PIOMAS August 2016

Another month has passed and so here is the updated Arctic sea ice volume graph as calculated by the Pan-Arctic Ice Ocean Modeling and Assimilation System (PIOMAS) at the Polar Science Center:

With a slightly above average drop during July 2016 is maintaining its position relative to other years. Although the monthly decrease was smaller than most years of the past decade, the difference with 2012 went down from 1136 to 924 km3. The difference with 2014 went up by a large margin, from 1218 to 1977 km3, but the difference with 2015 was almost halved, from 1852 to 1020 km3. This was to be expected, of course, as melting conditions during July 2015 were perfect (see last year's PIOMAS update).

Here's how the differences with previous years have evolved from last month:

2016 is currently 4th lowest, after 2010, 2011 and 2012.

Wipneus' version of the PIOMAS volume graph clearly shows this year's steady drop, closely following the 2010 and 2011 trails:

Last month I speculated whether whether the trend line on the PIOMAS sea ice volume anomaly graph would drop some more and leave the light grey band like it did in 2010, 2011 and 2012, but there has been an uptick instead taking the trend line back to 'just' 1 standard deviation territory:

Looking at Wipneus' comparison maps that show the differences with 2010, 2011, and 2012, we can see that the main difference lies still on the Siberian side of the Arctic (red means ice is thicker there now, blue the opposite):

There is a lot of melting potential in the East Siberian Sea region, extending into the Central Arctic, that could make this year end up close to the 2011 minimum, which is second lowest after the 2012 record lowest minimum. Here's a close-up of that region on the latest Uni Bremen sea ice concentration map:

As for average thickness, here's the PIJAMAS graph based on my crude calculation of PIOMAS volume numbers divided by total JAXA sea ice extent:

2016 is definitely following the path of other post-2010 melting seasons, from which 2014 and 2015 deviated. Interestingly, the trend line follows that of 2013 quite closely. Perhaps this is because the 2013 melting season was also characterized by a series of cyclones that dispersed the ice pack. It could just as easily be coincidence, of course.

On the thickness plot from the Polar Science Center: the distance between 2013 and 2016 is somewhat larger, but here too the 2016 trend line is more or less following the path of other post-2010 melting seasons that marked the new volume regime:

As with other metrics, it will be interesting to see whether this year can end up in the top 3 lowest volume minimums somewhere next month. Remember, after a spectacular start to the melting season, things slowed down due to a switch in weather conditions. Only now has high pressure returned to the Arctic (more on that in the next ASI update), but it has been mostly low pressure since May, which means cloudy skies. A lack of melting momentum has been compensated, however, by early melting of the land snow cover and exceptionally high SSTs across the Arctic. And so 2016 can still match big melt years like 2007 and 2011.

I can't escape the feeling that the Arctic sea ice has dodged a bullet this year. And if the Arctic sea ice dodges a bullet, so do we. That's the good news. The bad news is that there will inevitably be more bullets. The bullets aren't the problem. It's the gun.

Comments

[Neven]

Over on the ASIF a forum member has set up a poll where you can vote on what you think the PIOMAS volume minimum will be come September. Be sure to vote!

[P-maker]

Neven,

the dwindling Arctic sea ice was just featured prominently during the 2016 Olympics opening ceremony in Rio. Their advice was to sow more seeds, plant more trees and save more lives. Our commercial TV channels are having a hard time swallowing these messages...

Have a good evening

[Neven]

the dwindling Arctic sea ice was just featured prominently during the 2016 Olympics opening ceremony in Rio.

Really? Wow, that's amazing.

[Rob Dekker]

Neven, about the Olympic opening ceremony, here in California we got to see that as one of the last ones on the planet.

Even though the NBC commenters did not say a word about the global warming issue raised during the event, and even though NBC's coverage of the event was interrupted by many car ads and even an Exxon Mobil ad (I kid you not) I still found it inspiring that the event raised awareness for the issue that is central to our efforts here, and proud to be part of the platform you created to share that with the world.

Thank you Neven.

[John Christensen]

Thank you for another great PIOMAS update Neven!

This year is certainly interesting given the very unfavorable conditions for sea ice since October last year, which then switched to being quite favorable sometime early/mid May, making the outcome in both extent and volume by Sept challenging to assess.

My own hope is that the current placement of HP and LP will continue compacting the ice towards the CAA and north of Greenland, as this could leave a larger surface open for new sea ice to form, overall with potential positive impact on sea ice volume gain in the fall.
However, the downside is that with any further compaction it becomes quite certain that this year will end in top-three extent-wise, where e.g. 2013 saw continued dispersal of sea ice in August, keeping extent numbers relatively high.

[John Christensen]

I would also just note that July 2016 saw less volume loss than 7 of the last 10 years from your list above, which is quite well from a sea ice preservation perspective..

[wayne]

"has been an uptick instead taking the trend line back to 'just' 1 standard deviation territory:"

Uptick? wow, I am definitely not impressed. Unless this PIOMAS graph has an explanation for it which I would like to read about. Is this graph a continuation from last month? If so, wow, more ice hey???

Also PIOMAS team should already use sea ice velocity to help measure volume:

http://eh2r.blogspot.ca/2016/08/massise-number-of-goodbye-waves-dont.html

The compaction from mini dipoles can only make things worse.

[navegante]

My own hope is that the current placement of HP and LP will continue compacting the ice towards the CAA and north of Greenland, as this could leave a larger surface open for new sea ice to form, overall with potential positive impact on sea ice volume gain in the fall.
John C., I find your reasoning somehow absurd.
Currently the pattern you describe is forcing a lot of ice toward hot ocean areas. This ice is going to melt out.
Also, in a previous post you contend that the current pattern is not causing real melting but just pushing the ice together. Following this thought (right or wrong), the area you say available for new sea ice is equal to the available area should compaction not happen. With a difference: if the new sea ice is formed at the periphery rather than within the pack, it may melt faster next year.
Not sure if you fall into the "ice pushed against CAA and Greenland is protected" illusion: this ice is exported to Beaufort sea and Greenland sea as always. Its safety however depends on summer weather, which comes warmer and warmer as years pass by. That is why the Arctic is losing old ice and volume.
However, heat lost during fall is greater for a compacted ice pack. But here again the total heat loss depends much more on weather from October to April, the late-refreezing effect being a small fraction of the total heat balance. And weather comes warmer every year.
What you can hope for is a cold, very snowy Winter 2017 with slow polar drift and Gyre, low Fram export, and a cold 2017 spring/summer weather that protects the peripheral ice. That would delay any potential minimum below 2012 probably until 2020, but in the meantime the climate keeps becoming warmer.

[Protege Cuajimalpa]

It was really interesting to see the importance that the 2016 Olympics opening ceremony gave to Global Warming. The message of cities flooded for sea level rise is one example.
Unfortunately, actions like the planting of seeds by the athlets, are incompatible with the huge fireworks that follow. The true is that many of the trees planted will have difficulty surviving.
On my humble opinion, we (humans in general) are not completly aware that global warming is real. We, as a society, are acting like if global warming is a science fiction movie, not a real danger. Hope we change our actions (not just a message) in the near future.

[John Christensen]

Hi navegante,

Currently ice drift models shows the main compaction going towards Q. Elizabeth Islands, which is fairly safe - at least in the short term.
But we will see..

wayne,

Regarding the 'uptick'; This is an anomaly model, not an absolute ice volume chart.

[Cato Uticensis]

Hi everyone and thanks Neven for this latest update. It's a thrilling end of melting season, open to quite different scenarios in my view: (almost) everything is possible.

Current conditions are leading to significant compaction due to the concurring action of a HP on Beaufort and CAA and LP on Laptev and ESS. On the other hand according to DMI thickness maps, there's much more ice today than 365 days ago, and this cannot be disregarded.

In line with the calendar, models show temperature dropping in the next 7-10 days, with prevailing LP conditions and (so far) no super-cyclones expected any time soon. Conditions that in my view are conductive to compaction much more than melting.

As usual, only time will tell.

[Neven]

On the other hand according to DMI thickness maps, there's much more ice today than 365 days ago, and this cannot be disregarded.

I think it's quite safe to disregard it, just like the output from the ACNFS model (which shows a much lower thickness than is probable). Either way, we'll see in Oct/Nov when CryoSat-2 data becomes available again.

[Cato Uticensis]

Neven is there any reason why the comparison between outputs from the same model relevant to different years should be disregarded? Thanks for your clarification!

[Neven]

After the mild winter, and 2016 being lower than 2015 on practically every extent/area graph, despite weather conditions, there is no way that 2015 is so much lower than 2016 as the DMI volume graph suggests. Remember, the 2015 melting season followed the culmination of the 2013/2014 'rebound', and apart from July, didn't have any extraordinary weather conditions either.

So, 2015 a bit lower than 2016? Sure, why not? But 2000 km3 lower, whereas the generally reliable PIOMAS has 2016 1000 km3 lower than 2015? No way, that's a difference of 3000 km3. Forget it, that's not realistic.

But again, I'm not saying it should be disregarded. I'm saying I think it's quite safe to do so. We'll see in Oct/Nov when CryoSat-2 data becomes available again.

[Cato Uticensis]

Thanks Neven, quite sensible points as usual. The comparison between today and one year ago in terms of DMI thickness maps, in fact, is hardly compatible with the extent data from the same DMI which show quite a significant lower extent. Sometimes it feels like the more you look the less you know :)

[wayne]

HI John,

"Regarding the 'uptick'; This is an anomaly model, not an absolute ice volume chart."

I am quite aware of that, it is baffling to say the least, June allegedly has a downtick, after the same June many said was guaranteeing 4.6 million to above 5.2 million at minima, and July, with strong melting has an uptick! If you are not confused by this,
I am glad to explain that this does not make any sense.

[wayne]

Let's play my unfavorite game, Conservatively. Lets say from now on, 2016 will have same melt numbers as 2015, a cautious estimate, then we are dealing with 3.9 million km2 at minima. #2 greatest. The Met Office is shining for now, but the big daily drops are not over.

There is beauty in dying sea ice, once existence shinned bright, back to infinite darkness.

http://eh2r.blogspot.ca/2016/08/individuals-always-melt-away-to-darkness.html

[Rob Dekker]

Cato,
Do you have the DMI thickness maps from 2015 and 2012 from around this time ?
Would be interesting where these exactly these years had less ice.

[Rob Dekker]

John said :

I would also just note that July 2016 saw less volume loss than 7 of the last 10 years from your list above,

I noticed that too.
Kind of puts the emphasis on Neven's remark that :

"I can't escape the feeling that the Arctic sea ice has dodged a bullet this year. "

I could not agree more.

[John Christensen]

On the DMI volume chart:

They significantly enhanced ice concentration and other algorithms in June this year - I have been following the volume development against PIOMAS to see if they correlate better, as prior years have not been accurate on the DMI volume chart, especially 2014 and 2015.

[Sam]

Changing a model to make it more concordant with another model only makes the two models more similar in results.

Doing this tells nothing about how concordant or how dissonant each model is to the reality they purport/intend to model.

Measuring a model against another model similarly tells little about reality. They can be in tight agreement and both be wildly wrong. They can each be widely in disagreement with one another and still all be wildly wrong about reality.

The one thing that is certain is that the many ice thickness/volume models disagree wildly with one another. That gives me no confidence in any of them.

I suspect, but cannot support or prove that each of the models is suffering to varying degrees to a form of error that is all to common in other fields. In several fields people and researchers make the blunder of averaging logarithmic values (e.g. pH or simple logarithms of parameters) and then presuming that the result has meaning. It doesn't. It never has.

The average of logarithms is a meaningless number that is exceptionally poorly correlated with the logarithm of the averages of numbers.

The only time it would make sense to average logarithmic values is when the processes involved act directly on the logarithmic value of the parameter.

In the case of the ice, the shattering of the ice, it's separation and the freezing of the waters between produces an ice thickness distribution that is quite complex. I don't believe it is anywhere near as bad as a logarithmic distribution. But it is still highly non-homogeneous and a very important component of the modeled analysis. And that compound field behaves considerably differently than any simple average can portray.

The various tools and techniques to measure thickness vary in their performance in measuring the average thickness with a scale dependency in many cases.

Even when they do a good job, the behavior of the complex assemblage of thicknesses is nothing like the behavior of the actual component parts.

Thin ice melts out early exposing thicker ice to attack on a greater surface area. The relative dimensions of these component parts is important.

Add to this the differing densities and salinities of the ice depending on a number of factors. The result is a reality that is extremely hard to model with fidelity, and which is very prone to errors as the conditions approach the extremes, such as the nearing of the terminal breakup of the Arctic sheet. Uniformity is rapidly falling apart, leading to vastly greater complexity in the real conditions, and increasing difficulty to successfully model.

We see that playing out all over the Arctic, but most especially in the Beaufort Sea.

[John Christensen]

"Changing a model to make it more concordant with another model only makes the two models more similar in results."

I wasn't aware and do not suppose the DMI team is trying to make their volume model more concordant with the PIOMAS model, so please share any info you have on this.

[wayne]

I am quite suspicious that PIOMAS may be measuring volume from "goodbye waves". Piomas data graph may be useful only for a very great long running period outlook. Meanwhile JAXA is by far the best, appears to be oblivious to nature's tricks, they do very inspiring good work, love to see more of this kind of effort.

In addition, I am not sure if 2016 "bullet" isn't continuing to do damage. The North Atlantic Front is surging wit activity not favourable to preserve sea ice.

http://eh2r.blogspot.ca/2016/08/atlantic-front-great-movement-super.html

[Sam]

John,

The only indication I have of that is the compound information that a) DMI's ice volume was becoming increasingly discordant with reality and your comment that b) they are changing factors and as a result becoming more concordant. However, as we have no reliable direct measures of volume the assessment must be to something else -e.g. One of the other models; with PIOMAS being the most prominent and hence most likely.

Perhaps it is fully independent, which is better. And I mean no slam on the modelers by this. They have a tough job, made harder by the biases that can all too easily creep in.

However, there is always the risk of concensus bias creeping in, which the modelers all have to work to avoid.

[TenneyNaumer]

Does anyone know why the US Navy's graphs seem to be offline?

http://www7320.nrlssc.navy.mil/hycomARC/arctic.html

[Jim Hunt]

Tenney - They've increased security! Try this link instead:

https://www7320.nrlssc.navy.mil/hycomARC/arctic.html

See also:

HYCOM vs ASMR2 Imagery

on the forum:

[Bill Fothergill]

@Jim

To my ageing eyes, you initially appeared to have repeated the link given by TN - until the "s" in "https" finally swam into view.

RE: The ASIF link. I remember looking at that last month and being even more confused than usual. From some of the comments posted therein, you would appear to have been ignoring someone whilst simultaneously following them around.

Does that mean you're becoming bi-polar?

(OT: I see that Northabout has just left the sheltered cove in Ostrov Pilota Makhotkina.)

[Rob Dekker]

Bill said

Does that mean you're becoming bi-polar?

Bill, that is quite ad-hominum.

[Neven]

Rob, these guys know each other (from Jim's blog). Bill is just kidding. :-)

[NeilT]

I took a very different view, this year, to our annual obsessive view of the charts, the models and the statistics.

I took a step back and looked at the woods instead of staring at the trees one by one. My assessment? This melt season looked remarkably like 2006. Not exactly the same, how could it be? We have massively less ice volume and a hugely more vulnerable pack. But the season itself, I predicted, would follow 2006.

It's a funny thing but most, not all but most, of the charts on the forum start in 2007. Which really misses a trick.

So what was the 2006 season like?

Massive heat and early melt in the spring
Slow down starting in May and running through June
Fairly average melt in July
Strong and rapid melt in August

And the last part we haven't seen yet. An early stall to the melt in September followed by a very odd event of the polynya in the Beaufort forming, which kept ice conditions variable right up to Sept 18th. However ice re-growth had begun in areas around Sept 12th.

So if the season follows 2006 to the bitter end, then we'll see the strong August melt grind to a halt in about 3 weeks time followed by a bit of toing and froing...

That will put 2016 somewhere in 3rd to 4th place, I believe, but with massive damage done to the older ice through the decimation zones in the Beaufort and the Beaufort gyre helpfully transporting all that thicker ice into it.

To me, that means 2017 should, all things being the same, be pretty close to the black swan event we're all waiting for.

Of course I could be wrong, but I've put a monthly post up on the forum every month so far, surmising what it would be like if it followed 2006. So far it has.

Time will tell but I'm not expecting anything dramatic, the DMI 80 North temps are firmly heading south towards freezing and I expect them to make it by the end of the month.

[John Christensen]

"the DMI 80 North temps are firmly heading south towards freezing and I expect them to make it by the end of the month."

Following the normal temp trend line, DMI 80N should pass 273K no more than a week from now..

[EthonRaptor]

How much Ice is going to b left below 75 N (Eli says a flat zero which is scary). How much below 80 N. Will it be possible to sail blue water to closer than 85N to the pole (looks like it) One of the problems with sea ice charts is that they show ice you know in March is going to vanish in August, e.g. Hudson's Bay.

[Hans Gunnstaddar]

"To me, that means 2017 should, all things being the same, be pretty close to the black swan event we're all waiting for."

That's my assessment too but maybe not a black swan event, NeilT, but I came to it in a different way. Namely observing there is a repeating 5 year pattern, starting in 07 with a record minima, followed by 2 years of rebound, followed by 3 years of declining minima's culminating in a new record minima during that 5th year.

The same bell shaped pattern has taken place since 2012. That would mean next year, 2017 should be a new record low. Based on the repeating pattern, we should be able to draw a line from the 2007 record thru the 2012 record to determine the 2017 record low or thereabouts.

The repeating pattern ironically appears similar to the breathing pattern of a dying animal. A lower volume of air in the lungs followed by a panic (rebound) finishing the pattern at a lower amount of air, repeating the bell shaped pattern until the lungs are empty and the animal expires, or in this case until Gaia gives up the last of the Arctic sea ice in some future melt season. I don't think 2017 will be unusually low, rather just fitting into the same pattern, i.e. until the pattern is broken.

[Rob Dekker]

Chris said :

On the DMI volume chart:

They significantly enhanced ice concentration and other algorithms in June this year

Do you have some more information about that ?
I see DMI's volume charts are used in denier circles more and more, to claim all kind of 'recovery' statements. To counterbalance such statements, it would be good if there were some more info on DMI's volume graphs.

For example, what kind of ice concentration and other algorithms were enhanced, and how ?
Did they retro-actively adjust past years with the same enhancements ?
Is there an overview of past year DMI volume data, as processed with the same setting of their algorithms, like there is for PIOMAS ?

[Bill Fothergill]

@ Rob D: " ... I see DMI's volume charts are used in denier circles more and more, to claim all kind of 'recovery' statements ... "

Rob, there may be such an example about to appear on Jim Hunt's "Great White Con" blog. I have just asked someone to provide a citation for their claim that, amongst other things, "... the ice volume is now very close to the 30 year average ..."

http://greatwhitecon.info/2016/07/northabouts-great-adventure/

The relevant part lies (pun intended) at the bottom of the comments section.

(PS Pursuant to Neven's earlier clarification, you might notice the bantering tone used between Jim and myself.)

[Jim Hunt]

Rob/Neven,

Actually Bill and I have met physically as well as virtually. Having bumped into each other here on the Arctic Sea Ice Blog we discovered we live within cycling distance of each other.

My "split personality" is a long running joke, although perhaps British humour doesn't always readily translate across the Atlantic Ocean and/or the North Sea?

[NeilT]

Hans, It might be worth stretching the line back to 2005.

[wayne]

Jim is really British, stiff upper lip and really sticking it to the Mail on Sunday which deserves every bit of truth he spanks them with.

So again we see a lowering of JAXA daily extent melts, it is not an illusion, JAXA is capturing a greater melt without numbers, look at their map:

http://eh2r.blogspot.ca/2016/08/expansion-and-dilution-at-once-nature.html

If the CAB drops extent a wee little, it means it lost a great deal of sea ice, thanks to the 15% threshold the numbers do not show........ yet.....

[Hans Gunnstaddar]

"Hans, It might be worth stretching the line back to 2005."

I get your point, NeilT, however the pattern since 07 is now in a 2nd repeat, and overall it has taken place over a 9 year span. That's a track record worth being aware of to see if it continues to be a good minima predictor. If 2017 is a new record and the subsequent next 2 melt seasons rebound, then the pattern is repeating again.

[Cato Uticensis]

I'm not following much as I'm on holidays... Looks like next 7-10 days will be dominated by LP conditions on the Arctic (what a surprise!) including a very deep cyclone forming at about h 96.

Very much will depend on the position of such cyclone, whether it will affect the very low-concentration tongue in ESS-CAB or not.. In the former case further big drops in extent might very well be expected. Otherwise dispersion would probably prevail, thus helping with extent.

From now on, heating from radiation will be less and less significant as weather conditions will prevail. Radiation would probably be negligible anyways, considering the forecasts for the following 7-10 days...

In my very humble opinion 2007 and 2012 are out of reach today, and the real competition is between 2015 and 2016. It will probably be the (super?)-cyclone to determine the third place on the podium...

[wayne]

http://eh2r.blogspot.ca/2016/08/atlantic-front-substantial-evidence-of_10.html

There should be careful study to prove if there is melting where it may not be necessarily measured daily. This may affect some peoples opinion too often mesmerized by the numbers. Here is an example of using 'Goodbye' Waves, where as, the Atlantic front sea ice expansion is being pummelled by warmer sea water artillery daily. The extent numbers may not reflect this. But Goodbye Waves signatures are all over the place, and they are very numerous indicating rapid massive melting.

[Rob Dekker]

Bill said :

Rob, there may be such an example about to appear on Jim Hunt's "Great White Con" blog. I have just asked someone to provide a citation for their claim that, amongst other things, "... the ice volume is now very close to the 30 year average ..."

Yes. I see that exact same comment on a WUWT post (by one Frank Lansner) which also argues with DMI volume graphs (completely ignoring PIOMAS).

DMI, "the gift that keeps on giving" strikes again.

John Christensen, any more info on "They significantly enhanced ice concentration and other algorithms in June this year" and if they retroactively adjusted the data or not ?

[viddaloo]

Hans Gunnstaddar, I find the 5–year pattern makes a lot of sense. Here's my take, based on the annual average extent:

[NeilT]

Hans, get your point but my point was slightly different.

I see a fuller cycle happening. 5/6/7 followed by the trough 8/9 followed by 10/11/12 followed by the trough 13/14 followed 15/16 and possibly 17 leading into the trough in 18/19..

If you also map it to the solar flux, it seems to come in on the 80 - 120 bracket on the rise and fall of the flux. Not at the bottom and not at the top, but in the change states.

http://solarham.net/averages.htm

I have no idea why, but it is what I see. What interests me most is whether the solar lows, allied to the cycle rebound creates a larger rebound (08/09) as opposed to the smaller rebound on the solar peak (13/14).

I guess we have to wait another 3 years for that to all unfold.

[John Christensen]

Regarding the DMI sea ice volume model and the algorithm changes in June, I did ask them both if these changes would impact the volume model and also how the DMI model might differ or align with the PIOMAS model.
And I got a response back earlier this week with these main points, somewhat abbreviated below:

- “Overall, the PIOMAS and DMI ice volume models are similar, but provide each their estimate for the total Arctic sea ice volume

- Both models are based on coupled ocean/sea ice models [I think he meant to say atmospheric/ocean models..]

- Both models have good estimates for sea ice extent and also to a certain degree on the ice concentration, which are based on satellite data captured daily and assimilated into the models – the main difference is the estimation of sea ice thickness between these models

- Ice thickness is a challenging parameter, little in situ ice thickness data available

- The models have differences in choice of parameters, are based on different atmospheric models with differences in surface temperature and surface radiation balance

- Consequently, at times the models are in good agreement, while at other times, e.g. the summer periods of 2014 and 2015, they differ in estimates

- Concerning the changes in OSISAF (sea ice concentration and extent) in June: These do not appear to have had a visible impact on volume estimations, no change in the quality of the OSISAF ice maps has been noticed

- A few individual days, however, did not produce good results, and some assimilation then took place

- For those days, the models were rerun with the assimilated data, but the erroneous ice maps would still have impacted the atmospheric model data for those particular days”

So, based on these responses, there should not have been any changes to DMI ice volume estimates based on the enhanced ice concentration and extent algorithm changes in June.

Regarding deniers referring to the DMI volume chart, I guess this must be due to DMI using a different reference point (2004-2013 mean) compared to PIOMAS (1979-2015 mean).
When looking at the two charts it actually seems like DMI is showing greater volume loss in July than PIOMAS..

[Jim_dowling]

Is another Great Arctic Cyclone (GAC) brewing for 2016?

If it comes about as forecast, it will be comparable to the original GAC from 2012 which had a minimum central pressure of 974.5 hPa.
http://psc.apl.washington.edu/zhang/Pubs/Zhang_etal2013_cyclone_grl50190.pdf

[Jim_dowling]

I should mention this is the GFS forecast for Tuesday 16th August...

[Neven]

Jim, I don't know what the 974.5 hPa for GAC-2012 is based on, as the lowest I saw it go at the time was 963 hPa.

I'll have a new ASI update up tomorrow, in which I'll discuss this cyclone.

[John Christensen]

The GAC;

Yes, I noticed that also, very interesting! - will hold on to comments for the ASI update..

[Jim_dowling]

Neven, it was just the first figure I read in the paper linked - although on closer analysis there is also a 966 hPa figure there in the paper. Different sources. Anyway, this looks like a big storm that will cover the whole Arctic....

[Hans Gunnstaddar]

Thanks for putting that together - Great graph, viddaloo and easy to see the repeating pattern. However, even if I + the screen several times, still missing right side. Any way to get all of it on there with a repost?

[Hans Gunnstaddar]

Interesting analysis, NeilT.

"I guess we have to wait another 3 years for that to all unfold."

Definitely agree. Should be fun to see how it plays out.

[Rob Dekker]

Thanks John, nice that DMI replied to your inquiries.
Seems from their notes that the OSISAF extent changes that they applied did not affect the volume numbers in any significant way (at least according to their own assessment).
What remains is the differences between PIOMAS and DMI volume charts.

Regarding deniers referring to the DMI volume chart, I guess this must be due to DMI using a different reference point (2004-2013 mean) compared to PIOMAS (1979-2015 mean).

Yes, that is one thing. But there are more fundamental differences between DMI's Hycom/CICE model and PIOMAS.
For example :

- DMI volume puts 2016 at this time in the middle of the (2003-2016) pack, while PIOMAS puts 2016 at 3rd place (more in line with the extent ranking).
- DMI puts 2007 volume as being lower than 2016. PIOMAS puts 2007 much higher than 2016, reflecting the higher ratio of MYI versus FYI in 2007.
- DMI puts ice volume loss from May to end of July as the smallest in the entire 2003-2016 record. We know that 2016's meting season was not conducive to melt, but smallest volume loss in 13 years is simply not plausible.

[Bill Fothergill]

@ Rob D
"...Yes. I see that exact same comment on a WUWT post (by one Frank Lansner) which also argues with DMI volume graphs (completely ignoring PIOMAS).

DMI, "the gift that keeps on giving" strikes again..."

This would be the same DMI that Watts was castigating a few months ago when a new algorithm for Extent calculation was introduced.

Ah, good old hypocrisy: nothing smells quite like it!

[wayne]

Hi Rob,

A couple of notes:

DMI and PIOMAS need a lot of work, I never use their volume data for analysis. I rather find it strange when extent drops a lot and volume doesn't change correspondingly.

JAXA sea ice extent rapidly is approaching 5,2 million km2, it will be attained in a couple of days, it is now very safe to say that one NASA sea ice model needs some serious reviewing. Is very good news, because they can find out how it went wrong.

The average drop in extent from now until minima (2008-2015) is 1.44 M km2. 2016 being not an average year, should be at least below 4 M, 2nd place. If it has the same extent drop than 2012, 1.76 M, 2016 would make the Met office model shine, but 2016 is not 2012. and has remarkable, unique circulation features.

Jim Dowling's long waited GFS and ECMWF Cyclone would seriously break up the North Pole area sea ice, already likely in its worse shape ever:

http://eh2r.blogspot.ca/2016/08/scant-near-north-pole-visuals-sea-ice.html

I would estimate a vast more open area of sea water right over the Pole because of the scattering properties of sea ice associated with sea level rise, a sea water surge at centre of Cyclone which has happened earlier this season with much more consolidated sea ice and much smaller 990 mb Cyclone:

http://eh2r.blogspot.ca/2016/07/see-through-cyclone-not-so-much-clouds.html

You can observe the greater water zone under the 'see through cyclone' centre . Much more open water at the Pole may make some news, but the over all picture is worse than a hole at the Pole.

[Susan Anderson]

"Extratropical Cyclone Over Hudson Bay"
http://earthobservatory.nasa.gov/NaturalHazards/view.php?id=88566&src=nha

Down in the US of A it's rather hot. Also Greenland melt has been rather high lately.

[Susan Anderson]

hmmm. Fossicking around at Earth Observatory, it also had "Melt at the Base of the Greenland Ice Sheet" dated 4 August 2016

http://earthobservatory.nasa.gov/IOTD/view.php?id=88505&eocn=home&eoci=iotd_grid

[viddaloo]

Hans Gunnstaddar, I think you can just right–click and choose 'Open in New Tab' or 'Download' on the graph, or on this link: http://i.imgur.com/seBIoH7.png

I'll attempt a repost per your request:

[navegante]

You are basically showing the negative trend of ASI with two dips followed by subsequent recovery years that happen to be apart five years.
If you zoom out on the y-axis and show me the same sort of dip in 2002 I buy your 5-year cycle, otherwise you are just filtering out a daily extent plot with a trailing average of 1 year (you could use a better centered, weighted filter by the way). That neatly shows the downward trend I must say.

[navegante]

Perhaps something really valuable that your plot shows is that the 1-year averaged extents have never intersected in a five-year period. Very nice way to show the downward trend. Due to the huge anomalous dip of ASI extent during April and May 2016, we safely saw we won't see an intersection in at least another year. Then we dont know...But still all this does not validate the existence of 5-year cycles.

[William Crump]

I have not posted for awhile. Are their any people left who are predicting "ice free" by 2019? Even with "ice free" meaning a million km2, odds do not look good for people with this prediction but they still have 3 more tries - not happening this year.

Every time a new month's data is added the extrapolation line extends out another year or two.

Remind me, what year did the extrapolation line suggest the arctic would be ice free in September after the September 2012 minimum?

The Central Arctic Basin does not appear to show much change in extent over last 5 years.

ftp://sidads.colorado.edu/DATASETS/NOAA/G02186/plots/4km/r11_Central_Arctic_ts_4km.png

Since the Canadian Archipelago and other areas will have a few 100,000 km2 or so of ice at the minimum the Central Arctic Basin will need to drop to around 800,000 km2 or so to get to the 1,000,000 mark.

I still think using arctic wide ice area data for the line drawing exercise gives a false reading of ice free predictions. Is there a data set for the Central Arctic Basin for volume that can be used to draw lines?

Situation still looks dire for Arctic ice - not sure it matters which year it becomes "ice free" as it does not appear to have a chance of coming back to pre-2000 levels.

[Neven]

When do you think the Arctic might go below 1 million km2 of area/extent, William? And what did you think 10 years ago?

[John Christensen]

"Are their any people left who are predicting "ice free" by 2019?"

Dr. Wieslaw Maslowski is probably the best-known scientist with aggressive predictions for early ice-free Arctic waters and has to my knowledge not changed this latest prediction

He originally predicted the Arctic to be ice-free in summer by 2013, which he in March 2010 adjusted to 2016 +/- 3 years.

[William Crump]

Hi Neven:

I posted quite a bit on this before 2012. I will check, but I think I was following the predictions made by NSIDC as they know more than I could ever hope to know.

My WAG was for sometime between 2025 and 2035, but I need to check. Also, I think the measure should be based on the month average and not a single serendipitous day, which would push the date back even further. Maslowski appeared to be extrapolating based on October-November average volume data.

I will look for the prior post.

Using the observed 2007/2008 September sea ice extents as a starting point, we predict an expected value for a nearly sea ice free Arctic in September by the year 2037. The first quartile of the distribution for the timing of September sea ice loss will be reached by 2028.

http://onlinelibrary.wiley.com/doi/10.1029/2009GL037820/abstract;jsessionid=94AA6BE57205F877BA5C45354769906A.f02t03

http://onlinelibrary.wiley.com/doi/10.1029/2007GL029703/abstract

The NSIDC experts cautioned against relying on simple extrapolation as the forces acting on the ice are too complex to be captured by a single measure and extrapolation of that measure.

Per NSIDC back in 2011, [N]one of the models perfectly replicate the Arctic climate, and weather causes big variations from year to year that are hard to predict. For example, the models that IPCC scientists studied lacked sufficient data on changes in sea ice thickness. On top of those challenges, changes in Arctic climate may alter the way weather and sea ice interact with each other, leading to unexpected effects. Studies by James Overland at NOAA and Muyin Wang at the University of Washington predict that the Arctic will be nearly ice free in three or four decades. Overland and Wang combined observational data with climate models to reach their conclusions. However, other research suggests that the Arctic could lose its ice even sooner. For example, a study by Wieslaw Maslowski, of the Naval Postgraduate School in Monterey, California, suggests that the Arctic could lose its summer ice cover by the end of this decade. Maslowski’s work is different from Overland/Wang’s in that it analyzed changes in recent observations and estimates of sea ice volume to project—rather than predict—future sea ice loss. That is, Maslowski’s study estimated how fast sea ice volume might decline if the current loss rate continues on a linear path. What is the right number? Nobody knows exactly when the Arctic will lose its summer ice cover, because changes in the ice are introducing even more changes to the sea ice and Arctic climate. However, most researchers agree that it is a question of when, rather than if we will see ice-free summers.

https://nsidc.org/cryosphere/icelights/2011/05/when-will-arctic-lose-its-sea-ice

[William Crump]

It looks like I was posting on this back in February of 2011 through May of that year. I was getting a lot of help and making people unhappy when I tried to refute their claims which were using data based on Arctic wide conditions and insisting that focusing on the Central Arctic Basin was the proper measure because its more northern location made it react differently from more southern regions.

I was arguing that these other regions had pretty much dropped to zero by the minimum and could go no lower and would not contribute to future ice decline as the regions could not produce a negative value.

Someone suggested a pencil analogy and I pointed out what I thought were flaws in this analogy as in my view there were multiple pencils decreasing at different rates and not a single pencil. I remember someone getting upset about my challenging their single pencil analogy.

Some took my view as a denial of ice decline, but I was urging caution that the decline might occur much slower than Maslowski predicted and that there was a danger of confusing people - particularly people who would not find 1,000,000 km2 of ice to be a condition that was "ice free" - and allowing the deniers to say the failure of the prediction was proof that global warming was a false theory.

Some people in the discussion were certain the condition would be met by 2016.

FrankD was helpful.

[John Christensen]

Regarding ice-free predictions;

Dr. Wieslaw Maslowski originally made his 2013 ice-free prediction for ice extent, not volume.
In an interview Dec. 2007, he had this to say about volume decline:

"And this way we are saying that actually if we already have lost probably 40% of the volume in the Arctic so far, if we project this trend ongoing from the last 10-15 years, we probably will hit zero sometime in the summer mid-next century, mid-next decade, I’m sorry"

In more recent papers by Dr. Maslowski, predictions have been based on volume, and the projection from 2010 for 2016 +/- 3 years is based on volume as well.

[William Crump]

Another piece of my "analysis" is that much of the volume loss could have come from the change in the character of the ice from thick multi-year ice to thinner first year ice and that this trend could not be maintained.

Since there was not much thick ice left, rapid volume loss from deportation of ice through Fram Straight and around Greenland would no longer occur as the ice flowing out of the arctic was thinner than ice in prior years and that volume loss would slow as a result.

This thinner ice still had some staying power and appeared to rapidly reform every year. I was proposing that a volume model based on first year ice survival was a better model of predicting an ice-free Arctic rather than looking at data that included thick multi-year ice which had largely vanished from the Arctic.

Some commentors kept looking at the arctic as if it were a single ice cube melting and I was saying it is much more complex than that with ice flowing into the central arctic basin from other regions replacing ice that was flowing and melting in the central arctic basin.

I was also looking at data that suggested ice volume began to recover in September before area recovered. This indicated to me that the ice had more staying power than others were attributing to it as the ice recovered in the central arctic basin even as other regions continued to lose area.

There was no data base that I could come up with to test my "theory" about the rate of volume decline for first year ice in the central arctic basin. It looked to me that this first year ice was the key to predicting an "ice-free" Arctic and not changes in the multi-year ice, as the Arctic was essentially "ice-free" of multi-year ice.

Pretty sure Werther and some guy who was pretty smart and had his own blog page but was in relatively poor health were in on the discussions and idunno.

I found one comment where I predicted that "ice free" would not occur before 2025, but this was a WAG as I did not have the data.

I was also willing to concede that natural fluctuations might cause it to occur earlier and that the test of "ice-free" should be based on several consecutive years and not just a single day in one year.

[John Christensen]

Hi William,

I would agree with your argument about 'staying power' of FYI, which is based on the near constant factor of inbound annual solar radiation cycle: As the sun is lowering in the horizon, the heat loss has started exceeding heat intake, so it will cool down, and new ice will form.

DMI 80N temps have already passed 273K, and melt ponds are starting to freeze over in the northern-most parts.
It seems like the DMI volume model somehow manages to measure ice gain from melt pond freeze, but possibly also mistakes early snow for ice, as the DMI model has volume starting to increase in the second half of August.
By comparison, PIOMAS indicates volume to increase a few weeks later, e.g. by 9/18 in 2012 and by 9/14 in 2013.

[viddaloo]

When do you think the Arctic might go below 1 million km2 of area/extent, William? And what did you think 10 years ago?

Moving the yardstick from some one day in September to the entire month of August, I predict based on PIOMAS ice volume collapse that we'll have an ice–free August 1st in 2023, at the latest.

http://wunderground.com/blog/viddaloo/arctic-sea-ice-collapse-19-july16-august-annual-average-volume

[William Crump]

viddaloo, no offense, but I hope you are wrong.

I will be happy to be alive then.

When you say ice free by volume do you mean zero and do you expect ice shelves in Canadian Archipelago to disappear?

http://onlinelibrary.wiley.com/doi/10.1029/92RG00956/abstract

Since this is floating ice the real issue for sea level is the volume of Greenland Ice sheet, although there is also thermal expansion of sea water.

Could an ice free Arctic increase snowfall over the Greenland Ice sheet slowing its destruction?

http://www.reportingclimatescience.com/2016/05/24/arctic-snowfall/

An ice reduced Arctic already appears to be altering weather patterns.

https://www.carbonbrief.org/five-reasons-why-the-speed-of-arctic-sea-ice-loss-matters

http://www.pmel.noaa.gov/arctic-zone/future/bib/Vihma_accepted_in_Surv_Geophys.pdf

[William Crump]

viddaloo all you are doing is line drawing. The science is more complex.

How well does line drawing methodology match current behavior based on past data? If you used data through 2004 and extrapolate that line, would the prediction from that data match 2016?

Why must the line continue to decline at the rate you predict rather than flatten out like a diminishing return curve would?

[viddaloo]

1. viddaloo, no offense, but I hope you are wrong.
2. viddaloo all you are doing is line drawing.

Are you still going with the "no offense" narrative, William? Calling it "line drawing" seems a tad offensive. So I'll just assume you were offended.

Do I hope I am wrong? Yeah. You're not the only one. But this is about science, not hoping.

3. When you say ice free by volume do you mean zero and do you expect ice shelves in Canadian Archipelago to disappear?

For this question I refer you back to my blog post, link posted above. I also assume the CAA will remain in the Arctic in 2023, so yeah, it is part of the prediction.

[William Crump]

viddaloo, what science says those ice shelves will disappear by 2023?

I read your post - it has a chart with lines - that is line drawing and is not the equivalent of a fancy computer model that incorporates multiple variables, but may in the end be no better than line drawing.

How can you be certain that past trends will continue at the same rate? You provide no information to defend this premise which is key to the accuracy of the prediction you are making.

If I did that with the stock market under Obama I would say the DJIA will increase regardless of who gets elected at the same rate as it recovered from the Bush recession - which is not possible.

The Canadian Ice Caps will continue to feed ice into the Arctic for a long time.

http://www.thecanadianencyclopedia.ca/en/article/ice-cap/

Canadian Ice shelves are breaking up, but will easily be around for much longer than 2023

http://onlinelibrary.wiley.com/doi/10.1002/2016GL067759/full

https://www.washingtonpost.com/news/energy-environment/wp/2016/03/17/the-vast-shrinking-northern-glaciers-that-we-never-even-talk-about/?utm_term=.3ccaf063222a

That defies belief. Care to wager?

[William Crump]

What if August ice volume has established a new equilibrium point and it is bouncing around it - some years up some years down.

[viddaloo]

William,

I believe your questions are already answered in the original blog post itself, but I've expanded a bit in a comment pertaining to the trendline in particular here:

https://www.wunderground.com/blog/viddaloo/arctic-sea-ice-collapse-19-july16-august-annual-average-volume#yourcomment

[viddaloo]

What if August ice volume has established a new equilibrium point and it is bouncing around it - some years up some years down.

What if.... But there's absolutely no scientific reason to expect that. Wishful thinking won't save the Arctic or postpone the inevitable. In fact, wishful thinking is what brought us to this precipice.

Remember, in Paris last fall they said: What if we can somehow magically remove carbon from the atmosphere? Problem solved! Then we'd have negative emissions even though Norway and every other oil nation keeps on pumping till the thing is gone.

[wayne]

Viddaloo,

"Wishful thinking won't save the Arctic "

Ignoring the North is at the Worlds peril, better they get tuned more to what is happening. We got here also because we cover fast news, not the very slow trending AGW train, moving 1 Kph towards all people, who think they can stand by its track and wave it bye.

[William Crump]

viddaloo, I understand the two graphs include extrapolations performed using mathematics. I do, however object to the fact that the y axis in the first set of graphs starts at 13.5 km3 instead of zero.

I am not challenging your ability to use mathematics to establish a curve - it certainly looks correct to me.

What I am challenging is why we should expect the future to follow the mathematical curves that have been drawn.

I am suggesting that the multiple complex factors for arctic ice melt can not be captured by a mathematical curve.

In the real world there are very thick ice shelves on the coast of the Canadian Archipelago that have volume. I can find no research paper which suggests these ice shelves will disappear by 2024. If you are aware of such research please list it.

Your graph is drawn using Arctic wide data. It assumes the arctic acts like a single ice cube that is melting in a glass.

Ice above 80 degrees latitude is not melting out as fast as ice at latitudes between 70 degrees and 80 degrees - it is simple physics that more heat is applied to the 70 to 80 degree band than the 80 degree and above band.

In order for the mathematical extrapolation to be accurate you must apply a data base of similar items. In this case, you are not doing that.

I would prefer that the volume graph extrapolation be done using only the ice volume above 80 degrees latitude and first year ice.

I do not have this data, but since there are differences in the melt rate of ice at different latitudes I strongly suspect that your data base is skewing your results.

Since most of the multi-year ice has disappeared, I suspect the graph you have drawn is more indicative of the decline of multi-year ice than first year ice. The volume of first year ice may be expanding as it is "filling" in gaps created by the loss of multi year ice. This is why the volume decline has been sharper than the area decline.

I am not challenging your mathematical abilities or your assessment of the dangers of an ice free Arctic.

I am challenging the suitability of the data base you are using to make the extrapolations in your post.

You can easily convince me of the correctness of the 2024 prediction if you use data like the MASIE time series plot for the Central Arctic Basin - Region 11 - which appears to have considerably more staying power than the extrapolation provided using arctic wide volume data. In the alternative, show me why I should believe the Central Arctic basin will go to zero by August 1 of 2024. It does not make sense.

I have no doubt the ice will some day reach the level in the extrapolation. I am challenging the use of an Arctic wide data base to predict that demise when the mixture of ice ages and ice thickness in 2016 does not match in a proportional fashion the ice mixture in the other data points being used in the graph.

First year ice now makes up a much higher proportion of the ice than it did in the past. First year ice has a different salt profile than multi-year ice.

[viddaloo]

William, I don't want to disrupt this post (which is on ice volume this current season), so I suggest moving the discussion to my blog (link above). Short reply: I may agree with some of your message if you can present your case in a <1 million km3 estimate year based on the data you suggest is available to you. Looking forward to seeing you in my comments section.

[viddaloo]

Sorry, I meant a <1 *thousand* km3 August 1st estimate year, ie what year Aug 1 will have less than a thousand km3.

[William Crump]

viddaloo I am trying but it wants money before it lets me in.

Will try again tomorrow.

[William Crump]

viddaloo After nearly 30 days of high melting, the Central Arctic Basin has the same ice extent as it did at July 25th, 3.08 MILLION KM2 PER MASIE. Why should I follow your line using Arctic wide data when it is clear (of should I say solid) that the Central Arctic Basin shows no signs it will be ice free by 2024
ftp://sidads.colorado.edu/DATASETS/NOAA/G02186/plots/4km/r11_Central_Arctic_ts_4km.png

[viddaloo]

Well, you shouldn't, you should think for yourself, not follow anyone else! :)

Apart from that, it would be nice if you'd a) discuss my post under my post, as we agreed, and/or b) stick to discussing volume, not everything else, which seems slightly cherrypickish. I'm sure Wunderground doesn't charge you for wanting to comment on a post, surely?

[wayne]

William

"the Central Arctic Basin has the same ice extent as it did at July 25th"

???? Would you care to look at NASA's most excellent images? And build up a comprehensive holistic mental construct, based on all data available. Surely the CAB July 25 was very different, but extent numbers are tricky if based on a sole source.

As far as Ice free, perhaps never within the next 25 years, but very close to between 1 and 0 million at times. Any year, per chance, with a warm winter, sunny spring and summer, and cyclonic fall would do it, it is a rare combination of events. But we never discuss the tides, the very reason we still have some sea ice . With current world wide warming trends, 0 will be a regular summer time feature.

[William Crump]

Hi Wayne

Per MASIE the "drop" is not that large. As of today down to 2.95 km2 ftp://sidads.colorado.edu/DATASETS/NOAA/G02186/plots/4km/r11_Central_Arctic_ts_4km.png

Since Neven's most recent post, 2016 Mega-Dipole, shows the temperature starting to drop below 0 Celsius at 80 degrees North the big melt for the CAB is over for 2016, although areas further south may melt some more. http://neven1.typepad.com/.a/6a0133f03a1e37970b01b7c88d75f3970b-pi

NSIDC shows that 2016 is above the minimum for 2012 and well below the average. http://nsidc.org/arcticseaicenews/

Satellite is bonkers on Cryosphere today so that source is kaput.

JAXA chart show a whopping 1 million km2 more ice than 2012, but still well below the average. http://neven1.typepad.com/.a/6a0133f03a1e37970b01b8d2172da0970c-pi

So there are three sources all saying that we are not setting a new low in 2016 compared to the low established in 2012.

I find looking at images to be deceptive as personal bias can color perception in a manner that data does not.

Neven's page shows Cryosphere Today as above 2012, but not by much. I am certain you guys understand why JAXA is so much higher than CT, but since I am concerned with comparisons within same data sets it does not matter.

The point is that we are not going to see the levels viddaloo is predicting with his line drawing. Go back to 2013 and see what the line drawing people predicted for 2016 ice extent. My guess is we are well above the level the line drawers predicted in 2013. If line drawing using Arctic wide data did not work back then, why is it a valid method today for predicting future ice levels in the next three years?

Wayne and viddalo, show me a line drawing projection using Central Arctic Ice data - you pick the data set - use volume for the CAB if you can find it - so that eliminates the charge of cherry picking - when does it predict an ice free CAB?

viddalo what makes you think the observations I am making do not constitute thinking for my self - who else has advanced this idea of only looking to CAB data for making the ice free prediction?

I will try again to get on wunderground, if its not free, at least it is not much to join.

viddalo, wayne appears closer to my WAG about ice free conditions than he does to yours.

[Neven]

If line drawing using Arctic wide data did not work back then, why is it a valid method today for predicting future ice levels in the next three years?

William, I'm not a fan of line drawing either, and you can see I'm fairly reticent most of the time. The stats of an incredibly rapid loss of Arctic sea ice so far, only tell part of the story, but the reason people are going out on a limb so much, is right here in front of you.

Heat is accumulating in the atmosphere and oceans, and a lot of it ends up in the Arctic, causing Arctic amplification. That's how you get the mild winter we have just experienced, which will most probably only get milder more often as years go by.

This year, that winter was followed by a very early and massive opening up of the ice pack on the Pacific side of the Arctic, and very warm waters on the Atlantic side of the Arctic that pushed the ice pack's edge back, well past Svalbard.

If this then gets followed by early, widespread melt onset and then melt ponding, like we saw back in 2012, the ice pack is primed for very large losses in August.

Make that an August with GAC-like conditions like we just saw, followed by a persistent Mega-Dipole, and you get...

...well, awfully close to ice-free conditions.

So, as much as I'm not a fan of extrapolating exponential or even linear curves, and I really dislike it when people announce an ice-free Arctic every year, I'm not excluding the possibility that one freak year, consisting of various elements of the most 'successful' melting seasons so far, could cause the Arctic sea ice pack to measure less than 1 million km2 in September.

All that needs to happen, is for a freak year to come early. I would say the required conditions (volume, etc) are very close for making that possible, if not there already.

Personally, I don't think it will happen before 2020, but I'm not ruling it out. Either way, anything before 2050 is really bad and much earlier than was predicted just 10 years ago (except by a handful of outliers that are generally mocked).

[William Crump]

Here is an ice projection done back in 2009 using Arctic wide data that suggests we should be at 0km2 for September and October by now.

https://images.search.yahoo.com/search/images;_ylt=AwrBT9yCx8VXUEcAL8NXNyoA;_ylu=X3oDMTByN2Ruc2MwBGNvbG8DYmYxBHBvcwM0BHZ0aWQDBHNlYwNzYw--?p=Wipneus+Arctic+Ice&fr=mcafee#id=22&iurl=http%3A%2F%2F4.bp.blogspot.com%2F-lZ4BNWYYhMg%2FULQ_AQ49g-I%2FAAAAAAAAG9M%2FEjcv4iMEL2s%2Fs1600%2FFIGURE13.JPG&action=click

I think this shows that using Arctic wide data will lead to false projections of when the Arctic will become ice free.

[William Crump]

Neven:

I am in full agreement with AGW - it is simple physics, more CO2 more warming.

The only item I am being contentious about is the issue of when the Arctic will be "ice free" and I am suggesting that the data set for making projections should be based solely on the Central Arctic Basin and not Arctic wide data as the temperature above 80 degrees north, as shown on your most recent post Mega-Dipole is clearly cooler than the rest of the Arctic.

I am advancing this position because I believe it will provide a more accurate prediction and I agree that the natural variability is sufficient that an individual year may result in an abnormally low result.

The problem as I see it is that aggressive projections of an ice free Arctic open the AGW supporters to unwarranted derision from denier groups when these aggressive projections fail.

I appreciate the fine and hard work you are doing in putting out this blog.