because we do not yet have good ice volume numbers to discuss. It would be nice to be able to compare daily ice volume by year on the graphs page.

Timothy Chase

Werther wrote:

I wonder what 2,8 million square km's of icefree waters in the Barentz-Kara region are going to do to fall weather in Europe?
... and Neven responded:
... We've had two freak winters in a row on the Northern Hemisphere. This, of course, could be a coincidence, but another one this year...

Here is the original paper on the possible link:

Vladimir Petoukhov and Vladimir A. Semenov (Nov 2010) A link between reduced Barents-Kara sea ice and cold winter extremes over northern continents, Journal of Geophysical Research, Vol. 115, D21111
http://eprints.ifm-geomar.de/8738/1/2009JD013568-pip.pdf

... that low ice concentration in the Barents-Kara sea results in a high pressure zone, a reversal of the direction of atmospheric circulation in the region, and in essence an Arctic corridor bringing Arctic air into Europe and colder temperatures into Southern Canada and parts of the United States.

A climatologist does a brief review of the ideas behind the paper here:

Why has this winter been so cold in Europe?
Andy Russell, 2011-01-06
http://andyrussell.wordpress.com/2011/01/06/why-has-this-winter-been-so-cold-in-europe

Personally I expect we are going to be hearing how global warming must be bunk because Western Europe (which, like the contiguous 48 constitutes only 1.5% of the Earth's surface) and parts of the US are having a chill.

Frivolousz21

http://www.iup.uni-bremen.de:8084/amsr/arctic_AMSRE_nic.png


If the prelim map is right we will be seeing a 75km2 loss or greater.

that is major compaction/melt in the Beaufort.

Paul Klemencic

Frivolousz21: Be careful about the edges of the pack shown in the preliminary map in the Beaufort, Chukchi, and E. Siberian. That area of the map often gets substantially revised when the final map posts, and a lot of lower concentration ice is added back to the map. However, there was enough of a pullback, that I agree with your guess of 70k loss. It could be worse, unless the map really fills back in, and because yesterday's slow melt day will keep the reported extent loss down.

The other side of the pack didn't move around much today, but a lot of low concentration ice showed up in the Greenland Sea, reflecting the poor ice condition in the Modis shots in your earlier comment today. I had expecting some deterioration in ice there, considering that is the one portion of the pack that has been exposed to very high melt conditions over the last week.

And if the high pressure starting to show up in Baffin Bay strengthens, then the Fram strait may start to see some incoming ice.

HenkL

Latest from Polarstern (Aug 21 - 18Z):

air temperature: -0.1°C
water temperature: +1.1°C
weather: fog
position: 89°30'N 60°54'E
ICE: 58095

(for explanation of ICE numbers, see: http://www.awi.de/fileadmin/user_upload/MET/PolarsternCoursePlot/ICE.html)

Seke Rob

Chris R, saw same when one of the posters here brought up Peterman's suspected crack increase. Noting from the blinker that the calving seems to have overtaken the forward movement of the glacier, and yes, me and myself have little doubt the break is growing. Would that ice there still be ground seated and would prolonged openness of the strait ahead cause more warmer water to creep under?

Anyone seeing any effects of the mentioned spring tide?

Seke Rob

On the CT SIA Global front, at the rate Area is declining we'll be seeing the 365 day moving average surpass the record set mid November 2007 sometime end of August, early September. More than 2 months earlier. That record was a negative anomaly of -1.356 million (decimal point ;>)

Preferring spaces for thousands, so it is if combined with a decimal precision, unambiguous. Fractional thousands I'd prefer to always have a Kilo sign suffixed. Yesterday noticed a post where the French M (mille) for thousands was used... that required a second look before it made sense [since I use M for million]. Such it is when nationalities meet :D

L. Hamilton

I was curious to see what a minimum volume graphic, analogous to my minimum area graphic above, might look like:
http://img.photobucket.com/albums/v224/Chiloe/Climate/sea_ice_VOL_min_to_date.png

Although PIOMAS generates daily values, they are updated less often, so my graph using data downloaded today only goes up to 7/31/2011. Already by the end of July, volume was just slightly above the 2007 minimum, and well below the minimums reached in 2008 or 2009. As others note above, 2010 set the benchmark.

Christoffer Ladstein

HenkL: I see that you continuosly do report of temperature above 0, but the log in the below posted link tell of the contrary.

http://sailwx.info/shiptrack/shipposition.phtml?call=DBLK

Also, in my opinion, due to all the ice surrounding the ship, a temperature of -1,1 is still some distance away from -1,7, which is the temperature normal salinated water start switching from liquid to frozen form! More over, the ice close to north pole is more or less compacted, leaving less room for the seawater to abstract heat from the sun?!

Nevertheless a great effort to travel to the North Pole by ship, certainly the ice must be in a bad rotten shape at this season.

From the same site I see the seatemps in both ends of the classical NW passage are reported to be in the range +5,7 to +7,1, no wonder the last remnants of ice is nibbled away rather rapidly! Now the passage will be open for 4 maybe 5 weeks?
Wonder how the friendly locals do benefit for this prolonged icefree state?

Seke Rob

Just updated the MASIE Spaghetti Chart [it is so far daily refreshed or whenever there's a new record added] and note a 19 to 20th change of rounded -84.0KKmSq (bottom of legend). Central Arctic, top of legend and graph, is now on consecutive decline, -27.6KKmSq for the 20th.

Chart reading tip: The bracketed day change values now have an explicit + sign if there was a regional or hemispheric increase. This round all were receding, except Chukchi, which showed holding. Overall, MASIE is about 200KKmSq above JAXA for this date.

Espen

2011 must be a record year when it comes to the Canadian Archipelago, I believe it must be the first year on recent records that the archipelago is sea ice free south of 75 north parallel, but I am still puzzled with the remaining sea ice in Foxe Basin!

Espen

Frivolousz21

Both the GFS and EURO the next ten days and beyond are above normal warmth for almost the entire arctic the entire time.

There will be almost no chance for any refreezing if this happens. Really not even close.

I am going to go check this to 07-10 and see where the last 10 days of August stood then in terms of temps

Frivolousz21

The Euro and GFS pretty much give us a 2008 redux the next 10 days if it is close to what they portray now. if not worse the 12z Euro is flat brutal....there would be a 15-30KT 300-500 mile wide, 3000 mile long stream of air From the East Siberian Sea to the Greenland Sea. With pockets of Gale Force Winds for 3-5 days with weaker but still DPA conditions in between.

The GFS first started to show this over 8 runs ago now and Euro 4 runs.

The ice has made it this far with good winds this year.

There is no doubt this would be historic.

Neven

Larry, I of course stole your graph and put it on the Daily Graphs page. Thanks.

Frivolousz21

that is 2007 not 2008.

this is quite the turn of events, now we wait to see how it plays out.

HenkL

Christoffer: you are right, the water temperatures around the Polarstern are negative.
I have to correct this bug in my decoder program. Thanks for reporting the issue.

Neven

Frivolousz21, I think I see what you mean. That high forming over the Beaufort Sea one week from now, right? In a week those forecasts can change a lot, but it would be very interesting if it came about.

What the heck, I'm doing another hypothetical prediction (even though the first two didn't come about which basically made me write off a new record minimum extent): If by September 3rd 2011 manages to get within 75K of 2007, there is still a very small chance of a new record minimum extent. :-)

Frivolousz21

This is two slow melt days:

Remember the 17th to 18th lost 77Km2 prelim. Then 80Km2 final.

the 18th to 19th lost 46Km2 prelim and 38km2 final.

the 19th to 20th lost 36km2 prelim and 37.5km2 final.


So the loss 2 days ago must have been very small to pull at 46km2 day revised to 38km2 after a 80km2 which was revised up.

then the next day comes in the same and goes up a tiny bit.

That suggest yesterday was larger than the 2 day average says.

So when you look at this graph you can see how we "might get a big loss day today.

http://www.iup.uni-bremen.de:8084/amsr/daybefore/NorthWestPassage_visual.png

Now this is subject to revisions. However even so, the movement is quite impressive. And when you look at the East Siberian Sea, look close there is quite a bit of loss there too.

http://www.iup.uni-bremen.de:8084/amsr/NorthWestPassage_visual.png

That fat area of ice in the East Siberian Sea is being compacted/melted out in the face of very cold 850s.

That is what happens when things like this are around.

http://ocean.dmi.dk/arctic/satellite/plots/satanom.arc.d-00.png


Look at SST anomolies yesterday and today in the Beaufort then all over.
Holy smokes.

there is reports by buoys of 5C rises in one day from ample sun, warm 850s and a warm powerful wind.

Temps have reached the low 80s on that Big Island today.

850s today over the Beaufort are on fire:

http://vortex.plymouth.edu/gifs/110821201831.gif


Those 850 are 6-10C above normal.

lastly the winds are howling. Sustained winds of 20-30mph over hundreds of miles wide thousands of miles long slowly sagging East The next 3 days as the SLP slowly migrates towards the Beaufort then Arctic Basin. But slow enough to keep ice pack out in front of the strongest winds.

We already saw on the prelim the ice move 30km or more in spots. This ice is thin and light with spaces in between it. How fast can it move per day until it compacts with the main pack that will also be pushed out...there may be little to no ice left in the CA Islands by Thursday or Friday. We will have to see how much compaction takes place.

also the winds in the E. Siberian Sea turn around by day 2-3 and don't change for 7-10 days on models with them being pushed into the main ice pack. So that area then will warm up some and have favorable winds for compaction.

Also the Fram straight winds turn around in 18 hrs. And by hour 30 pick up between 10-15kts with gusts to 20kts at times right out into those 6-10C SSTS.

After that area of ice was beaten up by the 12-14C 850 temp anomalies and record 2m temps in Greenland and Iceland.

We will see. But this picture is showing possible record extent loss for the next 12-15 days.

Daniel Bailey

@ Seke Rob

The grounding line for the Petermann Glacier is marked in blue:

[Source]

With that in mind, the crack is seaward of the grounding line and thus is part of the floating ice tongue. I could probably find the links to the studies documenting the warm water penetration under the Petermann floating ice tongue all the way back to the grounding line, if any are interested.

Greenland glaciers references for the interested are here and here.

L. Hamilton

Neven, glad you liked the graphic, another Sea Ice Blog exclusive. I'll update it whenever new PIOMAS data becomes available.

Frivolousz21

http://www.iup.uni-bremen.de:8084/amsr/arctic_AMSRE_nic.png


The ice took a massive pounding today.

I would think that would be a near 75-100Km2 loss.

But with the two day averaging it's hard to say how it will all play out.

D

-60.5km2 prelim on jaxa.

He arctic was hammered today. That slush ice was moved 30-40 km in spots.

Now down to 5,274.500km2

Seke Rob

Went about digging further into why 1996 was so anomalously behind in ice-off days and added also the line that displays first days that CT SIA fell below 9MKmSq, but that spike remains. Did find bits on low pressure and a comment here comparing Aug.2 2011 with 1996, which I would not have done (in the same vain as comparing 1998 to 2009 temps to claim we're cooling), but it remains extraordinary how flattish the decline turned after the out-off sync 1996 year, then changing the 5M steps into an accelerating pace of earlier and earlier. What happened? Is this beyond Mark 0.1 Eyeball, a significant cycle change point for the Arctic?

Neven

Polarstern reaches North Pole

There's a snippet of info info that y'all will find interesting.

Frivolousz21

Extent will be hurt today because the flow from the Kara to the fram has turned around to flush ice out with it being so thin it will spread out some for a couple days but not for long.


The 12z GFS is out and not only sets up a mini DPA for the next 3 days, from day 4 on through at least day 8 it sets up a full DPA that gets stronger throughout the run while a HP slides West towards the Beaufort and SLPs line up from Siberia to the Barrents.

Neven

I agree things look interesting, Frivolousz21, but I would hold my horses for a day or two-three longer. Lots of lows out there, eager to spoil the party.

Wayne Kernochan

OK, really, really crude calculation. Last year, this date, area was 3.74; now it's 3.22. Minimum area last year was around Sept. 20, 0.7 less, or about 3.04. By the same logic, minimum area this year would be about 2.5. CAPIE of 60%; minimum extent of about 4.2.

Oh, and by the way, that says the diva ain't doing solfege on the 1st.

Chris Biscan

http://www.iup.uni-bremen.de:8084/amsr/arctic_AMSRE_nic.png


Might set a record for extent drop in one day.


this proves to whomever wants to say it that the ice out there is super thin.

talk about vanishing.

Paul Klemencic

The preliminary Bremen map is out, quite late. The map shows the pack shifted toward the European side of the Arctic, and the Beaufort, Chukchi, and E. Siberian regions saw huge, and I mean HUGE, losses of ice extent. The losses shown are likely too big to be entirely real, and I suspect the guys at Bremen were double checking their data before releasing the map.

This area gets revised a lot in the final map, but if the losses hold up, we could see the largest single day decline in extent in recorded history.

Ian Allen

The lows should not spoil the party, we don't really need the fram full-time, we need gales over the slush.

Neven

The updated map will have to look a whole lot different. It's impossible for all that ice to disappear so fast. It's very cloudy there.

Chris Biscan

Paul, they are real. Might be worse by tonight.


http://vortex.plymouth.edu/gifs/110822174242.gif


Those are sustained winds.

So 20-40mph sustained over that area plus torching SSTs and surface air temps:

http://www.uni-koeln.de/math-nat-fak/geomet/meteo/winfos/synNNWWarctis.gif

That was at like 5-6AM local there.

already in the mid 40s and 50-60 over the mainland.


850s were in the 6-10C range over the open warm water.


wow.

Chris Biscan

Neven, when ice is super thin. And that area gets torched. Remember cloudy with 2-3 days of 4-8C 850s with 10-20C 850s right over land west of there.

SSTs there:


http://ocean.dmi.dk/arctic/satellite/plots/satsst.arc.d-00.png

Go back and see how they warm up in response to such warm air intrusion.

When you have ice 1-2 feet thick maybe a bit more in spots with spaces in between face winds like that for 48 hours+

it's moving and moving rapidly.

Neven

Chris, sure. But not in one day. Impossible. And if it's not impossible, I'll go outside naked and scream to passersby that the end is nigh.

we need gales over the slush.

There you go:

Ian Allen

For those looking at station temps in the Canadian arctic, bear in mind some are misplaced on the graphic, including Wunderground map and the map on the graphs page here, e.g. Sachs Harbor, Banks Island and others when you investigate are in Alberta and plotted in the wrong place. some of the hot arctic isle temps are thus spurious and have been for months at least.

Chris Biscan

Well..

under normal winds that ice would of slowly been compacted.

When it gets to sit there for this long and become paper thin(relative). It can get melted/compacted out.

Look at the E. Siberian Sea.. It has faced -8 to -12C 850s the last 3 days and the ice there is still melting. From the Bottom and top.


When we loop the SST map we can see warm water out of the Bearing straight flowing into the Arctic the last 4-5 days.

It just so happened that we have had 30-45 mph winds slowly move over a 300 mile wide area in 48-60 hours.

This is the consequence. As you can see the thicker ice further south also moved 20-30km today. so it's not hard to believe even thinner ice can move rapidly and melt.

Ian Allen

Don't forget the 850's are 5000 feet up. we have cold 850's regularly in UK, but surrounded by mild seas, snow is unusual at the surface. Just gives a very steep lapse rate and incessant showers

Chris Biscan

http://vortex.plymouth.edu/gifs/110822180532.gif

The winds will be doing this for another 3 days.

by then that side of the Arctic will be fully compacted.

And the Other side(E. Siberian Sea) gets compacted down the East Side of the pact where the flow takes it to the Fram.

The cold air stays in that area as well while warm air sits on the thickest part of the ice.

Geezus.

Chris Biscan

yeah I know that 850s are 5000feet.

But the point is since the SSTs leading up to the ice are 4-8C with Land around not covered in snow. Nothing is there to cool the air.

if there was 850s of -6 to -10C with near freezing SSTs with those winds the melting factor would be low and the land around it would be cold.


with such low Heights. H5 heights were very low there 2 days ago, still low.

There is no cold air to generate because the wind flow coming off the dry hot Western part of North America shunted all the cold air to the other side of the arctic.

In other words this is about as good of a set up as it gets for localized compaction.

While upper level maps suggest cold temps there.

Low Level warm air was brought in with the powerful winds.


Paul Klemencic

Chris Biscan: I agree that the winds help speed up the melt process, but mainly due to increasing heat transfer as the floes are moved around over warmer water. The amount of heat that can be effectively transferred out of a warm wind is minor compared to heat coming from the water, and likely less than insolation, even at this time of the year.

I have to agree with Neven that melting out this much ice in one day is impossible. The maximum melt rate is certainly less than 20 cm/day, and likely less than 15 cm/day. Further, the amount of heat required to melt out all that ice that fast is huge, and the delta temperature isn't high enough from the water to the ice to get the fast heat transfer needed.

What this does do, is really move the floes around, and keeps the bottom melt going fast, as water cooled by ice melt is replaced quickly with warmer water. So even if this ice survives today, it won't survive even a week, with conditions like this.

Chris Biscan

The ice didn't melt.


it was shoved into the thicker ice East and SE of it.

crandles

Modis has lots of cloud which isn't very clear. 3-6-7 view is often unclear but there seems a surprisingly large amount of empty patches quite far down North in row 5 column 3. Is that further HUGE melt or is that as expected and just me being confused?

I cannot tell from modis about Beauford disappearing ice.

Chris Biscan

http://lance-modis.eosdis.nasa.gov/imagery/subsets/?subset=Arctic_r05c02.2011232.aqua


Paul we saw the Eastern side of the Sheet recently move 20-30km in one day over quite a large area.

How far do you think ice half as thick and in chunks can move when there is a stream of winds 300 miles wide and 1500 miles long that are constantly blowing 25-40mph with gusts 30-45mph.

Also this air was moving off land over shallow water.

the top 1-3 feet of water where the ice is probably started to flow at an insane rate.

If the ice was 2-3 meters thick it would not have been able to move so fast.

Christoffer Ladstein

An average extent decrease of "only" 65K for the next 10 days will bring 2011 were we had 2007, exactly, 4,6 mill km2. I say that is VERY possible!

Ian Allen

Agitation speeds up rate of reaction.
You stir your coffee to dissolve the sugar.
Once there is a thin enough slushie the remainder is primed to disappear when agitated-
Surface ice dampens wave action, but low concentration slush can be caught by the wind, and swell action will continue to jostle the remnants.

Paul Klemencic

Chris, I agree a lot of extent loss is due to compaction, but some of the ice that disappeared today in the Bremen preliminary map was over 100 km from the ice pack edge shown. That ice would have had to move, and then compact into denser ice pack very quickly to explain the change observed in a snapshot taken only 12 hours or so after the final map last night. And this would have happen over a wide area as well. Highly unlikely, if not impossible.

If the missing ice doesn't show up in the final map today, it will show up tomorrow or the next day.

But the point is, this front is really ripping the ice pack in the Beaufort and Chukchi regions. This should accelerate 2011 extent loss significantly. Instead of 120k+ today, followed by less than 60k over the following days, we could easily see 80K losses for 4 days. The end result is the same.

Neven

I was wrong. Those lows may not spoil the party. I hadn't paid attention to this big mama which unfortunately isn't staying in place for a couple of days, but moves towards Siberia and weakens on its way.

We'll need some sort of DA and/or strong Beaufort Gyre in September to keep the melting season going. Too bad PIPS won't be there to guide us.

Chris Biscan

Paul,

Also remember all of the ice in that area was moving not just one small area. So the ice downstream into the arctic was moving as well. Look at how the Eastern side moved East a bit. So extra room was made.

Also:

http://www.iup.uni-bremen.de:8084/amsr/daybefore/arctic_AMSRE_nic.png


http://iup.physik.uni-bremen.de:8084/amsredata/asi_daygrid_swath/l1a/n6250/2011/aug/asi-n6250-20110821-v5_nic.png


That was pretty absurd in itself.


For everyone,

the compaction machine heads over to the E. Siberian Sea and Laptev by day 3 and setting up shop with a DPA forming that will move the Eastern Half of the Ice pack out the Fram.

Both the GFS and Euro have this now and they are very close in agreement.

Chris Biscan

When you look super close you can see the ice on Modis left there.

Its there but it's so scattered it is not showing up on the 6.25km2 sensor as thick enough.

You can only see a small portion.


Jaxa will likely show up with more ice as well as some put back in for the final. but with winds like as you guys have said it won't take long.

either way we also saw other areas lose ice/compact.


Id think a 75Km2 loss day is coming or more.

Paul Klemencic

Chris, I pointed out the entire ice pack moved toward Europe in the first comment today.

More on compaction: the wind isn't pushing the ice directly into the pack, because the wind direction is roughly parallel to the ice pack edge. So we know the ice can't melt that fast, and it can't move that fast across the wind. Therefore, a lot of that ice is still there.

I think you should keep the focus on the ice pack movement in the next week. If the edge of the ice pack continues to get ripped up in the Beaufort and Chukchi, then the E. Siberia ice pack is pushed toward Siberia or into the Laptev as the storm moves that direction, then today isn't going to be a one day wonder.

Then later in the week, if we get even bigger pack movement toward Europe, with some being pushed into the Fram strait, then 2011 will catch 2007, and then some. Moving the pack 120 km toward Europe pushes over 300k-400k sq km over warm seas, increasing the bottom melt rate on some already weakened ice pack.

Chris Biscan

There is definitely still ice there.


probably just doesn't reach the 15% criteria now. in the grids.

Ian Allen

Paul, no-one can designate a maximum melt rate for a portion of the sea with billions of newly mobile crumbs of ice. The faster they are stirred, the sooner they go- surface area to volume ratio comes in also. Stronger wind tends to help break down the negative thermocline that supports the very existence of any of this ice above the warmer, saltier water beneath.

Espen

Healy is back in "ice" water at N 74°48' W 155°36' so can follow the situation by the hour.

Espen

Neven

Thanks for letting us know, Espen! Will it go into the ice, or does it stay there off the coast of Barrow?

Paul Klemencic

Ian, chemical engineers estimate heat transfer rates for conditions similar to this all the time. We maybe led you down the wrong path by calling this a 'slush puppy' sea. The ice in these seas does not consist of small particles or mobile crumbs of ice. Ice like that wouldn't have survived very long at all, and wouldn't be in the pcak for very long.

Clearly the bulk of the pack ice mostly consists of fairly dense blocks or floes of ice that range in thickness from 30 cm to 150 cm in thickness, and several meters across up to several km across. The maximum ice melt rate for this type of ice is certainly less than 20 cm per day and probably less than 15 cm per day, because the delta temperature driving force is only several degrees C (between the water in the vicinity of the ice, and the ice). Higher rates of melt would require a very fast heat transfer rate that is unachievable due to the low temperature differential.

I think you are thinking about ice melting at room temperature, but in that case the temperature differential is about 20 deg C, so the heat transfer rate is about ten times faster. If you put a block of ice 50 cm in diameter in an ice chest, fill it half full of water, then put an aquarium heater in to heat control the water temperature in the chest to 2 deg C, that ice won't melt out in 24 hours, let alone 12 hours.

These kinds of estimates can be calculated.

Ian Allen

Paul, I know these charts change on update, but chemical engineers would tell you that a fundamental means of increasing rate of reaction is agitation. That is why sweet-tooths stir their coffee- otherwise the sugar never dissolves. Waves of sufficient size churn deeper water also. The only reason the arctic has ice these days is the persistence of the thermo-halocline- see my post on the "polar ice caps can recover" thread. This leaves the ice open to billows of warm water drawn from beneath, as seems to be happening with the remarkably persistent clear blob N of the Laptev you have been alerting us to.

Espen

hi Neven
I dont know their plans but it heading towards the "Ring of action" north of the 75 parallel.

http://www.sailwx.info/shiptrack/shipposition.phtml?call=NEPP

http://mgds.ldeo.columbia.edu/healy/reports/aloftcon/2011/

Regards Espen

Seke Rob

Chukchi must be hard to read as it's been stuck at 371505.99 KmSq for 3 days in a row, whilst all other seas & bays show movement, down, for a total of -72648 KmSq from the 20th to the 21st.

Nick Barnes

I'm tempted to build a voting widget so everyone can enter their estimated IJIS extent delta for the next day. I think the hyperbole in this echo chamber sometimes gets a bit much, and some sort of tool to score our predictions, and to show each person's track-record, might calm people down a little.
Maybe next year.

For the record, today I predict an IJIS extent delta of 40,000 (that is, the corrected number for August 22 will be 5,236,719).

Werther

Well, distracted by another climate phenomenon in the Caribbean, I took a late gaze at UB an hour ago.
Put it in my CAD. Pack losing 5% extent in one day! Put MODIS r05c05 right over the battleground. Hard to tell through all these clouds. But look at the jet out of Alaska right up north!
When true, it could bring 2011 right under 5MK within two days! And close the gap on extent with 2007.
All depends on the physical behaviour of very thin, spread out ice. There’s no significant volume there since july. The slush puppy contains less than 1000 km³ and is spread out over at least 2MK.
I didn’t expect anything like this in the rest of this season. But, when it holds,FI when there's now less than 15% ice in these grids, it shows us how the end stage will look like, soon. Didn’t someone say, darkly, that at one time ‘it just suddenly disappears’?

Neven

I agree with Nick Barnes. If that big cyclone is doing anything to the numbers, it will show up with a lag, as it will mainly cause the ice pack to disperse at first. Besides, today's IJIS extent number was revised slightly upwards.

Nothing wrong with a bit of hyperbole to stir things up a little though.

Nice idea about a day-to-day prediction widget. But the excitement would soon wear off, I think, as it is very difficult to predict daily extent decreases (area being even more difficult).

Chris Biscan

Probably going to see a pretty big drop of the 30% one as well since alot of that ice that was compacted was 30-40% which gave that graph a very deceptive look with this ice being gone now or in the next few days. That number will drop buy quite a bit to near 2007.

Jon Torrance

Widget or not, it might be fun to do some retrospective analysis comparing the track record of predictions here compared to various mechanical strategies (average for the date in the JAXA record, same as the day before, same as the day before plus or minus the difference between that day and the preceding day, usw). I think there's a decent argument to be made that many of the predictions here are read as more confident than is truly warranted, which may contribute to making us look excessively alarmist in the eyes even of a neutral observer.

Bob Wallace

Just some minor observations while flipping back and forth between 8/20 and 8/22 Bremen technicolor maps...

1. Ice in the Parry Channel gets slammed up against the northern shore. Looks like one could drive through there now.

2. Greenland Sea ice looses a lot of concentration while not changing area much. Ice pushed out and melted?

3. Ice which was hanging out in a few different parts of the Gulf of Bothnia takes a trip to Gdansk.

4. Colors in Hudson Bay disappear. Now there is a gray band along eastern shores.

Lots of little bits of color disappear and gray areas show up where there once was blue all over the place. Does the gray mean that the data hasn't all been processed in the prelim map?

Chris Biscan

http://ocean.dmi.dk/arctic/satellite/plots/satanom.arc.d-00.png


This is from a different Satellite or maybe it's just a different Sensor.

But it shows the massive recede in the Beaufort as well and really shows the other movements of ice well.

Looks like the powerful winds churned over 4-5 feet of warm Sea Water which can be moved very fast...the ice being 1-2 feet thick on average there would be moved and melted very quickly because so much warm water is being churned.

This is so impressive just on the fact that none of us has seen this. And it validates the thinness of the ice.

The 0.9 meters for ice thickness around North Pole is nuts. Which validates Buoy data and completely invalidates Cryosat2 and the Navy thickness charts.

Because there is no way there was 3.5 to 4.5 meters of ice all over the inner arctic circle that just vanished in 2-3 months of melt.

Given what we are seeing, we may not set a min extent until very late September or early August which would be historic.

Chris Biscan

http://lance-modis.eosdis.nasa.gov/imagery/subsets/?subset=Arctic_r05c02.2011234.terra


http://lance-modis.eosdis.nasa.gov/imagery/subsets/?subset=Arctic_r05c02.2011234.terra

1. The ice is off the land mass..Crazy....

2. The ice in the Beaufort is there but has been decimated so it's not at 15%.

Chris Biscan

http://lance-modis.eosdis.nasa.gov/imagery/subsets/?subset=Arctic_r05c02.2011234.aqua.250m

Wow.

The ice compacted but literally fell to "soup". No wonder it doesn't come up on the concentration.

Paul Klemencic

Ian and Chris, just to give you an idea of the heat transfer rate needed to melt out 30 cm (one foot) and 60 cm (two feet) in 12 hours:

For each square meter of ice, the 30 cm melt loss is about 300 kg of ice, which at 334 kJ/kg latent heat, needs a heat transfer rate of 2320 watts per square meter for 12 hours. For 60 cm (two feet) of ice melt, the heat transfer rate is twice that. For comparison, the heat transfer rate would be about 8x to 16x a reasonable Arctic summer surface solar insolation rate of 300 w/sq meter.

Even if the melt took 24 hours, the heat transfer rate required is 1160 watts to 2320 watts per square meter to take out ice this fast; which is an impressive heat transfer rate.

The 100,000 kJ transferred in these 12-24 hours in order to melt 30 cm, would be enough to raise the water under the ice one degree C to a depth of 25 meters! (It takes about 4000 kJ to raise one cubic meter of water one deg C). To melt 60 cm, the water is raised one degree to 50 meters. To do that over an area of approximately 100,000 square km is very, very impressive; perhaps too impressive!

On this issue, call me a skeptic.

Andrew Xnn

Guys; I'm a Chemical Engineer and you all seem to be over-estimating what we can do.

To develop an accurate model of melting sea ice would require an extraordinary amount of data and computation. It'd be a great project and perhaps somebody has applied for a grant to do something like that. However, this Chemical Engineer recognizes the incredible complexity of the arctic.

Patrice Monroe Pustavrh

Well, I think there is just simple explanation for great drop in Uni Bremen extent. Ice area in specific location was just above 15% threshold one day before and it dropped to just below 15% today. Given the spread of ice it seems most logical explanation to me. We may see some of this area filled back next day. This is the problem of extent as a measure in such conditions and the volume would be much more reliable indicator of the state of the ice. But, unfortunately, it is much, much more difficult to measure and extent is still the most reliable proxy for ice amount we currently have.

Kevin O'Neill

http://lance-modis.eosdis.nasa.gov/imagery/subsets/Arctic_r05c02/2011234/Arctic_r05c02.2011234.terra.4km.jpg

I've been disappointed in the new PIPS product for some time. PIPS has the frothy mess in the Beaufort (75N, 120W to 140W) as 3 meter thick ice with a concentration of 65 - 80% ... ummm ... someone in the US Navy needs to check the satellite images.

Similarly, buoy data has thicknesses one-half to one-third the PIPS nowcasts.

I suspect some of the discrepancies are a matter of definition, but even bearing this in mind they are increasingly useless.

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