Record dominoes 11: NSIDC September SIE

There are several scientific organisations that keep an eye on the Arctic sea ice cover and put out graphs to inform us of the amount of ice that is left. You can see most, if not all, of them on the ASI Graphs webpage. The minimum records on ALL of these graphs have been broken this melting season.

---

We already knew this would happen, so the excitement isn't commensurate with how big a thing this really is, but it's official now: the NSIDC September average sea ice extent record from 2007 has been smashed to smithereens.

Graph:

Larry Hamilton's excellent bar graph:

Numbers:

year mo    data_type region extent   area

2005  9      Goddard      N   5.57   4.03
2006  9      Goddard      N   5.92   3.97
2007  9      Goddard      N   4.30   2.78
2008  9      Goddard      N   4.73   2.99
2009  9      Goddard      N   5.39   3.47
2010  9      Goddard      N   4.93   3.07
2011  9      NRTSI-G      N   4.61   2.89
2012  9      NRTSI-G      N   3.61   2.11

Like I've said a couple of weeks ago: You thought 2007 was big when it smashed the 2005 records? Well, 2012 is to 2007 what 2007 was to 2005. If my calculator doesn't deceive me, the 2007 record was a drop of 22.2% from the 2005 record. The 2012 record is a 23.6% drop from the 2007 record. (Edit: I screwed up, mistaking the 2008 number for the 2007 number. Misfratz has the right numbers in a comment below. 22.8% drop from 2005 to 2007 September average sea ice extent, and a 16% drop from 2007 to 2012 September average sea ice extent.)

As you can see the 2007 sea ice area record has also been thoroughly demolished. But the same of course goes for IJIS September average SIE (graph courtesy of Seke Rob):

So now we wait and see if the CT SIA anomaly drops below the 2007 record, and perhaps the CT Global SIA record anomaly is in the works as well (depends on the Antarctic sea ice mostly). Oh, and of course, the PIOMAS minimum volume. The record was broken a while back.

And then we'll watch the freezing season a bit. I'm working on a couple of changes. More on that later...

Comments

[idunno]

...this one being significant in that it is the September average Sea Ice Extent which is predicted in the SEARCH predictions:

http://www.arcus.org/search/seaiceoutlook/index.php

...all of which were too high.

[Neven]

Indeed, idunno. Thanks for the additional info (here are all the blog posts I wrote concerning the SEARCH Sea Ice Outlook).

We also had monthly polls in the right hand bar for this metric. More on that later as well.

[Chris Reynolds]

And now I can stop downloading CT Area every day...

I'm not convinced we'll see CT area anomalies beat 2007. In 2007 due to clear skies over open water there was a massive heat gain (500% of average IIRC), I don't think that happened this year. Whether I'm right or wrong, it'll be interesting to follow.

In a few days we'll have PIOMAS figures out to confirm the actual volume minimum and date. I'm still betting this March will see a volume drop on last March, that would be 3 years out of the last 4. Models show March volume drops during RILEs (Rapid Ice Loss Events) - just sayin'. ;)

[Neven]

I'm not convinced we'll see CT area anomalies beat 2007.

I'm not so sure any more either. On the other hand, now is the time for the anomaly to grow big, as the baseline average is starting to go up very fast. In the end it's quite simple, if 2012 stays below 2007 for a while longer it will come even closer than it is already. Like I wrote in a blog post at the time the 2012 CT SIA anomaly dipped below -2 million km2:

First dip 2007: Aug. 19th - Aug. 23rd

Big dip 2007: Sep. 25th - Oct.29th (reaching the record anomaly of -2.635 million km2)

2012 is still 381K below 2007, which is a big advantage, and 2007 stopped being 'special' around this time.

[Neven]

Oh, and BTW, I have updated the sea ice concentration maps on the ASI graphs website. I will probably continue to do so throughout October and November.

[L. Hamilton]

I have been putting together an updated set of long-term bar graphs. You've already seen the north/south area version (1-day CT area min):

http://img.photobucket.com/albums/v224/Chiloe/12_Climate/2012_sea_ice_CT_min.png

The new NSIDC bar graph (Sep mean NSIDC extent) now extends back to 1972, based on my rescaling of Cavalieri et al. (2003) NIC and NIMBUS estimates:

http://img.photobucket.com/albums/v224/Chiloe/12_Climate/2012_sea_ice_NSIDC_extended.png

There will be a 3rd bar graph when the PIOMAS shoe drops.

[L. Hamilton]

Only slightly off topic for this thread, a note from my day job: survey reseach paper
"Did the Arctic ice recover? Demographics of true and false climate facts"
just pre-published (in a hard-to-read unformatted version) by Weather, Climate, and Society:

http://journals.ametsoc.org/doi/abs/10.1175/WCAS-D-12-00008.1

[Aaron Lewis]

Last spring, I posted here that this year's sea ice melt would obliterate all previous sea ice melt records, but not approach ice free conditions. It think that was the best and earliest estimate for this year's sea ice. I did not bother do a SEARCH entry because the smart guys all read this blog.

Next year, I expect sea ice free conditions in the Arctic based on heat transport via water vapor in the Arctic atmosphere, storm conditions driven by latent heat in the atmosphere, and a good deal of snow this fall that insulates sea ice and permafrost from the cold, thereby allowing them to remain warm and weak.

Finally, I expect that by 2015, we will see substantially sea ice free conditions by June 21, meaning that the Arctic will be trapping a great deal more heat.

Much of that heat will get transferred via water vapor to the GIS. We should be thinking about how the GIS will behave under those conditions.

[Brian_henderson]

WOW!!

Besides data on sea ice extent, is there data showing changes in chemistry of arctic waters that could impact it's freezing point? Wondering if higher CO2 (or other changes, including PH) in today's oceans would have an effect on future extents of arctic ice.

Thanks, for all the informative blog posts.

[Protege Cuajimalpa]

The NSIDC area has been dropping at a faster rate than the extend. That means that there is less ice that the one that we see at the extends graphs.

Year Extend Area Ext.-Area %
2005 5.57 4.03 1.54 27.6%
2006 5.92 3.97 1.95 32.9%
2007 4.30 2.78 1.52 35.3%
2008 4.73 2.99 1.74 36.8%
2009 5.39 3.47 1.92 35.6%
2010 4.93 3.07 1.86 37.7%
2011 4.61 2.89 1.72 37.3%
2012 3.61 2.11 1.50 41.6%

12-05 35.2% 47.6%

Everybody agrees that the ice that is left is thinner. So, with less Area and less width, we can conclude that PIOMAS figures should be closer to reality. Even if PIOMAS figures could be exaggerated, they reflect the tendency better than anyone else. So I concluded that the Arctic will be near ice free before 2020.
Defining the extend of 1 million km2 as “near ice free”, an interesting poll could be the year that each of us think that this is going to happen.

[Protege Cuajimalpa]

Just to make the numbers that I post clear, the Extend dropped 35.2% from 2005 to 2012, but the Area dropped 47.5% in the same time frame. Similarly, the Area was 27.6% less than the Extend at 2005, but it increase to 41.6% less at 2012.

[Brian_henderson]

Since Ice Extent is area measurement (sq. km) … and Sept 2012 extent being ~50% of 1979-2000 mean. Wondering, with reports of thinner ice in recent years, is it possible to estimate ice volume (cu. km) for Sept. vs. for the 1979-2000 mean?

[Nightvid Cole]

is it possible to estimate ice volume (cu. km) for Sept. vs. for the 1979-2000 mean?

In a few days, PIOMAS should update

http://psc.apl.washington.edu/wordpress/research/projects/arctic-sea-ice-volume-anomaly/

Be patient...

[wayne]

Ideally, sea ice forms when the waves are not so high, when surface temperature is colder than -11 C, when surface sea water is -1.8 C, especially in clear skies. All these factors are created by sea ice packs. When its windy, ice calms the waves like a peninsula, above the ice pack there is colder air, the pack cools sea surface temperatures and a huge pack creates a drier sky environment. 2012 sea ice is particular because it is all in roundish spot. There is no gap between two huge ice sheets, which is very favourable for a quick refreeze. Ice begets ice.

[Lewis Cleverdon]

Aaron - you're to be congratulated on your judgement - which would take some beating.

WRT the GIC under increased water vapour, what effect, if any, should this have on the altitude at which melt lakes and moulins develop ? I gather they're limit had risen to something over 1400ms in 2010, but from around 1800ms on up the incline tends to get much shallower, favouring much larger lakes, and the vulnerable area gets much larger, allowing many more of them.

Given that the great majority of such lakes south of about 73N already occur over the inner slopes of Greenland's 'encircling ridge' (all of 50ms high for some W, NW & NE stretches)
then IF those lakes' moulins drop near-vertically
(rather than tracking the slope to the coast for up to 60kms)
they must presumably feed a central water table of some sort.

From which perspective it would seem that bottom-melting/degrading might not be just an open ocean issue.

Apart from the solar energy collected by the lakes, there is also the distinctly non-trivial energy delivered by several million tonnes of water suddenly draining in 2 hrs or less, and dropping potentially 1400ms (as witnessed at lesser altitudes by teams from both Woods Hole and Aberystwyth Uni). And such lakes have till now been around the mean of the range, and they are very numerous -

Which leaves me rather puzzled - I can't find anything published on the rising energy injection of melt-lakes' solar or kinetic potentials and their likely scale of effect on the ice-cap's stability. Can you (or anyone else) post a link for anything useful & public that you know of ?

Regards,

Lewis

[Twemoran]

Larry

Your article sounds fascinating, but I'm loath to spend $25 to find out for sure.

Is there another way to view it?

Terry

[LRC]

The Greenland lakes that get formed either refreeze or drain through crevices. If they drain then they tend to drain into the ocean under very high pressure. Saw a report about it a month or so ago, but am sorry that I can not remember what is was called or where to find it.

[Dromicosuchus]

Wayne, would you mind giving me a link for that "-11 ˚C air temperature required for freezing" bit that you mention? I've done some (admittedly, cursory) scrounging around, and I can't seem to find a reference that mentions that value.

[Misfratz.wordpress.com]

Neven:

You thought 2007 was big when it smashed the 2005 records? Well, 2012 is to 2007 what 2007 was to 2005. If my calculator doesn't deceive me, the 2007 record was a drop of 22.2% from the 2005 record. The 2012 record is a 23.6% drop from the 2007 record.

I think you have made some sort of a mistake, or you have a mischievous calculator, or I will shortly be greatly embarrassed.

[Extent] 2007/2005 = 4.30/5.57 = 77.2% ie 2007 was a drop of 22.8% on 2005.

[Extent] 2012/2007 = 3.61/4.30 = 84.0% ie 2012 was a drop of 16% on 2007.

[Area] 2007/2005 = 2.78/4.03 = 69.0% ie 2007 was a drop of 31% on 2005.

[Area] 2012/2007 = 2.11/2.78 = 75.9% ie 2012 was a drop of 24.1% on 2007.

Have I done something wrong?

2012 was still a big decline, and what was most notable is that this decline happened without what we've thought of as the optimal conditions for sea-ice melt.

I'd also be interested to know if this year has increased the linear rate of decline - I'd guess that it has, but I don't have the old September graph saved anywhere to check.

[Misfratz.wordpress.com]

Also, if we're thinking about predictions, here is one worth keeping an eye on.

After 2007 set a new record below 2005, all the subsequent years have also been below 2005. My prediction is that all years subsequent to 2012 will now be below 2007.

Yes, next year might well be higher than this year, but I think it's doubtful it will fail to go below 2007.

[Neven]

Have I done something wrong?

No, you're right, I did something wrong! I used 2008 instead of 2007. I'll update the post.

[Neven]

The new NSIDC bar graph (Sep mean NSIDC extent) now extends back to 1972, based on my rescaling of Cavalieri et al. (2003) NIC and NIMBUS estimates:

Thanks, Larry. I've put it in the post.

[L. Hamilton]

"Is there another way to view it?"

Terry, if you (or others here) want to send me an email I will send a copy of the author's draft.

Larry dot Hamilton at unh dot edu

[Donald]

Aaron Lewis: "Next year, I expect sea ice free conditions in the Arctic based on heat transport via water vapor in the Arctic atmosphere, storm conditions driven by latent heat in the atmosphere, and a good deal of snow this fall that insulates sea ice and permafrost from the cold, thereby allowing them to remain warm and weak.

"Finally, I expect that by 2015, we will see substantially sea ice free conditions by June 21, meaning that the Arctic will be trapping a great deal more heat."

I am surprised that no one has commented on this prediction.

[Espen]

Donald,

"I am surprised that no one has commented on this prediction."

I believe it is because most of the readers and commentators on this log, do have more or less the same opinion about ice free summers in the very near future ranging from Aarons next year, to the 20 - 30 ties, and my own 2015 - 16.

[wayne]

Hi Sam, -11 C was an on site accidental observation, it took a scuba diving team sledging from the North Pole to Canada from March onwards exploring while observing and measuring ice conditions under sea ice, which incidentally is not flat, neither in any way or shape imagined , at some point before abandonment a scuba diver touched the ice bottom disintegrating away after often doing so before never sensing this, the temperature outside was -11 C, from that point the ice bottom kept on disintegrating. Subsequent to this on local High Arctic re-freezes I carefully monitored sea ice onset vs water and surface air temperatures. True enough warmer than -11 C there was no significant ice forming, after this temperature threshold was passed ice forms quite fast. But the sea water temperature must be -1.8 C.

Its likely the thermal temperature of the sea, its total energy output, which matters. This -11 C may be cooler or warmer, for fast ice forming depending on the thermal output of the ocean.

Now look at the temperature and sst of the many remote sensing graphs about, you will find this number, -11 c , quite useful.
I'll find direct online reference later.

[Artful Dodger]

Hi Misfratz,

Interesting prediction, with some justification :^)

The configuration of the pack ice at the end of Summer 2007 was quite different. In addition to being larger, it was also thicker, more compact, and older (higher proportion of MYI). This made it more resistant to melt the following 2 seasons, as the gyre transported MYI to die in the Beaufort and Chukchi seas.

That period has now passed. In contrast to 2007, end-of-Summer 2012 had relatively light winds, allowing the pack to freeze in place without significant compaction. There is 1.5 M km² of new, weak and saline sea ice gluing thinner ice floes together.

In the Laptev sector of the Central basin, there is over a million km² region that teetered on the brink in early Sep 2012. Had weather conditions been different, we could well have gone below 2 M km² SIE this year.

As Winter 2012/13 advances, it will be interesting to watch 'snow cover over ice' and NASA Icebridge results. Another thin end-of-Winter pack virtually assures a 2013 melt exceeding 2012.

Cheers,
Lodger

[Seke Rob]

So now we wait and see if the CT SIA anomaly drops below the 2007

Daily, monthly, annual, for starters a monthly to include the "just in" last September day... a little ditty from the chart factory [ask and you can get any month you please to see]

http://i137.photobucket.com/albums/q210/Sekerob/Climate/CT_SIA_Monthly_September.png

[L. Hamilton]

Update to cycle plot of NSIDC extent and area, through September:

http://img.photobucket.com/albums/v224/Chiloe/12_Climate/2012_Cycle_Arctic.png

I also tried out a different version of the "trends" cycle plot, using lowess smoothing instead of linear regression:

http://img.photobucket.com/albums/v224/Chiloe/12_Climate/2012_Cycle_Arctic_trends.png

[r w Langford]

Recent paper on influence of melt ponds on the accuracy of models for arctic sea ice. Models incorporating melt pond data are more accurate in predicting observed levels of melting.
http://www.agu.org/pubs/crossref/pip/2012JC008195.shtml

[Seke Rob]

The curious but about the enormous increase in FYI... it's nice and smooth and promotes much larger and interconnecting ponding than in the days of the MYI prevalence[until wave action turns FYI to shreds... then ponds run off the side]. I'm surprised at the 20% albedo change. Thought to have seen much more dramatic percentages.

[crandles]

Aaron,

Well done. While my July outlook prediction of 4 for Sept Avg extent looks better than other SEARCH contributions at that time and area of 2.6 wasn't bad, my PIOMAS 2.2 was badly out. Also 4.2 in August wasn't so good

Obliterate but not approach ice free is a very good qualitative description that I would say clearly beats my efforts at later dates.

Nevertheless, once can be luck and I am not sure of your record on other prediction, so whether you can maintain that standard seems the obvious question.

I admit the possibility that you might be right, but I think I am inclined to be willing to agree a £100 bet that on June 30 2015 Cryosphere Today arctic sea ice area will be more than 1 million Km^2. You might get better terms elsewhere (like stoat) so I won't be surpried or offended if you don't want to take me up. Just thought it might help shine light on how strongly you believe what you said.

[NeilT]

For the CT SIA anomaly I have a question. I know they update the mean baseline from time to time. From my recollection the anomaly measured in 2007 was compared to a mean of 1979 – 2003 (not sure about 2003 but it was somewhere there).

The 2012 anomaly is being measured against the 1979 – 2008 mean. Now I’m aware that mean trends are not overly affected by one or two numbers, however adding 2004,5,6,7 and 2008 to the mean HAS to change the baseline to some degree or other.

So what I’m asking is: Should we use the same figures as the NSIDC (1979 – 2000) as a fixed and non moving mean; what would the anomaly figures be for:

1) 2007
2) 2012

Comparing apples with Apples, have we actually already broken the 2007 anomaly?

[Seke Rob]

If you want to compare anomalies between the different products, then yes, you'd have to normalize the baseline. Is that what you want to do? Otherwise if you recalculate the baseline for CT back to 1979-2000, you make all numbers just bigger, but relative the difference does not change... tried that and nothing changed in the trend line either. Maybe I did not understand.

[crandles]

Umm, Whatever the baseline, shouldn't the difference between 2005 and 2007 be the same. Likewise, whatever the baseline, the difference between 2007 and 2012 should be the same.

Or are you trying to get some idea of difference from trend rather than difference from average?

Am I missing something?

[A-Team]

"surprised at the 20% albedo change. Thought to have seen much more dramatic percentages."

Right, when wavelength-integrated albedo is experimentally measured along a transect line over an Arctic melt season time series, the changes observed at an incipient melt pond are indeed dramatic.

The abstract is poorly worded -- the authors presumably meant a drop in albedo of 0.2 on its 0 to 1 scale, eg from 0.6 to 0.4 which is not 20% relative to initial state as the abstract reads.

For on-the-ice measurements of albedo, see Fig 6 of "Seasonal evolution of the albedo of multiyear Arctic sea ice" Journal OF Geophysical Research, VOL. 107, NO. C10, 8044, doi:10.1029/2000JC000438, 2002.

The authors published an 2012 update called
"Albedo evolution of seasonal Arctic sea ice" at Journal OF Geophysical Research, VOL. 39, L08501, 6 PP., 2012
doi:10.1029/2012GL051432 in which they write:

"four years of field experiments indicates that seasonal ice undergoes an albedo evolution with seven phases; cold snow, melting snow, pond formation, pond drainage, pond evolution, open water, and freezeup. Once surface ice melt begins, seasonal ice albedos are consistently less than albedos for multiyear ice resulting in more solar heat absorbed in the ice and transmitted to the ocean."

Free full text of these is a bit elusive though I do have both (sorry: travelling) or just request from the author: perovich at crrel dott usace dott army dott mil

[Kevin McKinney]

"I think I am inclined to be willing to agree a £100 bet that on June 30 2015 Cryosphere Today arctic sea ice area will be more than 1 million Km^2."

In the same spirit of inquiry, crandles, would it change your willingness if the effective date were August 31, 2015, instead? (I'm not offering, just asking!)

[NeilT]

Crandles, the anomaly trend is measured against the mean. But the mean is a moving target.

The required area to get the 2007 anomaly record is larger than the area required to get the equivalent anomaly in 2012.

Because the mean in 2012 is smaller, therefore the area must be correspondingly smaller to get the same anomaly result.

Or put another way, the more melt we add to the mean, the more additional melt we must have to get the same anomaly from the mean.

[Neven]

I believe the mean is the same for all years. There are no oranges.

[L. Hamilton]

Anomalies are not ordinarily a moving target, but calculated from a stationary base, e.g. from the mean for a particular day of the year, across the whole baseline period (1979-2008 for CT). If you change the baseline period, all anomalies in the whole series should be recalculated.

[Seke Rob]

That's the discussion I remembered, Thnks. I'll have a go-ogle scholar at your references to see if I can some more understanding.

[Seke Rob]

Some posts snug in-between... that was in response to A-Team (slow typer and thinker, need to make it a habit to include a poster reference)

[Seke Rob]

As "waiting for" is not something we're all good at, here an animation [apng compatible browser only] of the 9 monthlies of CT area and anomaly Jan-September.

http://i137.photobucket.com/albums/q210/Sekerob/Climate/CT_SIA_Monthly_Anim.png

A mosaic of the 9 months is found here to look in quite: https://sites.google.com/site/allthingsclimatechange/Home (escape will stop the anim too, F5 restarts)

More glaring, the winter trend is negative, in case there were any doubters in the wishful thinking department. (there was a book (Stephen King?) with a arctic scenery... The Thing... maybe something comes loose that had been frosted in for millenniums)

[Kris]

Arctic 1st of the month parade updated for the 1st of October.

Also updated September with NSIDC's home record of 16 September.

[Chris Reynolds]

A-Team,

You'll find a copy of the Perovich 2012 paper and commentary on it in this blog post:
http://dosbat.blogspot.co.uk/2012/09/sea-ice-albedo-changes-and-seasonal.html

[Jim Williams]

Larry: "Anomalies are not ordinarily a moving target, but calculated from a stationary base, e.g. from the mean for a particular day of the year, across the whole baseline period (1979-2008 for CT). If you change the baseline period, all anomalies in the whole series should be recalculated."

The question then would be, has the anomaly for 2007 been recomputed for the purpose of our comparison? I know I've watched the peaks in 2004 move relative to zero over the years, so I know the tape as been recomputed -- at least once. But I don't know where the numbers we are using for 2007 come from. (This would mean that my eyeballs see us as not there yet.)

[Seke Rob]

Chris, is this line right in your [first time seen] article "Due to my work on PIOMAS gridded data I'm convinced that the transition to a mainly MYI pack can now be considered largely complete." Transition to FYI I'd think.

[Chris Reynolds]

Seke,

Thanks, corrected.

[crandles]

>"In the same spirit of inquiry, crandles, would it change your willingness if the effective date were August 31, 2015, instead? (I'm not offering, just asking!)"

It is obviously a lot more likely at 31 Aug 2015 than 30 June 2015 so obviously that would change the odds and bet size I would be prepared to accept. I think 31 Aug 2015 is too far into my uncertainty zone that I am not even sure which way I would want to bet. Maybe tend towards more likely to be above 1M than below but it is far too uncertain to be keen to bet on it.

I have 4 bets with Dr Connolley for £100 each where I am betting on lower ice than him but remaining three are for average of 3 years being less than numbers like 3.94 M Km^2 September average extent.

[Jim Williams]

Their Season Summary is out: http://nsidc.org/arcticseaicenews/

I think I want to start collecting statements like this one, as it isn't the first x of the x I've seen lately: "The six lowest September ice extents over the satellite record have all occurred in the last six years. "

[L. Hamilton]

"The question then would be, has the anomaly for 2007 been recomputed for the purpose of our comparison?"

Jim, not sure if I'm answering your question, but the CT anomalies (like temperature anomalies) are calculated as
{this day's value} minus {mean value for the same day across all years of the baseline period}.

So, the means are more or less constant (with small complications from leap years) and repeating for every year in the CT time series. It wouldn't make sense to shift the baseline dynamically, though from time to time people start over and rescale the whole series using a different baseline.

A visual way to put it: a scatter plot of CT area vs. day of year for all years looks like this:
http://img.photobucket.com/albums/v224/Chiloe/Climate/anomaly_demo1.png

But if we graph the means (anomaly baseline) with a point for every day of every year, all 12,000 points trace out a single curve:
http://img.photobucket.com/albums/v224/Chiloe/Climate/anomaly_demo2.png

[Jim Williams]

Thanks Larry, but the answer I'm looking for (or it's negation) would be of the form the "maximum negative anomaly x which we have been using for 2007 used the baseline y; which is (not) the same as the baseline we are currently using for 2012."

The question is, are we comparing apples to apples?

[Chris Reynolds]

Jim Williams,

Perhaps I'm not following you at all but: Surely we want to use a single baseline and stick with it. i.e. not change the baseline as time proceeds. I use 1980-99 in my work, other may use different, it's a simple scaling matter to change from one baseline to another. But the key thing it not to move the baseline forward as the process drives changes.

So the baseline for 2012's anomalies is the same as that for 2007, or for that matter 1985.

[Jim Williams]

Chris, what we want and what CT does are two different things.

I agree with your principle, though I understand they have the problem of a very short baseline.

[Dan P.]

Jim - I think the confusion is that it looks as though you could be saying that on the current graphs we're all looking at, CT is using different baselines at one time. We all agree that's a terrible idea and so does CT since every graph they produce for a given year has a single baseline. (currently 1979-2008).

I think what you're actually saying is that CT or NSIDC shouldn't update their baselines periodically, given the obvious trend, since that steadily minimizes the actual ice loss from averaging over the trend. I agree as well, but also agree with your comment about their motivations (having a short baseline).

However I don't think it's particularly misleading unless you're very focused on the specific anomaly value; the absolute values of the area/extent graphs are right there, and dramatic enough. And I don't think anyone is remembering anomaly values from graphs 5 years ago and getting confused.

[Chris Reynolds]

Jim

Ahhh, I see what you're saying. Sorry, can't help. I ignore the CT anomalies and just use my own calculations. At least that way I know exactly what's going on.

[Artful Dodger]

Jim, look at the content of the file:

http://arctic.atmos.uiuc.edu/cryosphere/timeseries.anom.1979-2008

1985.7480  0.2239319 5.5354614 5.3115296
2007.7479 -2.1007576 3.2107720 5.3115296
2012.7479 -2.4903851 2.8211446 5.3115296

The last column is the daily mean, and is the same for the same day each each 1979 - 2012, after adjusting for leap years.

The apple moves each time they recompute the baseline period.

[bluesky]

Following Twemoran advice, I wrote to all London MEP (8 representatives) a little more than 2 weeks ago, summarizing the impact of the Arctic amplification(on permafrost, methane hydrate and Greenland ice sheet) and the impact on NH climate with the slowing down of the jet stream and more extreme weather (+ further down the line potential issue on food security) I also attached the "Weird winter mad March Part 2" video with extract of numerous scientists of which Jeff Masters and J. Francis to illustrate the impact on NH climate. And finally I mentioned that despite IPCC 2007 was 50 years behind the 2012 melting, the European Commission and its climate policy commissioner was basing its policy on IPCC 2007. For the moment I have had only one answer, well not really an answer, this MEP wrote that he transferred my request to its colleague member of the relevant committee! Don't know what to do to motivate our representatives, or am I being too impatient? ( I am not used to write to our elected representatives)

[idunno]

(Off topic)

Not sure if this helps...

http://vvattsupwiththat.blogspot.co.uk/

...but I found bits of it funny.

(On topic)

I presume that the 1979-2008 baseline was not being used in 2007. I believe that climatologists like to use a 30-year period for temperature data, to eliminate random noise. (This comes up regularly, elsewhere, whenever a septic wants to use the last 14 years as a reference point.) Now they have a 30 year baseline from 1979-2008, I presume CT stick with this.

My prediction for 2013... Septics will have adopted a 15 year baseline for temperature comparisons.

Ice free prediction... Mine dates back to 2011, when I thought the Arctic would be ice free by 2014 +/- 3 years. Based on thinking that Maslowski is probably right, but was using data up to 2006, so not including 2007 data. (Incidentally, until recently, Wadhams was basing his predictions on thinking Maslowski was right. He (Wadhams) has only recently come/been pushed forward as an ice-free prophet in his own right)

A further note on predictions... Zwally's.

In 2007, Jay Zwally, talking to a journalist, said something like "Well, 20% of the ice disappeared this year. If it goes on at this rate, it will all be gone by 2012." - a statement of fact, not a prediction.

This has been misrepresented extremely widely, most notably, on the WUWT sidebar (with associated story from May 12). I had, however, been looking forward to Tonino's September 22 report on Arctic Sea Ice.

As his May 12 piece begins, "Its [sic] always important to remember what has been predicted by the elders of science, and to review those predictions when the time is right". Then four months of a clock on the sidebar ticking down to September 22.

Then silence.

WUWT?

[crandles]

WUWT?

Didn't you know they have a god given right to always be waiting for the imminent recovery?

[idunno]

One last September SIE prediction worth mentioning:

http://neven1.typepad.com/.a/6a0133f03a1e37970b017744cf5360970d-pi

Eyeballing this, it looks like IPCC4, from 2007, predicts around 7M km2.

This should not really surprise anybody much. The IPCC4 report's suggestion for how much sea level will rise due to increased Greeenland Ice Sheet melt is zero.

The IPCC is a deeply conservative organisation. QED.

Anybody referring to the IPCC as "alarmist" is probably in need of psychiatric assistance.

(P.S. I have several times this evening tried to access the Climate Progress site. This brings up a message that it is infected by malware, and I should not proceed. If anybody here has a way of communicating this to CP, I'm sure they would be grateful.)

[Neven]

PIOMAS has been updated. Looks like the minimum was 3263 km3. Post will soon follow.

[L. Hamilton]

So here's the bar graph on PIOMAS volume:

http://img.photobucket.com/albums/v224/Chiloe/12_Climate/sea_ice_PIOMAS_min.png

to go with the extended/NSIDC extent:
http://img.photobucket.com/albums/v224/Chiloe/12_Climate/2012_sea_ice_NSIDC_extended.png

and north/south CT area:
http://img.photobucket.com/albums/v224/Chiloe/12_Climate/2012_sea_ice_CT_min.png

Also, NSIDC area and extent cycle plot:
http://img.photobucket.com/albums/v224/Chiloe/12_Climate/2012_Cycle_Arctic.png

[Neven]

Thanks, Larry. Your PIOMAS bar graph is in the update. I'm also putting it on the ASI Graphs page, together with the NSIDC SIE bar graph and the CT graph (if I can find the link).

[wayne]

Sam and sea ice fans , look at what it looks like from below:

http://www.plongeurs.tv/Ils-ont-plonge-sous-le-pole-_v85.html

Extraordinary scenery from Ghislain and friends...

This is what I wrote in 2010 from my main web page:
-------------------------------------------
"Sea ice is an expression of –11 C air temperature

~ Close to the Pole and old notion is confirmed

~ NSIDC forgets to mention: thin ice melts fast!

It is known as the breaking point, when Arctic Ocean ice turns from consolidation to a more fluid state. Years of observation has revealed -10 to –15 C common to spring ocean ice break time. In
Other words, when this happens ice plates flow and collide much more frequently, rather difficult to live on, let alone travel. Now scuba divers from a fantastic expedition near the Pole provide some insight:

“Aujourd’hui a pratiquement été un jour blanc, même pas d’éclaircie devenue habituelle en soirée. Nous avons trouvé un nouveau site de plongée, très proche du précédent mais encore différent. Nous voyons très bien maintenant la banquise fondre par en dessous : elle se désagrège quand on la touche, il y a un mélange d’eau salée et d’eau douce, on peut facilement décrocher des blocs entiers.”

Its been –9 C outside, and the divers saw the ice melt, literally fall apart from the mere touch, fragile, and full of biological activity. This shows, despite, what appears to be no melting on surface, a loss of balance, between the powerful heat in the Ocean and the colder atmosphere, a balance broken from the higher sun.

Back in frequent fall times, I found that sea water freezes when air equals or is colder than –11 C, especially in no winds. The reverse may be so, by conduction air warms the ice, to the point where it sets the bottom from freezing to melting. Thus sea ice. Is an expression of cold air, when gone, so is the ice."

[GeoffBeacon]

Yesterday's NSIDC press release says

Climate models have suggested that the Arctic could lose almost all of its summer ice cover by 2100, but in recent years, ice extent has declined faster than the models predicted. Serreze said, “The big summer ice loss in 2011 set us up for another big melt year in 2012. We may be looking at an Arctic Ocean essentially free of summer ice only a few decades from now.”

Comments?

[Dromicosuchus]

Thanks very much for the info, Wayne! That's very interesting; I wonder if that ~-11 ˚C temperature would change with different ice thicknesses? That is, would warmer air temperatures be needed above thicker multiyear ice vs. first year ice before the fragility you mention started to become apparent?

On another note, that video is breathtaking; I'm particularly interested by all the beautiful, silvery air bubbles (I presume?) visible on the underside of the ice. I highly doubt that they have any real importance in terms of the behavior of the ice, but I do wonder where they come from; surely, no gases released from further down in the water column would make it that high without being dissolved. Air trapped under the ice by wave motion, maybe, or perhaps a much gentler version of the famous diet Coke + Mentos "reaction," with the underside of the ice providing a highly textured substrate that makes it easier for gases to emerge from solution.

[wayne]

Your welcome Sam, -11 C changes with the weighted thermal flux of the ocean on its surface. If the sea becomes warmer, freezing requires much colder air. In time as AGW progresses, the sea will warm as well, this means air surface temperatures will have to be colder to create sea ice. Eventually the average temperature of Arctic air will fail to be cold enough, at this point the Arctic ocean will be open year round.

The bubbles were from the divers. The colours were spectacular, but the irregular appearance of sea ice bottom and brine formations were like being in a gothic cathedral, as I recall the divers comments. I recommend the video for any avid sea ice followers.

[Jim Williams]

Thanks Lodger! I think I'll bookmark that link.

[Chris Reynolds]

Geoff Beacon,

"Comments?"

Serreze could prove to be right. Which means I might have changed opinion on this matter too early.

[NeilT]

Thanks all for that discussion on the anomaly baseline for CT. Clearly they had to update all anomalies as they could not have had a 1979 - 2008 baseline in 2007.

I found an old image of the 2007 anomaly track rather than a link. It very nearly broke 3m back then. Now it is adjusted as they realigned the baseline.

It just means that it's not possible to keep the "number" from year x and compare it with the number from year y. You must always go to CT and get the latest year x number to compare with year y.

Useful to know.

[Ethan O'Connor]

The mean September SIE (SSIE) reached this year may have particular significance.

Massonnnet's work on interpreting model output for future sea ice state (http://www.elic.ucl.ac.be/repomodx/elic/index.php?id=73) has identified an extent threshold that initiates a marked acceleration in SSIE decline across models:

"...we find that the CMIP5 models projected anomalies of September sea ice extent (SSIE) (with respect to their own 1979–2010 climatology) are linked in a complicated manner to the 1979–2010 characteristics of their sea ice cover, owing to an acceleration of the trends (and thus larger anomalies) in SSIE, which occurs at different times during the 21st century, but at a mean SSIE of ∼2–4 million km^2."

[Ethan O'Connor]

Ah, sorry, forgot the source for that quote: http://www.the-cryosphere-discuss.net/6/2931/2012/tcd-6-2931-2012.pdf

[Chris Biscan]

http://www.drroyspencer.com/2012/10/uah-global-temperature-update-for-september-2012-deg-c/#comment-61877

I am Chris there.

I think it's a conspiracy. I think they have worked on a way to use the noise to slightly alter there data set. They said the warming is the same just the recent extra record warmth is spurious.

Yet there is literally ZERO EVIDENCE of it being spurious.

http://i174.photobucket.com/albums/w109/frivolousz21/compday-195.gif?t=1349393271

NCEP has spurious warming to it appears.

I think climate crook Christy and Dr. Roy have no room left to hold their personal position. And when you believe a lie you will go to the end of the Earth to protect if your self identity is tied to it, and there's is, there entire life's work is tied to this lie.

And there own data set is vehemently disproving it.

While all other evidence supports there data set.

Now they claim up to 0.2C of spurious warming?

I guess the record level energy imbalance globally was changed by David Copperfield.

Unlike Sea Ice there is very few people who can contest what they are doing.

I am so discouraged by this, If I am insane or that bias then I guess I am wrong.

But I can't even find one piece of evidence I am wrong.

On Americanwx of course no one says a word except to act like I am nuts.

Please check this out and give me some feedback.

[wayne]

Sea ice anomaly chart on Cryosphere Today seems to be stuck at the bottom -2.5 km2, which is quite expected given the roundness of the remaining pack. There is no gap of sea water between 2 large ice sheets, this makes the winds over wide open water more difficult to tame. Outside of the pack area, Arctic weather is likewise very warm with North winds not as cold as the word use to mean.

[Frank Dantuono]

Neven et al.

I've been tracking NSIDC SIE dailies this year and have a question about the anomaly from the 1979-2000 base line.

Is the anomaly data the mean of the 5 day rolling average they use or the mean of numbers from the same day?
Because if the numbers posted are the mean of the 5 day rolling average, then the anomaly would be 3.65 million km2 for Oct 4th 2012. Same day mean would make the anomaly "only" 3.55 million km2.

[Patrice Monroe Pustavrh]

Hi guys, I have a small problem when trying to calculate NSIDC september average myself:
If I use daily values from nrt file, I get 3.58 mio km2 instead of 3.61 mio km2. What am I doing wrong ?
Any help would be well appreciated.

[Wipneus]

Patrice:

This was discussed in the record dominoes #8 thread. Peter Ellis came with the best explanation, the calculation of the low 15% threshold:

http://neven1.typepad.com/blog/2012/08/record-dominoes-8-nsidc-daily-sea-ice-extent.html?cid=6a0133f03a1e37970b017d3c7aafc2970c#comment-6a0133f03a1e37970b017d3c7aafc2970c

[idunno]

Hi Neven,

Now that the results of the predictions polled on the right sidebar are all in, may I suggest another one?

I would be interested in a poll of when people here expect to see an ice free Arctic...

2013-2019 (2016 +/-3)

2020-2029

2030-2039

2040-2100

Never

[Kris]

Record-lovers,

Record high of exactly 15,0 °C for the 5th of October at Big Delta/Delta Junction in Central Alaska.

[Neven]

idunno, that poll will be created soon. Good idea.

[Jim Williams]

Neven, be sure to define "ice free." This seems to be a moving goal-post lately.

Excluding bergs calving off Greenland, I've already claimed for 2013 -- though I admit this is mostly what I see as worst case.