Support the Arctic Sea Ice Forum and Blog

Author Topic: The 2014 Melting Season  (Read 1413602 times)

Michael Hauber

  • Grease ice
  • Posts: 896
    • View Profile
  • Liked: 74
  • Likes Given: 14
Re: The 2014 Melting Season
« Reply #2950 on: August 08, 2014, 06:04:19 AM »

If you want to convince me of this (not that you do), then quantify it. "Significance" implies a statistical test.



A hack way of quantifying it:  We are double the previous max distance above the trend for July PIOMAS volume.  Maximum over 30 years is roughly 2 sigma above the trend (1 in 22).  So the current position is 4 sigma above the trend.  This is a 1 in 16 000 probability of happening by chance.

Of course this calculation assumes normal distribution which is not true, but it should be accurate enough to give the general idea that the current situation is extremely unlikely to have occurred if an exponential trend in July Piomas volume is the true underlying trend.
Climate change:  Prepare for the worst, hope for the best, expect the middle.

greatdying2

  • Grease ice
  • Posts: 574
    • View Profile
  • Liked: 0
  • Likes Given: 0
Re: The 2014 Melting Season
« Reply #2951 on: August 08, 2014, 06:13:28 AM »
A hack way of quantifying it:  We are double the previous max distance above the trend for July PIOMAS volume.

What trend? [Edit:] Oh, some specific exponential trend based on previous years? Yes, clearly this is just a description of data up to a certain year. And exponential seems a bit severe to me. Is it well supported.

Are you saying that if the decline is not exponential, that we are in a recovery?
The Permian–Triassic extinction event, a.k.a. the Great Dying, occurred about 250 million years ago and is the most severe known extinction event. Up to 96% of all marine species and 70% of terrestrial vertebrate species became extinct; it is also the only known mass extinction of insects.

ktonine

  • Frazil ice
  • Posts: 363
    • View Profile
  • Liked: 0
  • Likes Given: 0
Re: The 2014 Melting Season
« Reply #2952 on: August 08, 2014, 06:24:15 AM »

A hack way of quantifying it:  We are double the previous max distance above the trend for July PIOMAS volume.  Maximum over 30 years is roughly 2 sigma above the trend (1 in 22).  So the current position is 4 sigma above the trend.  This is a 1 in 16 000 probability of happening by chance.



Sorry, Don't follow your reasoning at all.  We're less than 1/2 SD above the linear trend - and the uncertainties actually allow for 'true'  volume to be below trend. 

Frivolousz21

  • Nilas ice
  • Posts: 1813
  • Live in Belleville, IL..15 miles SE of St. Louis.
    • View Profile
  • Liked: 517
  • Likes Given: 5
Re: The 2014 Melting Season
« Reply #2953 on: August 08, 2014, 07:14:31 AM »
As the ESS melts down/out and the Laptev is pushed well into the 85N level of the pole.  I think losses will be well above climo in the 10-20th period at the least.


Whether or not that is enough to make a big difference remains to be seen.

But the physical impact of the pattern can clearly be seen now.





I got a nickname for all my guns
a Desert Eagle that I call Big Pun
a two shot that I call Tupac
and a dirty pistol that love to crew hop
my TEC 9 Imma call T-Pain
my 3-8 snub Imma call Lil Wayne
machine gun named Missy so loud
it go e-e-e-e-ow e-e-e-e-e-e-blaow

Frivolousz21

  • Nilas ice
  • Posts: 1813
  • Live in Belleville, IL..15 miles SE of St. Louis.
    • View Profile
  • Liked: 517
  • Likes Given: 5
Re: The 2014 Melting Season
« Reply #2954 on: August 08, 2014, 07:17:22 AM »

If you want to convince me of this (not that you do), then quantify it. "Significance" implies a statistical test.



A hack way of quantifying it:  We are double the previous max distance above the trend for July PIOMAS volume.  Maximum over 30 years is roughly 2 sigma above the trend (1 in 22).  So the current position is 4 sigma above the trend.  This is a 1 in 16 000 probability of happening by chance.

Of course this calculation assumes normal distribution which is not true, but it should be accurate enough to give the general idea that the current situation is extremely unlikely to have occurred if an exponential trend in July Piomas volume is the true underlying trend.

??????

There is a very high probability with the way July ended and August is going that volume will finish around 5500km3 or below 6500km3 of 2007 almost certainly.

Which would make it the 5th lowest on record. 

How can that possibly be 4SD about the trend.  Just eye balling it things would need to be like mid 1990s levels to be anywhere near that.






I got a nickname for all my guns
a Desert Eagle that I call Big Pun
a two shot that I call Tupac
and a dirty pistol that love to crew hop
my TEC 9 Imma call T-Pain
my 3-8 snub Imma call Lil Wayne
machine gun named Missy so loud
it go e-e-e-e-ow e-e-e-e-e-e-blaow

cesium62

  • Frazil ice
  • Posts: 286
    • View Profile
  • Liked: 9
  • Likes Given: 1
Re: The 2014 Melting Season
« Reply #2955 on: August 08, 2014, 07:46:14 AM »
The jump from 2012 to 2013 is roughly equal to the largest previous single season jump.  I would argue that if the final September value this year has an equal increase that the trend has been broken and that we have a significant 'recovery' and the trend line on that chart has been broken and a new trend has to be found. 

Yes, if the 2014 September value manages to be higher than the current value and above the 1981 to 2010 average, that would be quite interesting.  I don't know that I'd call it a recovery:  the path of the melt is so strange with the minimum suddenly occuring in August or early September followed by a freak freeze...

jdallen

  • Young ice
  • Posts: 3188
    • View Profile
  • Liked: 395
  • Likes Given: 200
Re: The 2014 Melting Season
« Reply #2956 on: August 08, 2014, 08:14:26 AM »

Exactly. Anyone who even tries to use the word "pause" or "recovery" to describe recent years is going against all the observational and historical data that shows otherwise.



I think there is no better word for what is happening right now than recovery.  As long as it is noted in the context of the longer term downward trend and that it is only temporary.  Of course temporary could end up more than a decade.  To me this recovery is more significant than pure random noise.  The two years of recovery has changed my opinion of the possibility of ice free conditions by 2020 from quite reasonable but not guaranteed to extremely unlikely.  It has not changed my opinion one iota on the inevitability of ice free conditions sooner or later.

Recovery is still too strong a word, Michael.  Recovery is a word I would use when we pass back over the volume we had in 1998.  It would be a word I would use if we see the physical integrity of the pack recover to what it was before 2012.  If that happens, I will use it, and be happy.

It is not a word I would use when the volume is still looks to be coming in under the average of the last 10 years.  Regression and feedback are two words I would apply to what we are seeing, but not recovery.
This space for Rent.

cesium62

  • Frazil ice
  • Posts: 286
    • View Profile
  • Liked: 9
  • Likes Given: 1
Re: The 2014 Melting Season
« Reply #2957 on: August 08, 2014, 08:24:22 AM »

A hack way of quantifying it:  We are double the previous max distance above the trend for July PIOMAS volume.  Maximum over 30 years is roughly 2 sigma above the trend (1 in 22).  So the current position is 4 sigma above the trend.  This is a 1 in 16 000 probability of happening by chance.



Sorry, Don't follow your reasoning at all.  We're less than 1/2 SD above the linear trend - and the uncertainties actually allow for 'true'  volume to be below trend.

I think y'all are purposely misreading Michael's argument.  He's saying two things.

1)  If in the linear PIOMAS trend graph the 2014 volume had shot up to about -1, that would have been damned interesting.

2)  On the exponential trend graph of the july PIOMAS volumes, 2014 doesn't seem to fit that line, suggesting the exponential trend graph is bogus.  Of course, my reading of the exponential trend graph was that it was not to be taken too seriously (see the comment on the graph for example), and there are various statistical issues you'ld have to walk me through very slowly so that I could see the 2-sd curve around that exponential trend line.  But Michael's basic point is not unreasonable.

6roucho

  • Frazil ice
  • Posts: 296
  • Finance geek
    • View Profile
  • Liked: 0
  • Likes Given: 1
Re: The 2014 Melting Season
« Reply #2958 on: August 08, 2014, 09:07:27 AM »
Exponential trends can be relatively volatile when recent outliers are absorbed by the linear trend.

Frivolousz21

  • Nilas ice
  • Posts: 1813
  • Live in Belleville, IL..15 miles SE of St. Louis.
    • View Profile
  • Liked: 517
  • Likes Given: 5
Re: The 2014 Melting Season
« Reply #2959 on: August 08, 2014, 09:11:47 AM »
The exponential volume trend is pretty irresponsible
I got a nickname for all my guns
a Desert Eagle that I call Big Pun
a two shot that I call Tupac
and a dirty pistol that love to crew hop
my TEC 9 Imma call T-Pain
my 3-8 snub Imma call Lil Wayne
machine gun named Missy so loud
it go e-e-e-e-ow e-e-e-e-e-e-blaow

epiphyte

  • Frazil ice
  • Posts: 384
    • View Profile
  • Liked: 21
  • Likes Given: 18
Re: The 2014 Melting Season
« Reply #2960 on: August 08, 2014, 09:20:00 AM »
I keep seeing "standard deviation" being invoked as an occult incantation rather than anything vaguely related to the scientific method. The term is meaningless unless there is a statistically significant baseline against which to measure the next sample.

One might just as well measure the position of a bullet before and after the gun has been fired, and conclude that the chances of it hitting the target are infinitesimal, since it would require an 11.3 SD change in velocity, measured in furlongs per fortnight.



Neven

  • Administrator
  • First-year ice
  • Posts: 7705
    • View Profile
    • Arctic Sea Ice Blog
  • Liked: 1061
  • Likes Given: 504
Re: The 2014 Melting Season
« Reply #2961 on: August 08, 2014, 09:45:52 AM »
Somewhat belated, but not too late I have posted the August polls for NSIDC SIE and CT SIA minimums.
Il faut comparer, comparer, comparer, et cultiver notre jardin

6roucho

  • Frazil ice
  • Posts: 296
  • Finance geek
    • View Profile
  • Liked: 0
  • Likes Given: 1
Re: The 2014 Melting Season
« Reply #2962 on: August 08, 2014, 09:47:56 AM »
I keep seeing "standard deviation" being invoked as an occult incantation rather than anything vaguely related to the scientific method. The term is meaningless unless there is a statistically significant baseline against which to measure the next sample.

One might just as well measure the position of a bullet before and after the gun has been fired, and conclude that the chances of it hitting the target are infinitesimal, since it would require an 11.3 SD change in velocity, measured in furlongs per fortnight.

The Arctic sea ice anomaly baseline is statistically significant.

Richard Rathbone

  • Grease ice
  • Posts: 764
    • View Profile
  • Liked: 123
  • Likes Given: 10
Re: The 2014 Melting Season
« Reply #2963 on: August 08, 2014, 10:10:08 AM »

A hack way of quantifying it:  We are double the previous max distance above the trend for July PIOMAS volume.  Maximum over 30 years is roughly 2 sigma above the trend (1 in 22).  So the current position is 4 sigma above the trend.  This is a 1 in 16 000 probability of happening by chance.



Sorry, Don't follow your reasoning at all.  We're less than 1/2 SD above the linear trend - and the uncertainties actually allow for 'true'  volume to be below trend.

I think y'all are purposely misreading Michael's argument.  He's saying two things.

1)  If in the linear PIOMAS trend graph the 2014 volume had shot up to about -1, that would have been damned interesting.

2)  On the exponential trend graph of the july PIOMAS volumes, 2014 doesn't seem to fit that line, suggesting the exponential trend graph is bogus.  Of course, my reading of the exponential trend graph was that it was not to be taken too seriously (see the comment on the graph for example), and there are various statistical issues you'ld have to walk me through very slowly so that I could see the 2-sd curve around that exponential trend line.  But Michael's basic point is not unreasonable.

In 2012 it looked like there was a new seasonal pattern. There shouldn't be a seasonal pattern to an anomaly graph, the whole point of plotting as an anomaly is to remove the seasonal pattern and there was a strong one.

In 2014 it looks like the old pattern has reasserted itself. Characteristics of 2007-12, the aggressive spring melt, summer Fram export are back to their pre-2006 pattern and the PIOMAS anomaly is back to its old pattern too.

Glenn Tamblyn

  • Frazil ice
  • Posts: 128
    • View Profile
  • Liked: 1
  • Likes Given: 0
Re: The 2014 Melting Season
« Reply #2964 on: August 08, 2014, 10:17:37 AM »
The seasonal pattern in the PIOMAS anomaly graph arises because their algorithm for removing a seasonal pattern is breaking down.

They use the average seasonal swing over much of the measurement period to remove the seasonal cycle from the anomaly values to try and present data which at every point is an anomaly after considering the seasonal cycle.

However in the last few years the size of the seasonal cycle has grown significantly with increased summer melt and noot as much of a decline in winter.

So their algorithm isn't adequately removing the larger current seasonal cycle, leaving a residual that appears in the anomaly graph.

They need a  better algorithm but how do you implement one that keeps the anomalies meaningful. Anomalies relative to what?

Peter Ellis

  • Grease ice
  • Posts: 617
    • View Profile
  • Liked: 34
  • Likes Given: 13
Re: The 2014 Melting Season
« Reply #2965 on: August 08, 2014, 10:21:48 AM »
Thanks Chris. Actually tritium is the only concern I have, and that is because it is still the most common contaminant being released from Fukushima, can not be measured in the atmosphere (if memory serves), and would have an effect on both ice formation and melt.
How?  The only webpage I could find by Googling this is this one, which is from someone who's so confused that (to quote Pauli) they're not even wrong. 
http://www.rense.com/general96/arctic.html

I mean, just look at this paragraph:
Quote
"Tritium, radioactive heavy water, is produced inside nuclear reactors in especially high concentration with the use of plutonium-rich mixed-oxide fuel (MOX). Tritium, which has two neutrons in addition to a proton, has similar physical properties as normal H20, including evaporation to form clouds and precipitation in rain. The one major difference is their freezing-melting points. Normal water turns to ice at 0 Celsius. The freezing-melting point of tritium is -252 C.  The presence of minute quantities of tritium can therefore destabilize the crystalline structure of ice and prevent normal water from freezing even in the coldest winter temperatures on Earth."

Tritium is an isotope of hydrogen. Yes, tritium gas freezes at -252 C, but that's T2 molecules, analogous to hydrogen gas (H2).  The freezing point of tritiated water (T2O) is higher than normal H2O.
« Last Edit: August 08, 2014, 10:32:49 AM by Peter Ellis »

plinius

  • Frazil ice
  • Posts: 403
    • View Profile
  • Liked: 0
  • Likes Given: 0
Re: The 2014 Melting Season
« Reply #2966 on: August 08, 2014, 10:36:15 AM »
You are not seriously suggesting that Tritium from Fukushima has a significant impact on arctic sea ice melt, are you?

F.Tnioli

  • Grease ice
  • Posts: 763
    • View Profile
  • Liked: 147
  • Likes Given: 36
Re: The 2014 Melting Season
« Reply #2967 on: August 08, 2014, 01:48:12 PM »
Its not all about 300 or 400 W/m².
Albedo is important and very different for different sun angles.


Neither ice nor water are plain surfaces. Ice is usually snow covered, actual angles between sunrays and absorbing surfaces of snowflakes fluctuate wildly. If not snow covered, ice is often not plain as well, as there are all sorts of bumps, holes and pieces of older ice frozen together. Open water is rarely strictly plain surface as well, - as long as there are winds (and summer-time, there are lots of winds due to insolation, which drives convectional processes in the athmosphere, which results in significant winds in most locations most of the time). Because winds create waves, and waves change water surface geometry.

I fail to see how the graph presented could significantly cancel the importance of 400 W per square meter of current peak insolation within ESS. Yes, geometry matters, but to properly account for it, much more complex than this single graph considerations are nesessary. Especially if melt ponds are involved, and i bet melt ponds are involved in quite much of ice covered regions of Arctic, at this time.
To everyone: before posting in a melting season topic, please be sure to know contents of this moderator's post: https://forum.arctic-sea-ice.net/index.php/topic,3017.msg261893.html#msg261893 . Thanks!

Gray-Wolf

  • Grease ice
  • Posts: 871
    • View Profile
  • Liked: 104
  • Likes Given: 296
Re: The 2014 Melting Season
« Reply #2968 on: August 08, 2014, 01:52:05 PM »
Merely for the fact that this years melt did not smash 2012's low extent/area we will see the crop of September 'recovery' stories in the denier media blogs and across the environment forums but folk should not be fooled into thinking that 'recovery' is the word to use?

I'm sure that many of us wanted 2012's stark warning to be repeated but knew that a couple of years of 'rebound' were probably the way things would pan out?

We had the same after 07' and , at the time, i thought we would need wait for the next 'perfect melt storm' synoptic ( every 10 to 20 years with the two before 07' showing a ten year spacing) to see any significant drop below 07' but by 2010 it had become clear that the ice was not waiting for that!

As it is 2012 seems to have had impact in that we have had two good summers across the UK ( ie the Jet pattern remains 'tweaked' but has shifted slightly west taking the 'stuck rainfall' patterns into Europe for two early summers running and placing central/eastern US under trough synoptics instead of the ridge they had been suffering prior to 2012).

I believe that the fact that Arctic ice is not repeating 2012 does not mean that we have lost the 'tweak' to the jet patterns with the high latitudes still suffering far higher temps than they should so still lessening the temp/pressure gradient between pole and equator and the 'altered' weather patterns this produces. We saw what last winters Jet patterns meant for ice development and we could just as easily see a 1980's style Fram train develop this autumn?

For me it will be next year that we see the sea ice again move in on a 2012 type melt? It's rebound years will be over and we will plod on with generally poor sea ice that is preconditioned for melt and only awaiting the wrong weather over the wrong part of the season?

As for 2016 + or - 3 years for an ice free Arctic? Well the earliest another 'perfect melt storm' synoptic can be expected is 2017 (if timings follow the two prior to 07') and I , for one, am waiting to see what that kind of 'weather' will make of the new Arctic basin!
KOYAANISQATSI

ko.yaa.nis.katsi (from the Hopi language), n. 1. crazy life. 2. life in turmoil. 3. life disintegrating. 4. life out of balance. 5. a state of life that calls for another way of living.
 
VIRESCIT VULNERE VIRTUS

F.Tnioli

  • Grease ice
  • Posts: 763
    • View Profile
  • Liked: 147
  • Likes Given: 36
Re: The 2014 Melting Season
« Reply #2969 on: August 08, 2014, 02:10:49 PM »
...  It's basically overlying the 2009 track for the last couple of weeks, and is if anything lower than the historical average melt rate for the time of year.

I mean that last sentence absolutely literally.

Melt over the last week was -376335 km^2.  Average for the 2000s is -508913 km^2.  Average for the 90s is -455647   km^2.  Average for the 80s is -501229 km^2.

That's not a cherry picked date either.  Whether I look at the last day, the last three days, the last week, the last ten days or the last fortnight, or any value in between, the current rate of loss of Arctic sea ice is lower than the 2000s average, lower than the 1990s average, and lower than the 1980s average.

...
This is a very important observation, but not in a way most collegues would initially suggest.

I ask everyone here: how, exactly, do we have much-slower-than-ever-recorded melt, given the fact of general warming in the Arctic and within subpolar areas of northern Hemisphere during last 3+ decades?

I mean it. We know Arctic is MUCH warmer than it was 30 years ago, in general. We clearly see - until last two years, - accelerating summer melt (the trend of increasing difference between any year's maximum and minimum Arctic ice coverage). We clearly see trends of decreasing maximum and minimum extents during 1990s and 2000s. It doesn't take an Einstein to say: yep, it's getting warmer, in general.

2013 had its "if"s and "but"s, but not everything was explainable with those. Now, even with a big (or is it "huge"?) area of high pressure right over Arctic, we see record-low melts.

Why?

I have no way to prove it, but i have my reasons to suspect (such as certain parts of some discussions which i - nor any person of "general public" - was not meant to see) that man-made cooling of Arctic - in fact, geo-engineering project, - has started in the Arctic in 2013. I had this suspicion in 2013, when rather unprecedented halt of Arctic ice area decrease happened for some 10+ days during early August 2013. Current events are but one more reason to suspect that such a project not only have started in 2013, but continues to be implemented right now.

If my suspicion is correct - i.e. if such a project is indeed being implemented inthe Arctic, - then there are cons and pros to it. Good thing, obviously, is that Arctic ice will continue its recovery (assuming the project will be as efficient as it is so far). It's awesomely great news for all of us, since consequences of losing practically all summer sea ice in the Arctic are no less than catastrophic for the climate of Earth (and consequently, for human agriculture, safety from "natural" disasters, sea level rise (Greenland melt would be massively affected), global warming itself (including methane clathrates problem, "no more heatsink in the Arctic" problem), etc. In the same time, it's bad news in that 1) mankind becomes dependant on ongoing (and inevitably intensifying) geoengineering project in the Arctic, and there is no certainty such a project could continue for any given length of time; 2) Arctic sea ice complete summer loss prevented, this gives a big-time argument to deiers, and big-time "go for it" to fossil fuel companies, resulting in worse-than-otherwise-expected pollution levels (all sorts related, from CO2 to oil spills); 3) such a geo-engineering project will possibly have unforeseen side effects, and nobody can know for sure how destructive such side-effects may be.

All this is not even a hypothesis - rather, it's just a thought, nothing more. But i am curious to know what you people would say about this. Especially in the way of "ok, if we'd suppose, just for a moment, that such geo-engineering project ("cooling") in the Arctic started some time in 2013 and goes on right now, affecting this year's melt season, then this allows to explain this-and-this-and-this, but this contradicts that-and-that-and-that".

So please, tell me.
« Last Edit: August 08, 2014, 02:21:02 PM by F.Tnioli »
To everyone: before posting in a melting season topic, please be sure to know contents of this moderator's post: https://forum.arctic-sea-ice.net/index.php/topic,3017.msg261893.html#msg261893 . Thanks!

Jim Pettit

  • Global Moderator
  • Nilas ice
  • Posts: 1175
    • View Profile
  • Liked: 40
  • Likes Given: 11
Re: The 2014 Melting Season
« Reply #2970 on: August 08, 2014, 02:18:13 PM »
I suppose it boils down to how one defines the term "recovery". To some denialists, if today's temperature is a degree lower than yesterday's, the climate is in a "recovery".

Ah, well, to each their own.

Having said that, this has been a confounding season for me. After a decent start, and in spite of many weeks worth of predictions that the Arctic ice would be "blasted" or "pounded" or "beat" or "torched" due to a coming weather pattern, the ice simply isn't going away. For instance:

JAXA sea ice extent started July in pretty poor shape, staying in third place for the first half of the month. Since then, however, extent has decreased at one of the slowest rates ever measured for the period. In fact, only 2010 lost less extent from 01 July to now, while both 2007 and 2012 lost a million or so square kilometers more for that period. Even "recovery year" 2013 had a much steeper rate of decrease. (From July 11 through now, JAXA SIE has experienced but a single century drop. By way of comparison, 2013 recorded eight, 2012 had 11, and 2007 saw 14. Even 2010, which was nothing special, managed to scrape together five century breaks over the period.) (2014 extent is, for the first time ever, more than a million km2 above 2012's same day number.)

Cryosphere Today sea ice area has been equally confounding, especially with its repeated plunging and stalling, plunging and stalling, plunging and stalling; this year, SIA hasn't been able to put together a long string of days with substantial drop as we've sen in previous years. And this wasn't due to a "bad start"; in fact, 2014 fellow below the 12 million mark two days faster than did 2012, and it fell below 11 million earlier as well. Since then, however, 2014 has fallen consistently back; it's now 16 days behind 2012. 2012 dropped below 3 million on August 15; it's highly doubtful that 2014 will manage to limp below 4 million by that date.

And so on.

So. If the very short term is considered, I suppose there's ample excuse to call 2013 and 2014 "recovery" years. But given the past 3-5 year periodicity of Arctic ice, I will be highly surprised if this current "recovery" lasts into another season or longer.

greatdying2

  • Grease ice
  • Posts: 574
    • View Profile
  • Liked: 0
  • Likes Given: 0
Re: The 2014 Melting Season
« Reply #2971 on: August 08, 2014, 02:28:41 PM »

I have no way to prove it, but i have my reasons to suspect (such as certain parts of some discussions which i - nor any person of "general public" - was not meant to see) that man-made cooling of Arctic - in fact, geo-engineering project, - has started in the Arctic in 2013.

Good one.  ;D

Where is the energy coming from, aliens?
The Permian–Triassic extinction event, a.k.a. the Great Dying, occurred about 250 million years ago and is the most severe known extinction event. Up to 96% of all marine species and 70% of terrestrial vertebrate species became extinct; it is also the only known mass extinction of insects.

F.Tnioli

  • Grease ice
  • Posts: 763
    • View Profile
  • Liked: 147
  • Likes Given: 36
Re: The 2014 Melting Season
« Reply #2972 on: August 08, 2014, 02:36:05 PM »
....
So. If the very short term is considered, I suppose there's ample excuse to call 2013 and 2014 "recovery" years. But given the past 3-5 year periodicity of Arctic ice, I will be highly surprised if this current "recovery" lasts into another season or longer.
If there is no (non-public, obviously) geo-engineering involved, then i am ALREADY highly surprised. 2013 could be "a freak cold year", ok, but two in a row, given the general conditions of more GHGs and rising temps? We see Alaska, Siberia, Scandinavia making lots and lots of big-time temperature records (maximum high for the day). I mean thousands of them, during 2013 and 2014. Sometimes several weeks in a row are all days with "highest ever recorded" temperatures in those subpolar/polar places.

To expect Arctic sea ice to end up with higher (2013) and then possibly higher yet again (2014) extent "naturally" in such conditions? Difficult, to say the least.

I am not alone, too. Wadhams - who, may i remind, spend some 15+ years doing udner-ice trips in submarines in the Arctic, - was firmly sure few years ago that ASI will only accelerate the decrease of its annual-minimum extent (and, of course, area and volume). Maslowski et al and, i guess, US Navy in general - were expecting it ice-free by 2016 plus-minus 3 years since ~2011 or even earlier. Papers are available (still available, i hope). PIOMASS showing ~80% minimum summer volume loss since 1979 by 2012, and obvious acceleration of the loss during 2000s. All those and other quite respectable works are pointing out that even if 2013 was "freak cold once-in-a-century kind of Arctic summer" - the general trends must lead to the 2014 being not so far from 2012, quite likely below it, in terms of minimum extent and volume.

I've been expecting it to happen this year, and mentioned that in this very topic some 2...3 months ago.

Screw me and my expectations, though. No big deal. The point is - without "something changed, big-time", 2013 events and current events taken together - are quite impossible to explain, in my humble opinion; what this "something changed, big-time" might be - THIS is what i am really curious about, and as mentioned in my previous message, currently i have only one guess: big-time geo-engineering "cooling the Arctic" is going on.

P.S. This year, perhaps they started earlier during melt season than in 2013, but with less intensity. To better hide the effect - 2013's early august halt of the ASI melt was highly noticeable. Eh?
To everyone: before posting in a melting season topic, please be sure to know contents of this moderator's post: https://forum.arctic-sea-ice.net/index.php/topic,3017.msg261893.html#msg261893 . Thanks!

F.Tnioli

  • Grease ice
  • Posts: 763
    • View Profile
  • Liked: 147
  • Likes Given: 36
Re: The 2014 Melting Season
« Reply #2973 on: August 08, 2014, 02:38:46 PM »

I have no way to prove it, but i have my reasons to suspect (such as certain parts of some discussions which i - nor any person of "general public" - was not meant to see) that man-made cooling of Arctic - in fact, geo-engineering project, - has started in the Arctic in 2013.

Good one.  ;D

Where is the energy coming from, aliens?
Please read about global dimming. Where's energy for THAT comes from? Even IPCC admits aerosols take out substantial part of radiative forcing - _globally_, no less.

Geez. HAve a BIT of scientific fantasy, would you. Cooling doesn't mean directly decreasing temperatures, - in this case, it certainly doesn't, since for such direct temperature decrease, there are no appropriate power sources indeed. Doesn't mean it's impossible, though.

Cheers!
« Last Edit: August 12, 2014, 08:24:52 AM by F.Tnioli »
To everyone: before posting in a melting season topic, please be sure to know contents of this moderator's post: https://forum.arctic-sea-ice.net/index.php/topic,3017.msg261893.html#msg261893 . Thanks!

sofouuk

  • New ice
  • Posts: 82
    • View Profile
  • Liked: 0
  • Likes Given: 15
Re: The 2014 Melting Season
« Reply #2974 on: August 08, 2014, 02:49:21 PM »
groan. fresh from denigrating the few posters with serious scientific credentials, the thread now descends into the realm of pure fantasy.

please, just stop

Shared Humanity

  • Guest
Re: The 2014 Melting Season
« Reply #2975 on: August 08, 2014, 03:07:43 PM »
I would call this a recovery, if only a recovery from a non-linear accelerating downward trend to a smoothly downward linear trend.


 :o

Recovery doesn't mean what you think it means.

From Merriam Webster Dictionary:

re·cov·ery noun \ri-ˈkə-və-rē, -ˈkəv-rē\

: the act or process of becoming healthy after an illness or injury : the act or process of recovering

: the act or process of returning to a normal state after a period of difficulty

: the return of something that has been lost, stolen, etc.

Shared Humanity

  • Guest
Re: The 2014 Melting Season
« Reply #2976 on: August 08, 2014, 03:27:05 PM »
This is my third melt season on this site. I come here to read and engage in substantive conversation regarding the Arctic. I have to say that, with a few exceptions, what has been happening over the last 100 comments is not substantive.

We are suppose  to be discussing "The 2014 Melting Season". When I have nothing to offer that can forward the discussion, I don't bother to comment. It would be great if others would allow this to guide their behavior.

Otherwise, I may have to just board my spaceship which is powered by dry ice and leave.  8)

deep octopus

  • Grease ice
  • Posts: 559
    • View Profile
  • Liked: 7
  • Likes Given: 17
Re: The 2014 Melting Season
« Reply #2977 on: August 08, 2014, 03:28:52 PM »
I would call this a recovery, if only a recovery from a non-linear accelerating downward trend to a smoothly downward linear trend.


 :o

Recovery doesn't mean what you think it means.

From Merriam Webster Dictionary:

re·cov·ery noun \ri-ˈkə-və-rē, -ˈkəv-rē\

: the act or process of becoming healthy after an illness or injury : the act or process of recovering

: the act or process of returning to a normal state after a period of difficulty

: the return of something that has been lost, stolen, etc.


6roucho

  • Frazil ice
  • Posts: 296
  • Finance geek
    • View Profile
  • Liked: 0
  • Likes Given: 1
Re: The 2014 Melting Season
« Reply #2978 on: August 08, 2014, 03:29:37 PM »
...  It's basically overlying the 2009 track for the last couple of weeks, and is if anything lower than the historical average melt rate for the time of year.

I mean that last sentence absolutely literally.

Melt over the last week was -376335 km^2.  Average for the 2000s is -508913 km^2.  Average for the 90s is -455647   km^2.  Average for the 80s is -501229 km^2.

That's not a cherry picked date either.  Whether I look at the last day, the last three days, the last week, the last ten days or the last fortnight, or any value in between, the current rate of loss of Arctic sea ice is lower than the 2000s average, lower than the 1990s average, and lower than the 1980s average.

...
This is a very important observation, but not in a way most collegues would initially suggest.

I ask everyone here: how, exactly, do we have much-slower-than-ever-recorded melt, given the fact of general warming in the Arctic and within subpolar areas of northern Hemisphere during last 3+ decades?

I mean it. We know Arctic is MUCH warmer than it was 30 years ago, in general. We clearly see - until last two years, - accelerating summer melt (the trend of increasing difference between any year's maximum and minimum Arctic ice coverage). We clearly see trends of decreasing maximum and minimum extents during 1990s and 2000s. It doesn't take an Einstein to say: yep, it's getting warmer, in general.

2013 had its "if"s and "but"s, but not everything was explainable with those. Now, even with a big (or is it "huge"?) area of high pressure right over Arctic, we see record-low melts.

Why?

I have no way to prove it, but i have my reasons to suspect (such as certain parts of some discussions which i - nor any person of "general public" - was not meant to see) that man-made cooling of Arctic - in fact, geo-engineering project, - has started in the Arctic in 2013. I had this suspicion in 2013, when rather unprecedented halt of Arctic ice area decrease happened for some 10+ days during early August 2013. Current events are but one more reason to suspect that such a project not only have started in 2013, but continues to be implemented right now.

If my suspicion is correct - i.e. if such a project is indeed being implemented inthe Arctic, - then there are cons and pros to it. Good thing, obviously, is that Arctic ice will continue its recovery (assuming the project will be as efficient as it is so far). It's awesomely great news for all of us, since consequences of losing practically all summer sea ice in the Arctic are no less than catastrophic for the climate of Earth (and consequently, for human agriculture, safety from "natural" disasters, sea level rise (Greenland melt would be massively affected), global warming itself (including methane clathrates problem, "no more heatsink in the Arctic" problem), etc. In the same time, it's bad news in that 1) mankind becomes dependant on ongoing (and inevitably intensifying) geoengineering project in the Arctic, and there is no certainty such a project could continue for any given length of time; 2) Arctic sea ice complete summer loss prevented, this gives a big-time argument to deiers, and big-time "go for it" to fossil fuel companies, resulting in worse-than-otherwise-expected pollution levels (all sorts related, from CO2 to oil spills); 3) such a geo-engineering project will possibly have unforeseen side effects, and nobody can know for sure how destructive such side-effects may be.

All this is not even a hypothesis - rather, it's just a thought, nothing more. But i am curious to know what you people would say about this. Especially in the way of "ok, if we'd suppose, just for a moment, that such geo-engineering project ("cooling") in the Arctic started some time in 2013 and goes on right now, affecting this year's melt season, then this allows to explain this-and-this-and-this, but this contradicts that-and-that-and-that".

So please, tell me.

Alternatively, these could simply be strong perturbations in a system on the edge of chaos, preparatory to a change to a new stable state. We can fail to explain these perturbations, or associate them with known physical factors, because the relationship between the system and its physical drivers is changing in a way we currently have no measurements for. Personally, I wouldn't be taking bets against any year in the next decade resulting in a substantially ice-free Arctic.

Frivolousz21

  • Nilas ice
  • Posts: 1813
  • Live in Belleville, IL..15 miles SE of St. Louis.
    • View Profile
  • Liked: 517
  • Likes Given: 5
Re: The 2014 Melting Season
« Reply #2979 on: August 08, 2014, 03:38:05 PM »
The arctic is not being geo engineered.

It's called weather
I got a nickname for all my guns
a Desert Eagle that I call Big Pun
a two shot that I call Tupac
and a dirty pistol that love to crew hop
my TEC 9 Imma call T-Pain
my 3-8 snub Imma call Lil Wayne
machine gun named Missy so loud
it go e-e-e-e-ow e-e-e-e-e-e-blaow

deep octopus

  • Grease ice
  • Posts: 559
    • View Profile
  • Liked: 7
  • Likes Given: 17
Re: The 2014 Melting Season
« Reply #2980 on: August 08, 2014, 03:50:46 PM »
The well-established high pressure system is forecast in GFS and ECMWF to continue through the waning days of August sunlight. The GFS is less bullish after 6 days, but only just. ECMWF has the high continue through at least the 10th day. For what it's worth. The "protective (or at least persistent) arm" pointing towards the ESS shore is narrowing and its contours gradually more defined per Worldview. The retreat is on all edges, but particularly from the southeast looking from Chukchi. There has been enough drift and warmth directed to this region by now to have a momentum in place for the time.

Rubikscube

  • Frazil ice
  • Posts: 254
    • View Profile
  • Liked: 7
  • Likes Given: 4
Re: The 2014 Melting Season
« Reply #2981 on: August 08, 2014, 04:04:56 PM »
This is my third melt season on this site. I come here to read and engage in substantive conversation regarding the Arctic. I have to say that, with a few exceptions, what has been happening over the last 100 comments is not substantive.

We are suppose  to be discussing "The 2014 Melting Season". When I have nothing to offer that can forward the discussion, I don't bother to comment. It would be great if others would allow this to guide their behavior.

Otherwise, I may have to just board my spaceship which is powered by dry ice and leave.  8)
+++

Please keep on topic folks. One of the nice things about this forum is that there are many boards to suit all kind of discussions, so it shouldn't be necessary to take everything to this thread just because it is currently most read.

iceman

  • Frazil ice
  • Posts: 285
    • View Profile
  • Liked: 7
  • Likes Given: 19
Re: The 2014 Melting Season
« Reply #2982 on: August 08, 2014, 04:42:29 PM »
... it's now becoming apparent that the long-term decline continues to be linear rather than exponential ...
More likely Gompertz.  I thought in 2011 that Gompertz fit was about to take over from exponential as the better approximation of reality.  Now it seems better substantiated on the basis of both empirical evidence and reasoning: see the "Slow Transition" thread and Dosbat post.

Frivolousz21

  • Nilas ice
  • Posts: 1813
  • Live in Belleville, IL..15 miles SE of St. Louis.
    • View Profile
  • Liked: 517
  • Likes Given: 5
Re: The 2014 Melting Season
« Reply #2983 on: August 08, 2014, 05:18:51 PM »
The exponential volume thing is amateur fiction. 

But it's talked about like a bunch of climatologists published papers making it an official position of some consensus.

The ice will melt out when the right set of conditions take place.  That could be 2016, 2020, 2030, 2040, 2100.

Who knows. 

So far 2011 is the closest that the arctic came to melting out and it wasn't that close. 

Spring snow cover and Spring sea ice albedo drop will probably have to go another 10-14 days earlier to get any realistic chance of a melt out then a 2007 repeat with the ridge closer to Canada.

I got a nickname for all my guns
a Desert Eagle that I call Big Pun
a two shot that I call Tupac
and a dirty pistol that love to crew hop
my TEC 9 Imma call T-Pain
my 3-8 snub Imma call Lil Wayne
machine gun named Missy so loud
it go e-e-e-e-ow e-e-e-e-e-e-blaow

Frivolousz21

  • Nilas ice
  • Posts: 1813
  • Live in Belleville, IL..15 miles SE of St. Louis.
    • View Profile
  • Liked: 517
  • Likes Given: 5
Re: The 2014 Melting Season
« Reply #2984 on: August 08, 2014, 05:23:40 PM »
Until we see appreciable MYI gains in terms of thickness outside the Southern arctic basin we are one bad summer from being back to 2011/12.

The albedo difference between bare FYI and bare MYI is typically 10% so until the MYI is well over 2-2.5 meters in a good melt situation it matters not.

What is better FYI growing to 2-2.5M or 1M MYI growing to 1.5-1.75M?
I got a nickname for all my guns
a Desert Eagle that I call Big Pun
a two shot that I call Tupac
and a dirty pistol that love to crew hop
my TEC 9 Imma call T-Pain
my 3-8 snub Imma call Lil Wayne
machine gun named Missy so loud
it go e-e-e-e-ow e-e-e-e-e-e-blaow

Bruce

  • Frazil ice
  • Posts: 132
    • View Profile
  • Liked: 0
  • Likes Given: 0
Re: The 2014 Melting Season
« Reply #2985 on: August 08, 2014, 05:51:15 PM »
... it's now becoming apparent that the long-term decline continues to be linear rather than exponential ...
More likely Gompertz.  I thought in 2011 that Gompertz fit was about to take over from exponential as the better approximation of reality.  Now it seems better substantiated on the basis of both empirical evidence and reasoning: see the "Slow Transition" thread and Dosbat post.
I think people are also getting confused about where to put the exponential/gompertz curve and why. Extent (or area) could move in or out of an exponential decline while volume remains linear -- depending on how the ice spreads out. Ice thickness varies a lot over a season, and from season to season.

Edit: I'll also note that this plot requires an additional data source to interpret properly. Since the thickness isn't uniform over the arctic, thickness can increase simply by the reduction of the amount of thin ice. So extent (or area) and volume in combination with the graph tell you something about the state of the ice. (This year seems an anomaly, but I suspect that's a problem with the model -- the rapid melt we're seeing in the Beaufort/Chukchi and ESS belies the idea that the ice is anomalously thick.)
« Last Edit: August 08, 2014, 06:01:57 PM by Bruce »

Frivolousz21

  • Nilas ice
  • Posts: 1813
  • Live in Belleville, IL..15 miles SE of St. Louis.
    • View Profile
  • Liked: 517
  • Likes Given: 5
Re: The 2014 Melting Season
« Reply #2986 on: August 08, 2014, 05:54:03 PM »
The waning Sun is taking it's toll.  Any chance of a large late season surge will require every last big of solar the arctic can suck up.  We can see that warm open water is detected in regions of the Chukchi and ESS within the pack ice.  Even the CAB is getting heat uptake around the ice.

The spotty pockets of satellite derived heat inside the ice pack essentially tells us bottom melt in those regions is likely being enhanced. 

The euro ensembles are actually showing a trend towards a more traditional dipole in mid August.

Here is the Euro OP from last night.

Winds are not favorable for compaction along the Pacific rim. But they are relatively strong.consistent which will also help aid in melt thru mixing and wave action.

The laptev is likely to pace with historic loses.








I got a nickname for all my guns
a Desert Eagle that I call Big Pun
a two shot that I call Tupac
and a dirty pistol that love to crew hop
my TEC 9 Imma call T-Pain
my 3-8 snub Imma call Lil Wayne
machine gun named Missy so loud
it go e-e-e-e-ow e-e-e-e-e-e-blaow

zworld

  • New ice
  • Posts: 21
    • View Profile
  • Liked: 0
  • Likes Given: 0
Re: The 2014 Melting Season
« Reply #2987 on: August 08, 2014, 06:06:07 PM »
You are not seriously suggesting that Tritium from Fukushima has a significant impact on arctic sea ice melt, are you?

No, I was just thinking out loud wondering if it had any impact at all. One of the hardest aspects of investigation work these days is the fact that modeling no longer works, not just for ice melt and the Arctic, but across the board in other environmental domains as well. And I am always looking for other possibilities that may be influencing things.

Earlier I brought up methane release from hydrates after the report came out that the big influx from permakarst didn't exist, and the melt lakes were actually storing carbon, not releasing it. Which meant the input from hydrates might be much greater than previously thought, so I threw that one out.

The reason I started to look at tritium is because of the ozone hole that formed right after the accident. Were they related, I don't know. Did the ozone hole affect the 2011 and 2012 melt, I don't know. I was just adding it to the list of possible influences.

But significant, probably not at this point. The summer of 2011, maybe.

To me, though some have already argued against this point, I believe we have entered territory that can no longer be charted, or even understood using the old parameters. The damage we have already done to the atmosphere is too far gone. We are cooking the earth while drenching it in a sea of toxic substances that never existed, or never in the quantities we now see.


zworld

  • New ice
  • Posts: 21
    • View Profile
  • Liked: 0
  • Likes Given: 0
Re: The 2014 Melting Season
« Reply #2988 on: August 08, 2014, 06:14:49 PM »
I keep seeing "standard deviation" being invoked as an occult incantation rather than anything vaguely related to the scientific method. The term is meaningless unless there is a statistically significant baseline against which to measure the next sample.

Good point. The term baseline shouldn't even be used when discussing AGW and Arctic conditions, because no baseline study was ever done way back when it would have been representative of natural conditions. All we see is the death spiral we started sometime ago.

Same reason the term recovery should never be used. It's like saying an AIDS patient is in recovery because their temperature went down from 102 to 101. There is no recovery in sight as far as I can tell.

ChrisReynolds

  • Nilas ice
  • Posts: 1714
    • View Profile
    • Dosbat
  • Liked: 1
  • Likes Given: 0
Re: The 2014 Melting Season
« Reply #2989 on: August 08, 2014, 06:51:00 PM »
The arctic is not being geo engineered.

It's called weather

 :)   :D  ;D Who Hoo!  ;D  :D  :)

I totally agree with Friv for a change.

I keep repeating this, so this will be the last time I say it, apart from my season round up on my blog.

http://www.cpc.ncep.noaa.gov/data/teledoc/pna_ts.shtml
That's a plot of the Pacific North American pattern. Notice that it was largely positive from the late 1990s until 2012. Last two years it has been negative.

Here's a narrative of my current wild ass guess:

In mid 2012 the PNA moved to a low phase, but this didn't affect the 2012 melt season because we'd already seen the June melt pond formation and the spring volume loss - both of which pre-conditioned the pack for significant loss. Then in 2012 we all saw how the weather turned crap yet the ice kept melting - was that preconditioning plus the late summer PNA flip?

Anyway both 2013 and 2014 have seen weather that has not been conducive to ice loss and this year high pressure, not centred over Greenland, but centred over the pack. The result, during negative PNA years we have seen failed early season melt that has meant preconditioning hasn't occurred, and we've had little melt.

So I agree with Friv, weather is far more likely than suggestions of geo-engineering.

What liabilities does someone have for detrimental impacts from their geoengineering. The potential costs of compensation could, at least in theory, come to billions. Is there anyone stupid enough to engage in it? Especially in a closely observed region like the Arctic, where any attempt at geo-engineering would be spotted by the scientists studying the region and reported in journals. I'll believe it when I read about it in a journal.

zworld

  • New ice
  • Posts: 21
    • View Profile
  • Liked: 0
  • Likes Given: 0
Re: The 2014 Melting Season
« Reply #2990 on: August 08, 2014, 07:44:00 PM »
The arctic is not being geo engineered.

It's called weather

 :)   :D  ;D Who Hoo!  ;D  :D  :)

I totally agree with Friv for a change............

Especially in a closely observed region like the Arctic, where any attempt at geo-engineering would be spotted by the scientists studying the region and reported in journals. I'll believe it when I read about it in a journal.

I totally agree with Chris for a change..... :)

Though some have been calling for the start of geo engineering in the Arctic, we would know if had really been going on as Chris states. The grid patterns of geo engineering have never, as far as I know, appeared in the Arctic Circle. If they have I would love to know about it.


dbostrom

  • New ice
  • Posts: 10
    • View Profile
  • Liked: 0
  • Likes Given: 0
Recovery is always at hand
« Reply #2991 on: August 08, 2014, 08:04:41 PM »
Per Richard Rathbone's PIOMAS graph and other metrics, it seems we can always count on a recovery, such as the one from ~'82-~'87, a pleasingly strong recovery, or the impressive extent recovery in the early '90s. Indeed, we have a plethora of recoveries in the record; why choose only one recovery, when so many are available?

None of them seem to stick.

Frivolousz21

  • Nilas ice
  • Posts: 1813
  • Live in Belleville, IL..15 miles SE of St. Louis.
    • View Profile
  • Liked: 517
  • Likes Given: 5
Re: The 2014 Melting Season
« Reply #2992 on: August 08, 2014, 08:40:04 PM »
Yep.

The NPAC is a much bigger driver of arctic weather then I realized going into 2013 and 2014.

For now the NPAC flipped it's pattern and we have a ridge now.

To late for any "big" damage this year I think but it's worth noting even last winter the NPAC forced the typical +NAO set up Eastward and killed the forecast the Italians had that had great success prior.
I got a nickname for all my guns
a Desert Eagle that I call Big Pun
a two shot that I call Tupac
and a dirty pistol that love to crew hop
my TEC 9 Imma call T-Pain
my 3-8 snub Imma call Lil Wayne
machine gun named Missy so loud
it go e-e-e-e-ow e-e-e-e-e-e-blaow

Frivolousz21

  • Nilas ice
  • Posts: 1813
  • Live in Belleville, IL..15 miles SE of St. Louis.
    • View Profile
  • Liked: 517
  • Likes Given: 5
Re: The 2014 Melting Season
« Reply #2993 on: August 08, 2014, 08:41:55 PM »
The other likely cause was snow cover in terms of preventing the albedo to drop earlier on in June when we had those ridges.

Some of those buoys showed some large snow cover from last Fall.
I got a nickname for all my guns
a Desert Eagle that I call Big Pun
a two shot that I call Tupac
and a dirty pistol that love to crew hop
my TEC 9 Imma call T-Pain
my 3-8 snub Imma call Lil Wayne
machine gun named Missy so loud
it go e-e-e-e-ow e-e-e-e-e-e-blaow

Lord M Vader

  • Nilas ice
  • Posts: 1310
    • View Profile
  • Liked: 38
  • Likes Given: 24
Re: The 2014 Melting Season
« Reply #2994 on: August 08, 2014, 10:28:46 PM »
Friv: and a large snow cover is also something we can expect as the Arctic warms up, especially during the winters. this year it was an advantage but another year it may be bad news for the ice.

I think another explanation could be that the neither 2013 and 2014 have seen as much of meandering jet stream.. Not as much as was the case in 2012.. A highly subjective judgement though. Anyone who does cconcur or have another opinion?

Even if 2015 manage to be another year with relatively "low" melt I expect things to happen after that as El Niño seems more and more likely. We had a glimpse of it as now april-june all have been the warmest on record. I think it was ASLR who said that we should see a switch to the positive PDO soon which should last for about 20 years. If that is to be the case one theory is that there will also be a rapid global warming...

Looking at AMSR pic indicates that there is a potential for some century breaks during the next weeks. According to JAXA there have "historically" (2007-2013) been a sea ice loss of 1,4-2,1 Mn km2 until the minima is reached. todays numbers from JAXA was 6,37 Mn km2 and if we are making a conservative estimation assuming a loss of 1,4-15 Mn km2 we'll end up roughly at the same number as 2013 and 2009...

//LMV

jdallen

  • Young ice
  • Posts: 3188
    • View Profile
  • Liked: 395
  • Likes Given: 200
Re: The 2014 Melting Season
« Reply #2995 on: August 09, 2014, 12:08:46 AM »
@JimPetit - confounding here as well, to the point it has me questioning whether conditions have changed such that our instruments are missing something(s).

Little compaction  low movement, low export.

There on place melt we are not seeing?  I've no sense of that from the Buoys, tho tantalizingly, a few have promptly dropped off "the grid".  Can't draw anything but anecdotal conclusions from it.

The amazing rising ice area numbers against positive melt conditions are also on my list of conundrums.  Yes, melt ponds, yes transport, but I'm wrestling with it in the face of this question...

Where is the energy going?

Increased water temps, modest air temp, all that insolation... What unseen (by me, anyway) changes in energy transport are saving the ice in the face of more measurably greater total energy in the system?
This space for Rent.

OSweetMrMath

  • Frazil ice
  • Posts: 137
    • View Profile
  • Liked: 0
  • Likes Given: 0
Re: The 2014 Melting Season
« Reply #2996 on: August 09, 2014, 12:15:26 AM »
This got super long. tl;dr: There is no recovery. If the exponential trend is no longer a good fit for the data, the entire trend should be replaced with another function, which will not show a recovery.

I hope it's not piling on to respond to Michael Hauber. One thing to be careful about is whether we are all using language the same way.

Typically, year over year data is broken into two components: the trend, which is predictable, and the noise, which is random and therefore unpredictable. For monthly or daily data, there is also a seasonal (or periodic) component, which is usually subtracted out before further analysis is performed. Therefore, the PIOMAS volume data is usually presented as an anomaly graph, where the estimated seasonal component has been subtracted out.

There are two assumptions that are typically made about the noise. The first is that the variance is constant, so the vertical spread of the noise is unchanging over time. The second is that the noise is uncorrelated, so knowledge about the past noise does not give any information for predicting the future noise. In practice, one or both of these assumptions are not valid. If this is not accounted for, model forecasts are generally less accurate, but not necessarily fatally. On the other side, attempting to account for these generally makes the model more complicated.

Another required assumption about the noise is that the mean noise is zero. In other words, the actual measured values spend as much time above the trend as below, over sufficiently long time periods. If the mean for the noise is not zero or appears to be changing over time, that should really be captured in the trend.

The trend is a deterministic function describing the predictable component of the data. Which function to use is a difficult question. In the absence of a physical model, less complicated trend functions are almost always better. If a more complicated function is used, it is very easy to incorporate the noise into the trend function. This is called overfitting the data, and it generally makes predictions worse. Simple trend functions, even when you know they are too simple, often provide more reliable predictions than complicated trend functions which overfit the data.

Which leads to "recovery". As Michael is using the term, it does not refer to the noise, so it must refer to the trend. (Denialists do not distinguish between the trend and the noise, so they use "recovery" to refer to the noise.) When the long term trend is toward ice loss, a recovery means an increase in ice in the short term trend.

In Reply #2945, Michael refers to a chart of PIOMAS volume to argue that the previous downward trend has broken and has been replaced by an upward trend. Unfortunately, his chart is not displaying for me, so I'm not sure of what he's looking at. From context, it sounds like he is looking at a chart with an exponential trend with indicated confidence intervals. (Possibly year over year July average volume?) The data from the last two years is now far outside the confidence intervals.

From this, Michael concludes that the exponential trend, which had been accurate through 2012, has broken, and should be replaced by a rising trend. If Michael is able to confirm that this is his argument, I would appreciate it.

In response, if the trend function changes between different time periods, the resulting function can never be considered a simple function. I would agree that the large differences in the past two years between the exponential trend and the observed data mean that the exponential function is not a good fit. However, I would replace this function by another simple function. Possibilities include a straight line. If that is deemed too simple, I would consider adding one (but only one) of x^2, x^1.5, and x ln x terms, and see if that results in an improved fit.

I would be extremely reluctant to conclude that the trend is represented by one function before a certain date and a different function after that date, unless there is a strong physical reason to do so. Tying into another recent discussion in this thread, if someone were to present convincing evidence that Fukushima had effects which permanently changed the behavior of the atmosphere, I might support using different functions to represent ice volume before and after that event. I would be more likely to support this if there were significant evidence that no reasonably simple function could adequately represent the ice trend.

My insistence on simple functions does have a consequence I should acknowledge. No trend represented by a simple function will ever show a recovery. Essentially, any function complicated enough to be able to show a recovery will be too complicated to use as a trend function by my standards. Anyone who is determined to find a recovery is likely to consider this a drawback. I just consider it a reflection of reality.

There is a way out. If simple functions do not represent the trend well enough, the trend can be represented by splines or other "non-parametric" curve fitting techniques. If it became clear that a linear function or other relatively simple parametric function could not capture important behavior of the trend, I would consider a spline or other approach. If the ice turns out to have alternating periods of loss and recovery, this could turn out to be necessary.

The danger here is that it is very easy to overfit the data. If a spline fit shows a recovery, especially one at the end of the data, it may be that the recovery is real, but it could also be a case of overfitting the data. While I'm more likely to accept the use of a spline than a break in the trend resulting in a different trend function, I'd also be extremely wary of announcing a recovery based on the behavior of a spline fit alone.

Nick_Naylor

  • Frazil ice
  • Posts: 291
    • View Profile
  • Liked: 0
  • Likes Given: 0
Re: The 2014 Melting Season
« Reply #2997 on: August 09, 2014, 01:12:56 AM »
I can't imagine any model you could choose would not show a positive error term in 2013 (and barring an August surprise, 2014). Such a comprehensive model is probably impossible if the short-term behavior is as chaotic as I think it is. 

I wouldn't get too hung up on semantics. If two successive years of positive error terms meet your personal definition of "recovery," I see nothing wrong with that. I imagine a financially-oriented person might very well use the term as they would refer to a stock market recovery - which basically just means a period of rising prices shortly after a correction, without implying additional future gains.

Just looking at the raw data over the satellite period, there have been a number of intervals where the year-to-year variance has been relatively large. It is only due to the small sample size, and the fact that we have been gazing intently at the emerging data for the last few years that gives the most recent data such exaggerated importance in our minds.

Peter Ellis

  • Grease ice
  • Posts: 617
    • View Profile
  • Liked: 34
  • Likes Given: 13
Re: The 2014 Melting Season
« Reply #2998 on: August 09, 2014, 03:42:37 AM »
When I say "recovery", I don't mean Arctic ice is going to increase year on year. I strictly mean a relative recovery which disproves the more aggressive predictions of complete Arctic melt-out in the next few years.  It's encouraging only in as much as it means it may not already be too late to arrest the process if the political will is there to fix carbon emissions.

The reason I'm now trying to combat the more aggressive predictions of imminent collapse (not just Friv)  is because I strongly believe they'll be falsified outright in the next few years - just as the couple of people predicting record or near-record values this year will be falsified in a few short weeks' time.  Arctic ice will be with us for a few years yet, and will not suddenly poof out of existence. As and when the wilder predictions fail, it is INCREDIBLY IMPORTANT that the failure is not used to discredit the whole (known) science of AGW.

Similarly, on a daily to weekly basis, as and when depictions of "torches", "smoking" , "slush" and whatever else turn out to be inaccurate over and over again, it's important for onlookers to realise that these are not mainstream climate science predictions, and that falsifying one does not not mean that the whole edifice of current scientific knowledge is wrong.

If that turns me into a denialist boogeyman on this board (for saying that the ice will go by 2040 instead of by 2020?), so be it.  I don't think any of my comments on the current ice state or my predictions for the future are far from those given by our gracious host on his ASI blog. These forums are noticeably more "fringe" in pro-melt terms even than the ASI blog, which in turn is generally makes more aggressive predictions than mainstream climate science.

Nick_Naylor

  • Frazil ice
  • Posts: 291
    • View Profile
  • Liked: 0
  • Likes Given: 0
Re: The 2014 Melting Season
« Reply #2999 on: August 09, 2014, 04:11:15 AM »
Visiting this forum seems to me like visiting Greenland for a few days, and watching one of the major calving fronts with fellow travelers, hoping to see a really big one fall off.

There are a few spectators who get excited whenever anything happens - however run-of-the-mill it might be to the locals or the scientists. There are a few scientific types who keep reminding to what extent these things happen all the time, and some who get discouraged when nothing happens for a while. They all add to the experience, but everyone doesn't always understand or value the different perspectives. We're not all here for the same reasons.

Most of us will be inordinately shaped by whatever random events we experience on our particular trip. If we see a gigantic calving, our sense of impending doom will be hugely out of proportion to what the event really adds to human understanding, and likewise if it turns out to be an uneventful week. It is our nature to demand a meaningful narrative to explain our experience, even when it's more realistic to recognize the strong role played by randomness.