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What will the NSIDC 2015 Arctic SIE September minimum be?

Between 5.75 and 6.0 million km2
0 (0%)
Between 5.5 and 5.75 million km2
0 (0%)
Between 5.25 and 5.5 million km2
1 (0.7%)
Between 5.0 and 5.25 million km2
6 (3.9%)
Between 4.75 and 5.0 million km2
6 (3.9%)
Between 4.5 and 4.75 million km2
37 (24.3%)
Between 4.25 and 4.5 million km2
31 (20.4%)
Between 4.0 and 4.25 million km2
29 (19.1%)
Between 3.75 and 4.0 million km2
17 (11.2%)
Between 3.5 and 3.75 million km2
8 (5.3%)
Between 3.25 and 3.5 million km2
5 (3.3%)
Between 3.0 and 3.25 million km2
2 (1.3%)
Between 2.75 and 3.0 million km2
1 (0.7%)
Between 2.5 and 2.75 million km2
1 (0.7%)
Between 2.25 and 2.5 million km2
2 (1.3%)
Between 2.0 and 2.25 million km2
2 (1.3%)
Between 1.75 and 2.0 million km2
0 (0%)
Between 1.5 and 1.75 million km2
0 (0%)
Between 1.25 and 1.5 million km2
1 (0.7%)
Between 1.0 and 1.25 million km2
0 (0%)
Between 0.75 and 1.0 million km2
2 (1.3%)
Between 0.5 and 0.75 million km2
0 (0%)
Between 0.25 and 0.5 million km2
0 (0%)
Between 0.0 and 0.25 million km2
1 (0.7%)

Total Members Voted: 150

Voting closed: August 13, 2015, 11:24:06 AM

Author Topic: NSIDC 2015 Arctic SIE September minimum: August poll  (Read 49140 times)

Neven

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Re: NSIDC 2015 Arctic SIE September minimum: August poll
« Reply #50 on: August 07, 2015, 10:10:42 AM »
You are right up to a point, Paul, but we can assess the situation after the freezing season, using different data sources and compare with previous years (see here, for instance). If this initial state is then followed by little preconditioning during May and June, we already know that there won't be a record. This year is a case in point.

It's not like we don't know nothing and the ice will suddenly disappear, God knows when. There will be signs beforehand that this community will pick up. I'm pretty sure of that.

And this is not the year.
« Last Edit: August 07, 2015, 10:51:06 PM by Neven »
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ChrisReynolds

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Re: NSIDC 2015 Arctic SIE September minimum: August poll
« Reply #51 on: August 07, 2015, 10:40:00 AM »
Chris,

It's striking that half of your scenarios end up in 0.36 million sq km gap between 2010 and 2014. I can't help feeling that's in agreement with my model, which puts a probability of 43% of being in that same range.

A difference is that in your case, that's the upper 50% of outcomes, while in my case, it's the middle of the outcomes. But I also think my model is likely to be too high, and the center of the "true" prediction of my model is very close to the center of your scenarios.

It's also striking that after you raised your vote by one bin, you are still two bins away from the median of your scenarios.

Thanks for the comparison with your approach.

I might be biassing needlessly low, and it is interesting that both your method and Slater's persistence model are high, as is this very simple method. But I expect that melt this August will be well above normal, keeping the minimum at the low end of the spread.

Of course I may be undershooting again...

Paul,

I agree with Neven, we have numerous metrics and before a really massive loss there will be leading indicators that something is unusual.

Gonzo

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Re: NSIDC 2015 Arctic SIE September minimum: August poll
« Reply #52 on: August 07, 2015, 02:38:20 PM »
Quote
Paul Beckwith
However, I think that when it goes it will be extremely rapid, and totally amaze everybody,
Your video was interesting. I think the melt season will be longer this year, due to warmest global temperatures in modern times (and less albedo than usual).

oren

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Re: NSIDC 2015 Arctic SIE September minimum: August poll
« Reply #53 on: August 07, 2015, 05:49:22 PM »
4.5-4.75. I believe we might be similar to 2011.
139 votes that's quite impressive!

Paul Beckwith

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Re: NSIDC 2015 Arctic SIE September minimum: August poll
« Reply #54 on: August 07, 2015, 07:57:58 PM »
Did anybody on these forums anticipate the massive loss of thick ice this year for the two weeks following June 25th, 2015 as shown clearly on my video? This loss seems to have been caused by warm water undercutting the ice, and it extended far into the ice pack. What stopped the loss extending further across the ice pack? Could such pulses continue, and destroy the ice? To assess this, one needs to assess the water temperatures in the North Pacific, and the causes for high temperatures. It is not just the powerful El Niño. I discussed this in a video here, and will discuss in more detail soon...

When #scientists call vast ocean regions "the blob" they are stumped. Video: Why vast regions of Pacific are saunas? https://t.co/0HiHfySzeZ

Peter Ellis

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Re: NSIDC 2015 Arctic SIE September minimum: August poll
« Reply #55 on: August 07, 2015, 08:19:44 PM »
Paul:  That's duff output from a model being fed with incorrect data, see here:
http://forum.arctic-sea-ice.net/index.php/topic,1320.0.html

Paul Beckwith

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Re: NSIDC 2015 Arctic SIE September minimum: August poll
« Reply #56 on: August 08, 2015, 05:40:12 AM »
Thanks Peter; I was not aware of the problems. Which time period is problematic; are today's maps decent?

Gonzo

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Re: NSIDC 2015 Arctic SIE September minimum: August poll
« Reply #57 on: August 08, 2015, 05:59:27 AM »
Believe me Professor Beckwith, there is plenty 5 metre ice left in the Arctic, but I guarantee you, it is just a few floating icebergs, and some thick ice stuck to a cliff off Greenland.

As you know, (which many of these Brits and Floridians can't even comprehend, even when they stand upon actual ice... if they ever have ) ...is that, yes, thick ice clings to islands...long after everything else has melted away.

The ice is melting very very fast.
Those models are like ghosts of the past.

-- Gonzo.
« Last Edit: August 08, 2015, 04:44:22 PM by Gonzo »

ChrisReynolds

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Re: NSIDC 2015 Arctic SIE September minimum: August poll
« Reply #58 on: August 08, 2015, 08:01:18 AM »
These clowns here, pretending they know something about models, are a joke.

Really?

1) What is the precise problem with HYCOM/ACNFS, in your own words not quotes.

2) Why is the PIOMAS grid centered over Greenland?

3) Upon which papes are the viscous–plastic rheology based for:
a) PIOMAS?
b) HYCOM/ACNFS?

This is not a matter of being big headed, I am an amateur too. But there are amatuers on this forum who have been at it for longer and have dug a hell of a lot deeper than you seem to suspect. This is quite a common issue with new posters, it is as well you learnt this fact early.

ChrisReynolds

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Re: NSIDC 2015 Arctic SIE September minimum: August poll
« Reply #59 on: August 08, 2015, 08:11:43 AM »
Thanks Peter; I was not aware of the problems. Which time period is problematic; are today's maps decent?

Paul,

The problem itself may not be too hard to fix, for the very sharp people who run the model. But there are ongoing problems with the model, it might take them time to make sure it's all fine. I can only speak for myself, but I have put it aside until I am convinced it is working properly. I  am not convinced right now, over the last week I have seen ice disappearing then appearing over the same region.

jdallen

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Re: NSIDC 2015 Arctic SIE September minimum: August poll
« Reply #60 on: August 08, 2015, 09:03:08 AM »
<snippage>
This is not a matter of being big headed, I am an amateur too. But there are amatuers on this forum who have been at it for longer and have dug a hell of a lot deeper than you seem to suspect. This is quite a common issue with new posters, it is as well you learnt this fact early.
Fetches popcorn, sits back...

No, wait... please don't distract the forum with ad hominem exchanges.  What Chris says is dead on, and something which I learned a couple of years ago, after a reasonably minimal amount of ear boxing.

Gonzo, you seem sharp, and have considerable concern, as do the rest of us. We are all on the same page, I think. It is completely false to presume stupidity on the part of the people posting here (for the most part...).  You would do well to listen more, and question more, rather than  insult and condemn.

IF you are so certain the models are wrong, present your arguments.  Be prepared to discard them when people with better information and experience prove you wrong.  Engage in a discussion with equals; question, synthesize, rethink; its how we'll move our collective hunch forward and come up with a coherent message which I hope might, *Just* might sway some people in the right direction, and give us a chance.

Don't P*ss on people who are as concerned as you are, because you dislike with the tools they are using.

Give them better tools and better arguments.  It's ahelluva lot more difficult to *build* something than it is to tear it down.

You choose.

This space for Rent.

Neven

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Re: NSIDC 2015 Arctic SIE September minimum: August poll
« Reply #61 on: August 08, 2015, 11:48:21 AM »
What jdallen said. Get a grip, Gonzo.
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kynde

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Re: NSIDC 2015 Arctic SIE September minimum: August poll
« Reply #62 on: August 08, 2015, 03:01:55 PM »
What jdallen said and ...

As you know, (which many of these Brits and Floridians can't even comprehend, even when they stand upon actual ice... if they ever have ) ...

As someone who lives above 60N and has stood (walked, skied, skated, slept, etc) on ice more than most I can safely say that I gives you precious little insight to the inner working of the beast we're dealing with here. Seasonal ice over some sea or lakes is quite different from the perennial cap over the arctic sea. You'll do well if you pay heed to these experienced and smart Britons, Floridians, Austrians, Dutch, you name it.
« Last Edit: August 08, 2015, 06:28:14 PM by kynde »

Richard Rathbone

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Re: NSIDC 2015 Arctic SIE September minimum: August poll
« Reply #63 on: August 08, 2015, 04:27:28 PM »
Thanks Peter; I was not aware of the problems. Which time period is problematic; are today's maps decent?

Paul,

The problem itself may not be too hard to fix, for the very sharp people who run the model. But there are ongoing problems with the model, it might take them time to make sure it's all fine. I can only speak for myself, but I have put it aside until I am convinced it is working properly. I  am not convinced right now, over the last week I have seen ice disappearing then appearing over the same region.

CICE is a model of sea ice that is designed to be a sub model of global climate models but is sufficiently generic that it can be coupled into other models too, e.g. HYCOM. One set of variables is output from CICE and input to HYCOM, and another is output from HYCOM and input to CICE.

In both the Navy and DMI implementations measurements are also taken and used to adjust some of the variables as they are passed between HYCOM and CICE. Sea surface temperature is one of the inputs to CICE and ice concentration is one of the outputs from CICE and measurements of both of these are assimilated.

However, measurements are subject to noise and bias and measurements on one of the exchanged variables are not necessarily consistent with the other exchanged variables so its possible for the assimilated data to be driving the model further away from reality rather than preventing it drifting. This was seen with the Navy implementation. (and known because they corrected a cause of unrealistic output after Peter drew it to their attention)

CICE is a pretty sophisticated model, but its not designed to have measurements assimilated to it, its designed to have an internally consistent set of variables supplied to it by another model and to return another set of internally consistent variables to that model.

If I saw something to show that those assimilating data into CICE were giving the same sort of attention to assimilation as is done in PIOMAS, I'd start to have some confidence in their output but I haven't seen it yet.


Gonzo

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Re: NSIDC 2015 Arctic SIE September minimum: August poll
« Reply #64 on: August 08, 2015, 04:32:33 PM »
Ok, the models seem out of date. People seem to think there is a similarity between this year and 2012 for example. There is no similarity whatsoever. The corrected way of looking at this won't emerge until next year. This year is pivotal I think. It will be warmer, longer, and that is the key factor, and many aspects seem different looking at some of those maps year to year.
I'll post something in the 2015 Melt Season to show what I mean.
« Last Edit: August 08, 2015, 04:43:02 PM by Gonzo »

jdallen

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Re: NSIDC 2015 Arctic SIE September minimum: August poll
« Reply #65 on: August 08, 2015, 05:40:11 PM »
Ok, the models seem out of date. People seem to think there is a similarity between this year and 2012 for example. There is no similarity whatsoever. The corrected way of looking at this won't emerge until next year. This year is pivotal I think. It will be warmer, longer, and that is the key factor, and many aspects seem different looking at some of those maps year to year.
I'll post something in the 2015 Melt Season to show what I mean.
Excellent! Look forward to it.
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themgt

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Re: NSIDC 2015 Arctic SIE September minimum: August poll
« Reply #66 on: August 08, 2015, 07:01:56 PM »
I see that HYCOM/CICE are available open source. Has anyone documented a step-by-step (or better yet setup a Vagrant image) that can get grab the code + real data and run an integrated model locally?

ChrisReynolds

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Re: NSIDC 2015 Arctic SIE September minimum: August poll
« Reply #67 on: August 08, 2015, 07:28:31 PM »
I see that HYCOM/CICE are available open source. Has anyone documented a step-by-step (or better yet setup a Vagrant image) that can get grab the code + real data and run an integrated model locally?

...and sort out assimilation of something like NCEP/NCAR or ECWMF, and assimilate sea ice concentration...

PIOMAS code is behind a password (IIRC), but I can't see why Dr Zhang wouldn't let me have the password so I can sort out my own run of the model. There is a very simple reason I haven't asked Dr Zhang, I know enough to know that I would be beset at each stage of getting it working by all sorts of amateur f--k ups to the degree that I just wouldn't trust the result.

If you Google 'C-ice documntation' you'll find a discussion of the model. To fully understand it you probably need to read the majority of the referenced papers, and read quite a few of the references of those papers. Checking on the papers I have in my PIOMAS/papers folder I have 12 papers, I have read them all and broadly understand them all. But I run away with my tail between my legs when I ponder whether I could use the papers to make a version of PIOMAS, and I am quite happy to admit that.

Like Harry Callahan once said "A man's gotta know his limits".  8)

JD Allen, Well Put.

Nightvid Cole

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Re: NSIDC 2015 Arctic SIE September minimum: August poll
« Reply #68 on: August 08, 2015, 07:51:36 PM »
Regression mentioned in correlation thread leads me to 3.9 M km^2 as central estimate.

Jim Hunt

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Re: NSIDC 2015 Arctic SIE September minimum: August poll
« Reply #69 on: August 08, 2015, 08:30:31 PM »
I see that HYCOM/CICE are available open source. Has anyone documented a step-by-step (or better yet setup a Vagrant image) that can get grab the code + real data and run an integrated model locally?

I've built and run standalone CICE 4 using the example data. Start here and then go backwards:

http://forum.arctic-sea-ice.net/index.php/topic,108.msg52498.html#msg52498

I rather suspected that running HYCOM coupled to CICE would over extend my limited computing power, so I've also played with the University of Hamburg's "Planet Simulator":

http://forum.arctic-sea-ice.net/index.php/topic,262.0.html

I use VirtualBox for my VMs, and have never experimented with Vagrant. However if you do get a HYCOM+CICE image working I'll happily beta test it for you!

« Last Edit: August 08, 2015, 08:36:08 PM by Jim Hunt »
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ChrisReynolds

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Re: NSIDC 2015 Arctic SIE September minimum: August poll
« Reply #70 on: August 08, 2015, 09:33:25 PM »
SeaIceSailor,

I really don't think it's so secret, if it was why give it a download page?
http://psc.apl.washington.edu/zhang/IDAO/codes.html

If you didn't want to make it publicly available you just wouldn't do such a page.

seaicesailor

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Re: NSIDC 2015 Arctic SIE September minimum: August poll
« Reply #71 on: August 08, 2015, 09:36:18 PM »
SeaIceSailor,

I really don't think it's so secret, if it was why give it a download page?
http://psc.apl.washington.edu/zhang/IDAO/codes.html

If you didn't want to make it publicly available you just wouldn't do such a page.

There you go, the exception that makes the rule.
 8)

seaicesailor

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Re: NSIDC 2015 Arctic SIE September minimum: August poll
« Reply #72 on: August 08, 2015, 09:37:46 PM »
SeaIceSailor,

I really don't think it's so secret, if it was why give it a download page?
http://psc.apl.washington.edu/zhang/IDAO/codes.html

If you didn't want to make it publicly available you just wouldn't do such a page.

But it is password protected ??

Maybe I expressed myself incorrectly. Everybody knows that they work with this or that code. It is just that they dont give it away. Maybe my English failed me.

themgt

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Re: NSIDC 2015 Arctic SIE September minimum: August poll
« Reply #73 on: August 08, 2015, 10:42:21 PM »
Thanks ChrisReynolds / Jim Hunt, that's all useful/interesting in understanding this situation. I have to say coming from the tech community, there's a huge value that's been placed on robust open-source systems with good documentation. I do find it disappointing that for a mix of perhaps lack of effort, lack of coordination, some turf-wars and secrecy, that an average citizen can't just easily download and run a climate model themselves, see the underlying data sources and inspect the code to their ability - to look at code diffs and see why changes were made, etc.

I realize people lacking deep expertise in these fields won't necessarily have a lot to contribute, but I do believe government-funded science missions showing us outputs of a model run, ought to really make their best effort to make it truly transparent to citizens how that model works, what data and other models it interacts with, etc. Doing that ought to be a fundamental part of what it is to do science, especially in a field as important to understanding the decisions facing humanity as this.

I will try to carve out some time, and put it on Github and post here if I make any progress.

Neven

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Re: NSIDC 2015 Arctic SIE September minimum: August poll
« Reply #74 on: August 08, 2015, 10:57:05 PM »
Great, themgt, good luck, and post your findings in the Developers Corner.
Il faut comparer, comparer, comparer, et cultiver notre jardin

ChrisReynolds

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Re: NSIDC 2015 Arctic SIE September minimum: August poll
« Reply #75 on: August 08, 2015, 11:13:09 PM »
SeaIceSailor,

I really don't think it's so secret, if it was why give it a download page?
http://psc.apl.washington.edu/zhang/IDAO/codes.html

If you didn't want to make it publicly available you just wouldn't do such a page.

Yet it is there. At work we make info available to customers, but never our procedures, they are secret. So they're on an internal server with no such reference via the internet.
But it is password protected ??

Maybe I expressed myself incorrectly. Everybody knows that they work with this or that code. It is just that they dont give it away. Maybe my English failed me.

ChrisReynolds

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Re: NSIDC 2015 Arctic SIE September minimum: August poll
« Reply #76 on: August 08, 2015, 11:31:16 PM »
Themgt,

The code for Giss model e was freely available, and some years ago IIRC there was a stand alone climate model that ran on windows. Anyway, that's enough diversion of this thread.  :)

A-Team

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Re: NSIDC 2015 Arctic SIE September minimum: August poll
« Reply #77 on: August 09, 2015, 08:55:22 AM »
We discussed a similar code kurfluffle the other day over at Eisenmann vs Comiso  on the 'Is Antarctic sea ice really expanding?' forum.

Anything scientific paid for with government or charitable grants is in the public domain. It would not be possible to publish a paper without the peer reviewers having full access to the code purportedly used to generate the paper. You can't hoard anything material to a paper whether that be a mouse line or a line of code.

If someone wants to work at home on their own computer and on their own time as a startup, fine, but be prepared to thoroughly document your firewall. You have to understand that your university is intent on getting royalties off your work and your govt is not real interested in buying again something they already paid for.

I was involved one time in an uncommon situation where the IP actually interested the outside world. The university was all over us with policies and rules about getting their cut for doing nothing. So it ended up freely available to anyone .edu and $50k/pop for .coms but they got quite a bit of handholding for that. The paper just got its 3,000th citation today which is the real coin of the academic realm.

For sea ice, I see the occasional paper thanking exxon-mobil etc for their support, meaning they had early access to what would not have happened without them for a lot less than in-house. In most cases that access wouldn't remain exclusive over time.

Here I think the password is there simply so you have to request it, identify yourself, say what you plan to do with it (hopefully something more creative than scooping them), agree not to distribute the code further yourself (as bugs fixes by the original authors would not get propagated and they would get blamed), maybe agree not to fork the code (ie not share improvements with source authors), and above all make sure visitors know how to cite the code originators. These are reasonable conditions but unlikely to be accomplish anything.

I agree with everything that 'themgt' says above and would add that I find code management in these little scientific enclaves behind the times. It sounds like someone in Comiso's group was making what they thought were minor changes in code but not documenting those changes, much less versioning them. Then they turned out not to be minor but nobody can recall just what the changes were, who made them, or why.

That's really unacceptable. I mean, just look at wikipedia. Nobody can touch a page without it being indelibly recorded who did what when and above all it remains easy to walk back changes as far back in time as you want. Just talking about pennies of storage cost here.

It also sounds like Comiso's group were not checking out code sections to make improvements and then checking them back in for centralized QA. This leads to a nightmarish situation over time with people inadvertently overwriting each other and inexperienced coders doing repeated damage before being detected and trained. Academic backwater stuff, doesn't scale.
« Last Edit: August 09, 2015, 07:14:07 PM by A-Team »

Peter Ellis

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Re: NSIDC 2015 Arctic SIE September minimum: August poll
« Reply #78 on: August 09, 2015, 02:37:21 PM »
We discussed a similar code kurfluffle the other day over at Eisenmann vs Comiso  on the 'Is Antarctic sea ice really expanding?' forum.
Can you link?  I've searched but can't find anything newer than 2014 on this forum.

Jim Hunt

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Re: NSIDC 2015 Arctic SIE September minimum: August poll
« Reply #79 on: August 09, 2015, 03:37:20 PM »
I do find it disappointing that for a mix of perhaps lack of effort, lack of coordination, some turf-wars and secrecy, that an average citizen can't just easily download and run a climate model themselves, see the underlying data sources and inspect the code to their ability - to look at code diffs and see why changes were made, etc.

Don't be downhearted. Instead see this shiny new thread:

The Community Earth System Model

Quote
The source code for CESM releases is distributed through a public Subversion code repository
Reality is merely an illusion, albeit a very persistent one - Albert Einstein

Gonzo

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Re: NSIDC 2015 Arctic SIE September minimum: August poll
« Reply #80 on: August 10, 2015, 12:29:45 AM »
Is there a reason (other than possible increase of albedo effect) that everyone focuses on area, when volume is probably more important when it comes to the melting of the polar ice caps and even Greenland?

seaicesailor

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Re: NSIDC 2015 Arctic SIE September minimum: August poll
« Reply #81 on: August 10, 2015, 12:40:03 AM »
Is there a reason (other than possible increase of albedo effect) that everyone focuses on area, when volume is probably more important when it comes to the melting of the polar ice caps and even Greenland?

Albedo effect by itself, during May-July, is a very powerful reason to keep an eye on area during these months.

Another one is that area x thickness = volume. People cant measure thickness as precisely as area. So, area becomes a (bad and rough) proxy for what can be expected for volume, especially at the end of season when there is little surface melting, and area  measurement is more accurate.

Edit: a third one is that a low minimum area implies a lot of weak FYI for the next season
« Last Edit: August 10, 2015, 12:47:42 AM by seaicesailor »

Gonzo

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Re: NSIDC 2015 Arctic SIE September minimum: August poll
« Reply #82 on: August 10, 2015, 01:04:45 AM »
Quote
seaicesailor
Albedo effect by itself, during May-July, is a very powerful reason to keep an eye on area during these months.
Another one is that area x thickness = volume. People cant measure thickness as precisely as area. So, area becomes a (bad and rough) proxy for what can be expected for volume, especially at the end of season when there is little surface melting, and area  measurement is more accurate.
Edit: a third one is that a low minimum area implies a lot of weak FYI for the next season

Thanks.
Makes sense.

epiphyte

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Re: NSIDC 2015 Arctic SIE September minimum: August poll
« Reply #83 on: August 10, 2015, 05:06:36 PM »
3.25-3.5 ... Back to where I was in June.

seaicesailor

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Re: NSIDC 2015 Arctic SIE September minimum: August poll
« Reply #84 on: August 10, 2015, 08:39:54 PM »

I will wait until August 13, then will look for 12Z GFS forecast and adjust my prediction, by how much depends if that extra-tropical goes into the hole or not.

In the meantime there is some interesting movement around Beaufort and nearby: weak cyclone and warm air dragged from continent. CAA anomalously warm, as usual.


DoomInTheUK

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Re: NSIDC 2015 Arctic SIE September minimum: August poll
« Reply #85 on: August 11, 2015, 01:43:46 PM »
4.0 - 4.25  It's a balance between expecting a lot of thin ice to go 'poof', and the reduction of insolation....oh and the bottom melt, compaction, diversion, export and many more. Hell, I have no idea.

The big one is coming, but I just don't feel it this year.

Gonzo

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Re: NSIDC 2015 Arctic SIE September minimum: August poll
« Reply #86 on: August 11, 2015, 06:32:24 PM »
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DoomInTheUK: The big one is coming, but I just don't feel it this year.
Watch ice concentration over the next week. I think that will be a huge indicator. If it reds, yellows (and greens) continue to grow throughout the icesheet, that could be a game-changer from previous years.

ChrisReynolds

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Re: NSIDC 2015 Arctic SIE September minimum: August poll
« Reply #87 on: August 11, 2015, 09:50:46 PM »
Before the poll closes I am jumping up for the last time. 4.5 to 4.75M km^2 for the Sept average extent.

That means I have meandered all over the place and ended up back where I was when I calculated my SIPN prediction in May....

From now on I advise people not to pay attention to anything I say.   ::)

Ho hum.

jai mitchell

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Re: NSIDC 2015 Arctic SIE September minimum: August poll
« Reply #88 on: August 11, 2015, 11:57:41 PM »
3.2 to 3.5

same as the first day.
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Paddy

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Re: NSIDC 2015 Arctic SIE September minimum: August poll
« Reply #89 on: August 12, 2015, 08:49:05 AM »
A late vote for 4.5 to 4.75.  Something in the vicinity of 2011's result looks pretty reasonable.  This is the same as my July prediction, and one bin lower than my June prediction.

EDIT: It's curious how "something in the vicinity of 2011" comes out at the upper end of the distribution for this poll, but the middle of the distribution for the Cryosphere poll.  Any ideas why?
« Last Edit: August 12, 2015, 12:45:52 PM by Paddy »

DoomInTheUK

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Re: NSIDC 2015 Arctic SIE September minimum: August poll
« Reply #90 on: August 12, 2015, 01:13:06 PM »
Quote
DoomInTheUK: The big one is coming, but I just don't feel it this year.
Watch ice concentration over the next week. I think that will be a huge indicator. If it reds, yellows (and greens) continue to grow throughout the icesheet, that could be a game-changer from previous years.

I think there will be some 'poofage', but not to the 'where did all the ice go?' stage. The coming refreeze will be critical. If we get an early cover of snow to insulate the ice, then next year could be very entertaining. This one isn't too bad either.

Of course it's all conjecture - I've given up assuming I have even half an idea. I'll just sit back and watch, we're all disinterested parties after all.

Gonzo

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Re: NSIDC 2015 Arctic SIE September minimum: August poll
« Reply #91 on: August 12, 2015, 04:04:33 PM »
I've stuck with 3.5-3.75. Nice to find out I am closer to Prof. Wadhams of Cambridge, than most folks (really hope it is much much higher though, more like 5 )

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Re: NSIDC 2015 Arctic SIE September minimum: August poll
« Reply #92 on: August 12, 2015, 04:09:14 PM »
DoomInTheUK
Quote
The coming refreeze will be critical.
I think the season will be longer because of record temps. set all around the world this year (and every month)

Quote
If we get an early cover of snow to insulate the ice, then next year could be very entertaining.
Maybe, but if it snows but the water is still above freezing?

Quote
Of course it's all conjecture - I've given up assuming I have even half an idea.
Yea, if you look at that chart posted in 2015 melting season by F.Tnioli, the scientists have about the same spread of predictions as this group here (apart from Wadhams...which is fascinating!)

Tor Bejnar

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Re: NSIDC 2015 Arctic SIE September minimum: August poll
« Reply #93 on: August 12, 2015, 05:36:45 PM »
A foot (sorry, I mean 30 cm) of snow on thin ice will insulate the ice/water system and slow ice buildup.

This much snow on water will lower the salinity of the surface layer and aid initial freezing.

Early in this melting season, I recall someone showed images of an iced over lead (near Siberia) that seemed more resilient than older snow-covered ice.  (It appeared black when older ice showed white, and vice versa, or something like that.)  I wonder if this was an example of early snow cover significantly affecting ice thickness.
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Re: NSIDC 2015 Arctic SIE September minimum: August poll
« Reply #94 on: August 12, 2015, 06:34:01 PM »
(really hope it is much much higher though, more like 5 )
A sentiment we all share, Gonzo, for certain.
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seaicesailor

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Re: NSIDC 2015 Arctic SIE September minimum: August poll
« Reply #95 on: August 12, 2015, 07:59:45 PM »
Sorry, does the poll finish today or tomorrow? GMT+2, EDT, Pitcairn time...?  :)

cats

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Re: NSIDC 2015 Arctic SIE September minimum: August poll
« Reply #96 on: August 12, 2015, 08:09:07 PM »
Just moved my vote down a bin to 4.25-4.5 - thinking it will be closer to 4.5, but might, depending on weather/compaction, be closer to the 4.25.  Totally unscientific most based on watching the Uni Bremen maps :)

ChrisReynolds

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Re: NSIDC 2015 Arctic SIE September minimum: August poll
« Reply #97 on: August 12, 2015, 08:41:38 PM »
Sorry, does the poll finish today or tomorrow? GMT+2, EDT, Pitcairn time...?  :)

Ooh! Ooh! I have more time to change my mind?  :o

Neven

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Re: NSIDC 2015 Arctic SIE September minimum: August poll
« Reply #98 on: August 12, 2015, 08:49:56 PM »
Sorry, does the poll finish today or tomorrow? GMT+2, EDT, Pitcairn time...?  :)

I believe forum time is CET (central Europe, my location), and so the poll should close in 14 hours.
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Re: NSIDC 2015 Arctic SIE September minimum: August poll
« Reply #99 on: August 12, 2015, 09:13:32 PM »
Changed from 3.75-4.0 to next bin up. 4.0-4.25. Getting toward end of melt season.