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Messages - jdallen

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1
Arctic sea ice / Re: Arctic Image of the Day
« on: Today at 02:30:16 AM »
I am dreaming of the North Pole and Central Arctic Basin full of round ice floes with no square shapes to be seen anymore. Today's thin sea ice in the CAB is no longer capable to survive intact when sea ice floes toss each other (due to winds and ocean currents), turning them all ....
Deli, you may have accidentally found the single largest surviving block of ice in the CAB...

2
Arctic sea ice / Re: The 2017 melting season
« on: June 27, 2017, 09:26:09 PM »
<snippage>

The ice pack isn’t very thick and badly fragmented.

The main difference is extent on the Atlantic side. But, over there, more fragmentation than ever. Under the right conditions, a lot of ice will be pushed South and melt, even though the Atlantic may not be that warm now.

There’s a dipole in the make. It could be the beginning of the event. Hold on.

To your point, Werther, while we have considerably more extent and area in the Barentsz, Greenland and Kara seas, that extent is mostly slash and extremely vulnerable.  I think the three images (first two using bands 7-2-1, last visible) I selected over the last three days illustrate that.  I tried to select periods with lower cloud cover.

The visible light shot of Svalbard/Fram very much highlight your point.  As the pack breaks out of the CAB into the strait, the infill around what appear to be MYI blocks rapidly disappears, and ice which is backed up against the islands themselves shows signs of attack from both above and below.

(Edit/post script)
I think it quite possible we could see 2017 reach lowest SIA but not quite reach lowest SIE.

As posted elsewhere, all hinges on July's weather now.  Unfortunately with the forecast Beaufort high and dipole, it's not starting out well for the ice.

3
Arctic sea ice / Re: The 2017 melting season
« on: June 27, 2017, 07:52:48 AM »
<snippage> If this set-up remains dominant into July, this year is top 3 material. At the very least.
Definitively not the weather we were hoping for, Neven.

4
Arctic sea ice / Re: Home brew AMSR2 extent & area calculation
« on: June 26, 2017, 07:39:46 PM »
Even Jaxa shows the torching Beaufort.
Direct sun plus bottom heat plus warm 2M temps could translate to 10 CM/day coming off some areas of ice.  When do we expect that high to show up? How long will it hand around!?

5
Arctic sea ice / Re: The 2017 melting season
« on: June 24, 2017, 08:09:06 AM »
Lot of clouds, but look at this ice mobility between North Pole and Kara Sea. Image: Worldview, Jun 23.
This, is a nightmare; peak of installation, major storm disrupting the pack and simultaneously pulling heat up from depth.

We arent even into July.

6
Arctic sea ice / Re: IJIS
« on: June 20, 2017, 05:44:55 AM »
Based on temperatures leveling out and the fact that the ice around the edges was thinner than usual and has melted out fast, there is a good chance the rate of melting will begin to decrease somewhat and ice extent will maintain 4th place for a while and then climb perhaps to 6-8th place. Just a hunch. If I knew how to project the future I'd be rich trading stocks!

For your "hunch" to come to fruition, the rate of extent decrease, which has been the second fastest on record for this time of year so far this month, would have to magically slow to by far the slowest on record.

Not. Going. To. Happen.

Friendly advice: stay away from the stock market. :)
I'm trying to understand this and, apparently, failing.

The most recent 2017 value for IJIS is 9982791.  FTB didn't specify an exact time frame, so let's say this is over the next two weeks:

* If the ice follows the pattern of 2003, 2005, 2008, 2009, 2011 or 2016 it would climb to 6th place.

* If the ice follows the pattern of 2015 it would reach 8th place

* If the ice follows the pattern of 2004 it would reach 9th place

So melt rates from 8 of the past 14 years would bring FTB's "hunch" to fruition. 

Maybe I've badly miscalculated something, or maybe I misunderstood the claim.  But Jim Pettit's comment makes no sense to me.
The problem lies in an assumption of equivalency of the ice across all those years.  Further it assumes equivaleny of other conditions - total enthalpy, volume. Weather among others - so using purely statistical methods of predicition are no more reliable for this years minimum than last year's price movement would reliably predict where your favorite NYSE ticker will be in two months. Don't bet on it.

7
Arctic sea ice / Re: The 2017 melting season
« on: June 16, 2017, 07:21:38 PM »
Happening now over Laptev Sea up to: 50km/h winds, 2.5C temps, and quite a bit of precipitable water (26.500 kg/m2) in the air column - could be raining as we speak?
A number of us had been looking ahead to this moment for several days.  If 2M temps are in the 2-3C range, it is very probably rain falling. The 850mb temps are similar or slightly higher, so I think parts of the Laptev are currently getting a shower.

8
Arctic sea ice / Re: The 2017 melting season
« on: June 16, 2017, 12:20:42 AM »
Please, don't get too excited about things beyond 6 days out. This is a forum, not a news paper.

And I believe that a moniker like GAC is given après le fait. Besides, it would be the third in 5 years. It's almost becoming normal.

For now, we have the dipole and a medium cyclone forecast for the next couple of days. It will be interesting to see what that does.
The weather 48-96 hours out could be significant with that storm in a tight loop on the north of the Laptev.  2M temperatures could be significant as well, with Siberian temps in the mid 20s and higher swept north,  which will reduce snow cover on land and potentially on ice.

Ice in the Kara may get swept back over open water, and more CAB ice shoved towards the exit along the Barentsz.

Yes, it will be interesting enough already, I expect, without looking further.

9
Arctic sea ice / Re: The 2017 melting season
« on: June 15, 2017, 07:43:07 AM »
Updated this again as the openings are getting bigger each day. Worldview has been so cloudy.
CLICK IMAGE Zoom         12th-14th

I would be fascinated to see an explanation for this, as the current visible images from Worldview really don't show any hint of a hole.  Here's a shot of the region; the "hole" *should* be in the lower right quadrant of the image.

Lots of very messed up ice, but no hole.

10
Arctic sea ice / Re: The 2017 melting season
« on: June 15, 2017, 07:35:48 AM »
Thankyou A-team, had to read this a number of times to get some level of understanding. My main take-aways:

- "As the biogeochemistry of the Arctic Ocean is already impossibly complex, it is delusional to think its rapid future change can be modeled in any meaningful way". General humility and the usage of the precautionary principal, rather than eco-optimism should be our guide

- Organisms will tend to trap heat near the underside of thin ice, increasing the rate of bottom melt

- Hopes for a Blue Arctic to foster algal blooms that will sequester large amounts of carbon dioxide are misplaced
Thank you as well, A-Team.  My take away is similar to rboyd's.  While the lack of potential carbon sequestration is disappointing, it's a side show to our long term concerns.  More concerning is the potential amplifying effect of increased plankton and organic material at shallow depths on heat capture.  Simply put, more heat caught closer to the surface means that much more redirected to the ice.

Pity we can't yet quantify it... 5%?  10% more?  Even 1% is going to be highly disruptive, especially when we are so terrifyingly close to a some boundary condition in the system.

11
Arctic sea ice / Re: The 2017 melting season
« on: June 14, 2017, 08:18:38 AM »
Well, yeah. D4 is not too far away. And yes, t should be extremely interesting to see what the usually more reliable ECMWF 00z op run says. We should know in about 45 minutes!

Oooh!! I just discovered that the GFS 00z run develops an unusually Cape Verde cyclone at D4. Should be a very weird event as such TCs usually don't show up until the end of July.
I'm holding out for the 48-72hr outlooks before getting too excited.

Even so, even a modest blow is going to present serious difficulty for the Laptev, Kara and Barentsz ice; those last two very specifically because of how late the Kara froze over, and how hot the Barentsz is under the ice forced into it from the CAB.

A good blow will turn the Kara into slush, and pull enormous heat up to the surface of the Barentsz via Ekman pumping.  This is could give us a clear demonstration of why the ice's lack of mechanical strength is a problem;  all that Barentsz ice is highly mobile and will neither keep the wind from stirring up the water nor be able to resist it itself.

Personally, I think the N. Atlantic heat previously transported into the Arctic is going to be this years 500KG gorilla lurking in the weeds waiting for the right moment to leap.  There's no way to predict when or if that will happen, but the stage is set for it to do exactly that if we get early and frequent storms roaring up to the Barentsz out of the North Atlantic. 1-1.5C temp increase from depth could tear 5CM/day off of the ice.  As we are starting with little more than a meter across most of that, the implications are self explanatory.

Addendum:  There's a certain amount of excitement over the high 2M temps - 2-6C - showing up over the basin.  The greatest impact of that might be to reduce snow burden on the ice and modify albedo in ways we don't want it to go.  Admittedly, quantity has its own quality, and with sufficient heat - consistently 5-10C above freezing - the ice would be affected directly.

That said, the real heavy lifting in the melt season is still going to rely on insolation and imported ocean heat. Surface air temps are a sideshow.

12
Arctic sea ice / Re: The 2017 melting season
« on: June 13, 2017, 04:25:04 AM »
I wonder how much of the sea ice anywhere in the Arctic has enough freeboard to allow for melt-ponding. Obviously, everything is whiter this year, but it may just be because there is not much more than snow above the water. If someone has some pics from here and there, they can easily shoot down that supposition.

P.S. A little tangent to this discussion; check this out.
www.bbc.com/news/av/world-europe-38562814/parts-of-greece-have-been-blanketed-in-snow



Could be paradoxically, lower freeboard, more snow and smaller blocks of ice might ablate the warmer winter. Damn the complexity...

13
Arctic sea ice / Re: The 2017 melting season
« on: June 13, 2017, 02:06:55 AM »
Neven isn't it soon time for you to do an article on Melting Momentum? Just from looking at the MODIS images it seems that we really don't have that much this year.
I've been in contact with David Schröder and he has confirmed (or rather his model) that this year (again) there is lesser melt pond formation than in years with record low minimums.

<snippage>

I think I'll be looking a lot at SSTs in weeks to come. And the weather, of course.
I'm comparing those coastal anomalies with what we've got in Worldview.  It looks very much like a significant percentage - I estimate over 50% - of the really dark anomalies are actually a result of ice being replaced with open water.  Consider the Kara for example, snap shot of today's ice state shown below.

A further difference to consider *again* is what passes currently for extent.  While large areas of the interior CAB are showing slight downward anomalies for melt pond fraction, we similarly do not have the wide areas of undisturbed extent that existed in 2012 and earlier.  I think we need a better picture of albedo over all, rather than just melt ponds, as there is an awful lot of extent that consists of pans and slash that barely has the structural integrity to walk on, much less hold melt ponds.

14
Arctic sea ice / Re: The 2017 melting season
« on: June 08, 2017, 06:20:31 AM »
What is going on and why is disinformation being published?


Different dates: The Snow and Ice Charts were from June 3, 2016 & 2017.  Veli posted images from June 6.  A lot can happen in snow cover over just a few days at this time of year.  Here's the latest:



Regardless, It doesn't seem 2017's lead is as significant as it was.

15
Arctic sea ice / Re: The 2017 melting season
« on: June 06, 2017, 05:06:17 AM »
HOLY SHIT:

Fournier Triangulation Reversion Processed Image of the Lincoln Sea Ice reveals substratum of further leads and coastal regions made of pulverized pancake ice heading to Nares and Fram. :-\

Bottom: Fournier Compression flattens the landscapes on the computer screens also. Here a close-up of Ellesmere Coast to avoid f-triangulation flattening that shows clearly pulverization towards pancake size ice substratum. .. run these methods to fill your pockets with dollar bills with a printer... :P
I find it striking how the ice along all the larger leads that opened up is disintegrating into what almost looks like long channels, 10-20 KM wide of slush reaching deep into the central pack.

If it is all disintegrating into sub 100 meter floes, that does portend rapid melting out of those channels and exponentially increasing instability as they do.

16
Arctic sea ice / Re: The 2017 melting season
« on: June 04, 2017, 07:44:42 PM »
North Pole today. Image: Worldview.

It is not the fracturing that worries me but the lack of those rhomboid floe structures that, if iirc, are evidence of thick, strong MYI.

*Exactly*, SH, exactly.

17
Arctic sea ice / Re: Latest PIOMAS update (June)
« on: May 30, 2017, 05:46:57 AM »
That volume number is important, which when combined with larger area and extent numbers indicates thickness is at least 5 possibly as much as 10% lower overall than 2016.

That's extraordinarily dangerous.

18
Arctic sea ice / Re: How soon could we go ice free?
« on: May 29, 2017, 03:06:06 AM »
I disagree that the chance for ice free September or even August is 0. The chance is certainly low and decreasing but it is not 0. A melt similar to 2012 will be enough to puts us in "virtuallly ice free"  territory. The chance for that is low but is there.

I think everyone should be at least aware of the possible danger and planning and preparation for the worst are very much in order with the caveat that it is a low probability event.
I hesitate to put a number on it and simply call it doubtful for the pure reason that the outcome is entirely dependent on weather; which at this juncture is entirely too unpredictable for us to make any rational, skillfull prediction.

In short, making any quantitative statement is rolling the dice and hoping your guessed outcome is close to how things turn out.  I don't think we're in any position to do that yet.

Conditions certainly are very dangerous for exactly the reason that there *exists a risk*  we could lose the ice.  That in and by itself is sufficient justification for alarm, even without the actual event taking place. We should never have gotten here.

So, it is a matter of random probability; in this pass through of the seasons just exactly how will our multi-armed pendulum swing?

19
Arctic sea ice / Re: The 2017 melting season
« on: May 28, 2017, 10:34:44 PM »
Uh oh. Could we be ice free by july?

Am very depressed over this now.
No. Some regions are likely to be hit very hard, but it is still unlikely we will have an ice free Arctic this season.

20
Arctic sea ice / Re: The 2017 melting season
« on: May 28, 2017, 10:09:26 AM »
DMIs model shows temps above freezing point over a large part of Beaufort Sea as well as partly over the CAB.
The Hudson and Foxe BASIN ad well. Wall-to-wall meltponds visible in Hudson's Bay.

21
Arctic sea ice / Re: The 2017 melting season
« on: May 28, 2017, 09:33:17 AM »
First attachment is Uni Bremen sea ice concentration.   I wonder if it rained on the Beaufort Sea.
EOSDIS worldview visual for 5/27 suggests significant melt pond formation has already taken place across much of the Beaufort and western ACA. That may be what Bremen is showing.

Best part of a quarter million KM2 of ice looks like it is rapidly turning to slush as we watch.

22
Arctic sea ice / Re: The 2017 melting season
« on: May 24, 2017, 11:08:26 PM »
Barentsz sea extent may be high, but the ice is decidedly not in a happy place.

23
Arctic sea ice / Re: The 2017 melting season
« on: May 24, 2017, 11:02:03 PM »
Will it keep on keeping on?

It's done, well and truly.

There's not any else to shatter, and what's there won't re-knit in the next few days.

In short, *every* bit of ice which isn't land fast (a little along the ESS/Laptev which is doomed, a little along Greenland which hopefully is not) is in motion and vulnerable.  That includes virtually all of our multi-year ice. 

24
Arctic sea ice / Re: The 2017 melting season
« on: May 23, 2017, 06:49:26 PM »
Seems like we are on the verge to see some decent action in work soon.

Yes, the Atlantic side is to blame for why we are lagging in extent numbers. Despite fairly cool weather conditions in Kara Sea, the ice there will start to see some major damage soon. The same should be true for the ice between Franz Josefs land and Svalbard but especially in the Labrador Sea.

At least 1-2, maybe even 3, Century breaks should not be of bound for the next 7 days as the Arctic continues to heat up.
Looking at the Barentsz, Kara, Labraffor and Greenland seas, I fully anticipate major flash melting in June that will have multiple centuries, possibly multiple double centuries of melt as the thin broad extent gets heated, and ice less than 1.5 meters their virtually evaporates.

25
Arctic sea ice / Re: The 2017 melting season
« on: May 22, 2017, 07:12:24 AM »
All the ice between the Beaufort and Chukchi is starting to break up.
A close up look.


Doesn't ice generally start fracturing extensively at this time in the Beaufort and Chukchi? I am more interested in how it breaks up which reveals the overall strength (thickness, temperature etc.) of the ice. Does it quickly turn into a melange or rubble, very small floes, or do we see it fracturing in large rafts, rhomboids and such? From that image, it looks like a mix (perhaps a little heavy on rubble) but I do not know the scale of the image. How large are the largest floes?
Not this early. Not this extensively.

26
Arctic sea ice / Re: What's new in the Arctic ?
« on: May 20, 2017, 08:55:56 PM »
Did the guys who decided to put the seed vault where it is on Spitzbergen get their climate change forecasts from Breitbart News, and / or Scott Pruitt and / or Lamar Smith ?
They were using the best information they had at the time using the resources available. There is no need to insult them.

27
Arctic sea ice / Re: The 2017 melting season
« on: May 17, 2017, 08:18:28 AM »
From the IJIS thread, SIE down nearly a century today, and the GFS model shows high pressure building over the Pacific side of the Arctic and expanding to cover most of the basin over the next two weeks.  Add also, temperatures warming over much of the region to near or above freezing.

Pretty much, perfect weather to accelerate melt pond formation and a rapid slide into extensive early surface melt.

Tropical Tidbits link for reference and the curious.

http://www.tropicaltidbits.com/analysis/models/?model=gfs&region=nhem&pkg=T2m&runtime=2017051700&fh=0&xpos=0&ypos=208

28
Arctic sea ice / Re: The 2017 melting season
« on: May 13, 2017, 09:03:12 AM »
Same Scene, different source, TOPAZ4 + a comparison with 2016 & 2012
Taken as an assemblage, I'd say they also portend the appearance of extensive melt ponds on the Pacific side, from the Amundsen Gulf all the way to the ESS.

Interesting yet disturbing to see if it pans out.

29
Arctic sea ice / Re: 2017 sea ice area and extent data
« on: May 13, 2017, 06:54:41 AM »
How is the situation wrt sea ice measured by NSIDC restricted to the Arctic Basin regions?

NSIDC extent has dropped from the 100% ice cover and is among the front runners (well behind 2016).

That can not be said of area, still in the middle of the pack and behind most of the recent (2006 and later) years.
For all of that, most of the difference in both extent and area is in three areas:  the Barents sea, Greenland Sea and Baffin Bay.

It will dissappear rapidly.

30
Arctic sea ice / Re: Latest PIOMAS update (May)
« on: May 04, 2017, 03:58:16 AM »
Scary:
《Snippage》
2. The ice that is thicker than average, can easily leave the Arctic Ocean following the Fram Strait route (according to PIOMAS thickness anomaly).

It's doesn't even have to move. The Atlantic flow around Svalbard typical of the last few years no doubt is already tearing at it.  It won't last through June even if it doesn't move a centimeter.

31
Arctic sea ice / Re: Stupid Questions :o
« on: May 01, 2017, 07:12:49 AM »

Lately I've been thinking that the best way to avoid cataclysmic global warming would be to cull a majority of the human population.

Now, the best way to do that would be a nuclear war.

Maybe Trump does care about Global Warming after all!
And that, is what we used to call, throwing the baby out with the bathwater.

33
There is a lot of buzz right now about Trump and discussions about N. Korea. (April 24, 2017)

Some of us have picked up articles about substantial numbers of US vessels transiting the Canal starting a few days ago.  I've found some in various Spanish language site, but am keen to find as close to original source as possible.  I'm suspicious english language search engines may not be picking up the threads on this; certainly our news outlets are not.

Here's an example of what I found:
http://www.7dias.com.do/portada/2017/04/22/i227865_estados-unidos-moviliza-submarinos-nucleares-hacia-peninsula-coreana.html#.WP7metIrJqM

34
...
The Beaufort sea cracks and sea ice in general may be refreezing at a good pace compared to last year even with no MYI. Cold temperatures and lack of movement again and perhaps thin ice negative feedback since January.
If some Beaufort sea ice survives this year, there may not be any record soon. It all, still, hangs on this summers weather.
(emphasis mine)
That's a lot of conditionals right there, seaicesailor. Back to the numbers/science, what is the trend? What is the statistical uncertainty associated with the data we have? What does it tell us?
It tells us that there is a high level of variability in potential outcomes. 

It is exactly that uncertainty that caused me to choose 2040-2050.  While weather may change, and we *will* see SIE bottoming out under 1 million KM2 soon, it will take far longer for net enthalpy to catch up such that we can expect ice to disappear in summer completely.

This does not indicate not one jot less concern on my part than yours for what's happening. It means I am thinking carefully.  Maybe you should make fewer value judgements about other participants, and perhaps consider the questions they pose. You could do worse than have some respect for that.

Have you thought for instance, how the ice might reach an end of summer SIE of greater than 1 million KM2 after 2030?  Your stridency suggest to me you have not.  I urge you to bring more light and less heat to the discussion.


35
Arctic sea ice / Re: The 2017 melting season
« on: April 20, 2017, 08:42:44 PM »
So much data saying Melt (DMI, Arctic anomaly, Fram export, destruction of  sea ice sheets integrity from multiple observations  etc. etc.). And yet jaxa sea ice decline remains at a glacial pace, and sea ice volume not declining yet.
And still at least 2 weeks before getting April PIOMAS  update. Am I the only one in confusion ?
I think the answer is dispersion, GC.  Less ice, spread more thinly.

36
Arctic sea ice / Re: The 2017 melting season
« on: April 20, 2017, 09:28:36 AM »
Browsing around tonight in worldview, there are hundreds of thousands of KM2 that look like they are right on the edge of vanishing; it's not just the Bering.  If  you look in the Kara, along the margins of the Barents, the Bering, the Okhotsks, Baffin, the Greenland, you will see huge expanses like that shown below. 

This image is from south central Baffin, and the image is about 250,000KM2 total.

37
Arctic sea ice / Re: The 2017 melting season
« on: April 20, 2017, 09:16:03 AM »
Look for major drops in extent in the Bering over the next few days.

38
I read the Booth paper quickly and it does suggest that HADGEM2-ES explains a part (but not all) of the 'bump' in temperature in the 30's-40's. Also, I understand that their HADGEM2-ES run is mostly driven by indirect (not direct) aerosol forcing. If I understand that correctly, it makes assumptions about cloud coverage affected by aerosols.

Now I'm not sure yet how important their findings are, but I do see that this paper (Booth et al) draws criticism in the scientific literature.

For example, here, by Zhang et al 2012 responds to Booth et al :
However, here it is shown that there are major discrepancies between the HadGEM2-ES simulations and observations in the North Atlantic upper-ocean heat content, in the spatial pattern of multidecadal SST changes within and outside the North Atlantic, and in the subpolar North Atlantic sea surface salinity. These discrepancies may be strongly influenced by, and indeed in large part caused by, aerosol effects. It is also shown that the aerosol effects simulated in HadGEM2-ES cannot account for the observed anticorrelation between detrended multidecadal surface and subsurface temperature variations in the tropical North Atlantic. These discrepancies cast considerable doubt on the claim that aerosol forcing drives the bulk of this multidecadal
variability
.

Don't you just LOVE science and the scientific process ?
Indeed; that said, it causes me to question somewhat the reference to that warming period as an indication of base-line "natural" increases driving Ding et. al.'s  conclusion, even if not responsible for *most* of the increase.

How would we eliminate human-sourced aerosols from baseline calculations of natural variability?

39
Quick off the cuff thought - I'm piqued by the idea the 30s/early 40s temperature bump could be a result of decreased aerosols (SO2 in particular) tied to the reduction in industrial zctivity and fossil fuel consumption during the depression.

40
Arctic sea ice / Re: The 2017 melting season
« on: April 18, 2017, 07:14:04 AM »
A stark illustration of how difficult our situation is.

Two daylight captures of the northern Bering, Chukchi, eastern ESS and Western Beaufort.

First is 04/17/2016

Second is 04/17/2017.

[Edit: Added for comparison, 05/17/2016]
[ADDITIONAL edit - I got the name stamps wrong on two of the images. 
From top to bottom:
2016-04-17
2017-04-17
2016-05-17
]

41
Arctic sea ice / Re: The 2017 melting season
« on: April 17, 2017, 05:16:03 PM »
Very difficult to vector that sort of mobility into any prediction for September.
What is frightening about these animations of the Beaufort and Chukchi is how fractured much of the ice is. Large portions look like rubble.
Both true statements.

Also true, 2017 open water in the Chukchi and Bering seas has caught up to and passed 2016 in almost a matter of hours.  Conditions appear extraordinarily volatile.

42
Arctic sea ice / Re: The 2017 melting season
« on: April 17, 2017, 07:33:31 AM »
Worldview is down. Uni-Bremen is down. So, I went with what I could get.
Beaufort 15th(left) vs. 16th
I highly recommend using the zoom.

Dramatic and massive changes.  It looks to be catching up with 2016 pretty rapidly.

43
Less heat, more light, everyone.  Prof. Ding has engaged us in a lively and productive scientific exchange to both explain the paper and hear our questions and criticism.

If you wish to convince him to abandon his findings, you must present compelling fact and arguments.  This requires patience and careful thought.  if you sought rapid results and gratification, I suggest you discard that expectation.

Your arguments will require:

1) work as thorough and compelling as his own and
2) time for everyone one (including the good professor) to digest it.

44
... if we want to have a good understanding while monitoring the comeback of Arctic sea ice. ...
:o
You are joking, right?
We are already committed to the complete and irreversible (on a human time scale) disappearance year round of Arctic sea ice.

That kind of makes me want to shut down the blog and forum, and build a big bunker. And so the narrative I tell myself (and hopefully others once I get back to blogging) is that what we need to fight for, is getting Arctic sea ice back after we lose it. Preferably prevent it from going ice-free all year round.

why would you intentionally attempt to assign a value of 'natural variability' to a dynamic system that is in the process of catastrophic collapse?  Is it because the collapse is not what you expected?

If it is all collapsing, there's not much sense in thinking about what the best way to do research is. Or post on a forum. And what I've said in reply to AndrewB.
Bunkers are attractive but in the long run ineffective.

I appreciate greatly Dr. Ding jumping into our discussion, even as I struggle to fully grasp the nuances of argument. His doing so is the quintessence of good scholarship.

While I generally understand his teams methodology, which in context of process seems sound, I am wrestling with the label "natural variation" to describe "unforced" departure from average.

That's a big bucket, and I'm wondering how much of that is anthropomorphic change outside of the Arctic translating into it. Perhaps, Dr. Ding, you could address that thought?

Last thought to Neven - even if we cannot recover the Arctic as it was,  we still must consider the potential loss of billions of lives due to climate change. That deserves our continued discussion.

45
Arctic sea ice / Re: The 2017 melting season
« on: April 13, 2017, 01:05:43 AM »
Given the forecast, we can expect more of that. I'll try and make an updated animation.

Edit: I still had the template from last year:
2017 Beaufort looks to be trying mightily to catch up with 2016's open water.  It becomes more clear looking at it in Worldview, where you can see in particular just how shattered the ice is.  There may be more coverage than last year, but it is not robust. The Amundsen Gulf in particular has disintegrated into a bowl of ice cubes.

46
Arctic sea ice / Re: The 2017 melting season
« on: April 12, 2017, 09:02:53 AM »
The latest Arctic Sea Ice News is out:

<snippage>

New work by an international team led by Igor Polyakov of the University of Alaska Fairbanks provides strong evidence that Atlantic layer heat is now playing a prominent role in reducing winter ice formation in the Eurasian Basin, which is manifested as more summer ice loss. According to their analysis, the ice loss due to the influence of Atlantic layer heat is comparable in magnitude to the top down forcing by the atmosphere.

This is an unexpected and very bad finding.

47
Arctic sea ice / Re: Arctic Image of the Day
« on: April 07, 2017, 08:34:14 AM »
Fragility of sea ice revealed by a topographic constraint: circular ice breaking area radiates from an island north of the Kara Sea: <snip>
Great Image, VeliAlbertKallio!

That demonstrates categorically just how vulnerable the ice is in that region.

48
Arctic sea ice / Re: The 2017 melting season
« on: April 05, 2017, 05:04:25 AM »
Baffin is really moving some ice lately.


Indeed.  Davis Straight is about 330 km wide at the narrowest there (on the Arctic Circle, thereabouts).  Measuring a big floe 17th to 23rd March which moved 100 km over those five days and assuming an average ice thickness of 1 metre gives an export of 6.6 cubic kilometres of ice per day.  That is darn a big ice-block to freeze, and quite a loss to the basin.  I've no data to tell whether this is in any way an unusual loss rate and how it compares, say, with Fram et al.  But it sure is an impressive number.
That movement is un-blocking ice coming out of Hudson's bay and opening the NW Passage up to pressure from tidal movement.

Looking at all of the exits - Bering, Barents, Fram, Baffin - it seems like a general "Un-corking" is taking place.

49
Arctic sea ice / Re: Latest PIOMAS update (March)
« on: April 05, 2017, 05:00:49 AM »
Adam Ash
Indeed!  A simple drag and drop of previous years shows the potential for a far-too-close-for comfort minimum.
That smells like a Blue Ocean Event.

The fat singing lady always makes her own damn mind  ;)
Indeed.  No prediction of Blue Ocean here until after I see the numbers at the end of May.  Far too much depends on weather and albedo.

50
Arctic sea ice / Re: The 2017 melting season
« on: April 04, 2017, 04:07:08 AM »
Last but not least, some detail using Aqua Modis bands 7-2-1 that shows just exactly what happens when that ice reaches the "scorching" Atlantic heat influx we've been watching for the last 2 years.

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