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Ned Ward

"In fact, 2011 responded by noting 4 century breaks in a row itself. Of the last 14 days 10 had century breaks reported."

Hey, if only 1100 km of ice could have held on through 10 July, instead of melting the day before, we would have just had an all-time record of (at least) 8 consecutive century breaks.

Neven

Indeed, Ned. It is a feast for century break lovers such as me. :-)

Peter Ellis

It looks to me as though slowdowns are associated with changes in the Arctic pressure regime, not necessarily with specific highs or lows. 2010 hit the buffers when the lows moved in and the Beaufort Gyre reversed, but then speeded up again. 2011 possibly slowed fractionally as we shifted into the Arctic Dipole, but if the pressure systems settle into place, it'll speed up again.

In fact, given that (as I understand it) the Arctic Dipole is the worst possible pressure pattern for melt, we may even see a speeding up of melt in the next week or so. Yes, the low brings clouds - over the Barents and Kata seas that are already mostly melted out. It also brings warm winds from Siberia up over the Pole itself, and strengthens the flow through the Fram strait.

Finger in the air - next week or two will be real shock and awe: look for 2011 to pull away from 2007.

michael sweet

I think we need to consider the large mass of multi year ice that was in the Beaufort sea at the end of the winter season. Last year when the melt reached to the edge of the old ice the decrease when way down as the multi year ice resisted melt. This year the decrease has continued even though the multi year ice in the Beaufort sea has reduced melt in that area. The Beaufort sea is low in concentration now and I think the multi year ice will start to melt out in the near future. Then decrease might really ramp up. I also see a lot of ice in the Healy web cam photos that looks like multi year ice. That ice will also melt out soon.

michael sweet

Piomas Updated. Wow!!

They show ice volume at a new record anamoly.

Neven

Michael, there's a separate blog post on PIOMAS June 2011.

Kevin O'Neill

Neven, I know exactly what you mean - with no daily IJIS update I was like an addict in withdrawal. I also was leery of the results when they did come in - and WOW is right.

I did spend a little time trying to find a good way of numerically describing Patrick Lockerby's assertion that a regime change has occurred. I agreed with him intuitively, but wanted a rational basis for believing it. I think I found the SIE graph that shows it visually: graph the percent of loss per year from the yearly maximum. The IJIS numbers sure make it look like a step function. http://i256.photobucket.com/albums/hh197/ktonine/SIELossPctofMax.jpg

My own personal projection now has 2011's minimum UNDER 4million km^2 the last week of September.

Looking ahead, the dates with the highest rates of loss (average of 2007-2010) are still to come; July 22,23, and 24 are each over 100,000 km^2. July still has more century marks to come!

Neven

Nice graph, Kevin! And keep those personal projections coming in. Needless to say, they will become more and more interesting.

Neven

Hmmm, the ECMWF weather forecast has changed quite a bit. Now that high will be completely pushed out by lows within a week or so. Those forecast maps look very similar to 2010.

Of course, these forecasts become less accurate as they go further ahead, but something to keep an eye on nonetheless.

Kevin McKinney

Further to Peter Ellis's comment above, remember Lodger's linked paper? For convenience, the link is:

http://epic.awi.de/Publications/Sed2010a.pdf

It was a two-week in-situ observational study carried out on the pack at about 82 degrees North, at the end of the 2008 melt season. Among the tantalizing bits in the abstract was this:

"Shortwave cloud forcing ranged between -50 W m-2 and zero and varied significantly with surface albedo, solar zenith angle and cloud liquid water. Longwave cloud forcing was larger and generally ranged between 65 and 85 W m-2, except when the cloud fraction was tenuous or contained little liquid water; thus the net effect of the clouds was to warm the surface."

Surely the shortwave cloud forcing--the degree to which cloud reduce insolation will generally be higher in mid-July than in late August/early September, when the study was done, since the 'solar zenith angle' will be less (hope I've applied that terminology correctly; I mean of course that the sun is higher in the sky now.) Still, that 65-85 W/m2 positive forcing shouldn't change, and I expect will still (at least) go a long way to offset the reduced insolation we expect next week.

And, yes, "WOW" goes for me, too.

Kevin Adams

Petermann Glacier questions, for anyone who might know much about it:

1.) Is it just me, or does that look like a large crack that's been growing over the past several weeks? (Not as big as the chunk from last year, but still sizable, assuming that is a big fissure.)

2.) Does anyone know where the "grounding point" is on it? Not sure of the right term, but the point where the beach would be sans glacier? I can't find anything specific to the Petermann on the intertubes.

crandles

I believe that without the Petermann glacier water could flow into centre of Greenland and out of other 'glaciers'. Now where was that scary lecture on rapid retreat mode of glaciers?

I think that fissure was visible last year.

Account Deleted

Yes it does appear that the crack is growing - see todays Modis Image
http://rapidfire.sci.gsfc.nasa.gov/imagery/subsets/?subset=Arctic_r03c03.2011196.terra.250m

crandles

It was this Seminar:

Waking Giants: Ice Sheets in a Warming World
http://www.youtube.com/watch?v=hnVtjnGRyDY&feature=relmfu

Here is a screenshot captured from about 51 min in:

http://farm7.static.flickr.com/6149/5941056869_ce9d7313b4_b.jpg

Daniel Bailey

Kevin Adams Try Rignot and Stefan 2008 (p. 2 has what you want). Other details on specific Greenland glaciers can be found here.

Bfraser

I think I already mentioned this on another thread, but does anyone agree that the arrow near 87N, 135W always seems to be inconsistent with the rest of the arrows on the PIPS chart?

Account Deleted

The latest SST image http://polar.ncep.noaa.gov/sst/ophi/color_anomaly_NPS_ophi0.png shows a small area by the Humboldt glacier with water temps 2-3 degree above normal.

Neven
I think I already mentioned this on another thread, but does anyone agree that the arrow near 87N, 135W always seems to be inconsistent with the rest of the arrows on the PIPS chart?

Indeed, Bill, well spotted. It probably has to do with this anomalous hole around that spot:

As it says on the PIPS homepage:

The unobserved opening near the North Pole is still present and can be seen in the ice concentration and ice thickness fields. PLEASE USE THESE FIELDS WITH CAUTION!
Artful Dodger

Neven said:

"Somebody call the UN."

Be careful, Rupert Murdock is tapping your phone! (He finds it very Educational...)

If we get a strong, persistent DA just as "compactness" (IE: CAPIE) hit's 70%... well in the word's of Dr. Emmett Brown, "we're going to see some SERIOUS SHIT". -- Back to the PETM, Redux.

Peter Ellis

Awww, the stalk of the "mushroom" on camera 2 just broke. Alas, cruel world!

Peter Ellis

PIPS 2.0 is a dead duck - we should transition to the replacement HYCOM/CICE system. Latest ice drift picture here:

http://www7320.nrlssc.navy.mil/hycomARC/navo/arcticicespddrf/nowcast/icespddrf2011071518_2011072100_035_arcticicespddrf.001.gif

Artful Dodger

Peter, according to Author L.FrankD, it was flying monkeys (commanded by the Wicked Witch of the North :^)

michael sweet

Neven,
Can the HYCOM/CICE map be added to the daily graphs page?

Peter: nice graph.

Neven

Michael, I was planning on doing that after the melting season:

ACNFS is currently undergoing operational testing at the Naval Oceanographic Office and the National Ice Center. This work is scheduled to be completed by the end of December 2011.

But maybe it'd be interesting to put it next to the PIPS ice displacement forecast map. I'll see what I can do.

Steve Bloom

An anthropomorphized look at the current melt season from David Appel. Very nice writing IMHO.

Neven

Thanks, Steve. Very nice indeed. I've put it under TIPS.

Espen

I believe Modis is having a problem, they did not finish yesterday and images are not arriving today.

Espen

Jason Furnell

What appears to be an increase in the crack on the Petermann glacier looks to be just a well placed cloud and it's shadow.

Piotr Djaków

Does anyone know if the GRIB or NetCDF files from HYCOM/CICE available?

R. Gates

Here's a rather eye-opening statistic:

On this date, 7-16 in 1979, Arctic Sea ice extent was 10.242 sq. km. That year, sea ice extent only dropped to 6.904 sq. km for the September low. A level we should see in the next week.

Here's the source:

http://polynya.gsfc.nasa.gov/datasets/nh_daily_observed_or_interpolated_sie_1972_2002.txt

Neven
Can the HYCOM/CICE map be added to the daily graphs page?

Is this better?

R. Gates

Neven, just to make your Sea Ice reference pages complete, you might want to put a link up to the Webcam from buoy #2 on Arctic Sea ice as part of the OBUOY program found here:

http://obuoy.datatransport.org/data/obuoy/var/plots/buoy2/camera/webcam.jpg

or one from summit camp in middle Greenland found here:

http://www.summitcamp.org/static/images/status/view/webcam.jpg

Neven

Oh boy, that OBUOY webcam is pretty neat. Where is it stationed?

I knew the Summit Camp webcam, but figured it'd be a bit boring as it never goes above freezing there.

Diablobanquisa has a page full of webcams.

I think I'm going to make a separate page for webcams one of these days. Perhaps leave the NOAA webcams on the main page.

Twemoran

With MODIS down I've been following a large, rounded chunk of ice shelf (I think) on DMI.
It may still be caught in the gyre in front of Petermann Fjord and could again smash into Petermann's now fractured ice shelf.

http://ocean.dmi.dk/arctic/image_container.php

is the latest image, but it's easier to track using MODIS
Sorry 'bout the re-post - had stuck it in wrong comment area.

Neven

According to the ECMWF forecast maps the Arctic is going to be heavily dominated by low-pressure areas in a couple of days from now. I think there's 2 more days of potential century breaks, and then a situation that'll resemble last year.

2011 is currently 250K ahead of 2007. Let's see if it can maintain the lead until the end of the month.

R. Gates

Nevin,

Obuoy #2 is approximately at 75.5N and 161W, putting it roughly 270 miles NW of Pt. Barrow out between the Chukchi and Beaufort seas.

You can also watch time-lapse animation (updated daily) of all the still shots the buoy has taken here:

http://obuoy.datatransport.org/data/obuoy/var/plots/buoy2/camera/buoy2-movie.mp4

And if you want to see more data from Obuoy #2 or info on the Obuoy program, you can go here:

http://obuoy.datatransport.org/monitor

Obuoy #2 is the only one fully operational apparently, and for a hoot, click on Obuoy #6.

Neven

Thanks, R. Gates!

AmbiValent

Is there currently accelerated melting in Beaufort/Chukchi Sea areas, or was the ice just spread apart?

R. Gates

AmbiValent,

Not sure what you mean by "accelerated" but certainly both regions are below their average sea ice extents for this time of year, and will be ice-free by the end of the melt season. Obuoy#2 referenced above is actually on the very edge of these areas and almost into the Arctic Basin. What you are seeing from this buoy are melt ponds opening up. Depending on how it might begin to drift, if Obuoy#2 keeps transmitting to the end up September, it should be floating with lots of open water around.

Lord Soth

Remember when I asked if the markers in the North Pole Web Cam #2 floated.

Well I got my answer.

A few days ago with four markers.

http://www.arctic.noaa.gov/npole/2011/images/noaa2-2011-0711-012241.jpg

Today with three markers.

http://www.arctic.noaa.gov/npole/2011/images/noaa2-2011-0716-173928.jpg

Twemoran

MODIS is up!!

partially

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

Lord Soth I think you'll find it's still there, maybe covered in ice? Opened the sequential images in Photoshop and see the stripes disappear but an angled structure remains.

Phil.

Kevin McKinney

Missed a century break, according to the prelim, but not by much.

Rob Dekker

R.Gates, that Obuoy #2 time-lapse animation is amazing ! With the frames 1 hour apart makes it really look like you are there, and you don't miss anything. If I figured out the timing of the sun passing correctly, then the camera is looking NNE.

With the last couple of days of clear weather notice how the melting pond gets bigger every day, especially during the time that the sun is highest (behind the camera).

Also, note that July 11, the Healy was only 100 miles south of this camera, and it found lots of open water there :
http://mgds.ldeo.columbia.edu/healy/reports/aloftcon/2011/20110711-0801.jpeg

The open part of the Beaufort and all that water between the ice floes must absorb insane amounts of heat right now (clear skies) which will have no mercy with this desintegrating ice pack. I give that camera (and the floe it's on) only a week in this weather.

Very cool camera !

Artful Dodger

Lars Kaleschke of the Institute for Oceanography, University of Hamburg, publishes a daily-updated prediction for Sep 2010 SIE.

The current (July 17) prediction for September 2011 monthly mean SIE is 4.25 m km^2, +/-0.25 km^2.

This is down from their May 31, 2011 estimate which was 4.8m km^2, +/-1.7m km^2.

A prediction time-series (2011 history) is here:

ftp://ftp-projects.zmaw.de/seaice/prediction/prediction_timeseries.png

The 'Goodness-of-Fit' (R^2) is 0.85 for their model. A more detailed explanation of the Group's methodology is here:

ftp://ftp-projects.zmaw.de/seaice/prediction/Outlook_May_2011.pdf

Artful Dodger

bah, by which I mean, "publishes a daily-updated prediction for Sep 2011 SIE.

Piotr Djaków

@neven

ECMWF forecast map concentrated on Arctic only (MSLP+T850):
http://gfspl.rootnode.net/ecmwfarct/T850/00
http://gfspl.rootnode.net/ecmwfarct/CIS/00

Neven

Thanks, Piotr!

Lord Soth

Anybody catch the prelim IJIS melt last night? The website appears to be down now.

Piotr Djaków

Now it's up :)

07,14,2011,7525000
07,15,2011,7440781
07,16,2011,7346563

Lord Soth

We now only need 50K or more ice melt per day to beat 2010 to the 7M sq km mark.

With this record practically in the bag, it may be possible is we get some really good melt days, to break 6M by August 1. If we don't, I think it will be close.

Lord Soth

That should read beat 2007 to the 7M sq km mark.

Andrew Xnn

Although it may not be visible in the following image; Greenland sea ice area has increased over the last week = greater export.

The increase is just barely visible in full size image in the following link: http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/recent365.anom.region.5.html

Seke Rob

Lord Soth said:

That should read beat 2007 to the 7M sq km mark.

Yes, we're riding the winds hard, to meet or exceed the July 21 central forecast date. Then current math[turbation] shows the number 6,928,889 km^2

Jaxa sometimes has funny numbers ending e.g. as at 3 zero's occasionally 4, such as July 26, 2003: 8,030,000. Are they pixel counting at times or filling in blanks [not that is of any significance to the total picture]

Frankly, though it will be signals if next marker point lows are beat to send a louder message, the underbelly is resisting to deal with all the nasty consequences for the years to come, no matter how Daltonish, Maunder, or other solar minima may go and their 0.2C-0.3C offset effect. Another Volcano just blew in Indonesia... http://www.bbc.co.uk/news/world-asia-pacific-14176465. The Equatorial positioned have most global impact if seriously getting on with the eruptions and hi atmospheric injecting... geo-engineering by nature.

Piotr Djaków

Arctic temperatures from ERA-Interim dataset:
http://gfspl.rootnode.net/klimat/arctic/index.php

Ennis George

Does anyone know the type of gases the various volcanos are releasing i.e. is it primarily CO2 or sulphur dioxide? Obviously it can make a difference in terms of short term impacts on the global climate.

Twemoran

The ice shelf at Petermann Fiord is seriously fractured and the object that impacted it is back where it was on the 17th - could slam into it again.

Twemoran

My bad - meant to say 'where it was on the 13th"

R. Gates

Ennis George,

There are various gases released by different volcanoes, depending on the type, but the most common gases are sulfuric gases than then are converted to aerosols in the atmosphere and can of course cause short-term cooling effects. These cooling effects usually last a few years before the sulfuric aerosols are precipitated out. More interestingly, and often not discussed are the long-term warming effects that can occur with certain types of volcanic eruptions that, along with the sulfuric gases, also emit large amounts of CO2. The CO2 can linger for centuries, long after the sulfuric aerosols have been removed. It is even speculated by some, that it was the large amount CO2 released by massive volcanic eruptions some 750 million years ago that brought the earth out of the ice-planet state it was in at the time.

For a quick primer on the short-term effect of volcanoes, go here:

http://earthobservatory.nasa.gov/Features/Volcano/

For a perspective on how the CO2 emitted from volcanoes might have broke the earth free from the ice-planet conditions of 750 million years ago, go here:

http://www.nature.com/nature/journal/v405/n6785/abs/405425a0.html

http://www.sciencemag.org/content/281/5381/1342.short


Ivan the casual

R. Gates,

I can't think of anything else other than volcanic CO2 that could have brought Earth out of the "snowball". Sunlight reflection would have had an incredible cooling effect, only infrared trapping C02 could have brought the planet back to open oceans again.

On that same topic, I have an albedo question for anyone who can answer it. In terms of forcing, are there any estimates (in watts per square meter) of increased warming due to albedo change in the Artic (ocean water instead of ice cover) for the entire globe? Many on here have commented about local anomalies over open water, but I would like to see how much an effect the last 5 years of decreasing ice extent/area have had on overall climate forcing.

Seke Rob

The summary of today's volcanic CO2 output is not anywhere matching the output from motor-vehicles alone, though it seems the initial hours [forgot the phase name] are generating vast numbers, and then there are those such as Plimer who would happily extrapolate those values and claim a "volcanic burb" outstrips anything of human output. Think there presently is also a subglacial volcano on Iceland acting up, one of fame. Tokyo was hit with an earthquake, so it feels like things are rippling around the planet, above average this year...

Global SIA just dropped again according CT, both poles. On Eyeball it's about 3 Std.Dev below the 1979-2008 mean for the day of the year . 2,269,000 km square.

Dust/aerosol fall out on ice is interesting and it's effect on melt.

Ennis George

R. Gates

Thanks for the info.

Rich and Mike Island

What is the latest date in the summer there has been a century break?

Rob Dekker

Guys, do my eyes deceive me, or is the NE at the point of opening up ?

The entire Siberian coast is ice free (or less than 30% concentrarion), except for a small patch on the East Siberian coast. Now concentration images from NIC and Uni Bremen suggest that the remaining ice (100 km or so along the shore) seems to be breaking up.

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

Unfortunately, there are too many clouds for MODIS to reveal the state of ice there.

When did the NE passage open up last year ?

Seke Rob

Curious... this webcam meltpool picture is as if the surface has frozen up. The 1 AM pic has a similar appearance, but then what to expect at 88N, almost 1 months after summer solstice.

Seke Rob

Rob Dekker,

Maybe posted before, the first Russian Arctic Tanker headed by a nuke icebreaker left earliest ever from Murmanks towards China

http://www.barentsobserver.com/seasons-first-oil-tanker-sails-northern-sea-route.4939088-116320.html

Probably they've passed that point by now, so what to say... it's been open :|

Kevin McKinney

Ivan the Casual--

S.R. Hudson (2009) estimated the global-annual forcing of an ice-free Arctic to be no greater than .7 W/M2. Not exactly what you asked, but somewhat close. More here:

http://adsabs.harvard.edu/abs/2009AGUFM.A22A..08H

R. Gates

One comment about volcanoes and CO2: Yes, volcanoes can emit vast amounts of CO2 under the right conditions for short periods of time. But truly, in looking at the last few hundred years, you could say the earth has been undergoing a long-term "Human CO2 Volcano" that started to erupt in about 1750, and continues today, with the eruption getting more intense each passing year. Over the course of this ongoing and strengthening eruption, CO2 has increased about 40% in the atmosphere.

Rich and Mike Island

Carbon Dioxide emissions are more than 100 times the emissions of carbon dioxide from volcanic activity. http://hvo.wr.usgs.gov/volcanowatch/2007/07_02_15.html

Rich and Mike Island

In a way, it really doesn't matter whether we set a new minimum this year or not. We've already set many record lows for the date.

Computing the average ice cover for a calendar year would be interesting. And maybe more valuable.

Whether or not we hit a new record low minimum this year or not, the trend is clear. We will hit new minimums this decade, and almost certainly break the 4 million square km mark--summer minimums in the 3s may be normal by the end of the decade.

And I'm sure we'll break the 3 million square km mark by 2025, if not earlier.

In my mind, when the arctic sea ice extent falls below 1 million square km, that will be 'ice free' by my standard. Especially considering that much of that will probably be area with less than 50% ice coverage.

Rich and Mike Island

A record low winter maximum is just as important. I wonder when we will have the first winter max below 10 million square km.

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

Seke Rob Jaxa sometimes has funny numbers ending e.g. as at 3 zero's occasionally 4, such as July 26, 2003: 8,030,000. Are they pixel counting at times or filling in blanks [not that is of any significance to the total picture]

No, the individual pixel area is an integral fraction of 10000 km^2 so you'd expect numbers ending in 0000 to occur fairly often, if I recall correctly there are 128 pixels/10,000 km^2.

Phil.

Kevin McKinney

"Computing the average ice cover for a calendar year would be interesting. And maybe more valuable."

You mean like this?

http://i1108.photobucket.com/albums/h402/brassdoc/MeanIJISSIEByYear.jpg

Anu

Speaking of "fumbling in the dark"...

I popped over to some typical Coolatta sites that I used to follow, to see how they are handling the 2011 Arctic sea ice melt, since the "official know nothing" position has long been that 2007 was a freak summer of unusual winds and weather, and we would be seeing a steady retreat back to the normalcy of the 1980's or 1970's. (Because the PDO is swinging back up, or because natural variability jumps both ways, or because they know global warming is a hoax so that's what must happen, or...). They have been greeting the increasing summer minimums of 2008 and 2009 as confirmation of this expectation, and 2010 as a slight hiccup in the climb back to the old days, so how are they handling 2011?

Pretty much ignoring it.

There's a thousand other "climate topics" that they prefer to attack "warmistas" on than an unusually fast Arctic sea ice melt. But one interesting twist I noticed on a few sites was a new argument that all those scientists crisscrossing the Arctic ice on their icebreakers studying the ice, combined with new shipping activity because of the thinning ice, is actually *causing* the ice to melt quicker.

See, even if the summer ice disappears in the next few years - it's NOT global warming, it's because of all the new icebreaker activity. They warned you, back in 2011.

See in my line of work you got to keep repeating things over and over and over again for the truth to sink in, to kind of catapult the propaganda.

-- President Bush, Greece Athena Middle and High School Tuesday, May 24, 2005, Rochester, NY

Artful Dodger

Sorry Anu, not a new argument just repetition of a previously debunked mime, repeated Ad nauseam:

"Do icebreakers contribute to climate change?"

http://nsidc.org/arcticseaicenews/faq.html#icebreakers

This is the same style of broken logic spurring the Majority in the U.S. House of Representatives to defund NOAA Earth Observation Satellites.

Kevin O'Neill

The earth is so large and the forces that shape climate are so great that us puny humans have no effect on it -- unless it's a few dozen scientists tramping around the Arctic -- then we're the straw that broke the camel's back. Anthropogenic climate change has nothing to do with CO2 and everything to do with footprints in the otherwise pristine snow.

I think I misplaced my tinfoil hat -- anyone seen it lying around?

Account Deleted

Unfortunately I am facing some of these arguments at work. CC is either a hoax generated by the CC scientists to get lots of grant money, due to volcanoes, or just a natural cyclical process.

Seke Rob

Question asked: "What is the latest date in the summer there has been a century break?"

Here the dates per JAXA, the latest in year summer century and the corresponding SIE at those dates:

DATE-------- Century Extent
07,27,2002 -142500 7861094
08,08,2003 -117188 7032031
08,08,2004 -108750 7199844
07,27,2005 -111250 7386094
07,09,2006 -101875 8456719
07,24,2007 -113906 6858125
08,25,2008 -121562 5305313
07,25,2009 -110781 7318438
07,20,2010 -109219 7657344
07,14,2011 -114063 7525000

Rough filter "< -99999", then handpicked latest for year, so it could be subject to correction, with 2008 as the clear winner. Of course, 2011 is very much underway :D

Neven

Check out the updated NWP animation, if you want to see some in-situ melting.

Russell McKane

Excited to find your site, not sure how I missed it having being tracking this stuff for many years. Comment on anomalies above and Crysosphere web site. Noticed this the first time the other day while wondering if the anomaly would beat the 2007 for the arctic. The current graph is set on a floating mean finishing at 2008. 2007's massive anomaly is already smoothing the current graph so I was wondering what it would be if recalibrated back to 2007 for a comparison. Also this anomaly occured in the regrowth sept/oct when the large body of warm water inhibited regrowth. So we can expect the big event this year to be in this period also.

Neven
Excited to find your site, not sure how I missed it having being tracking this stuff for many years.

Better late than never, eh? Welcome, Russell.

The CT area anomaly is wrt the 1979-2008 baseline. I think the same goes for 2007 in retrospect. So to compare this year's anomaly to that of 2007 is apple to apple, I believe. But good question.

FrankD

@Rich and Mike Island: I wonder when we will have the first winter max below 10 million square km.

The feedbacks that come with an ice free summer (which will predate a sub-10 million winter max) are very uncertain, so I can only say with any certainty that I wonder too.

But the question lead me back to PIOMAS curve fitting, and there are some hints in the graphs that Neven has published, if one is happy with a purely numerical extrapolation in the absence of a rigourous physical model.
(Rider: I believe the data shows that a lot of volume loss over the last decade has come from a reduction in the average thickness of the pack. That process appears to be slowing, ie the pack can only be so thin before it becomes too weak to hold together. At that point volume and extent are tightly coupled - volume loss sees equivalent extent loss and the average thickness remains unchanged. The significance of that rider will become clear later).

So:
1. We currently drop below 10M in June (getting earlier) and rise above it again right at the end of November (getting later).
2. Conveniently, these two 10M extent months are the months showing the highest and lowest average thickness of the pack - June is slightly thicker and Nov/Dec slightly thinner than it is at the extent peak in April.
3. Quick sanity check: Because the Nov/Dec thickness is lower than June, logically the volume will be lower for the same extent - and that's what we see in the PIOMAS output.
4. In the past, volume and extent could change fairly independently due to fluctuations in the thickness of the pack, but as per my rider above, I think we are now a fairly hard floor value for November (June still has some wiggle room) for minimum average thickness. Because of that, I think we can correlate volume changes to extent changes far more closely now than even a decade ago.
5. If we can estimate the range of minimum volumes that provide a 10M extent (I think we can), and if we can project when winter max volume will fall below that threshold (we can, sort of), then we can put some rough boundaries around the question.
6. Projecting current estimates forward, we find that future April volume will drop below current June volume in around 2020, and will drop below current Nov/Dec volume at or before 2030 ("current" being the average of the last few years).
7. If my assumption that Nov/Dec would provide a better correlation as it is already at my putative "floor" average thickness, I would suggest that we would see a winter max below 10 million sq km's in the late 2020's, depending on the weather. If I had to name a date, I'd say 2028.

Lots of qualifications, lots of guesswork, probably pushing the numbers too hard. But I believe a volume-based approach will give better results than curve-fitting extent (which would suggest a date sometime in the 2050's or later).

Sorry if thats tl;dr. I wanted to step through some slightly curly logic and layout my assumptions. It seemed better to do that up front than just reply "2028!.

Russell McKane

Done on the same graph I agree one can make a direct comparison but not being a statastician and as 2009-2011 are not included yet I'm not sure if it is apples with apples?

Neven

Russell, if 2007 and 2010 are both compared to the same baseline (ie 1979-2008) then we're talking apples.

ECMWF is still forecasting a very big low to move in over the Chukchi/Beaufort area. On the one hand, I think this should cause some divergence and a slowdown in extent decrease. On the other hand, if positioned the right way, it might push all of those loose floes (the yellow colours on the sea ice concentration maps) back towards the main pack again, compensating divergence elsewhere.

And now that I'm talking about compaction/divergence: One big difference - something that Nick Barnes alluded to with respect to satellite images - with 2007 is the CAPIE percentage. In my spreadsheet current CAPIE is at 74.25%. Around this time 2007 was at 69.52%. 2010 at 69.02% even. That's quite a big difference, meaning 2007 would be well ahead of 2011 if the difference in percentage would be converted into hard numbers. Any thoughts?

Neven

Robert Grumbine has returned from his blogging hiatus, with two excellent pieces on Arctic sea ice: How Large a Conspiracy? and 2011 Sea Ice Outlooks.

Peter Ellis

IJIS saying 7,242,813 on the front page - another century if no further revision.

Neven

Wow, Peter, you're fast. Thanks.

Kevin Adams

Thanks to everyone for the good info on the Petermann.

Just based on some very rough analysis, there's not much of a chance of 2011 not winding up very low for SIE. Assume ice loss for the rest of the year mirrors 2003, a fairly mild recent year: 2011 winds up around 2008 for September minimum. Given conditions, though, it doesn't look like 2011 will be that forgiving.

Nick Barnes

It's completely obvious, using a Mk I eyeball on the IJIS extent chart, that 2011 and 2007 have broken away from the pack. It would be very surprising if 2011 doesn't break 7M ahead of 2007. Whether it can keep with the breakaway down to 6M is less clear: 2007 did that million in 12 days.
I have to say, these races remind me more of the Tour de France than of snooker.

Kevin McKinney

"7,242,813 km2 (July 17, 2011)"

Take that, 2007!

Figured someone'd be ahead of me with news of the update. (I was wondering there for a bit if we'd be seeing another protracted IJIS outage.)

Kevin Adams

Back-of-the-envelope math:

If SIE decline for this year mirrors 2003 from the same date through September minimum, we wind up at 4.5mil, below 2008 but above 2007.

If it mirrors 2007, we wind up just barely breaking 4.0mil, recording a new low for the satellite record.

It seems highly unlikely that 2011 will not be at least our second-lowest on record unless something odd happens.

Kevin Adams

(IJIS AMSR-E data, btw)

Artful Dodger

Kaleschke et.al (UniHamburg) now predicting Sep 2011 SIE at 4.2 m km^2, +/- 0.2 m km^2

ftp://ftp-projects.zmaw.de/seaice/prediction/estimate.png

Seke Rob

Posted 3 x but it's not sticking.

On Neven's CAPIE percent:

Maxima compared:

JAXA 2007 > 2011 by 58,437 km^2
CT 2007 < 2011 by 172,778 km^2

Curious is the 2007 date differentials of CT and JAXA maxima:

CT Feb 26, 2007 (Area)
JX Mar 10, 2007 (Extent)

CT Mar 08, 2011 (Area)
JX Mar 08, 2011 (Extent)

Maybe I'm squinting, checked twice, but it seems that Extent in 2007 kept expanding whilst Area was already on slight decline.

What was special then in 2007 with the seed set in 2005/2006? What else... the weather :D

Seke Rob

Tongue in cheek, take CT AREA as percent of MASIE extent for July 16: 7,928,193.37 = 68.39%

Neven

The sea ice in front of Petermann Glacier has broken up and is flowing out. Not that this necessarily means anything. :-)

Espen

Now it is time to watch North East Greenland, the next 2 weeks there is usually a lot of heavy action in North East Water and Joekelbugt area, so now you are warned!
Regards Espen

Wayne Kernochan

Some comments on recent thoughts on volcanoes and CO2. Hansen in his recent unpublished paper distinguished between eruptions undersea, caused by movement of plates under/over each other, and eruptions above ground. Eruptions above ground cause greater cloud cover but have very little effect on CO2 levels. They do lower global temperatures significantly because of cloud/aerosol cover, but the effect wears off after 5-10 years, leaving us with the same temperature level and CO2 as if the eruption hadn't occurred.

Eruptions under the water tend to occur over a long time. In particular, Hansen suggests that sudden movement of the India plate northward to collide with the Asian plate 60-50 million years ago cause a small but steady increase in CO2 emitted, which over time led to what Joe Romm called Hell and High Water.

The alternative hypothesis is apparently the Milankovitch cycle, which may have a 100,000 year periodicity and can vary from period to period in its effects. There doesn't however, appear to be an explanation of how it could produce such a wide swing in temperature/CO2.

Previous data had suggested, however, that much of the switch to subtropical Arctic had happened in a matter of 1000 years -- which would seem to cause difficulties for both hypotheses. A new paper appears to both back Hansen's hypothesis and suggest a reason for a faster climb. It found that this warming and increase in CO2 happened over 20,000 years and coincided with a massive eruption underneath the Indian plate, thereby kickstarting the plate movement and also releasing much greater amounts of CO2 from undersea than previously believed.

The net of these findings would seem to be: volcanoes will not save us from global warming; on the contrary, we had better hope that no such under-plate eruption happens, as it will exacerbate present trends. Moreover, while an extended period of above-ground eruptions may seem as if it is counteracting the effects of CO2 on temperature, it is only lulling us into a false sense of security as the underlying CO2 levels continue to build up, while we delay dealing with our emissions.

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