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Darvince

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Re: The 2016 melting season
« Reply #3300 on: July 14, 2016, 12:26:45 AM »
The Story of Big Block
On February 24, we got our first glimpse of the floe that was to become Big Block:


Over the next several weeks, it drifted towards the southwest as the Beaufort Gyre turned, along with many other pieces of ice which suffer much worse fates. On March 8, it suffered its first of two major cracks, before it became resistant and differentiated from the rest of the pack in the area:


Over the next few days, it continued drifting, but the Gyre paused on the 17th, for it cracked again on March 18:

This would be its final major crack before it became an isolated floe, for it did not crack in any of the future crackings across the Gyre.

It became established as the biggest floe in the Beaufort Gyre as the floes all around it succumbed to cracking straight through their middles. By April 12th, it had become an independent floe on three sides:


Soon, it found itself on the southern edge of the gyre and became established as a solid, long-lasting floe as it wasn't subject to cracking like all the other ones around it. It continues its meanderings, slowly but surely becoming more and more the greatest and most dominant floe in the gyre. It also made a 90 degree rotation as it moved across the gyre. It was protected from most melting throughout May and June as they were very cloudy over the Big Block. Some very thin ice became attached to its western end around the middle of June, as exemplified in this screenshot:


On June 24, some internal stresses and melt ponding in Big Block became visible, making some wonder if its demise would be soon:


However, Big Block endured, even as wind and rain ravaged it and brought out even more stresses, showing that even it was not immortal in the melting Arctic. Here it is, rotating about near the center of the gyre in early July with melt ponds visible:


Currently, Big Block still endures, even though its melt ponds are extensive and other floes are hitting it, certainly causing great amounts of kinetic energy to transfer between the two.

Neven

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Re: The 2016 melting season
« Reply #3301 on: July 14, 2016, 12:29:57 AM »
Cool stuff, Darvince! Thanks!  :)
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oren

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Re: The 2016 melting season
« Reply #3302 on: July 14, 2016, 12:44:04 AM »
Wonderful!

JayW

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Re: The 2016 melting season
« Reply #3303 on: July 14, 2016, 12:45:20 AM »
That was fun Darvince.  :)  looking forward to the next chapter.


Hopefully it remains relatively clear over the Chukchi-Beaufort area so I can extend this animation  The brash ice north of Alaska offers an opportunity to watch the currents at a "higher resolution" so to speak.  Unfortunately, there was only a single image from July 11.  So the best I can do for now is a 44 hour loop, ending July 13 1945z.

http://feeder.gina.alaska.edu/search?commit=Search&search%5Bend%5D=&search%5Bfeeds%5D%5B5%5D=1&search%5Bsensors%5D%5B3%5D=1&search%5Bstart%5D=&utf8=
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seaicesailor

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Re: The 2016 melting season
« Reply #3304 on: July 14, 2016, 12:51:30 AM »
Yep that was great Darvince (and Jay)!
Questions: what is pushing the block right now toward the insides of the pack? Couldnt it be a branch of the Alaskan current out from Barrow point, or just the clockwise rotation?
Will it survive storm or R.I.P. ?

seaicesailor

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Re: The 2016 melting season
« Reply #3305 on: July 14, 2016, 12:54:47 AM »
That was fun Darvince.  :)  looking forward to the next chapter.


Hopefully it remains relatively clear over the Chukchi-Beaufort area so I can extend this animation  The brash ice north of Alaska offers an opportunity to watch the currents at a "higher resolution" so to speak.  Unfortunately, there was only a single image from July 11.  So the best I can do for now is a 44 hour loop, ending July 13 1945z.

http://feeder.gina.alaska.edu/search?commit=Search&search%5Bend%5D=&search%5Bfeeds%5D%5B5%5D=1&search%5Bsensors%5D%5B3%5D=1&search%5Bstart%5D=&utf8=
BTW Jay your animation shows the Alaskan current at Barrow thanks to the slushy ice that acts as a ink marker! Pretty vigorous being just 40 hours!

JayW

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Re: The 2016 melting season
« Reply #3306 on: July 14, 2016, 01:43:12 AM »
Yep that was great Darvince (and Jay)!
Questions: what is pushing the block right now toward the insides of the pack? Couldnt it be a branch of the Alaskan current out from Barrow point, or just the clockwise rotation?
Will it survive storm or R.I.P. ?

I can't say with certainty, and I would hesitate to attribute cause to any single variable.  Like with so many aspects of the arctic, there's lots going on, and the effects are difficult to quantify, especially for me.   

But I do believe that wind played some role, but that's largely a guess.

Here's 48hr hours of AVHRR, partly mostly what I'm basing my guess on. 

http://weather.gc.ca/satellite/satellite_anim_e.html?sat=hrpt&area=dfo&type=nir
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Tigertown

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Re: The 2016 melting season
« Reply #3307 on: July 14, 2016, 01:50:51 AM »
Looks like Nares Strait is trying its best to get unclogged and start moving. Maybe another few days or a week?

6roucho

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Re: The 2016 melting season
« Reply #3308 on: July 14, 2016, 04:23:31 AM »
Yes Slater doesn't consider insolation, because his model is a statistical model based on regression. He mentions this on his SIPN report and on his website with the most up to date data.

Quote
These are probabilistic projections of sea ice extent. I use a very simple regression/projection method based on prior years and assimilation of the latest data - it's not the most sophisticated method but it does have a fair degree of skill.
Website:
http://cires1.colorado.edu/~aslater/SEAICE/about.html

SIPN report:
https://www.arcus.org/files/sio/25659/sio-2016-june_slater-persistence_0.pdf

In my opinion regional forecasts more than 14 days ahead are unreliable anyway because winds can push ice a few kilometers a day and change the distribution significantly.

Yes, I read that. I'm just not convinced by your explanation. I understand that a statistical model doesn't usually look at physics directly (I'm responsible for a statistical model in finance, for my sins) but the strength of statistical modelling is that it captures physics by proxy, in the observed behaviour of systems. Any model that predicts a melt season must (at least by proxy) incorporate insolation.

The problem this model has with the Hudson *might* mean he doesn't include the insolation effects of changes of latitude but absent a look at the code, my bet would be on something more subtle.

Bear in mind that I have no information about Slater's model beyond what I can glean from the few words in those links.
« Last Edit: July 14, 2016, 08:44:55 AM by 6roucho »

Apocalypse4Real

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Re: The 2016 melting season
« Reply #3309 on: July 14, 2016, 04:58:06 AM »
We just hit new all time high temps for the Alaskan Arctic coast this afternoon - 84F at Alpine and Deadhorse. A cold front is expected to shred the Arctic Ocean ice north of Barrow, AK.

See the blog post: http://www.megiddo666.apocalypse4real-globalmethanetracking.com/2016/07/all-time-high-heat-for-alaska-arctic.html

Michael Hauber

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Re: The 2016 melting season
« Reply #3310 on: July 14, 2016, 06:09:11 AM »
An ENSO Arctic sea ice link?

As the recent el nino broke down convection switched from central and east pacific to the east Indian Ocean.  This switch happened around May, with a marked change to tropical trade winds with easterly anomalies developing to the north of Australia, and westerly anomalies in the Indian Ocean.  At the same time there was a noticeable increase in upper trough activity through Australia.  Recent research into ENSO and Australian rainfall suggests that this is caused by atmospheric Rossby waves that transmit instability from the equator towards the south and east (in SH, north and east for the NH).  Checking the 200mb height anomalies recently I noticed that there is quite a strong anomaly to the south of Australia.  And at the same time there is a similar anomaly over the Siberian region, very roughly mirror imaging the SH, and perhaps caused by the same mechanism.

It is also interesting to note that the switch in Australian conditions occurred in mid May, the change in tropical trade winds was about mid May.  And the recent Arctic cool down?  That was also mid May.

Linking ENSO and Arctic sea ice is not easy or obvious.  For instance 2007 was a similar transition year, and we didn't have anything like the recent cool down.  But what we did have was a strong dipole.  Perhaps if such an ENSO transition triggers upper troughing in the Siberian sector while high pressure is strong over the central Arctic we get a strong dipole similar to 2007.  But Siberian troughing this year without a strong high and we get lows pushing more towards the central arctic and a stronger cool down effect.
Climate change:  Prepare for the worst, hope for the best, expect the middle.

jai mitchell

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Re: The 2016 melting season
« Reply #3311 on: July 14, 2016, 07:27:14 AM »
Haiku of Past Futures
My "burning embers"
are not tri-color bar graphs
+3C today

Andreas T

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Re: The 2016 melting season
« Reply #3312 on: July 14, 2016, 09:33:15 AM »
Yes Slater doesn't consider insolation, because his model is a statistical model based on regression. He mentions this on his SIPN report and on his website with the most up to date data.

...
Website:
http://cires1.colorado.edu/~aslater/SEAICE/about.html

SIPN report:
https://www.arcus.org/files/sio/25659/sio-2016-june_slater-persistence_0.pdf

In my opinion regional forecasts more than 14 days ahead are unreliable anyway because winds can push ice a few kilometers a day and change the distribution significantly.

Yes, I read that. I'm just not convinced by your explanation. I understand that a statistical model doesn't usually look at physics directly (I'm responsible for a statistical model in finance, for my sins) but the strength of statistical modelling is that it captures physics by proxy, in the observed behaviour of systems. Any model that predicts a melt season must (at least by proxy) incorporate insolation.

The problem this model has with the Hudson *might* mean he doesn't include the insolation effects of changes of latitude but absent a look at the code, my bet would be on something more subtle.

Bear in mind that I have no information about Slater's model beyond what I can glean from the few words in those links.
I am trying to find more information provided by Slater. The link on the NSIDC site to an AGU poster doesn't allow access, does anybody know of an accessible copy?
I found this paper which has an intersting graph comparing regional prediction in a way. It confirms that areas like Beaufort which had ice drifting in makes prediction from observed concentration basically inaccurate. http://onlinelibrary.wiley.com/doi/10.1002/2015JC010989/full
To add my own guessing to what has been said already, if Slaters extrapolation (I hesitate to call it a model because it does not work from physical mechanisms) shows a probability of ice in Hudson it must have "learned" this from the probability of finding it in previous seasons. The question to ask would then be "how far back does the basis of previous seasons go". I have spent more time than I should on this so I'll leave it to someone else to check whether in previous years there has been ice there in Sept.

Neven

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Re: The 2016 melting season
« Reply #3313 on: July 14, 2016, 11:19:50 AM »
The ECMWF forecast is starting to look extremely interesting now, with a large, intense high pressure area coming in from Siberia and taking position in the CAB. I'll post an overview later today.

If this comes about...
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BornFromTheVoid

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Re: The 2016 melting season
« Reply #3314 on: July 14, 2016, 12:00:48 PM »
That is a massive change on the ECM. The forecast charts from about 6 days out would likely bring about some high melt rates. It will be interesting to see if the 06z GFS begins to follow the ECM

Sigmetnow

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Re: The 2016 melting season
« Reply #3315 on: July 14, 2016, 01:21:28 PM »
Quote
Eric Holthaus:  New all-time high on Alaska’s north slope, 1400mi from N Pole.
Deadhorse, AK was warmer than Los Angeles today.
https://twitter.com/ericholthaus/status/753406192500740098

Quote
Brian Brettschneider:  The new all-time record of 84°F at Deadhorse is also an AK record for any station within 50 miles of Arctic Ocean.
https://twitter.com/climatologist49/status/753395414175330305
People who say it cannot be done should not interrupt those who are doing it.

Ninebelowzero

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Re: The 2016 melting season
« Reply #3316 on: July 14, 2016, 01:27:21 PM »
That is a massive change on the ECM. The forecast charts from about 6 days out would likely bring about some high melt rates. It will be interesting to see if the 06z GFS begins to follow the ECM

Do we have some jet stream predictions to go with that?
« Last Edit: July 14, 2016, 01:50:41 PM by Ninebelowzero »

iceman

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Re: The 2016 melting season
« Reply #3317 on: July 14, 2016, 02:01:01 PM »
Question. I've skimmed a few papers on Fram export, and it's deepened my confusion (so that's progress of a sorts). Is there a chart of monthly export that is somewhat current? Thanks in advance.

Wipneus includes a PIOMAS-derived chart on his ArctischePinguin website:
    https://sites.google.com/site/arctischepinguin/home/piomas
The seasonal breakout is useful, though it makes it a bit tricky to read.  My impression is that Fram Strait export during the spring has the greatest effect on volume loss (and, later, on ice concentration) in the Central Arctic Basin.  So if the uptrend in the AMJ trace continues, that would be bad for end-of-season conditions in future years.

EDIT: Sorry, I see this graph is not current. Anyone know of a more up-to-date source?

slow wing

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Re: The 2016 melting season
« Reply #3318 on: July 14, 2016, 02:49:22 PM »
GFS forecast now agrees with ECMWF on impressive ridging on the Pacific side of the Arctic Basin, only 2 days away.

A ~1030 hPa high pressure region is predicted to be sitting right in the Bering Strait, and with a ~990 hPa low directly on the Arctic side of it.

So strong winds (e.g. ~50 km/h) should push the Chukchi and Beaufort ice around, westward into the Beaufort Sea and southward towards the Alaskan Arctic coast. That will disperse the ice pack, including stretching it into the warmed up open water off the Alaskan coast. Not good for the Pacific-side ice at all!
« Last Edit: July 14, 2016, 02:57:11 PM by slow wing »

Apocalypse4Real

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Re: The 2016 melting season
« Reply #3319 on: July 14, 2016, 03:26:26 PM »
The high comes after a cold front moves through the Arctic Ocean dispersing the ice into the Alaskan coast, and accompanied with 20-30 mph winds. Here is the Barrow special weather statement. There is also a small craft advisory for most of the Arctic Ocean coastal areas. This will shred the last sea ice.

 SPECIAL WEATHER STATEMENT UNTIL 12PM AKDT FRI

... SEA ICE EXPECTED TO MOVE TOWARD THE NORTHWEST ALASKA COAST FRIDAY MORNING...

A STRONG COLD FRONT WILL MOVE OVER THE NORTHWEST ALASKA COAST FRIDAY MORNING. 20 TO 30 MPH SOUTHWEST WINDS EARLY FRIDAY MORNING ARE EXPECTED TO SWITCH TO THE NORTHWEST AND CONTINUE THROUGH FRIDAY AFTERNOON AT 20 TO 30 MPH BEFORE BECOMING WEST AND DIMINISHING TO AROUND 15 MPH EARLY FRIDAY EVENING. THE STRONGEST WINDS ARE EXPECTED MID MORNING FRIDAY.

jplotinus

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Re: The 2016 melting season
« Reply #3320 on: July 14, 2016, 03:32:12 PM »
From 4 June to 9 July, BIG BLOCK went from being in the pack to being surrounded by relatively open water. I'm not sure if it is within the current weather advisory area or not?



Edit: I'm wondering if BIG BLOCK will become visible off shore from Barrow? 😮
« Last Edit: July 14, 2016, 03:49:58 PM by jplotinus »

A-Team

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Re: The 2016 melting season
« Reply #3321 on: July 14, 2016, 03:39:29 PM »
Quote
AndreasT: trying to find more information provided by Slater. The link on the NSIDC site to an AGU poster doesn't allow access, does anybody know of an accessible copy?
That link has gone dead. It worked for people here 3x in the past. The incompetent AGU only has the abstract, not the poster. Session C31A0622S
Quote
Sea ice in the Arctic is changing rapidly. Most noticeable has been the series of record, or near-record, annual minimums in sea ice extent in the past six years. The changing regime of sea ice has prompted much interest in seasonal prediction of sea ice extent, particularly as opportunities for Arctic shipping and resource exploration or extraction increase. This study presents a daily sea ice extent probabilistic forecast method with a 50- day lead time. A base projection is made from historical data and near-real-time sea ice ...
I do have to wonder why this has never been published. Maybe something is in the works or it needed a few years to build a track record. Looking at AG Slater publications on google scholar (he is not on ResearchGate), recent years show quite different research interests (titles below):

Surface Solar Radiation in North America: A Comparison of Observations, Reanalyses, Satellite, and Derived Products*
Snow: A New Model Diagnostic and Seasonal Forecast Influences
Surface Solar Radiation in North America: Observations, Reanalyses, Satellite and Derived Products
Permafrost thaw and resulting soil moisture changes regulate projected high-latitude CO2 and CH4 emissions
Effects of excess ground ice on projections of permafrost in a warming climate
Hydrologic controls on the permafrost carbon-climate feedback
Hydrologic implications of different large-scale meteorological model forcing datasets in mountainous regions
Inference and uncertainty of snow depth spatial distribution at the kilometre scale in the Colorado Rocky Mountains
Probabilistic Forecasting of Arctic Sea Ice Extent
Evaluating methane dynamics under thawing permafrost using CLM4. 5BGC
Understanding uncertainty in process-based hydrological models
Using Satellite Data to Monitor Changes in the Cryosphere
Diagnosing present and future permafrost from climate models
Uncertainty in seasonal snow reconstruction: Relative impacts of model forcing and image availability
Modeling excess ice and thermokarst in the Community Land Model
Climate change 2013: the physical science basis. Contribution of Working Group I to the fifth assessment report of the intergovernmental panel on climate change
Long-term climate change: projections, commitments and irreversibility
Modeling excess ice and thermokarst in the Community Land Model
A computational framework to advance hydrometeorological prediction capabilities in cold regions
Modeling permafrost and hydrological cycle interactions in CESM

https://scholar.google.com/citations?hl=en&user=2M_V2wsAAAAJ&view_op=list_works&sortby=pubdate

BornFromTheVoid

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Re: The 2016 melting season
« Reply #3322 on: July 14, 2016, 03:56:11 PM »
In the 8-10 day range (which is when HP really takes hold across the Arctic in the ECM) only the ECM favours a strong ridge penetrating the Arctic ocean. All agree on a strong north Pacific ridge, but the GFS and CMC both have weak height anomalies over the Arctic.



While the ECM is generally the leader at those ranges, the lack of support in consecutive model runs and the lack of support from other models, means the scenario presented by this morning's ECM is unlikely at this stage.

Jim Hunt

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Re: The 2016 melting season
« Reply #3323 on: July 14, 2016, 04:22:07 PM »
The Story of Big Block

Big Block might be in for a bit of a bumpy ride. Here's the current Beaufort Sea surf forecast for July 17th:

Reality is merely an illusion, albeit a very persistent one - Albert Einstein

bbr2314

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Re: The 2016 melting season
« Reply #3324 on: July 14, 2016, 05:08:22 PM »
Today's ARC forecast for the 21st shows a very interesting development. Besides the cliff-fall impending/ongoing across the Peripheral Seas, losses continue deep into the CAB.

But more importantly, it looks like Nares activates and that enough water gets into the southern CAB that it detaches completely from Greenland and the CAA (water also seems to be set to make inroads from the unprecedented Greenland Sea melt).

Even worse, there is enough water that will split the southern CAB into multiple floes (with large crack visible in the below), instead of allowing it to maintain any integrity.

Given how the season has evolved so far it would seem to make sense, but it would make sense if we are indeed heading for ice-free this year.



DMI does a good job of showing the warmth.. those blues are new!


sedziobs

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Re: The 2016 melting season
« Reply #3325 on: July 14, 2016, 05:21:09 PM »
HYCOM nowcast and one-day forecast.  Notice how the Laptev opens up and Baffin crashes in just one day, and the Kara and Atlantic front is covered with thin ice.  Clearly there are some issues.


Also, if you watch the one year animation, you can see that the model shows Nares Strait being active all winter long.
http://www7320.nrlssc.navy.mil/hycomARC/navo/arcticictn_nowcast_anim365d.gif
« Last Edit: July 14, 2016, 05:27:32 PM by sedziobs »

bbr2314

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Re: The 2016 melting season
« Reply #3326 on: July 14, 2016, 05:22:22 PM »
HYCOM nowcast and one-day forecast.  Notice how the Laptev opens up and Baffin crashes in just one day, and the Kara and Atlantic front is covered with thin ice.  Clearly there are some issues.

Yikes. Looks like (and hopefully was) just an off-run.

Laurent

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Re: The 2016 melting season
« Reply #3327 on: July 14, 2016, 05:24:13 PM »
The only area that remains pretty stable receives heat at 2.5°c...

Jim Hunt

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Re: The 2016 melting season
« Reply #3328 on: July 14, 2016, 05:25:19 PM »
Enough water gets into the southern CAB that it detaches completely from Greenland and the CAA

I'll believe it when I see it! Here's one such event that I recorded earlier, in March 2013 in actual fact:

Reality is merely an illusion, albeit a very persistent one - Albert Einstein

BornFromTheVoid

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Re: The 2016 melting season
« Reply #3329 on: July 14, 2016, 05:28:50 PM »
bbr, really not meaning to sound combative here, but not a thing you said supports the idea of going ice free this year.
No more than the current warmth in northern Alaska suggests that it is heading toward being a popular sun holiday destination this year.

We are now at the period where melt rates are typically at their highest, and this period will last for another 2 weeks, it won't continue indefinitely. After that, the average extent loss rapidly declines, from about 90k/day (81-10 average) at the end of July to about 40k/day by the end of August. Even if we lost extent at a rate 25% greater than 2012, something that would truly incredible, we would still have over 2 million km2 by mid September.

There is no way, barring some environmental catastrophe, that the Arctic ocean will go ice free this year.

bbr2314

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Re: The 2016 melting season
« Reply #3330 on: July 14, 2016, 05:33:51 PM »
bbr, really not meaning to sound combative here, but not a thing you said supports the idea of going ice free this year.
No more than the current warmth in northern Alaska suggests that it is heading toward being a popular sun holiday destination this year.

We are now at the period where melt rates are typically at their highest, and this period will last for another 2 weeks, it won't continue indefinitely. After that, the average extent loss rapidly declines, from about 90k/day (81-10 average) at the end of July to about 40k/day by the end of August. Even if we lost extent at a rate 25% greater than 2012, something that would truly incredible, we would still have over 2 million km2 by mid September.

There is no way, barring some environmental catastrophe, that the Arctic ocean will go ice free this year.
You are looking at extent, I am looking at area, which is now at 5.5M KM2. It would not be difficult to lose, 2012 lost another 3.2M KM2, adding another 1.3MKM2 on top is more than feasible given 2012's departure from the previous worst year (to get under 1M).

Putting it another way, in the two months to the minimum, 2016 has to lose only 53K KM2/day to match 2012. That will be *difficult* to do in the sense that current momentum is giving us sustained 100K KM2+ drops most days.

More simply, we only need to average 75K KM2 daily drops over the next sixty days to go sub-1M KM2 in area.
« Last Edit: July 14, 2016, 05:39:00 PM by bbr2314 »

sedziobs

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Re: The 2016 melting season
« Reply #3331 on: July 14, 2016, 05:49:44 PM »
... hopefully was just an off-run.
I edited my earlier post to add that the model shows Nares Strait being active all through the winter, which is certainly not a single run issue.  That is one of the model shortcomings discussed over the past few years here.  More seasoned forum members aren't dismissing the model simply because it doesn't fit their preconceived notions.  The are legitimate issues that are present in each version of the model:

Last year there was a major problem with salinity: http://forum.arctic-sea-ice.net/index.php/topic,1320.0.html 
Neven posted about an outlandish model prediction in 2013: http://neven1.typepad.com/blog/2013/05/if-this-is-real.html
Chris Reynolds dealt with issues at his blog: http://dosbat.blogspot.com/2015/06/are-we-facing-crash-in-2015.html

These issues, combined with the constant revisions, is why it is seen as less trustworthy and less reliably consistent than other tools.

BornFromTheVoid

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Re: The 2016 melting season
« Reply #3332 on: July 14, 2016, 06:01:44 PM »
You are looking at extent, I am looking at area, which is now at 5.5M KM2. It would not be difficult to lose, 2012 lost another 3.2M KM2, adding another 1.3MKM2 on top is more than feasible given 2012's departure from the previous worst year (to get under 1M).

Putting it another way, in the two months to the minimum, 2016 has to lose only 53K KM2/day to match 2012. That will be *difficult* to do in the sense that current momentum is giving us sustained 100K KM2+ drops most days.

More simply, we only need to average 75K KM2 daily drops over the next sixty days to go sub-1M KM2 in area.

All years lose area at a rapid rate at this time of year, so the current losses, which are averaging just over ~110k/day over the last 5 days, are nothing unusual, not anything to get carried away by. Area, it appears, is already about 300k above 2012 and is also above 2007 (according to CT). Area losses begin to level off in about a months time, so maintaining 75k/day losses into mid September would be completely unprecedented.

Richard Rathbone

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Re: The 2016 melting season
« Reply #3333 on: July 14, 2016, 06:07:27 PM »

We are now at the period where melt rates are typically at their highest, and this period will last for another 2 weeks, it won't continue indefinitely. After that, the average extent loss rapidly declines, from about 90k/day (81-10 average) at the end of July to about 40k/day by the end of August. Even if we lost extent at a rate 25% greater than 2012, something that would truly incredible, we would still have over 2 million km2 by mid September.


There was some analysis of average rates posted earlier this year, that showed a decline pretty close to linear once into July. This allows a simple rule of thumb. Halve the current rate to project an average for the rest of the season. (or double the necessary average to see what sort of rate is needed now)

A-Team

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Re: The 2016 melting season
« Reply #3334 on: July 14, 2016, 06:31:50 PM »
Here is Big Block motion at three scales over the last 24 days: whole Arctic, Beaufort Gyre, and visible paired with infra-red cloud imagery.

The AMSR2 3.125 km (L1R JAXA, 89V GHz processed at UHH with ASIv6) is by far our best resource for a daily synoptic view of sea ice concentralion. It has sufficient resolution to allow daily tracking of individual floes regardless of cloud cover. There are however weak artifacts under some atmospheric conditions as with all passive microwave emission viewers.

The UHH imagery is very unusual in that the palette and images are done correctly (as uncompressed blue tint over linear grayscale) with the WorldView projection used. This allows composite images to be made for successive days simply by letting the darkest (bluest) pixel show through. However the ice moves between frames. This is where floe level resolution comes in: setting the warping framework for motion correction.

The cloud cover is better distinguished in Suomi bands M3-I3-M11 (similar to 3-6-7 Terra, not available for Aqua) than in Modis visible. Because clouds move quite rapidly, it's best to have simultaneous imagery (ie sensors on the same satellite, not just in the A-train). It is straightforward then to make a graded mask (done by posterization, last frame of 4th image) of cloud optical thickness.

After rescaling (but not reprojecting) that mask can then be applied to the sea ice concentration map to localize artifactual areas and show degree affected.

ftp://ftp-projects.zmaw.de/seaice/AMSR2/3.125km/
« Last Edit: July 14, 2016, 09:10:54 PM by A-Team »

Archimid

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Re: The 2016 melting season
« Reply #3335 on: July 14, 2016, 06:33:59 PM »
Attached is GIF  of sea ice concentration for the July 13 2002-2016 according to VISHOP_JAXA

Below that is the image for the same data for July 13 2016.

 
« Last Edit: July 14, 2016, 08:36:25 PM by Archimid »
I am an energy reservoir seemingly intent on lowering entropy for self preservation.

seaicesailor

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Re: The 2016 melting season
« Reply #3336 on: July 14, 2016, 08:24:21 PM »
You see when one sees a pic comparison like that is when one wishes this forum's existence did not make sense.


Tigertown

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Re: The 2016 melting season
« Reply #3337 on: July 14, 2016, 09:39:26 PM »
Its about to cut loose.(Nares)

Archimid

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Re: The 2016 melting season
« Reply #3338 on: July 14, 2016, 09:53:20 PM »
One last useless post, after this I'll give it a rest for the peace of mind of everyone.

  The first image is the sea surface temperature over the arctic from here. http://polar.ncep.noaa.gov/sst/ophi/color_newdisp_sst_north_pole_stereo_ophi0.png

What I find interesting of this image is how the higher SST seems to match the parts of the arctic with low ice concentration or no ice. The area of "warm" water surrounded the blind spot of the north pole is very distressing to me. It might be normal, but I just can't see how.

The second image is from the same site but showing the temperature anomaly. Again what worries me is the warm center, warm Atlantic and warm pacific.

The third image should be familiar to many here. What worries me about the third image is the acceleration of melting in September. In my mind if that graph continues behaving the same way it has, at some point instead of recovering like it has for the last million years it will spiral into nothingness.

Will it be this year? I don't know. I am not a climate scientist and I have proven how little I really know, but does it really matter? The point is that the Arctic is shrinking, if it disappears it will fundamentally change the planet Earth and it will suck.

To finish I leave yo the Degree thawing days graph from: http://cires1.colorado.edu/~aslater/ARCTIC_TAIR/

 There is a whole bunch of melting left.  If it hits more than 4.5 million by September then it is a sign it is stabilizing, we might have some decades left in the arctic.  If it continues its decreasing trend, we might have very few years left. I think that's my main argument.

I think that hitting 0 sea ice by September can pretty much be ruled out. What can not be ruled out yet is a North Pole without sea ice in September. I still think we will see that based only on the record warm year and the potential for extreme weather.

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

A-Team

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Re: The 2016 melting season
« Reply #3339 on: July 14, 2016, 10:34:01 PM »
Here is an update on the interface between the ice pack and the North Atlantic. 20 June to 13 July 2016. There are a couple of surge fingers that have been retreating between Franz Josef and Severnaya Zemlya. They might indicate regions of stronger Transpolar Drift or alternatively just a localized cold patch in the North Atlantic where the floes don't melt as fast.

The second animation is a product that probably should accompany the daily AMRSE2 3km product since it is informative and easy to script (wipneus?). Since UHH and WorldView are on the
'same page' in terms of map projection, only the scale of WV needs adjustment. The snapshot tool at WV enforces a constant scale (some multiple of 250 m). Note Worldview allows a 2x zoom to 125m zoom but puts out those yellow warnings after that in the layer pane.

Timothy A suggested earlier that bloom is probably that of the coccolithophore Emiliania huxleyi, a  oxygenic photosynthetic plankton. These blooms commonly form in nutrient-depleted waters after the reformation of the summer thermocline though this bloom is getting rather far north.

AVHRR is used to map these blooms through clouds but it seems to work better just to amplify the peculiar color in WorldView infrared channels.

There's been a fair amount of work on the effects of warmer temperatures, higher CO2, and lower pH on its carbon fixation and calcite formation, quite interesting but also rather complicated (534 papers at PubMed). The term 'algae' is grossly polyphyetic and best forgotten --  Emiliania's place in the modern phylogenetic tree is displayed as fig.1 in its 2013 whole-genome article.

http://www.nature.com/nature/journal/v499/n7457/full/nature12221.html free full text.
« Last Edit: July 15, 2016, 05:25:47 AM by A-Team »

Michael Hauber

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Re: The 2016 melting season
« Reply #3340 on: July 14, 2016, 11:05:17 PM »
Some of the area of dispersed ice has become visible between the clouds and MODIS 3-6-7 channel shows an almost complete lack of surface melting.

In contrast 2012 shows strong surface melting over the dispersed ice.  And if the ice surface is melting I'd be pretty sure the ocean in between is absorbing some significant heat for further melting later in the season.  Shots showing dispersed ice and visible surface melting have been a lot harder to find this year than in 2012 and I expect this will be important by end of season.
Climate change:  Prepare for the worst, hope for the best, expect the middle.

Tigertown

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Re: The 2016 melting season
« Reply #3341 on: July 14, 2016, 11:23:07 PM »
Archimid, I like the one quarter C0 scale on that SST anomaly map. It shows even minor variations that don't show up on other anomaly maps. I would think those spots out near the Pole would be indicative of where insolation is taking place, through leads and such.

Laurent

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Re: The 2016 melting season
« Reply #3342 on: July 14, 2016, 11:29:12 PM »
Huge melting going on http://go.nasa.gov/29Lbrcr some do need to buy googles or more surely remove that filter.
At some point all this rubble will vanish... poof ! (Still plenty of time)

Tigertown

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Re: The 2016 melting season
« Reply #3343 on: July 14, 2016, 11:38:28 PM »
I have a gut feeling(not being a borg and all) that the Fram is about to shift gears and get rid of a lot of it.

Laurent

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Re: The 2016 melting season
« Reply #3344 on: July 14, 2016, 11:47:37 PM »
Tigertown you may be right, but haven't you listened other posts (not from me), the Fram doesn't matter anymore there is a 1000 km line of melting inside the Arctic absolutely no need for Fram Export just a little push toward Franz Joseph-Svalbard.

Michael Hauber

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Re: The 2016 melting season
« Reply #3345 on: July 15, 2016, 12:06:27 AM »
Huge melting going on http://go.nasa.gov/29Lbrcr some do need to buy googles or more surely remove that filter.
At some point all this rubble will vanish... poof ! (Still plenty of time)

Rubble is not the same as melting.  There is a difference in colour, which is much easier to see with the red filter on, but once you know what to look for is discernable in true colour as well.
Climate change:  Prepare for the worst, hope for the best, expect the middle.

seaicesailor

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Re: The 2016 melting season
« Reply #3346 on: July 15, 2016, 12:08:12 AM »
I still look in wonder from the amazing A-team animations what is going on in Beaufort. It seems the threshold of '2 m thick ice is done' has been reached and much of the ice is vanishing all of a sudden. Further thresholds will be reached quickly. Sun radiation and warm saline currents, together with stirred waters and now surface melt are still inputting heat in an already hot pan that won't stop melting at amazing rate until october. See the ice being imported from CAB and it already shows signs of melting. It won't last, too much heat.
Chukchi is impressive, it always is when it blows from the Pacific and now the Pacific waters are pouring thru Bering too (caveat I got that from ACFNS model).
That sudden ESS bite opened by a storm in an already weakened ice. Appeared in a blink and no day passes it grows a few tens of k
Then the Atlantic, the silent killer this year. No fanfarres, polynya, big floes, no melt ponds..., just a sharp knife-cut front that slowly advances North  even when the ice is drifting against it.
Hudson did not give us much time this time.
And then the boring CAB holes.

Tigertown

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Re: The 2016 melting season
« Reply #3347 on: July 15, 2016, 12:59:41 AM »
Tigertown you may be right, but haven't you listened other posts (not from me), the Fram doesn't matter anymore there is a 1000 km line of melting inside the Arctic absolutely no need for Fram Export just a little push toward Franz Joseph-Svalbard.
Hear that loud  and clear. I still think a lot of stuff that is about to break loose is going to end up going that way.
« Last Edit: July 15, 2016, 02:17:50 AM by Tigertown »

Aikimox

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Re: The 2016 melting season
« Reply #3348 on: July 15, 2016, 03:57:35 AM »

...Timothy A suggested earlier that bloom is probably that of the coccolithophore Emiliania huxleyi, a  oxygenic photosynthetic plankton. These blooms commonly form in nutrient-depleted waters after the reformation of the summer thermocline though this bloom is getting rather far north.

AVHRR is used to map these blooms through clouds but it seems to work better just to amplify the peculiar color in WorldView infrared channels.

There's been a fair amount of work on the effects of warmer temperatures, higher CO2, and lower pH on its carbon fixation and calcite formation, quite interesting but also rather complicated (534 papers at PubMed). The term 'algae' is grossly polyphyetic and best forgotten --  Emiliania's place in the modern phylogenetic tree is displayed as fig.1 in its 2013 whole-genome article.
....

This is exactly what I meant earlier. Changes in the biosphere result in changes in air/water chemistry, which in turn can add to arctic amplification in a number of ways. We need models that reflect these factors. Chlamydomonas nivalis or snow algae affects albedo. Desulfovibrio vulgaris produces hydrogen sulfide and is in delicate balance with oxygen concentrations in water. These are just two examples in addition to the phytoplankton bloom you mentioned. Too few models ever mention these when looking at ice extent...

Tigertown

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Re: The 2016 melting season
« Reply #3349 on: July 15, 2016, 04:22:15 AM »
Dramamine anyone?
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