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michael sweet

Someone asked about tides in the Arctic earlier. The tidal range in Kimmirut is 20-30 feet (6-10 m) (!!) and in Barrow it is 1-2 feet (.5 m). Obviously tides would affect the ice in Kimmirut more than in Barrow. Last week there were some people among the ice at the base of the road in Kimmirut and it was amazing how big the ice pieces were. Some were 3 meters high. I had thought it was snow with tire tracks in it.

Alberto Silva

Anyone has any idea what will happen with the arctic weather in a few days?

Will that low inside the AO persist, or will be repplaced by highs?

What are the chances of the Dipole Anomaly to form again?

Do anyone knows if these forecasts are trustworthly?

WhiteBeard

Rob, June 21, 11:34;
G of L, 16:45,

Well, I increased measurable the flux locally, from the visible red down into the IR, when I read your comments. Thanks. It brings the values into the reasonable range, though I’m a little surprised by a June average of only ~280 w/m^2. I would have expected just a bit more, especially for an area that normally still has almost all of its sea ice at this time of the year.

While I’m at it, I should make use of the blush. The fooling around I did with the Canadian solar power site, didn’t really didn’t point to anything with respect to insolation level and latitude

Ghoti,

Thanks for replying with that Brazilian source. The first graphic, on slide 10, “Media da Radiacao Diaria, Mod. GL1.2 (W/m), Periodo: Dezembro 2003” indeed seems be for a Southern hemisphere solstice month. But it’s for a single year, and appears to be model output, apparently in a progress report on a measurement project. That’s not to disqualify the info which seem credible to me, but rather treat it with caution.

This may be a good starting point in looking for insolation data.

http://www.gewex.org/srbdata.htm

I’d say insolation caches haven’t had much processing for the general public, or at least much that I could find, and that mostly by clicking around NOAA and NASA sites only to pass “go” repeatedly.

It’s at the level of being useful as input for someone seeking a processed commodity for further use in making something like the tool at the Enviro Canada site. That would be a person who knows more about the field than I, and has an affinity for alphabetic hash. I couldn’t find anything besides ReadeMe recipes and piles of ingredients (at least that’s what the links seemed to be when I sampled some that looked likely), but no “take-out”, much less any junk-food.

Is this the Barrow graph you’re looking for?

http://seaice.alaska.edu/gi/observatories/barrow_breakup/Melt-out-20100709.png

tDoger posted it on the 1st page of comments, with ASI blog citation history. Nice touch, that.

Daniel Bailey

@ Alberto

"Do anyone knows if these forecasts are trustworthly?"

Personally, I make it a rule to never rely upon anything hosted by denier websites. Especially when similar information can be found on reputable science-based websites.

Alberto Silva

Daniel Bailey,

could you give some links to those science-based websites?

Neven

Will that low inside the AO persist, or will be repplaced by highs?

What are the chances of the Dipole Anomaly to form again?

There was a forecast 2 days ago of something that looked a bit like the start of a DA, but it's off the maps now. It looks like that low will continue to dominate for 4-5 days at least.

Do anyone knows if these forecasts are trustworthly?

It looks trustworthy enough (although I agree with the point Daniel Bailey makes). I usually look at Wetterzentrale at the ECMWF forecasts, but GFS is also there.

Rob Dekker

Whitebeard,
Don't worry about making a calculation mistake. It happens. Last year I was a factor 10 off with the amount of ice melt that this 280 W/m^2 insolation would cause :
http://neven1.typepad.com/blog/2011/06/temps-june-2011.html?cid=6a0133f03a1e37970b01538f8edafa970b#comment-6a0133f03a1e37970b01538f8edafa970b

Luckily, it was corrected quickly by another poster. Compared to that, your factor 2 mistake is not a big deal :o)

The main issue is that you were trying to make a point, and the question is if that point still holds after the calculation mistake is corrected. Does it ? And if so, can you re-state your point and your conclusion ?

Rob Dekker

Whitebeard,
Couple of notes :

Comparing Arctic summer insolation, which we now know is about 280 W/m^2 average over the month of June, you mentioned that Sahara study which reported peak insolation numbers above 400 W/m^2.

But what are these numbers really saying ? Are they full day (24hr) averages over the entire month of June ? Or are they averages of the 'peak' insolation each day ? Or averages of the 6-hour 'peak' each day as the paper suggests ?

I have a hunch that by the time we figured out all the details, Neven's remark that Arctic summer insolation is "close to" that of the Sahara may not be far off...

Rob Dekker

The other thing that I'd like to note is that the Canadian site that GofL linked to :
http://goo.gl/qXso9
shows that summer insolation in the Arctic actually increases with latitude.
Which is a point that Lodger made here not to long ago, and a point that may be actually be an amplifying factor of albedo-effect when we realize that the ice margin shifts further and further North over the years.

Al Rodger

Re the 280 W/m^2 & 400 w/m^2
I'd say they have to be the average surface insolation over the 24hrs x 30 days, by the following reasoning.

From a cursory web search, the Sahara gets 2,200 kWh/sq m. That would work out to 400W x 24hrs x 230 days.This seems reasonable, with the peak month 60% above the annual average. That graph of insolation at the top of the atmosphere linked to back up the thread said pretty much the same.
http://earthobservatory.nasa.gov/Features/EnergyBalance/page3.php

Chris Biscan

The models torch the Canadian Archipelago, Baffin, Greenland region, and the Russian Sea's on and off.

A general Weak Dipole Anomaly starts to organize.


It begins with the SLP moving to the Russian Side and Oscillating around.


Next, HP forms around Greenland and the Eastern Archipelago.


While another elongated SLP forms in the Beaufort.

This is the perfect conveyor belt for warm air to move off Alaska and Canada from the mainland.

The GFS is more aggresive with the warmth over the EURO.

The GFS has 10-18C 850 mb temps over the same region for a long time flooding the North American Side.


With as warm as the models are now.

They will almost certainly go warmer as this goes on.


http://i174.photobucket.com/albums/w109/frivolousz21/2012173.png?t=1340372991

There is literally no snow. I can't wait to see the weekly updates from Rutgers. It's been stuck on week 22 for a while. Just eyeballing the graphs, it's almost certain 2012 will hold lowest on record on week 23, 24, 25.


Just comparing the day to day graphs from June 7th to now, 2010, 2011, and 2012. It's very clear 2012 had it's snow pack basically vanish.


The Snow Pack is a negative feedback for Earth Warming.

I am sure we could look for any reason under the Sun and find some correlations.


However we all know this new event is from GHG Forcing/Feedback's during the Northern Hemisphere Spring.


Quite Frankly the Climate has changed.

Apocalypse4Real

Chris,

Regarding Rutgers snow data, it does appear at the scale they are calculating that all US or North American snow is gone except in small areas. However, in at least one case that is not true.

While the US appears to have no snow or ice cover, in reality, in the Rockies there are mountain ranges with some snow.

See: http://www.nohrsc.noaa.gov/interactive/html/map.html

That said, what remains will have far less impact on warming temperatures and sea ice melt.

Rob Dekker

Al Rodgers said :

From a cursory web search, the Sahara gets 2,200 kWh/sq m. That would work out to 400W x 24hrs x 230 days.

Thanks Al. This number seems to refer to TOA insolation. Do you have the link to that 2,200 number, and do they have numbers for insolation "on the gound" too ?

Seke Rob

TSI TOA is on all of the planet 1361-1366 [depending on whom you refer to as compiler of the insolation]. SORCE atm is showing practically the same now as what they peaked at in 2003 [the European Heatwave year] http://lasp.colorado.edu/lisird/sorce/sorce_tsi/ . At 0.1% variation from highest to lowest in a solar cycle, we're global average varying about 0.21 Watt/M2 at surface [yes that little]. The GHG and knock on forcings we've added are multiples of that. It's the sun [yes], because it's encountering more GHG/Less Ozone on it's way down (SW) and up (LW reflection/emitting).

The interesting element within TSI is UV, which is deep water penetrating. This varies quite a bit more with sunspots counts. Now we got a MM ozone layer depletion, particular at the polar regions, so count out what that effect has on sea ice and snow. No data, but little left to the imagination.

Al Rodger

The 2,200 kWh/m^2 for the Sahara is not TOA as it is the figure being used by solar heating folk.
Top of page 2.4 here:-
http://ocw.tudelft.nl/fileadmin/ocw/courses/SolarCells/res00026/CH2_Solar_radiation.pdf

To be more specific, there is "'global' horizontal annual surface irradation" for the Sahara. "Global" means 'not just direct' so it also includes deffused irradation.
The site here has some maps (model based) showing both 'direct' & 'global' but sadly not extending to the Arctic. Note the fourth map showing parts of the eastern Sahara going above 2,400 kWh/m^2.
http://www.greenrhinoenergy.com/solar/radiation/empiricalevidence.php

Arctic-wise (and what set me off on this irradiation web searching lark), a while back I bumped into this site which does provide a map of Arctic irradiation (probably "global horizontal annual surface" as its a solar power site) but sadly only over land. Note the Greenland ice sheet gets above 1,000 kWh/m^2 even in the North of Greenland.
URL a tad too long for use outside HTML.

Werther

Different climate…
Due to clouds, comparing the state of the ice north of Greenland to last year day 160 is difficult. From what I get, the pack out there has fractured further. Mean floe area is smaller than it was in 2011, leads filled with rubble smaller than 1 km have grown in size/area.
FWIW I compared UB day 174 2206 to last year on CAD. I find 2012 on the lead, minus 6% or some 660K. Mainly through big losses in the Baffin/Labrador and Barentsz regions.
Meanwhile, that low, now centered 800 km north of the CA, is driving in situ grinding and melt in a 1 million KM2 region on the Siberian side of the Arctic Basin. Mean floe size has dropped to 16 km2. The ice pack pattern has shifted from more or less uniform floes within a mesh pattern of rubbled leads (2011) to a disarrayed swarm of small floes. Area must have dropped to 60% out there.
In 2007, that region was on the edge of the minimum.
So, while the Atlantic region is bound for lowest minimum, the formidable void on the Bering side in 2007 will possibly repeat itself. Weather and El Nino driven cloud cover should line up pretty soon for the ice pack to avoid a shattering blow.

Bob Wallace

"El Nino driven cloud cover"

Explanation please. Wouldn't more clouds lower solar input?

Kris

Today at Obuoy 4 , a little bit to the right from center photo, wouldn't that be new formed ponds?

Seke Rob

Kris, zoomed in towards the shot wide ridge, looks like ponding from left to right... quite a few.

Bob, I think that's what Werther said, that the El Nino driven clouding "... to avoid a shattering blow."

Bob Wallace

Sorry, sloppy reading.

But el Nino should increase cloud cover? That's just from warmer temps causing more evaporation?

Twemoran

I few moments ago I posted about the new ice bridge that's formed in Nares on the wrong thread. It's north of Hall Basin in Robeson Channel, and may be the result of the very high southerly winds last night.

The arch appears reversed, as though ice movement in Lincon Sea was responsible, rather than movement in Nares.

At the moment it's only visible using MODIS agua at 250M - r03c03. As MODIS fills in we'll be able to get a better idea of the situation.

Terry

crandles

>"That's just from warmer temps causing more evaporation?"

I doubt it. While for global temperature the lag behind MEI is 1 to 7 months, I believe that the heat tends to start in Southern hemisphere and move northwards. So if the increased cloud cover is simply from warmer temperatures causing more evaporation, then I don't think that increased cloud cover will arrive until well after the minimum. (Though possibly some effect from La Nina beginning to decline starting approx Feb might begin to show up by Aug.)

However, there could be other reasons for el nino to drive increased cloud cover in Arctic before the minimum. A different teleconnection?

Neven

Chris Biscan wrote:

A general Weak Dipole Anomaly starts to organize.

Yes, the forecasts have been tentatively showing this for days now, but it seems it will come about, with a rather large forming over Greenland and part or all of the Canadian Archipelago. We'll see what the effect on SIE and SIA will be. I think the change will be slow, as usual when things transition. But the high over Greenland should give us a nice view of Nares Strait as that ice arch breaks up. It has to be breaking up any day now, right?

That low really is leaving its marks, though. Have you noticed those holes in the ice pack? I never really looked at lows at this point of the melting season before, so I don't how 'unusual' this is. There were a lot of holes in 2010, but this early? Can't remember.

WhiteBeard

Rob on Decker, June 22, 08:57,

Appreciate the replies and really am not upset. I’ve been around for quite a while and long have had a book mark with a thought balloon over a cartoon Garfield that nicely sums things. “I live like I type, fast and with lots of mistakes”. It’s quite true of me, except the fast part.

The specific, limited point goes way back to a statement of Kevin’s, “there is a huge amount of insolation there [the Arctic], more than anywhere on the planet” to which I replied the “more than anywhere on the planet” bit is wrong. All that follows, for well more than a week now, is trying to find evidence. The Sahara paper is only relevant to sea ice in the “more than” context, though interesting in itself.

Besides trying to get some actual numbers on arctic isolation around the solstice, for me, the bigger point has become trying to raise some consciousness, provoke a better understanding, about insolation during the polar summer. And, the numbers relate to another topic, the future year’s pattern of ice loss, that I may or may not take-up here sometime.

Annual Insolation values aren’t difficult to find. Getting much evidence at monthly resolution, is proving to be difficult and I’m having to do some construction (which, by the way, is the local name of one of our 4 seasons; the other 3 are Early Winter, Winter, and Late Winter) rather than simply post a link to nicely packaged data. I’m working with the 2 Arctic locations I’ve been lead to, both of them having useful stuff but both require interpolation and checking for reasonableness. Fortunately others are pointing out the banana peals I’ve stepped on.

From the Barrow and the Canadian Artic Archipelago I think I’ve worked out (with help) that June daily average surface insolation is, very roughly, 280w/m^2, with clear sky going to ~370 (Barrow).


09:30

I created another red herring I see. I should have skipped the table 1 references and just directed attention to Figure 2 of the paper. I skipped over the word peak, though I read the legend several the times. Sheeeesh.

http://www.tau.ac.il/~pinhas/papers/2006/Alpert_et_al_JGR_2006.pdf

It shows daily average insolation value of 350-360 w/m^2 for June (actually for ~5 weeks centered on the solstice) by my eyeball. From the paper, [6] In the aforementioned formulations, the solar insolation, i.e. the downwelling solar flux averaged over the day....

That rarely occuring clear sky value for Barrow is actually slightly more that the Sahara’s (75º of longitude between 20º-35ºN) daily average.

09:42

Ya, but it shows a continental effect as well. The Prairie Provinces, most of the far north, and Ontario have higher insolation over a truly wide range of latitude than do more coastal areas. An insolbar (?) line runs NNE from the northwest tip of Baffin Island to the central Queen Elizabeths with greater then ~280 w/m^2 to the east. But to the west, the area of less than 280 extends at least some 5º further north, to somewhere in the Central Arctic Basin. Before going to sea, it proceeds above ~75º N. The greater than area to the east and north is noticeably narrower along its north/south axis than along the latitude axis. Messing around with angling the plate produces a greater that area much narrower still, and a new isolbar now running parallel to the eastern coast of Ellesmere Island, where none was before. I’m leery of a graphic that shows that pattern as much proof of the general conclusion that around the solstice, increasing latitude leads to increasing insolation.

The angle of the sun above the horizon decreases. I've covered this earlier in this thread but the basic reasons why I think this offsets, in great part, the increase in photo period for “daily” insolation at Arctic latitudes at the surface. The low angle factors aren’t linear and change ever more rapidly as that angle nears zero. The core of my contention is based on this:

http://www.physicalgeography.net/fundamentals/6i.html

Fig 6i-3 integrates the idea shown in Fig 6i-1 with the data from Fig 6i-2. Note that around the solstice, the 30th parallel has more surface insolation that the 60th and, at the pole, it’s only about 4 or 5 % greater than either. Optical depth of the atmosphere increases nonlinearly with the angle, becoming much larger at very acute angles. Low clouds are much more common then clear skies in the cold marine area of the Arctic. It adds up.

There is a surge of energy, just past its peak, going into the Arctic system now. It’s just not as great as the longer photo period, that most everyone is familiar with, would suggest.

crandles

>"There is a surge of energy, just past its peak, going into the Arctic system now."

I would suggest you might need to be careful with the terms 'going into' and 'peaked'. I am thinking that while bottom of atmosphere (BOA) insolation may have peaked, the energy 'going into' arctic system almost certainly hasn't peaked. As ice area decreases a higher proportion of the BOA energy is absorbed by the ocean. So ice volume declines at a faster rate in July than in June. Or am I mistaken about this?

Ghoti Of Lod

Many people have spent many years collecting irradiance data from all around the world. There appear to be large organisations devoted to this kind of work. Baseline Surface Radiation Network (BSRN) seems to have been doing this for over 25 years. Maybe you can find what you are looking for at http://gewex-srb.larc.nasa.gov/

Stevemosher.wordpress.com

Ghoti.

Environment canada has insolation data in it's Hourly format (hly11) but I believe you have to order the CDs. The online hourly, daily, and monthly products which you can download to csv dont have this variable. My current project ( CHCN) allows you to download all the monthly data-- using R, but I've been unable to locate any online insolation data from Envcanada. You can look on their web page under products and services.. then look at the technical documentation. There are, as others note, other sources for insolation data.

Werther

The teleconnection…
For a clue on how the arrival of El Nino is manifested over the Arctic best read Wayne Davidson’s blog. He identifies ‘cloud seeds’, I suppose they spread fast in the high troposphere. IMHO that would diminish solar irradiation at first instance, but would probably enhance local greenhouse effects later on. As for Crandles’ remark, I would agree that lower tropospheric cloud formation and effects have a lag of months.
For another alarmist stunner, I noticed on MODIS day 173 r02c02 that ‘meanwhile’ the calving front of Sermeq Kujalleq, the Ilulissat glacier, seems to have receded more than 2 kilometers, or 10 square km’s. Checking on day 183 2011 I found the snowline, 60 km up on the sheet, a 100 to 6000 meters further up (about 10-50 meters in height).
I am aware that I notice the bad easier than the good ( though I like a good laugh ), but it looks like the differences in height on the sheet margin are rising. In the glacier feeding ice canyons I see hints of blue, suggesting melt rivers, and some deep grey marks, maybe moulins, that weren’t there last year.
Temps in Kangerlussuaq (S.Stromfjord) have been around 16dC consistently since the end of may.

Rob Dekker

Whitebeard, Ghoti Of Lod, Al Rodger,
Thank you guys, for your input on solar irrandiance between the Arctic and other areas (such as the Sahara) during the month of June.

Allow me to summarize some of the findings.
For starters, there is no doubt that the Top Of Atmosphere (TOA) insolation in June is higher in the Arctic than anywhere on the planet :
http://en.wikipedia.org/wiki/File:InsolationTopOfAtmosphere.png
with 90 N checking in at more than 500 W/m^2.
In fact, Arctic TOA insolation is higher than anywhere and any time on the planet, except for Antarctica during the Southern Hemisphere summer.

But how much of that TOA insolation makes it to the ground ?
The Canadian web-site that Ghoti Of Lod linked to suggests that on AVERAGE, June insolation on the ground in the North of Canada is something like 280 W/m^2. However, during a cloud-free June, insolation average can get well over 300 W/m^2 and peaks at 375 W/m^2. Barrow :
http://seaice.alaska.edu/gi/data/barrow_breakup/2009/Melt-out.png

Further North, the TOA insolation graph suggests that insolation is higher than that still.
During cloudy days, insolation drops back to 50-75 W/m^2, which brings back the average very significantly.

Either way, the average of 280 W/m^2 and a peak of 375 W/m^2 sets the range in the Arctic during June.

Then there is the Sahara. Al Rogers reports 2200 kWh/m^2 per year average, which suggests about 250 W/m^2 average.
This average seems consistent with what Whitebeard reported in the Alpert et al 2006 JGR Sahara study.
That study suggests (as Whitebeard points out correctly) that average insolation in June over the Sahara tops 350 W/m^2.

The data in that study suggests that even though TOA insolation in the Sahara in June is lower than in the Arctic, that insolation on the ground is still significantly higher in the Sahara than in the Arctic (presumably due to more clouds in the Arctic than in the Sahara) in June.

Trusting this data, I would tend to agree with Whitebeard, that on average the Arctic in June receives not as much insolation as the Sahara does in June, although on cloud free days, the Arctic wins hands-down.

I drove through the Sahara in June, and yes, insolation is brutal. Very much so, and then some. Temperatures are even worse (120 F was common during my trip). If that is what is to be expected of an Arctic without sea ice due to AGW, then there is no doubt that loss of Arctic sea ice will have a very profound effect on Northern Hemisphere climate patterns.

Seke Rob

The sun facing earth is practically sunspot free http://www.spaceweather.com/ i.e. good reduction of UV [but then with a damaged Ozone layer...]

Atmos CT was late yesterday [no update], so looked this morning and it's like 150KKm2 less area. Is this another attempt at breaking the 2MKm square anomaly mark?

2012.4657 -1.8339245 7.7707324 9.6046572
2012.4685 -1.7785462 7.7382598 9.5168057
2012.4712 -1.8484062 7.5873981 9.4358044

me.yahoo.com/a/nSjChi4X3vr8X3DRw93GkY1.cerja.8nvWk-

For those interested in the polar insolation go to the N Pole webcam site. On several years they measured hourly data there and it's still available. At this time of year I recall days when for 24hrs it was over 300.

Phil.

idunno

Hi all,

...and two come along at once.

CT area falls a more modest 83k. (We are now in the period of the year when the 1979-2008 average can fall by over 100k.)

The negative anomaly slips back to -1.819M.

Whilst 2012 is still in the lead, 3 other years (2007, 2010, 2007) are now due to do some speedy catching up over the next week or so...

http://arctic.atmos.uiuc.edu/cryosphere/arctic.sea.ice.interactive.html

Voyageur

If you haven't already seen Jim Pettit's powerful new graph -- a version of 'death spiral' -- but this time based on PIOMAS, then a visit to
https://sites.google.com/site/pettitclimategraphs/home
is recommended.

Seke Rob

MASIE (Chart) decided to turn in 169.5KKm square less for day 175 compared to day 174. There's one puzzle. Sea of Okhotsk is stuck on 30KKm square of ice.

33545
29402
29402
29402
27814
27814
30684
30806
30806
30806

Anyone more familiar with that corner of the world? Nearest name found on G.Earth is Pervorechenskiy, Kamtsjatka (out of this world remote and cold place the B&W pictures suggest). The UBI Bremen picture does not show anything but blue for that sea.

Espen Olsen

I believe we got a ice break up just outside the Petterman Fjord to the right in Nares Strait: http://rapidfire.sci.gsfc.nasa.gov/imagery/subsets/?subset=Arctic_r03c03.2012176.aqua.250m

Twemoran

Espen

Going back to the 22nd on Terra - the split is almost across Nares from the Canadian side.
On the 23d the split has widened at runs all the way across as seen using Aqua - The Lincoln Sea also looks bad.
Today Aqua and Terra are both showing the split, as well as shore leads on the Greenland side.

DMI Lincoln makes it easy to flip through the images

The polynya at the north end of Kane
basin on the Canadian side has a large crack all the way around it.

Even though the Smith Sound/Kane Basin ice bridge is still holding, I don't think it's going to last too long.

Terry

George Phillies

It appears to me from the latest Uni Bremen map http://www.iup.uni-bremen.de:8084/ssmis/arctic_SSMIS_nic.png for June 24 that the ice that had been attached over a long distance to the Greenland East Coast has let completely go and is headed for Iceland. There is this long North-South patch of blue right at the coast. I don't recall having seen something quite this dramatic, which means that everyone else on the list now gets to point out that I am noting a regular event seen many times before.

Neven

Well, George, I don't know about th eperiod before 2005, but I'm not seeing anything like it on the concentration maps for June 25th. Only 2009 comes near it.

L. Hamilton

Clear skies and a fine view of that E Greenland coastline today, you can see the ice swirling away.
Clear skies and a fine view of that E Greenland coastline today, with the ice leaving town.
http://rapidfire.sci.gsfc.nasa.gov/imagery/subsets/?subset=Arctic_r02c03.2012176.terra

L. Hamilton

^^^ edit fail

Apocalypse4Real

George, Neven,

The East Greenland ice melt began to appear in the MET NCOF Godiva imagery on 17 June, was apparent on the 19th, and really stands out today.

It almost appears that the whole run of ice out the Fram Straight is beginning to melt away - perhaps in the next week or so.

My glance through prior years shows the ice flow through the Fram Straight does melt back up the coast, but I did not find a case of simultaneous effect along the Greenland coast.

Pete Williamson

With the Nares Ice bridge still holding, just, and forming around the 10th of december.

http://ocean.dmi.dk/arctic/images/MODIS/Kane/201112100040.ASAR.jpg

I make that about 197 days of stoppage and counting. That put's it above the average, 188 days, for recent years according to this great paper.
http://rkwok.jpl.nasa.gov/publications/Kwok.2010.GRL.pdf

But it looks like the bridge would have to last until the start of July to match the norm for break-up in recent years. The unusual early formation date is what seems to making the stoppage days look good.

Rob Dekker

George Phillies, good observation !
That ice West of Greenland sure seems to be moving. The ice there seems to be moving off-shore because of a rather persistent high over South Greenland, but it may be worth noting that that East Greenland ice has built-up quite far South and not melted out much over the past couple of years. In the regional graphs, the Greenland Sea has been one of the few regions remaining on 'long-term-average' over the past couple of years, even though ice export through Fram Strait has not been excessive over the past few years. So keep your eye on this graph in the next few weeks, as that now freely drifting ice enters warmer waters...
http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/recent365.anom.region.5.html

Rob Dekker

Fix : /West of Greenland/East of Greenland/

Seke Rob

IIRC, Larry Hamilton has inroads to the DMI folk. Maybe he'd like to speak to the people responsible for this page: http://ocean.dmi.dk/arctic/icecover.uk.php The text surrounding the chart does not seem to jive. There's now the 8th year with data, and maybe they'd like adding an average curve computed from 2005-2011. The simple merge I did of MASIE/DMI/IJIS has an added line added JAXA base 2003-2011.

Seke Rob

It's a workday today, for those going by the western livestyle, and Atmos/CT was on the dot, loosing about 119Kkm square in area:

2012.4712 -1.8484062 7.5873981 9.4358044
2012.4740 -1.8195076 7.5040622 9.3235693
2012.4767 -1.8411558 7.3851199 9.2262754

crandles

Using area data to 2012.4767 = 23rd June?

My estimate of NSIDC minimum that estimates residual from gompertz fit of NSIDC minimum extent using residual from gompertz fit of 23 June CT area predicts 4.0m Km^2. (Record low is 4.30m Km^2.)

The RMSE of the linear regression fit is 0.328 but this is likely to be an underestimate of the standard deviation of forecast errors. So I think, at the moment, my estimated probability of the record low NSIDC extent being broken this year is somewhere around 60%.

(At least until I find a better method, or get some more data, or find an error in my calculations or ....)

Neven

Keep us up-to-date, crandles.

Well, those weather forecasts keep changing, but now that high is really taking over Greenland and the Canadian Archipelago, and I think I'm seeing a Dipole more clearly. Am I right to assume we'll see another nosedive in SIA and SIE around this weekend?

Bob Wallace

ARC drift forecasts are for several days of moderate rate, but steady, transport through the Fram. Lots of 95% and 100% concentration ice lined up for the trip to meltland.

Then there's that interesting open water along the east side of Greenland. The ice no longer attached to Greenland looks like it's also setting sail....

Werther

As Chris Biscan announced a couple of days ago, a warm southern wind has reached the Beaufort Sea. Yesterday, Tuktoyaktuk on the Mackenzie delta shore reported 27dC, Cape Parry on Amundsen Gulf 18 dC, as Sachs harbour on Banks Island did.
As a result, half a million km2 of adjacent sea ice had an extra boost in melt ponding. On MODIS this part of torn floes is completely blue today. With 300K in the Chukchi Sea rapidly thinning and 1 million km2 on the ESAS side shredded the 2007 void on the Bering side is in the process of recreation.

Werther

Melt season is on the path of crossing 8 million K early in July/5 mK in august. Next phase now is 250K left in Baffin Bay, 570K in Hudson/Foxe. Of course, the normal retreat elsewhere is continuing too…

Rob Dekker

Colin :

I won't be suprised if denialists started to pick up on this apparent discrepency and start making noise.

It seems that the 'denialists' are more excited about the term 'denier' being using in scientific literature than they are about the discussed and explained 'apparent' discrepancy between Modis and CT ice area.

Rob Dekker

Kevin,

A wild ride this last fortnight, for sure. And to think that a number of us here were looking for a slowish season just a month or so back! But as we all know, the system appears to just love making ice prophets look foolish--in the short term, that is.

Thanks for rubbing it in, Kevin :o(

The only defense I have is that the Chukchi seems to actually hold back a little bit after that harsh winter.

On the East side however, the Death Spiral rules. And now even the normally rather resilient Greenland Sea is going completely into a tailspin, after the entire ice pack separated from the Greenland coast, and is disintegrating very, very rapidly. Some 300 k km^2 is up for grabs, right there.

http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/recent365.anom.region.5.html

Espen Olsen

Talking about the ice at Joekelbugt, can someone tell (link) me to where I can find "old" Modis images from the area prior to 2007?

Neven

There you go, Espen (fill in 'Date').

Espen Olsen

Thanks Neven, If you go back to 30. th August 2002, Joekelbugt was actually ice"free", what happened in the mean time?

Sgustaf59

This could be the wrong place to ask this, but it seems like a lot of people here spend some time looking at MODIS. This year I noticed that the west coast of the Greenland ice cap is very dark http://rapidfire.sci.gsfc.nasa.gov/imagery/subsets/?subset=Arctic_r02c02.2012177.terra much darker than a lot of historical pics I looked at, but it was a limited sample. Is this unusual? I remember reading on Jason Box's blog how the icecap is getting darker and darker in the summer months and how that might effect the melt.

Espen Olsen

Hi Sgustaf59, it is the blue dissease, it is meltwater on top of the ice cap, and the blue spots are melt warter lakes.

Jim_pettit

After 16 consecutive days of being in 1st place, 2012 SIA dropped to 2nd place behind 2010 thanks to yesterday's minuscule drop in area of under 14k km2. For all but three days in the next two weeks, 2010 is currently in 1st place, while 2007 and 2011 take turns in 2nd and 3rd. It'll be very interesting to see whether 2012 regains the lead. Given the forecast and observations, my guess is that it will.

idunno

Hi all,

CT area falls only 14k, so 2010 is now in the lead.

Sgustaf59

Thanks for replying Espen, if you look at 250m you can see it is a mix of melt ponds and soot deposits http://rapidfire.sci.gsfc.nasa.gov/imagery/subsets/?subset=Arctic_r02c02.2012177.terra.250m here is a graphic of the changes since 2009 http://img266.imageshack.us/img266/9026/greenkq.jpg

Seke Rob

Let's not forget that if there is extensive top melting, the accumulated dirt starts building on the surface.

Mentioned this before... not a R/A trace of any of the open air nuke experiments is found at the top... a sign the snow layer since the 40's of the last century is Gone Gone.

Al Rodger

This is a link to the Jason Box blog that Sgustaf59 referred to above. It is specifically about the Greenland Ice Cap where muck in the ice inderlying the winter's snow cover is being increasingly exposed during the summer melt, darkening the ice & reducing albedo.
http://www.meltfactor.org/blog/?p=453
Being decades old, the Greenland Ice Cap has a lot more muck within it compared to even the oldest MY sea ice.

Seke Rob

Interesting how the Greenland coastal sea ice is pushed offshore and MASIE jumping overall 58K, of which 56K was added to... the Greenland Sea. http://bit.ly/MASIEA

The Sea of Okhotsk is not moving... stuck for 5 day now to 30,806 . How real is that?

Keith Jackson

I think that's to be expected isn't it Rob? It's spreading out (and melting) but hasn't melted enough to fall below 15% coverage yet.

Re: Greenland, the lower West Coast just became visible for today on Terra. Comparing with last year (from yesterday's date due to cloud cover), is it just me or has the melt ponding line moved inland quite significantly?

Christoffer Ladstein

Keith:
Your observation about the snow melt line, seem to be very correct. The melt line didn't reach this far inland until 1 month from now last year, if we're to trust MODIS. And we better do, in lack of any other good sources...

So if this Heat continue, Greenland alone will see to a global searise of about 2 mm in 2012 alone.
Luckily I'm positioned 130 m above sealevel, but still I'm worried...

L. Hamilton

"IIRC, Larry Hamilton has inroads to the DMI folk. Maybe he'd like to speak to the people responsible for this page"

Rob, I passed along your suggestion and will let you know if anything results. Curious what it might look like, I also drafted my own version of a DMI "average" graph:
http://img.photobucket.com/albums/v224/Chiloe/Climate/sea_ice_DMI_this_date2.png

Doug Bostrom

Further to Al Rodger, Jason Box and MeltFactor have an update on Greenland albedo. The news is darker (sorry!).

Greenland ice sheet reflectivity at record low, particularly at high elevations

Werther

Ilulissatday17726062012

Referring to my entry 24 june and the Jason Box article on reflectivity, I revised last years CAD scheme of Jakobshavn Isbrae's surroundings.
The basis is r02c02 day 177. I hope on this scale the calving june 2012 in red is still clear. The other area of interest is to the right hand corner. Notice the change in snowline 11-12? I've been going through that part on pixel level. Though MODIS is 2 dimensional, I interpret the pattern as a sinking sheet surface. It is progressively showing meltwater 'canyons'.
Box concludes that the intensifying mass loss is not a prelude to collapse.
As I imagine,the structure of the sheet under the snow line can be compared to that of a sponge. Each year melt water going down provides energy to this structure, weakening its strenght. Melting is a process, compaction (through gravity) is too. Together these processes are rapidly changing the ice sheet.
To be continued...

Rob Dekker

Espen said

Thanks Neven, If you go back to 30. th August 2002, Joekelbugt was actually ice"free", what happened in the mean time?

When we look at the regional chart :
http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/recent365.anom.region.5.html
it seems that every 10 years or so, the Greenland Sea sort of "empties" itself.
The Greenland Sea of course is special, in that it mostly accumulates old ice that comes there to die. So it's not suprising that there is a multi-year cycle of build-up and disintegration.

If that happens again this year, then this will reduce the overall September minimum by an additional 100 - 150 k km^2 or so below where any of the previous years would have ended up.

P.S. I wonder if the 10 year cycle of the Greenland Sea has something to do with the 10 year solar cycle or if it is just coincidence...

I Ballantinegray1

Hi Espen! If we see a link between a propensity to High Pressure blocking in the Atlantic through solar min then there may well be a period more conducive to 'flush out/melt' of this section of the Greenland Sea associated with a phase of the solar cycle?

Espen Olsen

Thanks for the answers to the Qs about North East Greenland aka Jøkelbugt, it will be interesting to follow what will happen op there this season.

Seke Rob

A link off from the Layman's sunspot sidebar titled JetStream Forecast: http://www.stormsurfing.com/stormuser2/images/dods/glob_250.swf .

Rob Dekker

Seke Rob,
I was kind of intrigued by your remarks about increased UV irradiance (due to ozone depletion) in the Arctic.
Did you find anything more about this subject, and specifically how much radiation difference this may imply ?

Al Rodger

And futher to Doug Bostrom's link above to the Jason Box blog (hat tip Doug), I notice also a very recent previous post on that blog.
It contains graphs of the dip in Greenland's summer albedo for five different altitude ranges, the last three of which are positively scary. (Their exact relationship to the less scary 2000-2500m graph in Box's last post entry is not clear to me. It appears to be more than their being more up-to-date. I speculate that they may include the use of some as-yet-unpublished data adjustments for cloud effects.)
http://www.meltfactor.org/blog/?p=514

Seke Rob

Rob Dekker. There's piles of [ignored lit] on Ozone depletion and UV effects in sea/land ice [and snow] reduction, but have no offhand quantification in energetic terms. 1% less ozone gives 2% more UV coming through was one number stuck in memory [and clouds offering little protection at ground level]. A search Google hits and visit http://www.ursi.org/Proceedings/ProcGA05/pdf/F10P.20%280096%29.pdf the chapter titled "Ozone-Hole Effect" discussing the forcing effect. Snip

At the shorter wavelengths the solar radiation increases very rapidly with the decrease in columnar ozone and decreases very rapidly with increase in air mass. Near the vertical (low zenith angle) the solar path length is less because of thin air mass; a little change in ozone will cause comparatively large difference in irradiance at shorter wavelengths. While at Large SZA, air mass increases and hence solar path, therefor slight change in ozone will not cause much difference in irradiance compared to low SZA.

The kicker mentioned before is that with sunspots the UV element from the sun changes substantially... low sunspots, lower UV. The last few years we've seen below average... but the Ozone holes have well offset that I think to have an additional forcing effect. Visit e.g. http://www.sidc.be/DATA/monthssn.dat to get the monthly numbers since 1749 as plotted in a tongue in cheek chart: http://bit.ly/TSISPT. The sun's been in a cooling trend since the 50's of last century, yet the temps are going up... OHC is going up. Maybe it's all due those UHI's based thermometer distortions ;P

-- Rob

Oh, yes, here it was in a wiki [plz no slapping]: http://wiki.answers.com/Q/Effects_of_ozone_depletion . Did I not mention 40% phytoplankton reduction? And more: http://www.lifesci.ucsb.edu/eemb/labs/prezelin/EEMB151_s06_home/readings/Ozone_Science255.pdf. Snip

The ratio of Quvb to total irradiance (Qtotal) is significantly greater inside than outside the hole.

Artful Dodger

Less than 2% of the sun's energy is emitted in the UV band. Ozone depletion primarily impacts biological systems, not the energy balance of the climate.

Seke Rob

The chart is interesting... here a variation:

Bernard Vatant

Great discussions here I've been lurking at for at least one year ... but I jumped in only yesterday (on a last year's post about Jakobshavn Isbrae evolution) and Neven pointed me back to this thread.
A question to all and maybe Werther in particular. Beyond reflectivity, aspects of the ice sheet surface, and calving monitoring, I was wondering if other indicators are taken into account, to assess the (liquid) water flow from the ice sheet into the sea. Based on my local mountains experience (France, Southern Alps), looking at the state of water downstream one can learn a lot about what is happening upstream. In particular the color of water is a good indicator of the quantity of mud or rock flour carried, itself an indicator of melting intensity.

This idea came to me while looking at http://rapidfire.sci.gsfc.nasa.gov/imagery/subsets/?subset=Arctic_r02c02.2012178.terra.250m and seeing how far the "muddy waters" extend downstream in the fjords. The various flavors of brown, grey and turquoise (the latter being characteristic of rock flour ... at least here at home), and how far they extend seaward down the fjords, is certainly something that can be compared at similar dates. Has that kind of study already be done?

FrankD

Fracture of the Western buttress of the Nares Ice Bridge seems very close. The calving front has receded and it is not properly anchored at the western end any more. Meanwhile the polynya that has slowly been growing behind it looks to have grown substantially. At a guess, I'd give it less than a week. Will be interesting to see whether Nares then opens up or remains choked higher up the channel.

www.facebook.com/profile.php?id=687386516

FrankD/
There are cracks in the eastern buttress also today.

http://lance-modis.eosdis.nasa.gov/cgi-bin/imagery/single.cgi?image=crefl2_143.A2012179095500-2012179100000.250m.jpg

Seke Rob

Whilst, watching the ice [in numbers] itself, JAXA after correction, recorded a century from the 25th to the 26th

9,571,094
9,454,219

No suggestion of a consecutive in their cards... The day on day 1st estimate only moved 55K down.

Doug Bostrom

Bernard Vatant asked an intriguing question about turbid runoff perhaps being an indicator of melting intensity. I notice that Jason Box entertains comments at his site; Bernard's question might be right up Box's alley.

Albedo appears to be running right off the rails this year; see MeltFactor latest post:

Greenland ice sheet albedo continues dropping at highest elevations

Box speculates about role of wildfires elsewhere in this year's precipitous plunge.

Werther

Bernard Vatant,
It’s great that you take this special interest in the Sermeq Kajulleq. I share that with you. I tend to spread my attention on (too) many aspects of climate change. But through this great panel Neven created, we as a group share and develop info and insight. Thus there’s always a companion ‘right on spot’. It would be great to have you in too.
At the moment I’m trying to find my CAD drawing layered over the geomorphology of the S.K.-fjord. I wonder whether the last calving took the front back from a mid-fjord threshold into the very deep middle section (1600 m below SL!). It puzzles me where all the melt lakes flush their combined waters. They probably drain through an intertwining maze. General pressure in the sheet should direct most of it into the deep fjord, under the glacier.
I think your idea to get a grip on what’s going on through the sediment laden melt waters in the fjords is a good and new approach. Hélas, in the S.K. this is hard to see, while it is choked with debris.
Other fjords give a better view. But they may well function differently. Not one of them is physically comparable to S.K. It’s the only one directly connected to the vast below SL rockbottom under the icesheet (at least on the SE side). That’s exactly why what is happening on the snowline zone behind S.K. is very important. Swiss Camp is out there. Hope to see more info from the Steffen Research Group. Great weather info there:
http://cires.colorado.edu/science/groups/steffen/gcnet/all_charts.php

WhiteBeard

crandles, June 24, 2012, 01:45

Quite true, “into the system” leaves a wedge for ambiguity. To be clear, I did not intend for “peak” to apply to the entire physical system, but instead to the input of solar radiation at the surface. The topic I alluded to in a comment up thread as being personally interesting is how the timing of insolation likely will impact the ice-water system.

GofL, June 24, 2012, 01:49,

Yes. Actually I’d looked there but was frustrated in trying to determine what was available by the common problem of acronym hash. People familiar with the data, using just the acronyms in the links on upper level web pages, as well as running into controlled passworded areas. What I found usable was in an practical application oriented topic area, not a sciencey one. But on going back, as I had intended (that is 1 of the 2 agencies that I think of as being the “usual suspects”), found what I was looking for.

To all who have left pointers, thanks.

I pasted June “Averaged Insolation Incident On a Horizontal Surface (kWh/m2/day)”, girded 1ºx1º, into Excel. The stuff used is at “Meteorology and Solar Energy”, then “Regional data subsets” which requires a case sensitive email registration to access.

http://eosweb.larc.nasa.gov/cgi-bin/sse/sse.cgi

The 24 hr period June Arctic insolation, summed into 5º latitudinal bands:

Latitude, Avg, Med, Max, Min (in w/m^2)

89º - 85º, 312, 314, 318, 312
84º - 80º, 284, 286, 311, 253
79º - 75º, 264, 261, 294, 232
74º - 70º, 255, 259, 283, 219
69º - 65º, 245, 242, 265, 225

89º - 70º, 279, 279

89º - 65º, 272, 270

Barring some further error on my part this is likely “napkin” close, although there are both methodological and source data issues. There are some substantial differences between adjacent cells scattered about, and that increases in occurrence moving to the south.

I looked at 3x3 1º areas with surface observatories, Barrow and three Canadian, having the ground station approximately at their center. I had tried for an extremely rough cut at Arctic surface insolation and was more lucky than skilful in that first attempt, or would have been had I tried to do one based on surface obs, which I couldn’t find, anyway. This 2nd arrow shaved some fletching off that 1st one. Those observations are all over, varying by 25 or more w/m^2 from the average of the 1º latitude band in which they fall, and by about twice that between some touching cells. Local conditions likely skew things. All are located on the coast and some have nearby mountains.

The 1º latitude bands have some surprising, to me at least, variance between adjacent ones, with values going up-down-up (or vice versa, if one is so disposed). A few adjacent ones show more than twice the change of the average step difference. The eastern and western hemispheres have a bit of difference.


Rob Dekker, June 24, 10:41,

That explains your Sahara v Arctic interest, I’d think. I’ve only been in the tropics in the winter (once around the equinox) and all times were just slightly over the line. Experiencing the difference between 23 and 65N is what what got this going.

I did NOT do a great job in coming up with my 350-360 w/m^2 working estimate. That arrow was well outside any ring. It was hard to extract from that small section of the graph, but I really thought the actual would be nearer the range I posted. Perhaps some differences exist in the data sets used, but that’s only a guess that I’ll make do with for soothing a bruised ego. The June daily surface data (all for a 20–35 N swath):

320 w/m^2 average for the total Sahara Region, 15W–60E (the area used in the graph);
307 w/m^2 average for West Sahara, 15W–10E;
333 w/m^2 average for East Sahara, 10E–40E;
315 w/m^2 average for Saudi-Arabia, 40E–60E.

Werther

Calving at Jakobshavn Isbrae
I found IceBridge reports for 21 april 2012, accompanied with a smashing image (I'll link that one ASOP).
MODIS for that day showed the front app. at the autumn 2011 position.
I'm convinced now the front did retreat more than 2 km since that date.

Rob Dekker

Whitebeard,
Let me complement you on your exemplary effort to uproot the details of insolation amounts between the Actic and the Sahara.
In the process, you have given us a couple of really interesting pointers. I just browsed around the 'eosweb' nasa site that you linked to, which seems to be a great source of observational data.
I like the 'table' data representation that they output, since that allows us to do our own analysis, and present our own graphs. I bookmarked the site.
So, thank you for you detailed follow-up and I hope you will stick around here at Neven's, as the 2012 melting season progresses.

As for the variance in insolation per degree latitude, this may very well be the result of variance in cloud coverage around the ice margins in June. Do you know exactly which satellite data they used to compile this data set ?

Rob Dekker

Seke Rob, Lodger,

Thanks, guys, for your data on the influence of UV on Arctic warming.
Even though UV constitutes a small amount of energy that contributes to surface isolation, please remember that only minor amounts of change make a difference between glacial periods and interglacials, and snow-ball-Earth versus Cretaceous warm periods.

For starters, CO2 concentration (due to human emissions) in the atmosphere increases with some 2 ppm per year. With doubling of CO2 w.r.t. pre-industrial levels (280 ppm) causing a 3.7 W/m^2 increase in TOA forcing, implies that currently we are at a rate of increasing TOA forcing by some 0.26 W/m^2/decade (calculated over the total surface of the planet).
On a solar-irradiance basis (w.r.t. the total solar output of some 1366 W/m^2) this implies that AGW increase is some 4*0.26/1366 is 0.076 % per decade.

So, even a minor change in irradiance (caused by ozone depletion) may make a big difference, at least on a decadal timeframe.

Seke Rob

MASIE recorded a 182KKm square loss for day 179. Pretty much across the board, except Laptev and the AB... even Okhotsk moved down, with Bering now racing towards a state of zero. Greenland sea push and shuffle and divide caused that cornerstone to drop 20K. With that, the Northern Hemisphere extent by that measure has gone below 10 million to 9,856,896, even passing the JAXA mean for 2003-2011 http://bit.ly/MASDMI

JAXA did not move much and is not likely to show a century after the coming night's adjustment. Pre-Adjmnt, the reduction logged -64KKm square.

On a different 'note', Atmos/CT recorded for day 177 a 140KKm square area drop.

24-Jun-2012 176 2012,4822 -1,7884034 7,2528086 9,0412121
25-Jun-2012 177 2012,4850 -1,8092500 7,1121540 8,9214039

With that huge empty expanse in the northern Baffin sector, whence Nares bursts, there's room for that ice to spread out thin and have a much larger above/below/and side melt exposure. A drop below 7M in area is certain to happen in 2-3 days [who doubts may speak up, and challenge the gods of melt].

Neven

[who doubts may speak up, and challenge the gods of melt].

Ehhhhhhh.....

Never mind.

Alberto Silva

With Sea level pressure in the Arctic Ocean forecasted to rise over the next week things should accelerate there as the direct sun radiation hits the sea ice and the clockwise rotation of the Beaufort Gyre starts again.

I am not sure however that sea ice melt will accelerate much because (at least according to current forecasts) the pattern will not be a typical Dipole Anomaly but a high pressure over and the Artic Ocean AND the Barentz-Kara Sea, with low pressure above Siberia.

However is still a change from a positive to a negative Arctic Oscillation,a transition that in other years had accelerated melt.

What do you think?

WhiteBeard

Rob Dekker, June 28, 09:33

Do you know exactly which satellite data they used to compile this data set?

The last paragraph under the “Methodology” link there is the statement that data used for, “SSE Release 6.0 were obtained from the NASA Science Mission Directorate's satellite and re-analysis research programs. .... Release 6.0 extends the temporal coverage ... to more than 22 years (e.g. July 1983 through June 2005)...”

I would look at the methodology pdf linked below the précis.

On thing; I did see that the data from the 4 ground stations I looked at were all ~20 or more years old (Barrow’s data is for 11 years ending in 1974).

I hope you will stick around here at Neven's

I’ve lurked fairly regularly since shortly after ASI arose as a Franken blog from a snooker table one dark and stormy night. I do leave links to ASI and particularly items from ASI Graphs (very handy, Nevin) at local media website when the subject of Arctic sea ice is subject to a storm of misinformation.


Neven, June 28, 19:42

Never mind.

“Hehe.”

Chris Biscan

The models keep trending to a Dipole Anomaly with with a widespread HP.

Inuvik Canada is going to be in the 70s and low 80s this week.

The models torch the region.

Neven

I am not sure however that sea ice melt will accelerate much because (at least according to current forecasts) the pattern will not be a typical Dipole Anomaly but a high pressure over and the Artic Ocean AND the Barentz-Kara Sea, with low pressure above Siberia.

However is still a change from a positive to a negative Arctic Oscillation,a transition that in other years had accelerated melt.

What do you think?

I think we will see a nosedive, but I'm not yet sure if it'll be big, and how long it will last. Like you say, the high will be spread out, I'm not seeing many isobars, so the wind won't be very strong.

However, what 2012 still has going for it, compared to other years, is that it's right down there with the big melt years, but it has much more ice in Hudson Bay, Chukchi and the Greenland Sea. So if the weather stays like this, 2012 should take the lead again on most if not all graphs.

Neven

For instance on the UB SIC maps from the 27th to the 28th Hudson Bay shows some huge changes. If those show up on CT and IJIS graphs, 2012 will be in the driver seat.

Misfratz.wordpress.com

The latest UB SIC map also shows the return over the last couple of days of a wide area of the Beaufort Sea/Central Arctic with reduced sea-ice concentration. This was present earlier in the month when it was most likely melt-ponding being picked up by the microwave sensor.

Could this be a proper retreat of the sea-ice this time, or is a repeat of melt-ponding more likely?

It's a really large area, roughly equal to the area that has melted out in the Beaufort sea already, which is 300,000 square kilometres.

Neven

Misfratz, you can check yesterday's Arctic Mosaic. I think it's mostly melt ponding (a lot of that ice has a bluish hue), but there are also quite a bit of leads between the floes. But mostly melt ponding. When large swathes of yellow, green, pink colour show up on the UB Sic maps, they usually don't mean a thing (melt ponds, clouds, etc), unless they are persistently in the same spot for more than a couple of days.

Luckily we have the Terra and Aqua satellite images to cross-check.

crandles

A double century to 6.9042220

21 day average decline is now over 131k per day - beating the record which was held by 1988.

Artful Dodger

Misfratz, Neven, tend to agree there's a increase in melt ponding. Latest 200k drop in CT SIA Uptick (reported by crandles) supports that. Should be matched by a drop in the Regional graph for the Beaufort Sea:

http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/recent365.anom.region.11.html

Hmmm, not too much decrease yet ( <50K ), but maybe tomorrow's report...

L. Hamilton

CT area has dropped almost 600k in the past 5 days, including 208k on 6/26.

Meanwhile DMI extent has dropped 520k over the past 5 days on its own calendar, including 173k on 6/28.

Graphs are agreeing again.

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