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Lord Soth

There appears to be a correlation with the final corrections on the previous day IJIS results and the next nights melt. With todays correction of only 469 km, I beleive we have a good chance of a century melt tonight, due to the delayed effect of the dipole anomality.

However after this, we are probably looking at lower ice melt for a while, which will allow 2007 to take a lead. However I expect 2011 to retake the lead sometime after the first week of August.

The ice is thinner in 2011 than in 2007, and all the latent heat in the arctic should be able to melt more ice in August for this year than in 2007.

Twemoran

'unless a high over the Canadian Archipelago reforms'

Environment Canada shows the high actually strengthening (slightly)today. Taking cyclonic/anti-cyclonic interactions into consideration, could be strong winds above Ellesmere Island headed toward Fram Strait.

Neven

Thanks, Twemoran. ECMWF on Wetterzentrale is the only source of SLP info I use, and it's working pretty good for me (and the DMI and Uni Köln maps for 'live' data). But maybe I should step out of my comfort zone and look at other sources too, like the GFS model or Environment Canada.

maltose

The IJIS SIE race is our daily feast, but I also have been thinking about what numbers might come up when PIOMAS releases its next monthly update in the near future.

For 2010, August 1st (day 212) had a volume of 7,026 km^3. August 1st, 2011 will almost certainly be below that in volume.

But will that number be below the volume min for (sept) 2007, 6,458 km^3? That would be pretty amazing feat, no matter the extent race.

It's going to be close...predictions, anyone?

George Phillies

The very latest (7/23/2011, 8 PM EST) Bremen map is showing extremely dramatic changes in ice, spectacular melting, near 150-165 E.

Paul Klemencic

George Phillies: I also am looking at the quickly dropping ice concentrations in the pack between 140E and 130W below the 80N latitude. Prior to today, I estimated that about half of the remaining ice extent overall is below 80N, and about half the ice below that latitude has an ice concentration below 75%, so this ice pack is in relatively bad shape, and is adjacent to some very warm surface waters.

We should lose about 70% of the ice below 80N, which works out to about 2.5 million sq km of ice extent loss from this ice pack and take us right against the 2007 minimum.

We could see a few more days of lower extent losses, where 2007 extent on the same days will drop below 2011, but then 2011 melt is almost certain to catch back up to 2007, leaving the final minimum a 50/50 proposition of breaking 2007. If we see the ice pack melt back north of Severnaya Zemlya, then the warm waters in the Laptev and Kara seas can more easily push ice into the Fram and melt into the pack north of 80N from 70E to 140E big time, and we could still see 2011 blow past the 2007 decline.

Rob Dekker

Guys, great analysis, and I have to admit that I am learning a lot from you regarding the influence of distribution of high/low pressure areas over the Arctic.

It seems to me that the winds can indeed greatly affect extent (even increasing(decreasing) extent when it blows away from (towards) the ice edge).

So overall, shouldn't sea ice area (SIA) be less sensitive to such short-term effects, and thus be more indicative of the state of the ice and the final minimum outcome ?

Rlkittiwake

Rob Dekker said, "So overall, shouldn't sea ice area (SIA) be less sensitive to such short-term effects, and thus be more indicative of the state of the ice and the final minimum outcome?"

It seems like SIA is in some ways more subject to the vagaries of arctic weather due to the instrumentation not differentiating between surface melt and real holes in the ice.

Last year, neither area nor extent really captured the shattered state of the ice. Hopefully there will be good volume data coming out that might provide a better measurement of the real state of the ice.

Neven

Speaking of SIA: CT reported another century break. It's still nr 1, with a lead of 127K over 2007. The same goes for CAPIE with a percentage of 67.85% (2010 has 67.98%).

The ice pack is diverging (and there probably still is some influence from melt ponds as well).

Paul Klemencic

I kept the Bremen image from July 23 on one of my browser tabs, then compared the image side by side with the July 24 image. I centered each image on the screen, and toggled back and forth to look at the ice pack changes and movement.

The ice pack not only pushed into the Fram Strait, but also into the Olga Strait and into the Kara Sea, all with warm surface waters. The Greenland Sea pack south of 75N declined sharply, and a lot of holes opened up. Meanwhile the Beaufort Gyre seems stalled, if not actually reversing a bit. And the Laptev Sea warm waters continue to chew on the ice pack, and appear about be melting out a big encroachment of low concentration ice pack above 80N.

We should see some pretty big drops in ice extent over the next week.

Neven

Indeed, Paul. I updated the Fram Strait animation 2 hours ago and you can clearly see the ice pushing towards Fram and Olga, etc, starting the 22nd.

Of course that big cyclone is displacing all the ice in an anti-clockwise fashion, pulling in those warm waters from the Laptev Sea you mention:

Neven
We should see some pretty big drops in ice extent over the next week.

Could be, but only if things stay in place a bit. If those highs and lows, well lows mainly, keep bouncing about, we'll get closer to last year's situation (though we're not there yet in many respects).

Seeing a big drop in extent, ie a century break, in the next couple of days would be somewhat surprising, and thus highly interesting. To me, at least.

But perhaps towards the end of the coming week chances improve.

Neven

Now here's a nice side effect:

Melting Arctic ice releasing banned toxins, warn scientists

Unknown amount of trapped persistent organics pollutants poses threat to marine life and humans as temperatures rise

The Guardian

Neven

ECMWF is showing some highs trying to get their foothold over the CA back in the coming 5-7 days. But it's very erratic, so I'm not drawing any conclusions yet.

Espen

Is the ice breaker Healy, leaving the arctic sea? It is on route towards the Bering Strait!

Espen

idunno

Hi Neven,

It's looking increasingly likely to me that we will soon be seeing significant ice export through the gaps between the Queen Elizabeth Islands in the Canadian Archipelago.

Perhaps worth an animation?

Seke Rob

On the Guardian article Neven linked ... the pollutants set free due melt, that Polar Bear in the picture is not edible. Some time ago read an article about a visit to an Inuit settlement what they did with killed PBs... they'd go into the chemical waste disposal. Says enough about what they've been eating being at the top of the food-chain.

Neven

Idunno, I will definitely do that CA animation real soon now. I was actually waiting for a nice clear image, but it's been cloudy in the past couple of days.

idunno

Hi Neven,

Very cheeky of me to set you more homework! I'm amazed at the amount you get done. But I think that the ice in the Archipelago could be very significant. I can't remember it ever looking quite this sketchy before, and if it does disappear, then it could open an exit from the Arctic Basin that has jaws as wide as the Fram Strait.

Also to note today: IJIS extent seems to have fallen below 2007, by very little, pre-revision.

The next couple of days should see CT area fall below the record minimum recorded for the 1980s.

Neven

It was in the works anyway, Idunno. You're not the first to ask, and I'm keeping a sharp eye on this one anyway (made an animation last year as well).

Yes, 2011 has lost the lead to 2007. It's a matter of not falling too much behind now. 2007 has a couple of less than average days in this last week of July, but delivers another body blow at the start of August with 4 small century breaks in a row.

dorlomin

Cryosphere Today is spectacular at the moment huge areas of below 80% concentration.

L. Hamilton

Going along with dorlomin's observation, CT area is now lower than its annual minima for 1979-1989. Tomorrow it will pass 1990.

For the date, 2011 leads them all, still 127k below 2007.

Seke Rob

For the first 204 days average, 2011 Arctic SIA is -1,094 Million below average, baseline 1979-2008. This compared with 2007 at -1,016 i.e. 2011 on average has been 78K KM^2 lower than 2007. Having a hard time to see 2007 to catch up on that: Chart

Comparing July 23rd SIE/SIA, concentration 66.94%... big change from the 75% Neven spoke off.

Global 2011 SIA holding steady distancing from 2007 as that saw a little less loss. 228K less. Chart

2010... a shade in the distance.

Kevin Adams

Is anyone aware of any work on albedo effects of Arctic dust? I mean dust from the Arctic that's been held in place for millennia by permafrost or soil moisture or trapped under snow or ice. The receding glaciers I've been to in the Andes have had lots of windblown sand (really uncomfortable for hiking). I've noticed some ice off of Greenland that seems to be covered with what appears to be windblown dust. Seems like this could be another feedback mechanism, especially around Greenland and the CA.

Kevin Adams

P.S. I've seen articles addressing windblown dust from distant deserts and local effects from road dust, but I've seen nothing addressing increase in transport of dust originating in the Arctic.

crandles

Here is a graph of NSIDC avg Sep Extent - CT end Jul Area

Sorry that goes off edge of page.

Does anyone think it is odd that there are only 5 data points in the middle band which is the widest (0.33 vs .28 for outer bands)?

Any reason for a bi-modal distribution? Neven has often commented on decreases either being rapid or changing conditions leading to a leveling off ie slow decreases. Is this evidence that medium decreases are rare? Or is there a different/more appropriate interpretation?

Neven

Yes, Seke Rob, CAPIE is going down extremely fast. This means the ice pack is diverging big time.

Quite a clear view of the ice on the Siberian side of things today. Nick Barnes, if you're reading: the holes you were looking for are starting to show up.

The (multiyear) ice in the Beaufort is taking a beating, the ice in the East Siberian Sea is brown and grey, the ice in the Laptev Sea is being torn apart by that low-pressure system. Man, this is exciting!

Seke Rob

Borrowed a chart of Didactylos posted at RC, based on PIOMAS data, and played the color scheme to let a few key years stand out as a smack in the optical nerve. Put it next to IJIS SIE and the AWI FYI thickness findings and one has a reasonable image that volume is not misrepresented by any great significance.

http://i137.photobucket.com/albums/q210/Sekerob/Climate/ArcticSIA-PIOMASv201979-Present.png

Chris Reynolds

Crandles,

That's fascinating. And yes I think it's odd and real - as opposed to noise.

You could call it only 4 in the mid zone as 2000 is so close to the demarcation.

My first thought was along the lines of some powerful factor driving the bimodal behaviour. Could it be the outcome of the ice-albedo effect?

Looking at the rates of change from Bremmen:
http://www.iup.uni-bremen.de:8084/amsr/ext_rates_n.png
That doesn't seem to support my notion, i.e. I can't find a supportive pattern in rates of decline either before or around July, or between July & Sept.

I'm stumped.

Neven,
"Man, this is exciting!"
Hear! Hear!

Neven

Lodger, could you please check your mail? I need some advice. Thanks.

Neven

I have updated the East Siberian Sea animation. Finally a relatively clear picture. The difference is absolutely stunning. Have a look see.

Nick Barnes

Sorry, Neven, I'm sick in bed tonight and can't spend long on this. Agreed that MODIS today is interesting. It's all in the weather; my forecast is still ~4.7.

Neven

I don't have any beef with your prediction whatsoever. Your most recent comments on the visual difference with last year were very inspiring, making me remember last year's spectacular Swiss cheese ice.

Get well soon, Nick! A bit of Arctic sea ice on the forehead can do wonders. :-)

Pete Dunkelberg

"Man, this is exciting!"
Perhaps one day when the ice is gone someone will write an epic poem about it in Old Norse. And a scientific book explaining how it went down. Will that be possible? Can you synthesize? It's reported here like a boxing match. ;) What's the scoop on heat import? The roles of melting in place vs blowing away? I don't expect anyone to have all the answers off the top of your head, I just want to plant some thought-questions.

Neven

Well, Pete, PIPS is forecasting a bit of a static situation for tomorrow, so the reported extent decrease will be mostly in situ melting:

Slightly tongue in cheek, but not entirely. I think we'll see a low daily extent decrease reported, ie below 50K.

ECMWF is still very erratic, forecasts change quite radically every update, so I have no idea what to expect the coming week.

AmbiValent

Uni Bremen shows even more green from 140W to 110 E, and at the latter end going up to 84N...

That's a lot of water between the ice - if some of it would absorb heat from sunlight or other sources, melting would speed up again...

Peter Ellis

Um, why are you subtracting an area from an extent? And why are you subtracting a monthly average from a single day point estimate? Neither of those comparisons make any physical sense. Why not subtract the September minimum (or September average) extent from the end-July (or July average) extent, working within a single dataset? For bonus points, do it for the area dataset once again on a like-for-like basis.

If the comparisons all show a bimodal distribution, that's interesting. If it turns out that you only get a bimodal distribution when you concoct some hybrid comparison of area vs. extent and/or monthly average vs. single day estimate.... not so interesting.

Paul Klemencic

Looks like the DMI site is showing a mild high pressure system over Svalbard and another forming over the East Siberian Sea. If these strengthen, is this what they call an Arctic dipole?

Comparing ice maps from 2007 with 2011 still shows a lot more lower concentration ice on the edges of the pack in 2011, so I still believe that the loss of extent should begin picking up again. And given the amount of ice extent in latitudes lower than 80N and the history of melt in those regions, there still is better than a 50/50 chance of breaking the 2007 low.

Rob Dekker

With 2011 tracking the 2007 area numbers so closely, I was wondering if the physics also are the same.

AFAIK, 2007 was marked by significant ice excursions through Fram strait. But it seems to me that this year these excusions are not so strong.

If that's true, then it is remarkable how closely the ice area graphs match over the past couple of weeks.

Do we have evidence for how much and when exactly ice export through Fram strait in 2007 was at it's maximum, and how that compares to 2011 ? I figure that the ice area graph from the Greenland sea in 2007 should at least give a clue. Do we still have that ?

Rob Dekker

What I'm getting at is that, if indeed (as PIOMAS and NSIDC suggest) the remaining ice is a lot thinner this year than it was in 2007, and the physics of ice excusions is about the same (or was larger in the early melt season of 2007), then there seems very little in the way of some real serious onslaught due to accellerated melting of that thinner ice (reduction of SIA) dipping further and further below 2007 in the month to come....

Again, I focus on sea ice area, since extent is so dependent on the winds (and air pressure distribution).

Chris Biscan

The Prelim for yesterday was around 50K

I am betting tomorrow and Wednesday will be closer to 75K or higher.

then maybe some 100K this weekend if we can get some of those chunky ice areas to melt out more.

Neven
Do we have evidence for how much and when exactly ice export through Fram strait in 2007 was at it's maximum, and how that compares to 2011 ?

I believe Kwok et al. had a paper on just that (God, I should know these things by now). I'll let you know if I come across it.

I figure that the ice area graph from the Greenland sea in 2007 should at least give a clue. Do we still have that ?

Unfortunately, no. They really should archive that stuff and put it online for the handful of people who are actually interested in that kind of stuff.

Espen

The massive ice pack of North East Greenland is starting to disintegrate of North East Water and Jøkelbugt, a piece of now two about +/- 2000km2 is leaving its "dockingstation", so better watch the area in the next couple of weeks, it is normally very fascinating !

Espen

Greg Wellman

Espen, are you talking about the fast ice (or ice shelf, not sure which it technically is) on the NE coast of Greenland? The seaward boundary of that ice has been remarkably stable (I've thought) but there's some interior breakup at the southern end now. Have you seen any recent changes in the seaward boundary north of there?

Tzupancic1

Greg,

I think this is 'fast ice'. A chunk just broke off in the far northeast of Greenland. You can see it at this link; compare 7/26 Modis with 7/25 Aqua and Terra.

http://ocean.dmi.dk/arctic/northeastwater.uk.php

Espen

If you want to see the disintegrating of the north east here is home produced "heavy image"
of the whole situation:
http://ecovery.com/northeast/northeast.html
Regards Espen

Chris Reynolds

Rob Dekker,

"Why would the 2007 ice extent and volume appear to be "normal" leading to summer and then "abnormal" suddenly in August and September?

This is because there is a significant increase over the recent average in ice export at Fram Strait in these two months (Figure 3d). The increase is 0.10 x 10^3 km3 in August and 0.13 x 10^3 km3 in September or 0.23 x 10^3 km3 in total (standard deviation of the combined August–September ice export over 2000 – 2006 is 0.076 x 10^3 km3). At the same time, the total ice production over the Arctic Ocean is reduced (Figure 3e). In summer, a decrease in ice production is equivalent to an increase in ice melting. The increase in ice melting is 0.30 x 10^3 km3 in August and 0.27 x 10^3 km3 in September or 0.57 x 10^3 km3 in total (standard deviation of the combined August–September ice melt over 2000–2006 is 0.19 x 10^3km3)."

From - "What drove the dramatic retreat of arctic sea ice during summer 2007?"
Zhang et al, 2008, GRL.
Google-scholar and you should be able to download a paywall free copy to see figure 3. NB the flux (red line) in figure 3 is negative because it's shipping ice out of the Arctic. It's a study using PIOMAS, which is probably the best available diagnostic tool for such questions.

Philiponfire

if you take a look at the north east of Greeenland on this site http://www.arctic.io/observations/ and compare 26th with the previous 2 days you will see a chunk broken off which is now 100km x100km. I suspect that the shelf will all be gone soon now that it is exposed at the northern end.


a lot of in place melt taking place off Victoria island and William island.

Tzupancic1

Neven,

Regaring papers on the 2007 melt; Lindsay, R. W., J. Zhang, A. Schweiger, M. Steele, H. Stern, 2009: Arctic Sea Ice Retreat in 2007 Follows Thinning Trend. J. Climate, 22, 165–176. "Arctic Sea Ice Retreat in 2007 Follows Thinning Trend" places 2007 into an historical context. The PDF is availble for free download.

Greg Wellman

Oh wow, right you are - the very northern part of that region of fast ice. That's been fast for decades, right?

I wonder if that will weaken the fast ice south of there. Another month of wear-and-tear on it at least.

Tzupancic1

And further, on 2007

Kwok, R., 2008: Summer sea ice motion from the 18 GHz channel of AMSR-E and the exchange of sea ice between the Pacific
and Atlantic sectors. Geophys. Res. Lett., 35, L03504, doi:10.1029/2007GL032692.

Tzupancic1

One more on 2007

What drove the dramatic retreat of Arctic sea ice during summer 2007?

R. Lindsay, M. Steele, and A. Schweiger, 2008: What drove the dramatic retreat of Arctic sea ice during summer 2007?
Geophys. Res. Lett., 35, L11505, doi:10.1029/2008GL034005

Greg Wellman

>That's been fast for decades, right?

No, I'm wrong. Actually most of that was gone in mid Sept last year.

L. Hamilton

As predicted, CT area is now below the 1990 September minimum. In a spirit of watching ice melt, I'll be updating periodically this graph of the current area compared to annual minima going back to 79.
http://img.photobucket.com/albums/v224/Chiloe/Climate/sea_ice_N_min_to_date.png

Chris Biscan

The Deniers or Skeptics over on Americanwx have pretty much concluded we are looking at 2010 or maybe even 2008 as a min this year now.

They use storminess and lower temps as the reason. Yet they said when that fat h5 ridge sat there a month ago destroying the ice pack with heat and warm SSTs and sun temps meant nothing.

I think given the fragile state of the ice pack a storm would be bad, expecially if it sets up to aid ice leaving the fram straight.

I think people are SEVERELY underestimating the impact the WARM ssts will have the next 45 days.

anyways, tonight is gonna be a 75-100K drop.

I will be there the moment is comes out like a huge dork going lookie lookie a big drop the same way a week of 50K drops is the sign its over.

Even though extent and area are still at record lows.

if we reach 2010 or 2008 we will see pretty much a complete hault to any major melting.

in other words less then 35K per day the rest of the summer.

good luck with that.

Chris Biscan

L. Hamilton that graph is small.

what does it mean that a large chunk broke off by NE Greenland?

L. Hamilton

I resized that graph so it should be readable now.

I noticed that NE Greenland fracture too. That area was a major holdout for shorefast ice last year, and Greenland Sea ice area (per CT) is still up about 100k. It's an interesting and dynamic area to watch.

Chris Biscan

Given that we are at a record anomoly for sea ice area.

and last night sea ice are slowed its drop.

It almost surely means there will be a much bigger drop in extent.

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

you can see the last day it turn south on the graph.

ussually that kind of turn on there graph is 100K or so on jaxa.

Neven

Thanks for those graphs, Tzupancic. I have some of them as PDFs in a folder, but never seem to be able to muster enough courage/time/energy to read them. I apologize for not having done so before, but by the end of the melting season I hope to have a depository of all papers that are of interest to what we are doing here.

Larry, that's a cool graph. If you update it, I'm going to put it on the daily graph page right now.

Neven

Don't forget, guys, I'm updating the Fram Strait animation on a daily basis.

Twemoran

'I noticed that NE Greenland fracture too'

It appears ready to peal away the fast ice once the flow again heads south.

A few days ago the shelf by Kong Oscar Fjord broke up and today it looks as though Walterhausen Glacier may have done something bad (but it might just be a cloud ;)

L. Hamilton

"If you update it, I'm going to put it on the daily graph page right now."

Neven, I can't promise to update it every day, but I could do so a couple times per week. Note that it has two date stamps reflecting the date drawn, and the most recent day of data used.

Tzupancic1

Neven,

Let me recommend "History of Sea Ice in the Arctic" 2010. Polyak et al. Quaternary Science Reviews. 29; 1757–1778. as a useful place to start for forum members who are interested in understanding current events in an historical context.

http://bprc.osu.edu/geo/publications/polyak_etal_seaice_QSR_10.pdf

One often hears about the Holocene thermal maximum and other 'warm' periods. This comprehensive review provides a useful summary to understand how today's events are simiilar or different.

Tzupancic1

I noticed that Chris Biscan posted a comment earlier today where he described the discussion on the Americanwx Climate Change forum. So I went over to check it out. (Given a limited tolerance for ignorance I didn't stay too long, but among the comments I read was one this morning by VirginiaHippie who repeated the classic denialist objection that the 1930's (or 'fill in the earlier decade or period', depending on the objector/issue) was just as warm as today and Arctic Sea Ice was just like it is now.

I just wanted to point out that the 2010 Quaternary Science Polyak et al review I mentioned earlier provides a useful analysis of historical Arctic Sea Ice extend observations from 1870 through 2003 (see Figure 2).

Following the Americanwx Climate Change forum discussion a bit further I see forum member'Sunny and Warm' suggesting people look at old newspaper references...

Whatever, this issue always comes up, how to compare modern Arctic records with hotorical observations; and beyond, comparing the present with the Holocene and earlier events.

Tzupancic1

Recent historical Arctic Sea Ice extents are investigated in "A changing Arctic seasonal ice zone: Observations from 1870–2003 and possible oceanographic consequences" Christophe Kinnard, Christian M. Zdanowicz, Roy M. Koerner, and David A. Fisher. GEOPHYSICAL RESEARCH LETTERS, VOL. 35, L02507, doi:10.1029/2007GL032507, 2008

They use "the historical grids of Northern Hemisphere (NH) sea ice cover from the University of Illinois for the period 1870–2003 [Walsh and Chapman, 2001; hereafter
termed WC dataset].

This data is avaliable for download from the Cryosphere Today website; http://arctic.atmos.uiuc.edu/SEAICE/

Seke Rob

Re Ellesmere and North Greenland landfast sea ice, Wayne Davidson of the EH2R blog made na interesting observation on FYI and never seen before polynia in that sport, for the time of the year. See the "2011 already startles the far North just as well" headlined item futher down on that website: http://neven1.typepad.com/blog/2011/07/sie-2011-update-13-one-step-back-two-steps.html


Courtesy DMI Polar NOAA AVHRR 2011-03-03 04:20 UT Amazing image for any with Arctic observation experience. Over the last 25 years this never happened. It is a sure sign of record thin ice. It very much appears like loose pack ice compared to adjoining older thicker ice. The proximity to Ellesmere of the zone where ice shatters and joins the North Atlantic was always at the North-East corner of Greenland. I dont recall seeing this kind of active ice so near to Canada by way of Northern Greenland even in the summer! The winds from multiple cyclone incursions over the Arctic Ocean also played a role.

Really like his observations and work on Solar Disk measurement and the readings he makes off that.

Seke Rob

Wish there was a 5 minutes edit option... wrong link... the right one to Wayne's site: http://www.eh2r.com/

Sorry

Seke Rob

A new chart, with a twist. NSIDC data has no year with a sea ice extent of under 6 million sqkm until 1999. Plotted these and JAXA through 2010 and added me prediction, mathurbated, for 2011... current weather developments suggest a possible earlier date, but hystirionics arrive at 2 days later for 2011 then 2007.

First Day below 6 Million SqKm Sea Ice Chart

The twist, which throws up an interesting eyeball induced question: The inter-annual variability through 1997 for SIA per CT data, and then it goes steadily down, year on year, with the 2007 excursion and 2011... computed as 2 days later passing 6 million sqkm area.

Food for thought, [tongue in cheek], if there was no warming since 1998, sure as heck, the system shows to have trouble getting rid of the extras. ;>)

PS: 2001 for NSIDC also shows not to have gone below 6M SqKm, hence the gap in the line. Interesting is that the lower the SIE gets, the closer NSIDC gets to JAXA

Neven

CT area notes another century break, increasing the lead over 2007 to 154K. As a consequence CAPIE is breaking through the cellar, loosing a percentage point per day for the last 10 days (amazing).

The melting hasn't stopped, the ice pack is diverging big time. If 2011 doesn't fall too far behind in the IJIS extent numbers the coming 2 weeks and the weather stays constant for a while (instead of constantly flipping, like it is now) it's going to be a very close race.

L. Hamilton

Updated my CT-to-date graphic. Today's area dropped below the 1991 minimum. Tomorrow will pass 1995.

http://img.photobucket.com/albums/v224/Chiloe/Climate/sea_ice_N_min_to_date.png

Kevin McKinney

Great interpretive comment, Neven. My observations have been limited lately, so I've mostly been noting just the IJIS slowdown (which you also called correctly, IIRC.) The context your remark provides is illuminating.

Also great is the new "Regional Graphs" page; I like the way that the corresponding graphs, vertically aligned, give you complementary information. Very well thought out, sir!

Neven

Thanks, Kevin! I'm quite content with the daily graphs page as it is now. Even smart bunny Eli hasn't found a flaw.

My Arctic muse has returned as well, so I hope to do some stuff on the content side. The end of the month is approaching so it's time to compare again and look ahead a bit. But one more day (and night) of work and then 2 days off to write a bit.

Chris Biscan

Breman shows the extent dropping even faster today. I would be surprised if Jaxa doesn't start to show this tonight.

Also the 30% chart shows a nosedive.

given how much of the ice pack is falling apart..it is not surprising.

Neven

IJIS has revised downwards (about 3K). Maybe we'll see an extent decrease of over 50-60K reported tomorrow. PIPS is showing this:

Lord Soth

There is definitely potential for some serious extent reduction.

AO is declining and may go negative.

CAPIE is 65.7 percent

DMI North of 80 temps are still high

Canadian Archipelago is above seasonal with mostly sunny weather for next week.

NSIDC now shows a tie between 2007 and 2011 and slope of curve is now parallel with 2007.

In a few days we should start to see some more century breaks, if this weather trend continues.

Neven

It could be, as there's a very weak high over the CA that is projected to stay there the next couple of days, with a low on the other side.

On the other hand: ECMWF forecasts some big highs coming in from Scandinavia via Svalbard. Combined with a deep low over Bering/Chukchi/East Siberia I see some isobars that favour ice displacement towards Siberia. That should make some nice holes in the central ice pack, but it won't do extent decrease much good.

But of course, as always, very interesting. ;.)

Artful Dodger

Lord Soth: CAPIE was 65.16% on July 25, 2011. CT area for July 26 has not been published yet.

Notonlythatbut.wordpress.com

I realize this may be silly, but what the hell:

Does anyone know: is there any noticeable impact of tides/moon phase on ice breakup and/or melting? As in, if the ocean is sloshing about with relatively more vigor, does the ice flex, break, tumble, melt more?

Before even getting an answer, I'm going to be logically irresponsible and predict big extent decreases during the next spring tide, i.e. around the new moon at the beginning of August :)

Chris Biscan

Norsex, Breman, dmi all have a sharp down turn in extent for the 26th and 27th.

I thought jaxa would drop more last night.

but the 3K downward revision shows its turned a bit.

I hope it's not to bad. but that 1.5+ mil KM2 area of below 75% concentration is not good.

L. Hamilton

Hey, there's a cool new graph on the graphs page! Now I have a reason to keep it up to date. ;-)

Neven

Larry, I'm refreshing every 5 minutes just to see if the graph has changed. :-P

Neven

Notonlythat, your question is a very good one. Years ago this was discussed on RealClimate in the comment section of a guest post by Cecilia Bitz, I believe. I can't remember what the conclusion was, if there was one.

I don't think the effect is very marked, but it isn't nil either.

Notonlythatbut.wordpress.com

Neven, thanks.

It occurs to me that if there's significantly more thin/weak/otherwise vulnerable ice out there now than there was years ago when that RC discussion happened, the answer could be (slightly) different now.

Artful Dodger

Notonlythat, the biggest effect of a Spring tide is on shore-fast sea-ice, where the vertical motion can split the ice from the land. Look for evidence of this now along Northern Greenland and the Canadian Archipelago.

A secondary effect was seen last year on the ground fragments of Petermann Glacier which got hung up for weeks at the entrance to Petermann Fjord. The fragment came adrift and began it's journey South on the first Spring tide.

Daniel Bailey

Re: Tidal Impact on Arctic Ice

I remember the thread in question, but not all the details, unfortunately. I believe Hank Roberts and another individual were involved and that there was visual evidence of a high tide causing ice rifting in 1 or more of the sounds (attributed to lunar effects on the tide).

Didn't think to bookmark it at the time, sorry.

Neven

89K reported by IJIS, quite a biggie, more than I anticipated. Only 4K less than 2007, which is now going to have 5 days of 50-60K extent decreases.

Artful Dodger

Of course, due to IJIS 2-day averaging, the reported number for July 27 is weighted down somewhat by the smaller decrease from the previous day.

The actual single day decrease for July 27 is likely closer to about -109K km^2. It the loss rate continues though July 28, then we'll see Century Breaks again.

Chris Biscan

I don't like how the ice flow is towards Western Russia where there are warm SSTS. It is crippling that side of the ice pack.

and the flow is right into the that warm water. that water has been aided by very very warm temps in NW Russia.

Chris Biscan

If we lose 40K per day in August we would have 5.160km2 on Sept 1st which= 4.660km2-4.960km2
If we lose 50K per day in August we would have 4.850kn2 on Sept 1st which = 4.350km2-4.650km2
If we lose 60K per day in August we would have 4.560km2 on Sept 1st which = 4.05km2-4.356km2
If we lose 70K per day in August we would have 4.230Km2 on Sept 1st which = 3.730km2-4.030km2

Give or take 100K based on the last 4 days in July.

I am going to predict 4,500,000KM2 at this point.

The 9 year median is 51.3K and the 4 year median is 55.5K loss.

Rob Dekker

Thanks a lot, Chris R, and Tzupancic, for pointers to Fram Strait ice export in 2007.

After studying the papers you referenced, it seems indeed that in 2007, the transpolar drift in Aug/Sept was much higher than normal, as summarized nicely by Zhang et al 2008 :

Overall, the Artic Ocean lost 0.80 10^3 km3 more ice than the recent average in August and September - about 30% of the loss is due directly to the strengthened ice export and 70% due to the enhanced ice melt. This corresponds to an anomalous loss of ice extent by 1.1 10^6 km2 in August and September (Figure 3a), which is about 12% of the Arctic Ocean area. This model simulated decrease in ice extent is, however, an underestimation when compared to satellite observations (Figures 1a and 2a)

where figures 1a and 2a then show that 2007 dipped another 300 10^3 km2 below what the model could explain.

Now, since 2011 has the same ice area at 2007, it seems reasonable to assume that the enhanced melt will occur again (ice albedo). However, if the transpolar drift does not crank up, then 2011 will have a hard time keeping track of the Aug/Sept decline of 2007.

On the other hand, if PIOMAS is even remotely correct, then ice volume (ice thickness) in 2011 is already more than 2.5 10^3 km3 smaller than it was in 2007, which makes the 2007 Aug/Sept loss of 0.8 10^3 km3 look insignificant.

So, overall, what will be the determining factor in Aug/Sept ? Transpolar drift, or melting of thinner ice ?

Well, considering that 2011 SIA is still reducing as fast as 2007 while there is not a lot of Fram stait export going on, and not even much clear sky to help that melting, it looks like 2011's ice pack does not need much transpolar drift or excursion through Fram strait to beat 2007...

2011 pack is looking very, very fragile, even when compared to 2007....

L. Hamilton

Heading different directions: CT area +27k for 7/26, UB extent -103.

Peter Ellis

Having spent some time noodling through the HYCOM pages, I really don't think modelling of ice drift is very accurate at present. To take a random example, compare these two figures:

http://www7320.nrlssc.navy.mil/hycomARC/navo/arcticicespddrf/nowcast/icespddrf2011072718_2011072500_035_arcticicespddrf.001.gif

http://www7320.nrlssc.navy.mil/hycomARC/navo/arcticicespddrf/nowcast/icespddrf2011072618_2011072500_035_arcticicespddrf.001.gif

These are both maps of ice drift on July 25th of this year, based on two different runs of the model. Although the general pattern is similar in outline, they're very different in intensity, and the details are likewise different.

The kicker? These are the model runs from 26th and 27th July - i.e. a hindcast after the fact. If the model can't even give consistent results for what's already happened, I'm afraid I don't put much credence in its ability to forecast the future.

Philiponfire

we have dramatic in place melt in Peel strait and Franklin strait( do a blink between 25th and 27th). Ice moving down into Nares strait at One kilometre per hour. Ice moving into the Kara sea and the extent map from Cryosphere today has more melt ponds and open water than anything I remember seeing in the last 4 years.(my eyeball guess is close to 2/3rds of the arctic ice area/extent is covered in at the least melt water.)
area is up today not down on CT so I think we are in for interesting times. have to ask are extent or area necessarily still going to be useful markers when the ice is so thin? so much ice looks transparent to me and has to be within days of simply vanishing. looks to me as though that is the future for the NW passage ice.all assuming no dramatic cool down of course.

Lord Soth

Finally we get a good melt with IIJS of 89K, and Cryosphere actually went up 25K. Interesting !

We are now 93K behind 2007, and have 5 days to catch up to 2007, if we can average 73K melt a day over the next five days.

After that, 2007 has four century melts in a row and then the show is over for 2007, with only 4 melts above 70K for the rest of the month.

By the end of the first week of August, we will have a very good idea if 2011 will beat 2007 for a new minimun, or if there will be a horse race for second place.

On another note NSIDC still show 2011 either tied or slightly ahead of 2007, so there is the potential of IJIS and NSIDC declaring differnt winners.

Lord Soth

The AO just went negative (subject to revision), and is projected to stay negative for the next week.

Although looking at the MODIS cloud cover band, its sure does not look that way.

Must be a lot of weak lows or dirty highs.

Philiponfire

IJIS revised to 73400.

Pete Dunkelberg

Thanks Tzupancic1 for posting this reference:

Kinnard, C., Zdanowicz, C.M., Koerner, R.M., and Fisher, D.A. "A changing Arctic seasonal ice zone: Observations from 1870-2003 and possible oceanographic consequences. Geophysical Research Letters 35(2): art. L02507, 2008."

"Notes: Changes in the extent of seasonal ice were investigated using historical and satellite observations for the period 1870-2003. The seasonal ice zone (SIZ) has been gradually expanding since 1870, with a marked acceleration over the past three decades, and has migrated north to encompass all peripheral Arctic seas. The expansion of the SIZ may be increasing the salinity of the upper Arctic Ocean, consistent with recent observations. The migration of the SIZ over continental shelves may also be enhancing the formation rate and salinity of Arctic deep waters, which are subsequently advected to the convective region of the Greenland-Iceland-Norwegian Sea, thereby influencing the formation of North Atlantic deep waters and related global thermohaline circulation."

1. I find no free pdf of this paper. A note from the redoubtable Neven blog would probably motivate the authors to put it online (ditto for other papers).

2. Isn't Arctic salinity now decreasing in some areas due to the de-permafrosting of Siberia? It would not be at all nice if the Arctic sea became fresh enough to freeze from the top down. I believe Lodger once posted a link explaining the freezing process but I can't find it now.

Lord Soth

A large IIJS correction is ussually not a good sign for melt.

I just looked at the weatherundergrond GFS model that projects two weeks in the future, and I don't see the return to conditions that led to the rapid July melt.

Now weather models are not cast in stone, and may change, but right now it looks like 2011 will be playing catchup with 2007 for the most of August.

Artful Dodger

Hi Pete. I provided a link to an open-source textbook chapter on salinity on January 02, 2011 at 23:10

Thawing of permafrost has no direct effect on salinity in the Arctic ocean. Near Siberia, salinity is lower because of river outflows, which are greatly affected by Winter snow pack.

Artful Dodger

For a short primer on sea ice, read Light on Arctic Sea Ice, from the Northern Passage 2010 blog intro.

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