Support the Arctic Sea Ice Forum and Blog

Author Topic: The 2016 melting season  (Read 1525681 times)

Jim Hunt

  • Young ice
  • Posts: 4288
    • View Profile
    • The Arctic sea ice Great White Con
  • Liked: 271
  • Likes Given: 27
Re: The 2016 melting season
« Reply #4650 on: September 07, 2016, 01:38:50 PM »
The claim that using models is "more scientific" than fitting data is totally wrong-headed

I disagree. Merely "fitting data" with no reference to the underlying physics is even more wrong headed IMHO. However I also have to say that I'm not wildly impressed with the current "expertise" of the operational sea ice models.

Quote
I agree that alarmist claims if false are damaging.

I agree. I also agree with much of what Prof. Wadhams has to say, but some of what he says is simply grist to the mill of the naysaying spin doctors.
Reality is merely an illusion, albeit a very persistent one - Albert Einstein

Tigertown

  • Nilas ice
  • Posts: 1650
    • View Profile
  • Liked: 5
  • Likes Given: 0
Re: The 2016 melting season
« Reply #4651 on: September 07, 2016, 02:21:30 PM »
 I would leave a little possibility in there for a late compaction event, which would actually be good for the ice, maybe. At the same time, it could easily change the numbers, though. The way everything is spread out, I would not completely dismiss the chances, however slim.

Adam Ash

  • Frazil ice
  • Posts: 305
    • View Profile
    • The 100 metre line
  • Liked: 8
  • Likes Given: 20
Re: The 2016 melting season
« Reply #4652 on: September 07, 2016, 02:24:28 PM »
Just wondering...'Extent' is nice, but isn't 'Area' the real thing? 

At the state the Arctic is in now, what does drawing a line around the outer edge of the smoke and mush tell us about the volume of ice remaining, and more importantly about the area of high-latitude ocean surface exposed to direct interaction with solar and atmospheric climate-changing mechanisms? 

Not even Volume helps describe that exposed surface helpfully, as a minimum of 3 million km3 could be all solid to the bottom above 80N, or spread over the whole Arctic's 14 million sq Km 0.2 m deep. 

At the moment I presume the Extent measure extends all the way down the CAA drain pipes to south of 75N, to the tip of the Wrangle Arm at 72N and the Barents at 82N. 

We could get to the silly point where all that remains is a ring around the edge of the bath, but that would define a pretty meaningless Extent, while the middle where the plastic ducks are bobbing is clear green sea where all climate-hell is breaking loose and total Area is pretty near zero.

So why, may I ask do we seem to fixate on Extent when the physical and chemical interactions that really matter in terms of impact on global climate are best (it seems) described by the inverse of Ice Area - the Exposed Water Area?

Thank you.

Shared Humanity

  • Young ice
  • Posts: 3943
    • View Profile
  • Liked: 405
  • Likes Given: 47
Re: The 2016 melting season
« Reply #4653 on: September 07, 2016, 03:09:26 PM »
I honestly don't see us fixating on extent here. I see deep discussions on volume, area, extent as well as the physical state of the ice and its behavior with weather among other topics.

FishOutofWater

  • Grease ice
  • Posts: 745
    • View Profile
  • Liked: 280
  • Likes Given: 109
Re: The 2016 melting season
« Reply #4654 on: September 07, 2016, 03:11:13 PM »
When a physics based model performs poorly scientists get to work to understand and describe the physics better. When a curve fit fails, you draw another curve and hope it works better. The goal with models is to develop scientific understanding. With a little luck and a lot of hard work the models may eventually make good forecasts.

Note that it is hard to improve models without data. This summer there were very few buoys measuring the properties of the ice and the ocean. Without better sampling we aren't going to make much progress on better predictions.

.....

It's clear that the huge jump on heat content in the Barents sea, where Atlantic water has replaced Arctic ocean water and ice year-round, has affected the NH atmospheric circulation. Additionally, more heat escapes to the atmosphere through thin, broken ice than thick multi-year ice. Water vapor levels are increasing, amplifying the greenhouse effect of CO2 and CH4.

Nightvid Cole

  • Frazil ice
  • Posts: 437
    • View Profile
  • Liked: 5
  • Likes Given: 0
Re: The 2016 melting season
« Reply #4655 on: September 07, 2016, 03:39:49 PM »
The amount of 100% ice cover for the 6th looks remarkably small.

Not significant. cf. July 12, 2015.


greatdying2

  • Grease ice
  • Posts: 574
    • View Profile
  • Liked: 0
  • Likes Given: 0
Re: The 2016 melting season
« Reply #4656 on: September 07, 2016, 03:41:21 PM »
The claim that using models is "more scientific" than fitting data is totally wrong-headed

I disagree. Merely "fitting data" with no reference to the underlying physics is even more wrong headed IMHO. However I also have to say that I'm not wildly impressed with the current "expertise" of the operational sea ice models.

Yeah, but that's the problem. A model could be anything. Given complete understanding of a system, a good model is obviously preferable. With perfect understanding, you wouldn't even need observations. But for a system that is barely understood to begin with and which is undergoing rapid, fundamental changes that are even less well understood, models are likely to be further from reality than data fitting. What is "more scientific", if that means anything, is I believe whatever in any given system gets closest to truth.
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.

A-Team

  • Nilas ice
  • Posts: 2360
    • View Profile
  • Liked: 272
  • Likes Given: 14
Re: The 2016 melting season
« Reply #4657 on: September 07, 2016, 04:08:20 PM »
Quote
melt season about over, sniff. fixating on extent, volume, area? Better: physical state of the ice, its 2D distribution and behavior with weather.
As noted above by Neven and Fish, the season looks about over in the Beaufort/Chukchi/Wrangel-arm sector, except for ice displacement by wind which continues through Sept 5th. However the action between the pole and the Barents front will continue for well into the fall because the surface water warmth is anomalously warm.

Along the lines of Shared's proposal, it may be better to look this winter at methods that retain the distribution map of the property being studied, rather than represent the state of the Arctic Ocean by single numbers (eg extent) which have discarded positional information.

Since daily maps of sea ice concentration are available for five years (2012-2016), I looked at methods for comparing whole maps.

First, the Sept 5th images were brought forward in time to a minimum binary state where each grid cell is classified as either open water or ice, done here by setting the whiter pixels to ice and the bluer to water. This was supplemented by a mildly 'greedy algorithm' that captures and converts isolated pixels of one type surrounded by a neighborhood of the other.

The Venn diagram below shows all the water/ice combinations for the five years. This a 5-bit number (32 cases). For example the very center represents that part of the Arctic that always has ice at the end of season (in the context of the last five years).

It is quite difficult to devise a satisfactory color palette for the operation used (multiplication) to fill out all the venn compartments so the images below just compare 2016 to the other four years. This operation works as (upper layer)*((lower layer)/255) on each channel which has the effect of darkening the resultant pixel.

The second image lays out the 32 venn colors in a speadsheet (miraculously drag-n-drop moves gimp palette colors to spreadsheet cell fill) and the third images constructs its (complex) multiplicative palette as 32x32 = 1024 color tabs. Gimp provides 20 logics by which layers can interact and ImageJ another 12; each of these leads to a different cross-palette.

Similarly 2x2 palettes are embedded in the upper right corner of each of binary comparison with 2016, ie a pixel in the 2012-2016 has one of four colors depending on whether both years had ice there, neither, or just 2012 or just 2016.

Quite a bit of distributional variation can be seen at the end of season in the final animation. Outlying ice, if it freezes in place amidst new first year ice, will affect the progression of the 2017 melt season. Consequently, dropping map information in favor of single numbers (integrals of the various scalar fields) will seriously impair forecasts just based on these daily numbers.
« Last Edit: September 07, 2016, 04:29:35 PM by A-Team »

crandles

  • Nilas ice
  • Posts: 2497
    • View Profile
  • Liked: 85
  • Likes Given: 46
Re: The 2016 melting season
« Reply #4658 on: September 07, 2016, 04:18:15 PM »
What is "more scientific", if that means anything, is I believe whatever in any given system gets closest to truth.

If data look like a straight line and you can justify why you would expect it to be a straight line and the models are poor, then straight line extrapolation may well get you closer to the truth than poor models that don't reflect reality.

However, what Prof Wadhams has done is completely different. Extrapolating a curve is very risky as there are all sorts of different curves that can fit the data and have very different projections. Despite this, he has gone with an aggressive exponential downward curve when (virtually?) all the models show a slowing down in the rate of extent decline (let alone volume decline) as ice free conditions are approached. This is absolutely asking to be criticised.

If he had prefaced his work saying 'the models show a slowing of the rate of decline, but so far the models have been too conservative and what if this continues a little longer?' then that would, I think, be acceptable, but he didn't. Even after 4 years of minimum extent greater than 2012, he still isn't acknowledging that the aggressive downward curve used might be inappropriate. If it was a mistake and he acknowledged it, well mistakes do happen. By not acknowledging this, he is setting himself out as an alarmist who should be ignored.

ghoti

  • Grease ice
  • Posts: 766
    • View Profile
  • Liked: 12
  • Likes Given: 15
Re: The 2016 melting season
« Reply #4659 on: September 07, 2016, 04:23:53 PM »
One factor keeping the overall extent value from dropping is the growth of extent in the Greenland Sea. This is of course just export through the Fram which for a change hasn't melted out almost instantly.

Thing is any ice that moves south of about 80N through the Fram is surely doomed. I guess this late in the melt season it will hang around until next spring. Or will it?

I can't help but feel like this gives a false impression that the ice is in better shape than it really is. There's something like 200,000 km2 of extent that is definitely not long for this world.

Archimid

  • Nilas ice
  • Posts: 2308
    • View Profile
  • Liked: 270
  • Likes Given: 183
Re: The 2016 melting season
« Reply #4660 on: September 07, 2016, 04:34:41 PM »
Quote
If he had prefaced his work saying 'the models show a slowing of the rate of decline, but so far the models have been too conservative and what if this continues a little longer?' then that would, I think, be acceptable

Wouldn't it be proper if the same standard was applied to the IPCC "5 ice free arctics in a row"? Given that the rate of decline is in fact accelerating, the models continue to over predict ice and the sheer unprecedented nature of this event that definition is downright absurd.
I am an energy reservoir seemingly intent on lowering entropy for self preservation.

Lord M Vader

  • Nilas ice
  • Posts: 1261
    • View Profile
  • Liked: 26
  • Likes Given: 19
Re: The 2016 melting season
« Reply #4661 on: September 07, 2016, 04:48:24 PM »
*BOOOM!* European Copernicus came in yesterday with a record smashing warm August 0,17oC higher than August 2015(!!!) Overall, the month was +0,62oC warmer than the 1981-2010 average for August.

See and read more at: https://climate.copernicus.eu/resources/data-analysis/average-surface-air-temperature-analysis/monthly-maps/august-2016

More or less crossposting my post from the GST-thread in "Consequences".


Tigertown

  • Nilas ice
  • Posts: 1650
    • View Profile
  • Liked: 5
  • Likes Given: 0
Re: The 2016 melting season
« Reply #4662 on: September 07, 2016, 04:50:56 PM »
One factor keeping the overall extent value from dropping is the growth of extent in the Greenland Sea. This is of course just export through the Fram which for a change hasn't melted out almost instantly.

Thing is any ice that moves south of about 80N through the Fram is surely doomed. I guess this late in the melt season it will hang around until next spring. Or will it?

I can't help but feel like this gives a false impression that the ice is in better shape than it really is. There's something like 200,000 km2 of extent that is definitely not long for this world.

As I pointed out in an earlier comment. If you look at it on polarview you can see a shear developing and its as if the East most mass of it is being pulled south and bent around the NE corner of Greenland. It is just a matter of how long it takes to move far enough south to melt.

Lord M Vader

  • Nilas ice
  • Posts: 1261
    • View Profile
  • Liked: 26
  • Likes Given: 19
Re: The 2016 melting season
« Reply #4663 on: September 07, 2016, 05:05:42 PM »
Right now I think, two things will determine the outcome of when the minimum will occur:

1) The westerly winds that the high pressure that is forecasted to build into the Laptev Sea just maybe will produce winds strong enough to push the loosy Wrangel arm toward Chuckchi and Berings Strait where it should be doomed.

2) Laptev Sea - the sea ice in this area still sees some top melting and, whether its my bad eyesight after looking at EOSDIS worldview or a fact, the sea ice seems to have been detached from Novaya Severnaya. The forecast from GFS calls for temperatures just above freeze point so some melting in this region should offset any refreezing.

My opinion is that given the lousy shape of Wrangels arm and the extent number it makes we should see a prolonged minimum where only small details will determine whether we'll get an early minimum or a more seasonal one.

Best, LMV

jai mitchell

  • Nilas ice
  • Posts: 2036
    • View Profile
  • Liked: 76
  • Likes Given: 18
Re: The 2016 melting season
« Reply #4664 on: September 07, 2016, 07:14:12 PM »

Since daily maps of sea ice concentration are available for five years (2012-2016), I looked at methods for comparing whole maps.

First, the Sept 5th images were brought forward in time to a minimum binary state

A-Team,

These graphics are intriguing, however for additional impact, could you reproduce the main graphic without the ven color palettes, just the first 5 maps?  I like the timing but hold the last image for 3X longer than the previous 4 slides.

The difference in the ice condition displayed by this graphic is so striking even to a complete novice who has never seen an arctic ice map, I think it would be really valuable.

please???
Haiku of Past Futures
My "burning embers"
are not tri-color bar graphs
+3C today

Archimid

  • Nilas ice
  • Posts: 2308
    • View Profile
  • Liked: 270
  • Likes Given: 183
Re: The 2016 melting season
« Reply #4665 on: September 07, 2016, 07:18:46 PM »
Quote
I don't see much if any connection to my comments on straight line extrapolation may be acceptable in some circumstances but curve extrapolation is much more likely to be problematic.

Yet the straight line extrapolations of Arctic sea ice volume point to an ice free Arctic inside 10 years. Wadhams assumes it curves down, the IPCC assumes it curves up. Since we live in a warming planet, with decreasing snow cover, increasing ocean surface temperatures and increasing air temperatures I believe Wadhams is probably closer to the truth.  The facts that the IPCC keep underestimating melting even after various adjustments, gives Wadhams even more credibility.

I am an energy reservoir seemingly intent on lowering entropy for self preservation.

Iceismylife

  • Frazil ice
  • Posts: 281
    • View Profile
  • Liked: 2
  • Likes Given: 1
Re: The 2016 melting season
« Reply #4666 on: September 07, 2016, 07:28:10 PM »
... The facts that the IPCC keep underestimating melting even after various adjustments, gives Wadhams even more credibility.
THE IPCC's underestimation of melting leads to the question are they also underestimating the consequences of melting?  Are we going to get enough melting to have to worry about cooling?

opensheart

  • New ice
  • Posts: 57
    • View Profile
  • Liked: 4
  • Likes Given: 0
Re: The 2016 melting season
« Reply #4667 on: September 07, 2016, 08:05:19 PM »
As ice melts on Greenland, the surrounding Sea Surface Temps get cooler.
But I'm not seeing Sea Surface Temps cool just because Arctic Sea Ice melts.
So it would seem to me that melting arctic sea ice is not cooling anything.

RoxTheGeologist

  • Frazil ice
  • Posts: 462
    • View Profile
  • Liked: 128
  • Likes Given: 95
Re: The 2016 melting season
« Reply #4668 on: September 07, 2016, 08:14:48 PM »
Quote
I don't see much if any connection to my comments on straight line extrapolation may be acceptable in some circumstances but curve extrapolation is much more likely to be problematic.

Yet the straight line extrapolations of Arctic sea ice volume point to an ice free Arctic inside 10 years. Wadhams assumes it curves down, the IPCC assumes it curves up. Since we live in a warming planet, with decreasing snow cover, increasing ocean surface temperatures and increasing air temperatures I believe Wadhams is probably closer to the truth.  The facts that the IPCC keep underestimating melting even after various adjustments, gives Wadhams even more credibility.

Whenever you fit a curve, you assume a model for the relationship of the two variables, be it a simple linear fit or something more complicated.

I'm not sure I have seen anything to convince me of an exact empirical fit for Arctic sea ice volume changes with time. It strikes me that there is not enough data to model the noisy and complex Arctic system predictably.

Right now we can say that there is a downward trend, and then draw broad error bars to bound future ice volume with worst and best model cases. Perhaps all we can see is that future ice volume is likely to be somewhere within the bounds of the different models.

dnem

  • Frazil ice
  • Posts: 309
    • View Profile
  • Liked: 105
  • Likes Given: 51
Re: The 2016 melting season
« Reply #4669 on: September 07, 2016, 08:16:09 PM »
As ice melts on Greenland, the surrounding Sea Surface Temps get cooler.
But I'm not seeing Sea Surface Temps cool just because Arctic Sea Ice melts.
So it would seem to me that melting arctic sea ice is not cooling anything.

The North Atlantic Blob: A Marine Cold Wave That Won’t Go Away
By: Bob Henson , 6:01 PM GMT on April 08, 2016

When you look at a map of global surface temperatures for 2015, the first impression you might get is a planet with a bad sunburn. Almost every part of the globe saw above-average temperatures during Earth’s warmest year on record, and there was unprecedented warmth across many parts of the tropical and subtropical oceans (Figure 1). The next thing you’d probably notice is a blue blob in the North Atlantic, sticking out like a frostbitten thumb. No one knows exactly why, but this blob of unusually chilly water, roughly half the size of the United States, has taken up what seems like semi-permanent residence in the North Atlantic Ocean.
https://www.wunderground.com/blog/JeffMasters/the-north-atlantic-blob-a-marine-cold-wave-that-wont-go-away


6roucho

  • Frazil ice
  • Posts: 296
  • Finance geek
    • View Profile
  • Liked: 0
  • Likes Given: 1
Re: The 2016 melting season
« Reply #4670 on: September 07, 2016, 08:16:37 PM »
As ice melts on Greenland, the surrounding Sea Surface Temps get cooler.
But I'm not seeing Sea Surface Temps cool just because Arctic Sea Ice melts.
So it would seem to me that melting arctic sea ice is not cooling anything.
Aren't the thermodynamics (approximately) the same? The net endothermic effect simply reaches the ocean by a different method.
« Last Edit: September 07, 2016, 09:13:40 PM by 6roucho »

Iceismylife

  • Frazil ice
  • Posts: 281
    • View Profile
  • Liked: 2
  • Likes Given: 1
Re: The 2016 melting season
« Reply #4671 on: September 07, 2016, 08:23:25 PM »
We've had far fewer hurricanes than normal in the Atlantic this year.  The heat those would've extracted from the sea water is still there, heading north.

That heat should wreck havoc with ice volumes.

https://goo.gl/maps/fCPrtWy7jbJ2

This place comes to mind.  In the 1980's the lake was going up.  So they built pumps to move water and reduce flooding.  Now they are high and dry and we want the water they pumped out back.  So currently it is headed warmer and into more melting.  Is that going to hold when we get a lot of melting?  Or are we going to wish we'd Kept warming things up as it cools off into an ice age?

The lake was headed up we needed to do something about it.  Now it is headed down and we need to do something about it.

Long term solutions to short term problems don't work so well in the long term.

http://www.deseretnews.com/article/1336530/Great-Salt-Lake-pumps-are-primed.html?pg=all

jai mitchell

  • Nilas ice
  • Posts: 2036
    • View Profile
  • Liked: 76
  • Likes Given: 18
Re: The 2016 melting season
« Reply #4672 on: September 07, 2016, 08:30:00 PM »
If the north atlantic cold anomaly of the last 2 years was due to ice melt then it would have a significant presence today.

it does not

Haiku of Past Futures
My "burning embers"
are not tri-color bar graphs
+3C today

Kethern

  • New ice
  • Posts: 11
    • View Profile
  • Liked: 0
  • Likes Given: 0
Re: The 2016 melting season
« Reply #4673 on: September 07, 2016, 09:09:13 PM »
As I pointed out in an earlier comment. If you look at it on polarview you can see a shear developing and its as if the East most mass of it is being pulled south and bent around the NE corner of Greenland. It is just a matter of how long it takes to move far enough south to melt.

Or more visually.

12Patrick

  • Frazil ice
  • Posts: 140
    • View Profile
  • Liked: 0
  • Likes Given: 0
Re: The 2016 melting season
« Reply #4674 on: September 07, 2016, 09:12:40 PM »
Thinnest Arctic sea ice ever recorded since 1979... Correct?

Check out the Piomas thread 12Patrick. Looking at what's left of the ice, its easy to assume that the ice is thinnest, but its not. If the arctic had a summer like 2007, there would have been a new record this year for sure. With low pressure dominating the arctic during peak insolation in June and July a second place finish speaks volumes on how fragile the remaining ice is.

My take home from recent PIOMAS posts is that it is *not* a good measure estimator of current ice thickness.
I would say that is correct which means we have a record year low in thickness... Correct?

12Patrick

  • Frazil ice
  • Posts: 140
    • View Profile
  • Liked: 0
  • Likes Given: 0
Re: The 2016 melting season
« Reply #4675 on: September 07, 2016, 09:17:39 PM »
There is still a huge area of MYI trying to to turn the corner of NE Greenland. If you look on polar view you can see a big shear (or other term that some prefer). If this much goes south and does manage to melt, even if too late to lower the final extent it is going to really hurt the amount of MYI left, which doesn't look great anyway.
I can't get a picture of polar view to look right , but it really shows this better.


Can't be that huge since 99% of ALL 3 to 5 meter multi year ice is now gone in the Arctic according to Navy Mil...

Tigertown

  • Nilas ice
  • Posts: 1650
    • View Profile
  • Liked: 5
  • Likes Given: 0
Re: The 2016 melting season
« Reply #4676 on: September 07, 2016, 09:24:57 PM »
 Thank you! That helps a lot. Remember everybody,  that is a giant section of reserve(sanctuary) 
MYI going down.

Tigertown

  • Nilas ice
  • Posts: 1650
    • View Profile
  • Liked: 5
  • Likes Given: 0
Re: The 2016 melting season
« Reply #4677 on: September 07, 2016, 09:59:00 PM »
For those who have time. Go to  www.polarview.aq/sic/arctic/

Click on the 1st of the month while zoomed on the NE corner of Greenland.
Click the animate button. You have to click 1st again and animate again to repeat.

Also interesting to zoom in on Nare's and CAA and animate the same way.

The clock is ticking, but if this continues very long at all, there is not going to be much thick MYI left for a starter.

P.S. If you want to you can go back earlier and click on a day and and animate from there. Not to insult those familiar with it.

effbeh

  • New ice
  • Posts: 19
    • View Profile
  • Liked: 0
  • Likes Given: 0
Re: The 2016 melting season
« Reply #4678 on: September 07, 2016, 10:08:09 PM »
*BOOOM!* European Copernicus came in yesterday with a record smashing warm August 0,17oC higher than August 2015(!!!) Overall, the month was +0,62oC warmer than the 1981-2010 average for August.

It starts to get a little bit unsettling.  Just a little bit.

jdallen

  • Young ice
  • Posts: 3019
    • View Profile
  • Liked: 185
  • Likes Given: 171
Re: The 2016 melting season
« Reply #4679 on: September 07, 2016, 10:19:52 PM »
Thank you! That helps a lot. Remember everybody,  that is a giant section of reserve(sanctuary) 
MYI going down.
The Bastion has fallen.

Larger view of the region to put it all in context.  Total area in view is probably about 800,000KM2.

[Edit:  The only thing saving it right now is the weather has wind pushing in from the SSE over most of the next week.  If another polar low sets up, it will be on its way out.]
« Last Edit: September 07, 2016, 10:26:14 PM by jdallen »
This space for Rent.

magnamentis

  • Guest
Re: The 2016 melting season
« Reply #4680 on: September 07, 2016, 10:31:37 PM »
As ice melts on Greenland, the surrounding Sea Surface Temps get cooler.
But I'm not seeing Sea Surface Temps cool just because Arctic Sea Ice melts.
So it would seem to me that melting arctic sea ice is not cooling anything.

if you open your fridge you won't see any cooling of your flat or house hence following your logics that would mean that a refrigerator is cooling nothing, hope you understand my logic LOL. cooling means that the temps are cooler than they would be without cooling, hence it's relative and not absolute, while we don't know how warm they would be without cooling through melting ice.

dnem

  • Frazil ice
  • Posts: 309
    • View Profile
  • Liked: 105
  • Likes Given: 51
Re: The 2016 melting season
« Reply #4681 on: September 07, 2016, 10:58:49 PM »
If the north atlantic cold anomaly of the last 2 years was due to ice melt then it would have a significant presence today.

it does not



here is the same data (as referenced by Masters through July 2015) from NOAA through July 2016 showing North Atlantic cool pool.

slow wing

  • Grease ice
  • Posts: 790
    • View Profile
  • Liked: 144
  • Likes Given: 390
Re: The 2016 melting season
« Reply #4682 on: September 07, 2016, 11:02:54 PM »
For those who have time. Go to  www.polarview.aq/sic/arctic/

Click on the 1st of the month while zoomed on the NE corner of Greenland.
Click the animate button. You have to click 1st again and animate again to repeat.
...
Thanks!

That's a lovely animation, very informative. This melt season we have been spoiled with some of the new graphic displays coming out - thanks to those involved. And that is not even to mention the terrific visual aids from some of those on this forum, e.g. A-team & Wipneus etc.

Ice Shieldz

  • Frazil ice
  • Posts: 233
    • View Profile
  • Liked: 41
  • Likes Given: 28
Re: The 2016 melting season
« Reply #4683 on: September 08, 2016, 01:00:14 AM »
Here is yet another perspective on temps provided by Zack Labe

Michael Hauber

  • Grease ice
  • Posts: 841
    • View Profile
  • Liked: 46
  • Likes Given: 12
Re: The 2016 melting season
« Reply #4684 on: September 08, 2016, 01:26:43 AM »

The claim that using models is "more scientific" than fitting data is totally wrong-headed,

I agree.  Lots of models use data fitting to some extent .  Data fitting is considered a 'model' in mathematical circles.  A model with poor understanding of the underlying physics is worse than data fitting with good understanding of the underlying physics.
Climate change:  Prepare for the worst, hope for the best, expect the middle.

Michael Hauber

  • Grease ice
  • Posts: 841
    • View Profile
  • Liked: 46
  • Likes Given: 12
Re: The 2016 melting season
« Reply #4685 on: September 08, 2016, 01:44:13 AM »

In AR5, RCP 8.5 assumes a most likely value for ECS of about 3.2C, while recent research indicates that ECS may well be closer to 4.6C.

Other recent research indicates it may be as low as 2 degrees.  Both extremes are probably nonsense.
Climate change:  Prepare for the worst, hope for the best, expect the middle.

Michael Hauber

  • Grease ice
  • Posts: 841
    • View Profile
  • Liked: 46
  • Likes Given: 12
Re: The 2016 melting season
« Reply #4686 on: September 08, 2016, 01:52:25 AM »

But emission-reductions (and therefore aerosols-reductions) might not be all good news,  especially for the arctic, the sea ice & snow cover. According to Najafi et al (2015):
Quote
... We show that although increases in greenhouse-gas concentrations have driven the observed [Arctic] warming over the past century, approximately 60% of the greenhouse-gas-induced warming has been offset by the combined response to other anthropogenic forcing [ (which are dominated by aerosols)] ...

Faustian bargain and so ...

RCPs 2.6 to 6.0 include the impact of reduced aerosols and predict lower warming.

And to add another point to what Abrupt SLR and jai have said. As far as I know, CMIP5 models do severely underestimate the decline of spring snow cover in the northern hemisphere, even compared to RCP 8.5 (By the way, does anybody have more recent data/papers on this. Would be highly appreciated). See for instance Derksen et al (2012) (attached figure):

CMIP5 errors go both ways.  Overall the model predictions of warming have been very close to what has actually happened.  It would really be quite extraordinary if warming over more than a century which has been tracking models to within maybe 10% suddenly increased to be 50% over model projections within a small number of decades.
Climate change:  Prepare for the worst, hope for the best, expect the middle.

AbruptSLR

  • Multi-year ice
  • Posts: 17393
    • View Profile
  • Liked: 581
  • Likes Given: 222
Re: The 2016 melting season
« Reply #4687 on: September 08, 2016, 03:48:27 AM »

In AR5, RCP 8.5 assumes a most likely value for ECS of about 3.2C, while recent research indicates that ECS may well be closer to 4.6C.

Other recent research indicates it may be as low as 2 degrees.  Both extremes are probably nonsense.

It would seem best to move any further such discussion of this topic to the linked thread:

https://forum.arctic-sea-ice.net/index.php/topic,1053.0.html
“It is not the strongest or the most intelligent who will survive but those who can best manage change.”
― Leon C. Megginson

jai mitchell

  • Nilas ice
  • Posts: 2036
    • View Profile
  • Liked: 76
  • Likes Given: 18
Re: The 2016 melting season
« Reply #4688 on: September 08, 2016, 04:10:55 AM »

CMIP5 errors go both ways.  Overall the model predictions of warming have been very close to what has actually happened.  It would really be quite extraordinary if warming over more than a century which has been tracking models to within maybe 10% suddenly increased to be 50% over model projections within a small number of decades.

Models that can reproduce the warming over a century you mean.  In nearly every case, in every iteration of the model results, the new model runs show increasingly severe impacts in scope, timing and scale.

We are now going to catch up to the warming that we should have been on all along but was offset by Asian aerosols which contributed to the negative PDO trend over the last 15 years.

the 'tale of the tape' so to speak is the Ocean Heat Content, which indicates we are on the verge of a period of rapid warming.  It is the aerosol impacts in the arctic and the likelihood for accelerated ice loss and regional temperature increases that will drive this new warming trend. 

Haiku of Past Futures
My "burning embers"
are not tri-color bar graphs
+3C today

slow wing

  • Grease ice
  • Posts: 790
    • View Profile
  • Liked: 144
  • Likes Given: 390
Re: The 2016 melting season
« Reply #4689 on: September 08, 2016, 04:34:08 AM »
As attached below, today is another opportunity to check Neven's year-to-year comparison of U. Bremen sea ice concentration maps:
https://sites.google.com/site/arcticseaicegraphs/concentration-maps/sic0907.

Today's map still resembles the one for 2010, only with the ice distribution on the East side skewed more towards the Atlantic.

How will the melt season end this year? The 'reverse dipole' weather configuration has settled in and is forecast to remain for several days yet - with low atmospheric pressure off the Canadian Arctic coast opposing high  pressure on the Siberian side.

As shown by the Nullschool map below, the Siberian side of the Arctic Basin remains breezy and quite warm for the date - above zero degrees C near the coast dropping away to slightly below zero further into the ocean. That trend also extends westwards to the Beaufort Sea off the Alaskan coast.

It appears then that what remains of the 'Wrangel Arm' of sea ice is still in peril of melting right out, or nearly so.

Further West, in the Beaufort Sea, it looks likely we will lose the remnants of the storied Big Block.


The American side is cooler and less windy, dropping down to below -10oC near the centre (I presume) of the low pressure. With little wind there as well, might that begin to freeze over?


As always for me, the wild card is the anomalously high amount of first year ice left in and around the Barents Sea. I doubt there is time for much fractional change here before freeze-over, but meanwhile will it grow slightly or shrink slightly? No idea.

And that carries over to whether we will have early or late minima in overall ice extent and area. No idea on that as well.

epiphyte

  • Frazil ice
  • Posts: 383
    • View Profile
  • Liked: 22
  • Likes Given: 17
Re: The 2016 melting season
« Reply #4690 on: September 08, 2016, 06:36:09 AM »
As attached below, today is another opportunity to check Neven's year-to-year comparison of U. Bremen sea ice concentration maps:
https://sites.google.com/site/arcticseaicegraphs/concentration-maps/sic0907.

Today's map still resembles the one for 2010, only with the ice distribution on the East side skewed more towards the Atlantic.

How will the melt season end this year? The 'reverse dipole' weather configuration has settled in and is forecast to remain for several days yet - with low atmospheric pressure off the Canadian Arctic coast opposing high  pressure on the Siberian side.

As shown by the Nullschool map below, the Siberian side of the Arctic Basin remains breezy and quite warm for the date - above zero degrees C near the coast dropping away to slightly below zero further into the ocean. That trend also extends westwards to the Beaufort Sea off the Alaskan coast.

It appears then that what remains of the 'Wrangel Arm' of sea ice is still in peril of melting right out, or nearly so.

Further West, in the Beaufort Sea, it looks likely we will lose the remnants of the storied Big Block.


The American side is cooler and less windy, dropping down to below -10oC near the centre (I presume) of the low pressure. With little wind there as well, might that begin to freeze over?


As always for me, the wild card is the anomalously high amount of first year ice left in and around the Barents Sea. I doubt there is time for much fractional change here before freeze-over, but meanwhile will it grow slightly or shrink slightly? No idea.

And that carries over to whether we will have early or late minima in overall ice extent and area. No idea on that as well.

It seems to me that obsessing over these numbers is missing the point. It's like watching an animal bleeding to death and judging it's health by the size of the pool of blood.

seaicesailor

  • Guest
Re: The 2016 melting season
« Reply #4691 on: September 08, 2016, 06:56:56 AM »
@ Slow wing thanks for your detailed posts, these are greatly appreciated indeed.
I am just echoing others opinions. I agree the Wrangel arm is slowly eaten away, little of it will survive, a lot of stirring and warm water yet; once one condition ceases and coldness sustained, it will start to refreeze water around. Barents bite is chewing ice as the Laptev ice is displaced toward east; air temperatures stay warm around Laptev, but there was no melting momentum whatsoever all the season thru there, and as Neven stresses this matters a lot, good for the ice there (which is going to be first goner by transport during winter/spring anyway). The low will disperse a bit and seems extent will keep fairly flat for a few days as other people stress.


budmantis

  • Nilas ice
  • Posts: 1219
    • View Profile
  • Liked: 5
  • Likes Given: 32
Re: The 2016 melting season
« Reply #4692 on: September 08, 2016, 07:04:13 AM »

It seems to me that obsessing over these numbers is missing the point. It's like watching an animal bleeding to death and judging it's health by the size of the pool of blood.
[/quote]

No disrespect to slow wing's analysis, but I do agree with what epiphyte is saying. In a way, it feels like we're pathologists performing an autopsy.

Michael Hauber

  • Grease ice
  • Posts: 841
    • View Profile
  • Liked: 46
  • Likes Given: 12
Re: The 2016 melting season
« Reply #4693 on: September 08, 2016, 07:24:31 AM »


Models that can reproduce the warming over a century you mean.  In nearly every case, in every iteration of the model results, the new model runs show increasingly severe impacts in scope, timing and scale.

Model projections have been made since the late 70s, early 80s, and the last 30 or more years matches these predictions reasonably well, so the models have substantial success in prediction, as well as in reproduction of past warming.  The climate sensitivity and warming rates from studies in the 70s and 80s is pretty much the same as what is being predicted by modelling studies today.  I've heard plenty of deniers claim that in nearly every case the new model runs shows increasingly slower impacts in scope, timing and scale.
Climate change:  Prepare for the worst, hope for the best, expect the middle.

Michael Hauber

  • Grease ice
  • Posts: 841
    • View Profile
  • Liked: 46
  • Likes Given: 12
Re: The 2016 melting season
« Reply #4694 on: September 08, 2016, 07:28:56 AM »
Looking at Slater's 925 hp temps we have now had a good couple of weeks of record matching temps in the Arctic.  The current last date for temps above 0 is quite a lot later than all recent years, although looking at the record line there must be a year prior to 2005 (how far back I checked) with a similar late temp at 0 or above.
Climate change:  Prepare for the worst, hope for the best, expect the middle.

Lord M Vader

  • Nilas ice
  • Posts: 1261
    • View Profile
  • Liked: 26
  • Likes Given: 19
Re: The 2016 melting season
« Reply #4695 on: September 08, 2016, 07:48:10 AM »
Michael Hauber: In 1984 and 1991 there was also a late season surge of warm air about this time at year.

//LMV

seaicesailor

  • Guest
Re: The 2016 melting season
« Reply #4696 on: September 08, 2016, 07:56:06 AM »

It seems to me that obsessing over these numbers is missing the point. It's like watching an animal bleeding to death and judging it's health by the size of the pool of blood.

No disrespect to slow wing's analysis, but I do agree with what epiphyte is saying. In a way, it feels like we're pathologists performing an autopsy.
Well there is a saying in some other language, poorly translated as  "everything is meat till you reach the bone" meaning "finish your meal!", and this is the melting season thread. The final state is such that, yes it sounds gory, but that's the way it is.
What is going on in the southernmost part of the Wrangel arm is fascinating from a physical point of view.

oren

  • Young ice
  • Posts: 4418
    • View Profile
  • Liked: 848
  • Likes Given: 1270
Re: The 2016 melting season
« Reply #4697 on: September 08, 2016, 08:35:50 AM »
It seems to me that obsessing over these numbers is missing the point. It's like watching an animal bleeding to death and judging it's health by the size of the pool of blood.

No disrespect to slow wing's analysis, but I do agree with what epiphyte is saying. In a way, it feels like we're pathologists performing an autopsy.
These sayings could be right but this is after all "The 2016 melting season" thread, and not "The long term consequences of sea ice loss" one. It's an ongoing autopsy, no one is forced to watch. I found Slow wing's post quite interesting in its level of detail, although of course in the long-term view it doesn't matter much.

magnamentis

  • Guest
Re: The 2016 melting season
« Reply #4698 on: September 08, 2016, 11:50:49 AM »
Models are like instrument flight rules which tend to lead to fatal errors once the conditions and topography has changed and/or new obstacles like high rise buildings are new in the path, especially if such changes are ongoing and rapidly though.

IMO in times of rapid changes of so many factors one should use visual flight rules and not fly on auto-pilot by assuming that it will be as it was last time. most of the ongoing discussions are based on that some watch out for life and actual information to get an idea while others tend to build their opinion on the past which is not entirly and in parts not at all valid anymore.

this is not about good and bad, right or wrong, just a remark as to my 2cents how to currently look at things. the keywords i mentioned many times this season starting around march:

- thickness
- fragmentation
- heat in the system (water mostly)
- changing wind patterns
- mobility of the ice in places where it was much less mobile only a few years back
- etc.

greatdying2

  • Grease ice
  • Posts: 574
    • View Profile
  • Liked: 0
  • Likes Given: 0
Re: The 2016 melting season
« Reply #4699 on: September 08, 2016, 11:53:53 AM »
What is "more scientific", if that means anything, is I believe whatever in any given system gets closest to truth.

If data look like a straight line and you can justify why you would expect it to be a straight line and the models are poor, then straight line extrapolation may well get you closer to the truth than poor models that don't reflect reality.

However, what Prof Wadhams has done is completely different. Extrapolating a curve is very risky as there are all sorts of different curves that can fit the data and have very different projections. Despite this, he has gone with an aggressive exponential downward curve when (virtually?) all the models show a slowing down in the rate of extent decline (let alone volume decline) as ice free conditions are approached. This is absolutely asking to be criticised.


No argument here. As I said initially, I think that publicizing alarmist projections is counter-productive. I was simply criticizing the model-centric view of science. Models play a valuable role, but so do other forms of analysis.
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.