Support the Arctic Sea Ice Forum and Blog

Show Posts

This section allows you to view all posts made by this member. Note that you can only see posts made in areas you currently have access to.

Messages - ChrisReynolds

Pages: [1] 2 3 ... 35

Interesting  question. There is a very good Wikipedia page on the North Atlantic Cold Spot.
This very likely being a symptom of the weakening of the Atlantic Meridional Overturning Circulation.  However this has been a long turn process on the way to a cessation sometime in the future (sooner than models have previously predicted). So I don't think it plays a role in the post  2007 'levelling' of Arctic sea ice extent as it was underway before then.

As for the ice shelves of the Arctic Ocean, these were far larger in the early 20th century and their loss has been a relatively early process, long preceding the recent late 20th Century start of the decline in sea ice extent/volume. There may be a localised role due to the topography of some glaciers but most glaciers are not floating and lie in valleys with their bases above sea level.

The politics / Re: The Trump Presidency (was "Presidential Poll")
« on: October 02, 2017, 08:42:20 PM »
58 pages of comments....

For a no-mark, double-digit IQ, sociopath, Trump is generating rather a lot of attention.  ;D

I started to ignore the moron some time back. That has improved my blood pressure.

Arctic sea ice / Re: Accuracy of poll predictions
« on: October 02, 2017, 08:27:12 PM »
I agree with Neven, good graph Steven. There is rather a low bias here, but once one is aware that's not an issue. And after all it should all be for fun.

The rest / Re: Europe - Collapse dynamics
« on: June 26, 2016, 05:21:31 PM »

The respect is mutual. You might have noticed, I rarely say how pessimistic I am about the prospects for dragging things to a more intelligent direction. At the moment we really are no better than yeast or bacteria...

Anyway, the reason I don't tend to express that pessimism is I don't want to reduce the chances for a change and for someone to get a solution I haven't thought of. So I'll shut up now.  :)

The rest / Re: Europe - Collapse dynamics
« on: June 26, 2016, 04:04:31 PM »

"Politics is the art of the possible.", so said Otto Von Bismarck.

I said above in my reply to you that I am the only person I know who doesn't own a car because of AGW, everyone at work drives to work and flies on holiday. When you and people like you are able to persuade say 50% of people to stop driving and flying we might be at a point where we can seriously talk about reducing CO2 and a paradigm shift. Until that point, I am sorry, but I view claims that we should shift the paradigm from the existing one of exponential growth as idle day dreams. So I will continue to reason under the prevalent paradigm.

The rest / Re: Europe - Collapse dynamics
« on: June 26, 2016, 03:47:10 PM »

I do get extremely annoyed by the meme that we have ample room (so can invite unlimited numbers of immigrants from all over the world). The UK is far too overcrowded already.

How do we define overcrowded?

The answer is IMO very simple.

The UK imports 40% of total foodstuffs.

UK Land usage does not permit for an immediate transition of other categories of land to food production. In any case there is not enough land to immediately transition to food.

Category / 1000hectares / %useage
Agriculture   15333   67%
Forestry   3059   13%
Urban   2748   12%
Other   1658   7%
Total    22798   

One might argue that we could convert pasture to crops, but this could not happen within one growing season. And much pasture is land unsuitable for crops, e.g. upland and wet flood plain pasture.

Thus if some catastrophe were to happen that led to other countries ceasing exports in order to feed their own population. If the catastrophe did not affect domestic food production we would face severe difficulty feeding our population, but would probably just about manage with organised rationing. In the event of a massive volcanic event, comet/meteor impact or some climatic event (tipping point) that does affect food production it seems we would have no choice but to let some people starve to death, especially if the catastrophic event happened in the Spring.

Thus we probably need to drop our population not increase it.

If Trump gets elected the world has gone mad even madder.

The rest / Re: Europe - Collapse dynamics
« on: June 26, 2016, 07:42:36 AM »
Magnamentis. Thanks.


Great quote from Yes Prime Minister.

I agree, there is another angle too: On our news it is being reported that the EU is already talking of internal reform. My advice to people in the EU is to act fast. This summer lobby your MEPs and local representatives, get out and campaign, if you can get the numbers; March in your capitals and regional centres. Use the UK's mistake and the EU's fear of contagion to try to forge a new and more democratic Europe.

In short, I think the EU could benefit greatly from the loss of the UK, but a lot depends on the people.

The rest / Re: Europe - Collapse dynamics
« on: June 26, 2016, 07:24:44 AM »
There is still the strange possibility, that the British parliament decides not to leave the EU just by not pressing the button of article 50. The referendum is not binding.

I have no clue what the British people would do in such case... But remember Tsipras did something like that after the referendum in Greece.


I think that would be very very dangerous. On Thursday, the day of the referendum, several of the women in the office were already claiming the ballot would be rigged (actually I  don't personally know anyone who voted exit, apart from at work). That is really rather insane reasoning! And we have already had a political murder as a result of the heated nationalistic rhetoric used by the exit campaigners.

Take this away from the 17 million who voted to leave and we could see the rise of extreme right wing parties who might actually get elected.

The rest / Re: Europe - Collapse dynamics
« on: June 25, 2016, 09:31:01 PM »

Perhaps I am being a bit negative about the negotiations. However from what I've been reading over the last few days it really looks like they'll be quite hard. My reading of the situation would support a hard stance, and various commenters are saying the same thing.
Of relevance: One French commentator on BBC news was describing reactions of the people she knew, she described an element who were cracking out the Champagne on Friday night celebrating a nuisance gone.

The longer we string things out and subject the Eurozone to uncertainty the less patience they may have. We'll have to see what this week brings. Will Cameron invoke article 50 or stick to waiting for October?

Anyway, the 3.7% I remembered must be from a transaction in my previous job. It turns out that tariffs are very very variable,

The rest / Re: Europe - Collapse dynamics
« on: June 25, 2016, 08:59:01 PM »
The demographics of the exit vote.
From FT

The exit voters may have 'Brexited themselves in the foot'
Areas with high exports to the EU have high votes for exit.  ;D

I really must find out what the sea ice is doing.

The rest / Re: Europe - Collapse dynamics
« on: June 25, 2016, 08:45:56 PM »

OK, Communists was lax, Russia is a kleptocracy run by former communists.

There are nascent leave referendum campaigns in several EU states. Yes? OK, so lets look at two scenarios. 1) The EU offers the UK generous terms of access without commitment, in which case the rest of Europe's leave tendencies may be increased and the entire EU unravels. 2) The EU offers 'punitive' terms, say the 3.7% import duty (IIRC) applied to any non-EU importer from a state without an explicit agreement.

In the case of 1 you set about the destruction of the EU. In the case of 2 you set about a process that drains industry from the UK and relocates it in the EU, whilst providing a solid example that deters people from voting to leave.

Which of the two options are in the interests of the EU?

The EU makes up 45% of the UK's export, the UK makes up 16% of Intra-EU exports. Intra EU trade is considerably more important to the EU than is UK trade.

How does that frame the coming Article 50 negotiations?

Once again, were I in Junke's shoes I'd play very hard, I'd probably not drop below a 3% tariff. And I would rely on the draw-down of operations into the EU from the UK due to that tariff barrier to offset any short term loss for the EU from loss of UK trade. Nothing personal, it's hard business calculations.

The UK, and any other EU member state can go it alone and very likely see a decline in GDP, which feeds through into a decline in living standards. Being poorer but having more sovereignty is a choice. Managed decline? Let me know when you get a government voted in that promises that. I remain the only person I know who doesn't have a car (that's because of AGW, I can afford one, I put away over £1k per month in savings and investments).

BTW - Greece isn't being punished they're paying the debt for living a financial fantasy for decades.

PS Will the banks leave the UK for Europe?
Probably yes, moves are starting.
Morgan Stanley were reported on the day of the referendum as being in the progress of shifting some operations out of London. They denied this fairly rapidly - nobody wants to create any more instability right now.

The rest / Re: Europe - Collapse dynamics
« on: June 25, 2016, 12:13:27 PM »
here on the border in Ireland a local diesel launderer is converting vehicles to suit the new people-smuggling opportunities .. it's an ill wind ...


Same here. I'm hard working, but I don't have a family, and it's all aimed at hardworking families. Cameron did quite a few things right, raising the tax threshold meaning lowest paid workers don't pay tax, gay marriage. He was a lot better than the little englander racists that will now take charge.

The rest / Re: Europe - Collapse dynamics
« on: June 25, 2016, 12:08:57 PM »
The vote to leave was an economically illiterate decision that will leave the UK poorer.
I keep hearing that, but nobody in the Remain campaign actually explained why, and as an economic illiterate I want to know. I am not willing to take it on trust. I have tried to find out but still haven't got a straight answer, so perhaps you can explain. What can your business do within the EU that you couldn't have done if it didn't exist?

The basic problem with the exit campaign can be easily understood without getting bogged down in detail. Virtually all independent studies by qualified economists found a serious detrimental impact to the UK economy from a UK exit from the EU. When challenged in TV debates the exit campaigners did the following things.

1) Tried to answer the question with an answer to a different question.
2) Claimed those doing the studies were biassed, or ignored the study discussed and made this point about another study.
3) Pointed out that economists and their models have got things wrong in the past.
4) Appealed to the unique and special nature of the British people.

Does this seem familiar? (Typical tactics of AGW deniers and other nuts)

For detail however take just one issue. They said we'd get a tariff free access to the Eurozone after leaving because we buy German cars. This argument not only neglects the need to avoid 'contagion' of leave referendums by making it easy for the UK. It neglects the fact that someone buying a BMW is going to be less put off by a 4% tariff barrier than a manufacturer buying engine parts. The equation is not equal both ways. I've just bought some pipettes that were about 25% more expensive than the cheaper ones, were I buying 1000 of them I'd not just have used a hunch that they looked better quality and a 4% price difference could swing my choice.

They also said that the USA would never consent to being part of something like a United States of Europe. Er... it's called the United States of America for a reason!

At every turn I was seeing gaping holes in their arguments that made me marvel at just who they were meant to be persuading, i.e.  the uncritical and stupid, key ingredients of nationalism.


Basically my business services the manufacturing sector (I don't want to give enough details to identify us because I have been indiscreet above, sorry).  Anything that hits British manufacturing hits us. Directly or indirectly (Euro firms or suppliers to Euro supply chains) most of British industry depends on Europe. As I was saying yesterday to someone at work, and have posted in a reply to someone on my blog: If the EU gives the UK favourable terms a lot of Europe will think they can leave but keep the benefits. To combat this contagion of exit referenda the EU must play hard in the coming negotiations, that has already started (Jean-Claude Junke this morning).

How did I expect that? I am not psychic, it's what I have done before in the cut and thrust of business and it is exactly what I would do in Junke's position. In fact, I'd offer the UK the same terms as any other country outside the EU without a special agreement (3.7% import tariff +VAT) and word it so it was clear this was my first and final offer.


I agree, but imperfect doesn't mean you chuck it in. We (UK) should have voted in, then joined together with others across Europe, as happened with the scrapping of TTIP. Europe and the drive to a United States of Europe is a worthwhile idea, it rests upon the people to work for it.

Has anyone watched Russia Today? Their angle, direct from the Kremlin, is that this is the start of the collapse of Europe with other countries seeking referenda. My general rule of thumb - if the Kremlin wants it, I want the opposite. (They're still bloody communists)

The rest / Re: Europe - Collapse dynamics
« on: June 25, 2016, 08:15:29 AM »
The EU is a monstrosity because it serves the interest of bureaucrats and big business, but that means you have to improve it, you have to fight fort it, and you will have to do so always, as with many things in life.

You don't just walk away, because it feels so good down in your belly and you enjoy saying 'fuck you' to people. Looks like the babyboomers are adamant on taking everyone with them to their graves.

I couldn't agree more Neven.

The vote to leave was an economically illiterate decision that will leave the UK poorer. I had a call from one of my customers yesterday. They're going to be sending a new (reduced) schedule of work and a new production line they had been planning last year (on hold since the referendum was announced) is now an indefinitely suspended project, with engineers from an EU country now evaluating the plans.

It's really hard to assess the hit, I was looking at it yesterday morning. My best guess, a minimum -8% hit on net earnings for my branch of the company, the last 5 years have seen strong (>3%) year on year increases I suspect that will change. But as I discuss in my most recent blog post, the 'Brexit' campaign were quite open about all this.

This is the opinion of one of their lead economic advisors.
Over time, if we left the EU, it seems likely that we would mostly eliminate manufacturing, leaving mainly industries such as design, marketing and hi-tech. But this shouldn’t scare us.
Patrick Minford of the Economists for Brexit.

Something like 17 million British people just voted for that!

Arctic sea ice / Re: Home brew AMSR2 extent & area calculation
« on: June 15, 2016, 08:01:18 PM »

As much as I appreciate the AMSR2 data you produce I'm finding the short time scale available frustrating. So I've just updated from your NSIDC concentration based data. I note that the massive errors in April have stopped. Is the source concentration data now from the uncalibrated F18 stream?

They are from now calibrated f18 data.

That's such good news, and far quicker than I'd thought it would be. The previous assessment suggested it could be months.

Thanks, I'm off to update what I updated yesterday. :)

Arctic sea ice / Re: Home brew AMSR2 extent & area calculation
« on: June 14, 2016, 07:25:12 PM »

As much as I appreciate the AMSR2 data you produce I'm finding the short time scale available frustrating. So I've just updated from your NSIDC concentration based data. I note that the massive errors in April have stopped. Is the source concentration data now from the uncalibrated F18 stream?

What so you mean I'll have to update the figures in my spreadsheet? Grumble. Grumble. ;)

Yes, sorry. But you shouldn't have reminded me that this was still on my to-do list.  ;D

I had thought it was in anticipation of the September data not being available. Based on the last news from NSIDC I expect it to be available by the end of the summer, maybe even August.

I apologize for putting up this poll so late in the month. I had made a mental note, but there's a cleaning lady who comes in and completely empties the desk every day.

BTW, I voted 'between 4.0 and 4.25 million km2'. Despite the current slump and weather forecast for the next 7 days, I think that one or two periods of weather that's conducive to melting will put this year firmly in the top 3.

What so you mean I'll have to update the figures in my spreadsheet? Grumble. Grumble. ;)

At least it'll all be off the same baseline metric.

Having a bad back I've been off work, and bored. So I went over the forum's previous polls. The June poll seems to me to best reflect underlying sentiment before evidence builds up over summer as to the actual likely outcome.

Green boxes show the actual bands in which the minimum fell. 5.5 to 5.0 million kmsq is added to the >5 million box as in 2013 there was only a >5 million box. 2016 is using a different metric, from comparison between those metrices (NSIDC and the one used here) one could bump votes up by two categories to match NSIDC. However, that would raise the problem that some, like me, will have translated the NSIDC expectation into the one used this year. Also the person who votes 0 each year would be dragged away from zero.  So I have not adjusted the 2016 data at all.

Original data from here:

Arctic sea ice / Re: The 2016 melting season
« on: June 13, 2016, 10:18:44 PM »
Melt season cancelled!!  ;D It started early and very exciting but after an extremely boring first half of June everything changed! :P

Kidding aside, a continued positive AO with cyclones over the CAB I no longer see how 2016 possibly would beat out 2012, 2007 or even 2011/2015 given the forecasts.

If the weather pattern isn't changing until the end of June, I strongly belive we have a chance to end up above all the minimas during 2010-2015, maybe even since 2007. In fact, I put the odds to 25% that we will end up somewhere between 4,9-5,1 Mn km2 by the middle of September IF this cyclonic weather pattern continues for the rest of the summer.

The bottom line is: given that the current weather conditions will continue for at least another week or so I put the odds to 1% that we'll beat 2012. Two years in a row with such strong high pressure dominance doesn't seem likely.


I've put beating 2012 as a low probability since the winter. But I'd not write off second place as yet.

Arctic sea ice / Re: The 2016 melting season
« on: May 01, 2016, 07:46:45 PM »
I'll just relay a reply I posted over on my blog....

Dreessen, David,

I am becoming much more optimistic about the prospects for a really exciting year in the Arctic Ocean.

Beaufort may prove critical. ASCAT shows some export over winter, so the crash I'll be discussing in my next post may well stall (a bit). Given ice state in Beaufort there is a reasonable expectation (IMO) of large tracts of open water early in the melt season under high insolation. From previous work for the whole Arctic, current ice thickness in Beaufort (~1.6m now) is well within the range of seasonal thinning - i.e. near 100% open water formation efficiency.

Under the Arctic Dipole (AD) regime of post 2007 summers the June/July average pressure shows a strong Beaufort High. This should drive water warmed in early season open ocean in Beaufort towards Chukchi and under the main pack. What goes towards Chukchi may then be entrained under the AD and driven into the East Siberian Sea. Ekman pumping may be expected to drive net flow to the right of the wind direction through the entire ocean column, but surface warming will be more in line with the wind flow.

The end result being that early inroads into the very thin poor ice state in Beaufort may then assist melt in the thicker (more normal) ice state in the East Siberian and Chukchi seas. That is before we get to considering the import of Pacific water through Bering due to the AD. The ENSO warmed tail from the tropics along the US/Canada East Coast may be entailed into Bering flow.


In 2012 nothing at the start of the season justified the outcome. I haven't seen a year more primed to large losses than this year (noting that I have not carried out a forensic study of all years since 1979).

It's early to be sure, but I think we're in for a really exciting melt season.  8)

Arctic sea ice / Re: Home brew AMSR2 extent & area calculation
« on: April 18, 2016, 08:53:10 PM »
Thanks Wipneus,

I just wanted to get things sorted in my head regards the recent satellite failure. I think I'm going to break off using your gridded based rework of NSIDC extent until they start to publish the Sea Ice Index again.

I am chatting with Dr Zhang about the situation. I've asked whether the early May release of April PIOMAS data will be affected / delayed. I will post the reply on your PIOMAS thread when I get it.

Arctic sea ice / Re: Home brew AMSR2 extent & area calculation
« on: April 16, 2016, 10:00:18 PM »
Hi Wipneus,

Am I correct in presuming that your NSIDC based extent and area data is using NSIDC 0081 for the most recent data?

Arctic sea ice / Re: The 2015/2016 freezing season
« on: November 14, 2015, 04:23:04 PM »
Judah Cohen has offered some thoughts on the upcoming winter on his blog.

The polar vortex is very strong atm. The AO is likely to trend back towards neutral the near to medium term, while there is a signal for a negative AO in the long term during winter.

Thanks for that, people at work have been asking me but I haven't had anything to say as I've been otherwise busy.

Thanks Wili, very useful.

Arctic sea ice / Re: The 2015/2016 freezing season
« on: October 20, 2015, 09:29:49 PM »
Well, I seriously haven't downloaded any data since my last ice releated blog post, and I don't intend to until our works Xmas shutdown...

So I can't help you there.  ;D

Arctic sea ice / Re: The 2015/2016 freezing season
« on: October 19, 2015, 07:51:26 PM »
I am not so sure that this means anything. Isn't heat still released through thin ice?

I calculate that across the Siberian quarter of the Arctic Ocean there has been a 37% increase in heat flux through the ice and I think this is probably warming the lower atmosphere.

Wow... sounds like the giant is trying to get out of the grass hut.  Speaks strongly to  the net increase in available heat.

Referencing my earlier comment, while the outgoing heat has increased massively, I'm now wondering how much additional is being retained; that's where my concern about ice comes in.  The sooner it appears, the sooner we have a buffer which will slow down heat exchange.  Black Body radiation will still carry off a lot, but we lose direct transfer to atmosphere via convection and evaporation which I suspect are much more efficient.  Add the insulative value of the ice as it thickens, and that translates into a big boost in year-over-year retained heat.

I subscribe to that. It all depends on weather, as always, but the prospects of a large extension of thin ice enabling early botton melt, while the heat of the post-mega Nino lingers around and may precondition early too,  are def bad for ice.

For what it is worth, I accept the Tietsche Effect, where by a lot of heat gained in the summer is vented over autumn/winter. But, I really find it hard to believe that all of the heat gained in summer is lost to the atmosphere.

There's a graph of August SSTs here:

In April, strictly speaking the surface under the ice would be near -1.8degC, perhaps a better indicator would be heat content of the top 50m (for example), such heat content for April would give an indication of how much heat was being retained.

PIOMAS has gridded ocean temperatures for the ocean model levels. Levels 1 to 5 give the top 50 metres.

Arctic sea ice / Re: The 2015/2016 freezing season
« on: October 18, 2015, 08:10:31 PM »
I am not so sure that this means anything. Isn't heat still released through thin ice?

I calculate that across the Siberian quarter of the Arctic Ocean there has been a 37% increase in heat flux through the ice and I think this is probably warming the lower atmosphere.

Cohen has done work on the link between sea ice loss and cold NH winters, this is mediated by increased early winter precipitation of snow due to late season open water in the Arctic Ocean. That link being shown by the unique isotopic composition of Arctic Ocean water being detected in snow fall over Eurasia.

Assuming cold enough conditions for the newly formed pack ice to have a dry surface, surely it is not beyond reason to suspect that early winter precipitation of snow over the Arctic Ocean ice pack itself may be increasing. And an insulating blanket of snow over thinning ice early in the winter (Oct - March) season would reasonably be expected to reduce winter thickening significantly.

The PIOMAS -1m experiment implies that to get massive inroads into the Central Arctic we need to see substantially thinner winter ice. Increased early winter snowfall might play a role in this.


Barents - 1980s average only 0.07M km^2 - discounted.
Kara 1980s average is 0.30M km^2 - OK
Laptev 1980s average is 0.34M km^2 - OK

Barents 1980s extent for September was 0.07, less than 1/3 of Kara, Kara 1980s extent was similar to that of Laptev, which is transitioning.

Once the peripheral seas become regularly seasonal the interesting action in those seas should be the ice edge receding earlier. It is this which should really allow the ice edge to penetrate the Central Arctic. That will be interesting, but at the moment penetration in the Central region seems to be relatively late.

Arctic sea ice / Re: The 2015/2016 freezing season
« on: October 05, 2015, 08:48:46 PM »
Thanks Slow Wing, I didn't know about the weighting.

JD Allen,

Yes, it does seem to support what we already know - the peripheral seas are acting as leaders for the entire Arctic. At some point it might be worth defining two (or more?) regions within the CAB, one that will hold the remnant ice off the CAA in the latter stages of the transition and one that will be next in line to fall once the peripheral seas have transitioned.


I've just taken the numbers based on the preliminary 'nrt' data, and am loathed to start messing around with them. At present Wipneus's calculations are to within a fraction of a % for the official NSIDC Sea ice index NH extent if we* start applying our own masks then we'll have a different product which still might change when the data goes from prelinary to final at the start of the following year.

* I say 'we' because Wipneus is producing the data, but I have my own code ready to go and have kept notes of discussions Wipneus has had with someone else about the correct application of masks. So in theory I could make the same numbers, but Wip's coding is far more automated than my approach (using Visual Basic) and it's easier for me to just use his numbers.

JD Allen,

In Wipneus's data the 1980s September average extent was 0.299, this September was 0.064, that's 22%. There may be some phantom ice involved here that will disappear when the data is reviewed by NSIDC and transferred from 'nrt' files to 'final'. But at present I have to report the data as it stands, sorry.


As stated in the original post, a common definition for virtually ice free in the NH is 1 million kmsq. This is roughly 15% of the 1980s September extent, I cannot help but wonder if this is by accident or design as 15% is conveniently the level used to determine extent itself. Applying the same criterion to regions as one would use for NH ice seems to be a neater approach to me than trying to establish a different criterion.

Chris, Would any of the discounted seas have been counted if you were to choose the 70s or the 60s as your baseline? I suppose I am being lazy but I figure you could answer this fairly easily. Anyway it's great to see you back and I have checked dosbat a couple times over the last month. Hope you got in some vacation. You said there you weren't feeling to driven to post so often of late and I figure that's probably healthy. I am here every day....maybe a borderline addiction .

Borderline addiction - yes I have reflected on that. I'm still on a sort of break but have had a really bad cold that in retrospect has been the flu, all my joints and various old injuries are killing me right now! I'm currently working through the spectrum of energy received by a loop antenna from a few Hz to 50MHz - the game is - can I identify all of the peaks and spikes? But I am too wiped out to carry on with that right now.

Sorry I don't have data from the 60s or 70s. If Chapman/Walsh isn't too flat (and it may be) one could extend the 1980s data back, so it wouldn't change much.

This follows on from a throw-away justification of a statement in my most recent blog post....

How do we define seasonally ice free? The ultimate definition is no ice at all, but that is too long a prospect for me. So I turn to virtually sea ice free...

The common definition seems to be total NH sea ice area extent of less than 1M km^2. But how might we apply this to the regional seas of the Arctic?

Average September extent for the 1980s in Wipneus's data set (near as damn it NSIDC Extent), was 7.219M km^2. 15% seems to be a good demarcation for working out extent, so let's try applying that to overall Arctic extent. 7.219M X 0.15 = 1.083M km^2. That's only a bit above the 1M km^2 level below which the Arctic Ocean can be considered virtually sea ice free.

So I propose that September extent of below 15% of 1980s September extent means that sea/region is virtually sea ice free.

Looking at the regions available:

Okhostk - ice free in summer most of the record - discounted.
Bering - ice free in summer most of the record - discounted.

Beaufort 1980s average is 0.34M km^2 - OK
Chukchi 1980s average is 0.25M km^2 - OK
ESS 1980s average is 0.67M km^2 - OK
Laptev 1980s average is 0.34M km^2 - OK
Kara 1980s average is 0.30M km^2 - OK

Barents - 1980s average only 0.07M km^2 - discounted.

Greenland Sea 1980s average is 0.30M km^2 - OK
Central Arctic 1980s average is 4.40M km^2 - OK
CAA 1980s average is 0.44M km^2 - OK

Baffin - ice free in summer most of the record - discounted.
Hudson - ice free in summer most of the record - discounted.
St Lawrence - ice free in summer most of the record - discounted.

Of the regions accepted as having a reasonable amount of ice in the 1980s during September, Central, Greenland and the CAA have no years with less than 15% of the September average. That leaves us with Beaufort round to Laptev, the peripheral seas of the Arctic Basin, and the Kara Sea.

The list below shows the regions concerned that do show a (virtually) ice free state in September.
1 means ice all year (>15% of 1980s September extent). 0 means ice free (<15% of 1980s September extent)

   Beaufort   Chukchi   ESS   Laptev   Kara
1979   1   1   1   1   1
1980   1   1   1   1   1
1981   1   1   1   1   1
1982   1   1   1   1   1
1983   1   1   1   1   1
1984   1   1   1   1   1
1985   1   1   1   1   1
1986   1   1   1   1   1
1987   1   1   1   1   1
1988   1   1   1   1   1
1989   1   1   1   1   1
1990   1   1   1   1   1
1991   1   1   1   1   1
1992   1   1   1   1   1
1993   1   0   1   1   1
1994   1   1   1   1   1
1995   1   1   1   0   0
1996   1   1   1   1   1
1997   1   1   1   1   1
1998   0   1   1   1   1
1999   1   0   1   1   1
2000   1   1   1   1   1
2001   1   1   1   1   1
2002   1   0   1   1   1
2003   1   0   1   1   1
2004   1   0   1   1   1
2005   1   0   1   1   1
2006   1   1   1   1   1
2007   1   0   0   1   1
2008   0   0   0   1   1
2009   1   0   1   1   1
2010   1   0   1   1   1
2011   1   0   1   0   1
2012   0   0   0   0   1
2013   1   0   1   0   1
2014   1   0   1   0   1

Update for 2015's melt season, using all the same assumptions and conditions for the above original post on this thread. This time I have added a column for Peripheral Seas (Beafort, Chukchi, ESS, Laptev).

1 means more than 15% of the 1980s September extent.

0 means less than 15% of the 1980s September extent.

0 is taken to be a year which meets the regional condition of 'virtually ice free'.

Year   Beaufort    Chukchi   ESS   Laptev   Kara   Peripheral
1979   1   1   1   1   1   1
1980   1   1   1   1   1   1
1981   1   1   1   1   1   1
1982   1   1   1   1   1   1
1983   1   1   1   1   1   1
1984   1   1   1   1   1   1
1985   1   1   1   1   1   1
1986   1   1   1   1   1   1
1987   1   1   1   1   1   1
1988   1   1   1   1   1   1
1989   1   1   1   1   1   1
1990   1   1   1   1   1   1
1991   1   1   1   1   1   1
1992   1   1   1   1   1   1
1993   1   0   1   1   1   1
1994   1   1   1   1   1   1
1995   1   1   1   0   0   1
1996   1   1   1   1   1   1
1997   1   1   1   1   1   1
1998   0   1   1   1   1   1
1999   1   0   1   1   1   1
2000   1   1   1   1   1   1
2001   1   1   1   1   1   1
2002   1   0   1   1   1   1
2003   1   0   1   1   1   1
2004   1   0   1   1   1   1
2005   1   0   1   1   1   1
2006   1   1   1   1   1   1
2007   1   0   0   1   1   1
2008   0   0   0   1   1   1
2009   1   0   1   1   1   1
2010   1   0   1   1   1   1
2011   1   0   1   0   1   1
2012   0   0   0   0   1   0
2013   1   0   1   0   1   1
2014   1   0   1   0   1   1
2015   0   0   0   0   1   0

In 2015 most of the regions here were seasonally ice free, the last time 4/5 met this condition  was in 2012. Only in 2012 was the composite region Peripheral Seas also virtually ice free.

Arctic sea ice / Re: The 2015 melting season
« on: September 02, 2015, 07:18:35 PM »
Chris:  If I understand the ice drift hypothesis correctly, it is that the Beaufort gyre takes (approximately) four years for one full "turn".

That means we can regard the gyre effectively as four quadrants, each of which may have different melt characteristics due to different proportions of MYI.  When a particularly "tough" quadrant rotates into the Beaufort, that year will have substantially reduced melt in that area - and when a particularly "delicate" quadrant is present, you see a high melt year in the Beaufort.

If so, then it should be quite easy to spot that in the ice age model.  If you take  the images from (say) April of each year, and average the age of the ice in the Beaufort region, is there a four-year periodicity, and does it correlate with high- or low-melt years?

Another possibility that follows from this model is that years with particularly high weather driven-losses in one region will impact other regions further down the line.  For example, if the Beaufort has high melt in year 1, then the Chukchi will have weaker ice in year 2 and be more susceptible to melt that year.  The next year, the ESS might in turn be more vulnerable, and so on.  This might show up in the general anomaly plots - is there a correlation between ESS extent in one year and Chukchi extent the previous year, or Beaufort extent the year before that?


All reasonable suggestions but I have already decided to wait to see what happens next year to see whether it is worth investing time on. Anyway today I started a three day audit session to maintain our accreditation, so sea ice will have to take a back seat for the rest of the week.

Arctic sea ice / Re: The 2015 melting season
« on: September 02, 2015, 07:13:14 PM »
The strongest evidence for a possible impending bifurcation has been within the extensive work of Ian Eisenman into simple models of the sea ice. This year Eisenman has published work showing that those modelled bifurcations are artefacts of the simple model, and by implication that the GCMs are correct in not showing bifurcation behaviour in the transition to a seasonally sea ice free state.
How can an artifact be evidence of anything?
I think that is the point Chris is trying to make, actually.
Is it? Then we're on the same page.

But I thought he suggested that the artifact implied something about other models being correct, which to me doesn't seem to follow.

if the bifurcation is just an artifact of the model, there's no reason to doubt the accuracy of other models which don't show a similar bifurcation. it doesn't show the GCMs are right, it just means you can't use the lack of bifurcation behaviour to argue that they're missing sth
Yes, exactly.

Have any of you read Wagner & Eisenman 2015 "How Climate Model Complexity Influences Sea Ice Stability" in its entirety?

That paper conclusively shows that the GCMs are right and the simple models are wrong in showing a rapid crash to a seasonally sea ice free state.

Arctic sea ice / Re: The 2015 melting season
« on: September 02, 2015, 07:06:56 PM »

Sorry, my mistake. I guess it comes from my drive to comprehend what is going on. As a lifelong nerd I have never really grasped the point of idle chatter.

But being rude is OK.

Got ya.

Here's my rude comment back: More than once in my life I have been ahead of the science. Implying we know enough of the complexity of the global/arctic system as to know what you, or the studies noted, claim, rather than it being educated guessing, essentially, is hubris defined.

It's fine to tell me the evidence is weak, it is another to impugn my approach.

And I repeat: Looks like is not is. Get that before bothering to respond again. You have literally added nothing to the discussion that wasn't already implied, rather implicitly, by the use of that simple phrasing. Say the evidence is weak, don't be patronizing about it.


Arctic sea ice / Re: The 2015 melting season
« on: September 01, 2015, 06:53:23 PM »
From the Beaufort Gyre project:
These studies indicate that the Arctic Ocean surface layer currents are consistent with the Arctic atmosphere surface layer motion, alternating between cyclonic and anticyclonic circulation regimes. Each regime persists from 4 to 8 years, resulting in a period of 8-–16 years. The cyclonic pattern dominated during 1989-1996. Since 1997 the dominant regime has fluctuated, with an anticyclonic pattern being more prevalent (Fig. 1). Figures 1-9 show annual simulated wind-driven surface ice and ocean motion for 2000 through 2008. The Arctic Ocean Oscillation index (bottom panel in Figure 1) illustrates alternation of circulation regimes at a period of 8-16 years. During anticyclonic circulation regimes the BG region accumulates fresh water and during cyclonic regimes the BG region releases fresh water and this water could be available for transportation to the North Atlantic via Straits of Canadian Archipelago and Fram Strait.

 It's possible we've seen a reduction in the circulation time post 2007.

Well that discussion of regimes is about atmospheric regimes, which I don't view as a likely candidate if the apparent emergence of a 4 year cycle in August losses is correct. The problem it that aside from seasonal cycles I can't think of a dead regular cycle in the atmosphere (or ocean), which is why I homed in on sea ice transport. This transport won't be dead regular but might be regular enough to cause a 4 year cycle which when acted upon by the dead regular cycle of insolation 'cuts off' any dither in the underlying ice motion cycle.

Anyway, I'm putting the issue aside and waiting to see what happens in August 2016. (And yes Sea Ice Sailor - I do now expect strong losses in August 2016)

PS - forgot to add, see this page (again).
The schematic on the right shows interplaying factors, any of these, or more likely all together might cause a regular four year cycle.

Arctic sea ice / Re: The 2015 melting season
« on: September 01, 2015, 06:47:31 PM »

The strongest evidence for a possible impending bifurcation has been within the extensive work of Ian Eisenman into simple models of the sea ice. This year Eisenman has published work showing that those modelled bifurcations are artefacts of the simple model, and by implication that the GCMs are correct in not showing bifurcation behaviour in the transition to a seasonally sea ice free state.

Looking at every small blip in the CT Area graph is, I am sorry to have to say, a prime example of the sort of loose throwing around of poorly understood terminology I was complaining about. The only evidence you could cite for bifurcation in all that you marked is the 2007 sea ice loss (Livina & Lenton). But even with Lindsay & Zhang's suggested 1990s 'tipping point', I find it hard to view that as a proper bifurcation (with hysteresis) as nothing in their work suggests it was harder to reverse than to play out. 2013/14 suggests that a mere run of cold weather could have reversed it.

And this is the primary problem with your pointing out all those little ticks in the decline, having read a substantial amount of the published science on sea ice bifurcation behaviour (in models), I struggle to see more than weather driven blips, apart from the 2007 event (which was weather driven - but a bifurcation can be stochastically forced).

False. You are talking about proving, or at least getting to viable theory. We are talking on a blog. Nobody said it *is* a coming bifurcation, only that it looks like one.

Sorry, my mistake. I guess it comes from my drive to comprehend what is going on. As a lifelong nerd I have never really grasped the point of idle chatter.

Arctic sea ice / Re: The 2015 melting season
« on: August 31, 2015, 06:58:08 PM »
Iceman, Ktonine, Sea Ice Sailor,

It is, I concede rather sketchy...

Kevin, if the cycle between entry into Beaufort and re-entry into Beaufort is something like 4 years it would be an oscillation driven by a physical feedback of ice mass/state (i.e. FYI/MYI). Consider the first graphic here:
Say something like, into Beaufort and to Chukchi = 1 year. Assume the same rate, that's about 1/4 of the circle, which sugests something like four years (I can't find the reference I read the ~4 years from originally). This feedback need not necessarily be actual packet of ice doing the circuit, more like the presence of ice at the end of the season affecting the ice state of the next leg of the trip.

It is worth noting that when looking at data to 2006 Zhang finds a shift to Arctic Dipole dominant weather after about 2003, might this explain the emergence of the supposed cycles after 2005?

It might be worth a seperate thread here, but not now as I am busy with stuff unrelated to sea ice.

Arctic sea ice / Re: The 2015 melting season
« on: August 31, 2015, 11:46:48 AM »
Killian, 6roucho,

Critical slowing is a decreasing recovery from perturbations and it is considered to be a useful indicator of approaching a 'phase transition' or 'bifurcation'. The problem here is that the idea of tipping points has become a common meme which is cast about with little understanding and little regards for physical reality, thus the casting around of the loose idea is likely to lead to incorrect expectation.

Could this oscillation be conceivably interpreted as critical slowing? Yes it could, it could be viewed as a reduction of ability to recover from perturbations (interannual variation of extent or thickness) leading to an oscillation in August extent loss. However would it be expected to have a four year period? I suspect not, I would expect a random periodicity, which with a sufficently large dataset (e.g. parallel runs in a model), might have similar frequency domain charateristics but not a regular cycle (e.g. 4 years in every run of the model).

To invoke the idea of critical slowing and to present this as an early warning of an abrupt transition one would need to establish the causal mechanism. I have already suggested a mechanism, one that does not lead to the conclusion of an imminent crash. If you view this as critical slowing in prelude to a rapid transition, what is the mechanism that you propose?

Arctic sea ice / Re: The 2015 melting season
« on: August 31, 2015, 08:46:08 AM »

Thanks for that. Isuspect that the likelihood that it's random might be higher because there are various oscillation processes within the Arctic, some of which may possibly have similar behaviour in the frequency domain.

Arctic sea ice / Re: The 2015 melting season
« on: August 30, 2015, 10:04:47 PM »
Before seeing Chris's graph, I've 'expected' large August sea ice losses every year.  The graph shows that I get what I expect about twice per 4 years (yellow and red dots are large, historically, if not when compared with 2012).  I do not believe this is a 4-year climatological cycle, however.  Per Chris's graph, I should expect a 50-50 chance of >1.75 August sea ice loss and a 1-in-4 chance of >2.0 August loss. This goes for 'any' August though, not just 2016's.

& SeaIceSailor,

I don't think it's weather related (climatological) I suspect that the cycling time for muti-year ice in the Beaufort flywheel is being revealed as the ice has thinned (winter peak thicknes) and open water increased in late summer. The increased in losses seems to be due to the Chukchi and ESS regions as shown below. MYI export into those regions seems to suppress August melt, lack of MYI enhances it.

The current blog post on my blog has a link to a previous study. If 2016's August losses bear out a third cycle I may revisit the matter.

Arctic sea ice / Re: The 2015 melting season
« on: August 30, 2015, 01:32:56 PM »
Interesting... your graph implies a 3+ million KM2 ice loss in August of 2016.

I wouldn't draw any such conclusion myself, it's just a three point series with the last point being strongly impacted by weather (2012).

But I do expect high losses next August.

Arctic sea ice / Re: The 2015 melting season
« on: August 30, 2015, 08:56:32 AM »

Dots put on that manually, to show the similarity with other recent years and what seems to be an emerging cyclic behaviour. It will be interesting to see if we have large losses next year in August. If there is a cycle, and not just random behaviour, this 'predicts' large August losses in 2016.

(Had to edit the graphic as I originally put 'four cycles'... too early in the morning)

Arctic sea ice / Re: The Slow Transition
« on: August 30, 2015, 08:32:12 AM »
Sorry Terry,

Been busy, so I'm late in getting back. I don't know what systems you are referring to.

Arctic sea ice / Re: The Slow Transition
« on: August 26, 2015, 07:58:10 PM »

Yes, that is basically the argument I was making.

Arctic sea ice / Re: The 2015 melting season
« on: August 20, 2015, 08:19:36 PM »
So the visualization tool will tend to exaggerate the age of ice.

Only if you don't read the documentation and don't understand what it's showing.  It very clearly says that it should be read as an indication of where ice of a specific age exists, and NOT that all ice in that pixel is of that age.

i.e. a red pixel contains ice of UP TO 5 years old.  A yellow pixel contains ice of UP TO 4 years old. A dark blue pixel contains ice of UP TO 1 year old, i.e. exclusively FYI.  With that understanding, the maps have done a very good job of showing where the MYI is from year to year, and thus provide a clear explanation for the comparatively slow melt in the Beaufort this year.

9/10 of the arguments on this forum come from people trying to make particular charts into something they're not, and this is no exception.

Right.  If the user interface sucks, it's not the fault of the user interface but of the user.  Got it.

If you don't like the product don't use it. But don't blame the product when people read stuff into it that just isn't so.

And yes, it is the fault of the user of a data product if they draw inaccurate conclusions from the data having failed to ascertain what the data means.

(That was my point to Neil T with my two questions, the first place to start is to acquaint themselves with the dataset. Sorry Neil, I didn't read anything in your lengthy reply that seemed worth replying to.)

Pages: [1] 2 3 ... 35