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Neven

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Re: The 2017 melting season
« Reply #1050 on: May 02, 2017, 02:30:19 PM »
Or is Mr S*%t meeting Mr Fan?

If they aren't meeting now, they will soon, when the Atlantic side comes into play.
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Ajpope85

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Re: The 2017 melting season
« Reply #1051 on: May 02, 2017, 04:05:35 PM »
That and it has more total exposed surface area for heat to attack it.

No.

To see why, try the following calculation.  The Earthwatch MODIS data source has a resolution of 250m, and so the smallest detectable ice floe from this data source is around that size.

Please estimate for me the total exposed surface area for a 250m x 250m floe. Let's assume it's thick first year ice of ~2m average thickness. Then, identify what proportion of the total surface areas is:

1)  Top face (exposed to Sun)
2)  Bottom face (exposed to water)
3)  Side faces (exposed to a mix of both)

Fragmentation is not relevant to the total exposed surface area of sea ice until the floes are too small to be seen by MODIS. The dynamics we so avidly watch - whether fragmented or not - do not appreciably alter the total surface area of the ice.

Does the ice have to be large chunks for the satellite to detect it or can it be a large amount of ground up ice concentrated in an area?  If it can detect the latter, then surface area should definitely play a part in melt rates.

Archimid

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Re: The 2017 melting season
« Reply #1052 on: May 02, 2017, 04:34:25 PM »
That and it has more total exposed surface area for heat to attack it.

No.

To see why, try the following calculation.  The Earthwatch MODIS data source has a resolution of 250m, and so the smallest detectable ice floe from this data source is around that size.

Please estimate for me the total exposed surface area for a 250m x 250m floe. Let's assume it's thick first year ice of ~2m average thickness. Then, identify what proportion of the total surface areas is:

1)  Top face (exposed to Sun)
2)  Bottom face (exposed to water)
3)  Side faces (exposed to a mix of both)

Fragmentation is not relevant to the total exposed surface area of sea ice until the floes are too small to be seen by MODIS. The dynamics we so avidly watch - whether fragmented or not - do not appreciably alter the total surface area of the ice.


Just to be clear, fragmentation does increase the surface area, but because height(1-2m) is so small relative to length and width (thousands of kilometers) the increase in surface area is extremely small for all but the smallest floes.

That is not to say that fragmented ice behaves the same as solid ice, specially regarding waves. Smaller floes are more susceptible to waves and currents.
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nicibiene

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Re: The 2017 melting season
« Reply #1053 on: May 02, 2017, 04:45:34 PM »
A nice explaination regarding the difference between solid/fractured ice regarding meltrate is to find in that video of Paul Beckwith minute 7:40

Beside other facts about Arctic feedbacks  - videos of him are worth to see for newbies. 😁
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epiphyte

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Re: The 2017 melting season
« Reply #1054 on: May 02, 2017, 06:25:22 PM »

Fragmentation is not relevant to the total exposed surface area of sea ice until the floes are too small to be seen by MODIS. The dynamics we so avidly watch - whether fragmented or not - do not appreciably alter the total surface area of the ice.

True. Increased fragmentation does affect the snow cover though - since a higher proportion of blowing/drifting snow ends up falling into open leads. The link below is to a pre-2000 paper which concludes:
 
Quote
A snow mass budget for the Arctic Ocean has been
presented. According to this budget, the combined
effects of blowing snow sublimation and redistribution
into leads remove 13% of the total annual snowfall over
Arctic sea ice. After surface sublimation and snowmelt,
blowing snow represents the most significant sink term
in the snow mass balance of the Arctic Ocean.

... I'd bet it's more than that now :-/
http://ocp.ldeo.columbia.edu/res/div/ocp/pub/tremblay/amsbudget.pdf

Jim Pettit

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Re: The 2017 melting season
« Reply #1055 on: May 02, 2017, 06:30:33 PM »
This discussion of fragmentation and meltrate is an interesting one, but it's off-topic in the melting season forum. Please take it elsewhere before The Scissors Of Doom relegate it to the ether.

Thanks!

Hyperion

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Re: The 2017 melting season
« Reply #1056 on: May 02, 2017, 06:31:31 PM »
That and it has more total exposed surface area for heat to attack it.

No.

To see why, try the following calculation.  The Earthwatch MODIS data source has a resolution of 250m, and so the smallest detectable ice floe from this data source is around that size.

Please estimate for me the total exposed surface area for a 250m x 250m floe. Let's assume it's thick first year ice of ~2m average thickness. Then, identify what proportion of the total surface areas is:

1)  Top face (exposed to Sun)
2)  Bottom face (exposed to water)
3)  Side faces (exposed to a mix of both)

Fragmentation is not relevant to the total exposed surface area of sea ice until the floes are too small to be seen by MODIS. The dynamics we so avidly watch - whether fragmented or not - do not appreciably alter the total surface area of the ice.


Just to be clear, fragmentation does increase the surface area, but because height(1-2m) is so small relative to length and width (thousands of kilometers) the increase in surface area is extremely small for all but the smallest floes.

That is not to say that fragmented ice behaves the same as solid ice, specially regarding waves. Smaller floes are more susceptible to waves and currents.
Yes as I draw attention to in the last animation I posted. Of the laptev. As soon as the pack loosened and jostled a little all the floes quickly lost their corners and rounded off. The debris from this may be too small to see but it is definately increazing melt surface. And It may be paedantic to risk another round of chants about the holy melting enthalpy figures but if litre of salty ice took the same energy to melt as a litre of fresh blue it would melt at zero C. And perhaps more important is that the water temp of the surface layer need not rise for it to melt. And Any briny slime exlosed to the air will take up energy and trnsfer it more effectively into the floe. I also stand by my assertion that wind assisted sublimation can hold temperatures well below zero in the central basin. And salty ice a little below in the periphery. But this does NOT mean melt is not occuring. It means it is. Some of these may only be a percentage point or two. But to be Significant one percent now could be the momentum that makes the difference between 2.5 and blue ocean.
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Hyperion

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Re: The 2017 melting season
« Reply #1057 on: May 02, 2017, 06:33:36 PM »
Hey Hyperion. Don't you mean pedantic? ;)
Policy: The diversion of NZ aluminum production to build giant space-mirrors to melt the icecaps and destroy the foolish greed-worshiping cities of man. Thereby returning man to the sea, which he should never have left in the first place.
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slow wing

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Re: The 2017 melting season
« Reply #1058 on: May 02, 2017, 11:16:37 PM »
All the tropicaltidbids.com ensembles are showing high pressure over the Arctic basin as far as the forecasts can see - 18 days - especially on the American side.


 It would be interesting if the weather experts here could please comment on whether the forecast is robust, for how far out, and what are the fundamental causes?


'Melt pond May'?

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Re: The 2017 melting season
« Reply #1059 on: May 02, 2017, 11:51:36 PM »
For the Fram Strait transport, new crevasses have been opening continually north of Greenland and on the area around the North Pole: https://worldview.earthdata.nasa.gov/?p=arctic&l=VIIRS_SNPP_CorrectedReflectance_TrueColor(hidden),MODIS_Aqua_CorrectedReflectance_TrueColor(hidden),MODIS_Terra_CorrectedReflectance_TrueColor,Reference_Labels(hidden),Reference_Features(hidden),Coastlines&t=2017-04-30&z=3&v=-191746.16054898838,-275659.2709927809,856829.8394510116,384820.7290072191

The innumerable parallel leads are a manifestation of ice weakness and facilitator for new ice floes to that feed into the Fram Strait exit, infinitely. Noting MODIS pixel representing 6.25 hectare ice area, it is not inconceivable that many more narrowly-packed leads in sea ice have been formed that simply are missed out in the scales of images. - This because not every fracture in ice necessarily leads to a wide sea ice separation. Indeed, how can the ice floes separate due to sea ice congestion constraining as surface area of ocen is fixed.

Slowly widening leads of sea ice growing with snow filling the dark gaps may contribute significantly at smallest levels of sea ice fracturization to be missed by MODIS <6.25ha. These smaller fractures, many of them may not have even completed their calving, any incomplete tear does contribute to surface area. Ice tends to break in straight lines this time of year, not like coastal margin fractals, so the ice floe perimetry does not grow to infinity at smallest scales. Honeycombed, 'rotten ice' has - on the other hand - fractal nature with surface growing to infinity at the smallest scales, but before this occurs, melt water ponds must have prevailed for weeks.

The number of hidden fractures by ocean surface stresses is instrumental when sea ice thins across large spatial territories and MODIS is bound to miss out these. Once tipping point is breached, wave bending will also travel under ice considrable ease and break ice when it is too thin. I see the increase in leads as symptom of this as some broken ice packs do scatter when the frature lines do not run parallel across the ice floe. If the fissures are parallel, such ice stays together like ///////////// and MODIS just will miiiis it out.

The absence of pack ice and large gaps in ice does not mean that there are no cracks and minor leads in ice caused by ocean surface stresses (rather than local winds that separate sea ice to group it by major leads into major ice packs or separated clusters of sea ice).
« Last Edit: May 03, 2017, 12:07:49 AM by VeliAlbertKallio »
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Ice Shieldz

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Re: The 2017 melting season
« Reply #1060 on: May 03, 2017, 01:49:22 AM »
The following animation is Cape Morris Jesup AQUA May 2nd comparisons between 2012, 2016 and 2017. Hard to do an apples to apples comparison here because of significant improvements to AQUA imaging since 2012. Because AQUA 2012 was so lacking, May 2nd was the only day in a 9 day span (4/24-5/2) in which i could find one remotely usable and comparable image.  (source - http://ocean.dmi.dk/arctic/morrisjessup.uk.php)

Edit: Click to animate - I went for a 710 by 810 pixel gif in hopes that i could squeeze a few more pixels in.  Looks like 700px is the upper limit before requiring a click to animate.

Ice Shieldz

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Re: The 2017 melting season
« Reply #1061 on: May 03, 2017, 02:27:35 AM »
Cape Morris Jesup AQUA 2017 (4-24 to 5-2).  9 days of Mr. S hitting Mr. Fan. . . or should we say Mr. Fram   :o  Seems like an anomalous amount of cumulative export for this season and last.  I'm also pondering to what degree this is behind the low volume we're seeing?

scaddenp

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Re: The 2017 melting season
« Reply #1062 on: May 03, 2017, 02:32:53 AM »
We did have some giant Bergs visit about ten years ago. Larsen remnants I believe they were believed to be.

WOW. Larsen fragments in NZ!

Hmm, this was speculation and later studies pointed to big berg B15 from the Ross Sea. See https://www.niwa.co.nz/coasts-and-oceans/faq/icebergs

jai mitchell

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Re: The 2017 melting season
« Reply #1063 on: May 03, 2017, 02:51:47 AM »
Mean annual volume export between 2003-2008 was 2,600 km^3

http://onlinelibrary.wiley.com/doi/10.1029/2009GL039591/full

I would be very surprised if that much ice was exported this year due to the anomalous thin ice (compared to the pre-2007 period)
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Ice Shieldz

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Re: The 2017 melting season
« Reply #1064 on: May 03, 2017, 03:07:28 AM »
@ Jai, thanks good to know. Where can we find more recent years? One other thing to consider is the higher ratio of 2016-17 thick ice which resided or resides closer to the fram. With continued export, one might surmise that the rate at which volume drops would be significant relative to our already diminished volume.

miki

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Re: The 2017 melting season
« Reply #1065 on: May 03, 2017, 05:18:21 AM »
Welcome to the ASIF, miki. Your profile has been released, so you can post freely now.

Thanks, Neven. I've been following this awesome community for quite a while. It feels good to be part of it. Sincerely thanks. And now, back on topic.

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Re: The 2017 melting season
« Reply #1066 on: May 03, 2017, 08:18:15 AM »
Looking at the Fram export ice getting spread out. Also, some wave action in the area lately may have stirred up heat from below. 5-1 on left    5-2 on right     The chart below shows water gets warmer with depth for about 200 or so meters.
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Re: The 2017 melting season
« Reply #1067 on: May 03, 2017, 09:10:32 AM »
I guess that means the spring thaw is getting underway in the upper reaches of the Mackenzie.

Just about, albeit slightly behind last year:

http://GreatWhiteCon.info/2017/05/facts-about-the-arctic-in-may-2017/

It looks as though breakup is starting in the upper reaches of the Liard River. The Mackenzie flow measurement at the junction with Arctic Red River seems to have gone berserk already though!

http://wateroffice.ec.gc.ca/report/real_time_e.html?mode=Graph&type=&stn=10LC014&startDate=2017-04-01&endDate=2017-05-03&prm1=46&y1Max=&y1Min=&prm2=47&y2Max=&y2Min=
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FishOutofWater

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Re: The 2017 melting season
« Reply #1068 on: May 03, 2017, 06:16:54 PM »
All the tropicaltidbids.com ensembles are showing high pressure over the Arctic basin as far as the forecasts can see - 18 days - especially on the American side.


 It would be interesting if the weather experts here could please comment on whether the forecast is robust, for how far out, and what are the fundamental causes?


'Melt pond May'?

The fundamental cause is enhanced atmospheric blocking linked to:

1: Subsidence from the stratosphere after the annual collapse of the winter polar vortex.  Warming of the tropical and subtropical oceans oceans has enhanced wave coupling of the subtropical jet stream with the winter night jet in the stratosphere. This has actually enhanced the upwards transport of tropical air into the stratosphere - the Brewer Dobson circulation. More air going up means more air must come down. A large area that extends from the Beaufort sea to the Aleutians and the far north Pacific is one of the places where the stratospheric air comes down. That sinking air warms the upper troposphere and intensifies the Beaufort high pressure area in late spring.

2: Enhanced south to north warm air transport from the Atlantic and Pacific ocean basins to the Arctic associated with a wavier jet stream as described by Jennifer Francis et. al. Note the very strong blocking high forming over Greenland thanks to the processes described by Jennifer Francis. Greenland is one of the most prominent locations on earth for blocking highs to form because there is so much heat in the Atlantic ocean basin that can be advected northwards over Greenland by Rossby waves. As warm air moves north and up the Coriolis effect tends to make it spin counterclockwise. Thus "blocking highs" are formed.

Greenland is going to have a strong May melting event.
The Beaufort sea is going to have May melt ponds and intense sun.
« Last Edit: May 03, 2017, 06:22:27 PM by FishOutofWater »

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Re: The 2017 melting season
« Reply #1069 on: May 03, 2017, 08:42:58 PM »
The immense size of the block means that it will also likely retrograde -- probably to a position near the CAA and NWT and perhaps eventually over the Beaufort, setting up a +AD along the way. Since we're pulling into mid or late May by the time this happens, early surface melting will likely indeed happen.

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Re: The 2017 melting season
« Reply #1070 on: May 03, 2017, 08:43:33 PM »
I think it is important to note that the ice in Okhotsk/Bering is seemingly at record lows at the moment.

Last year's Beaufort melt was very bad, but it was not catastrophic in the way that this year could be, due to the gyre pushing relatively thick ice into the pathway of the Bering Strait, which stalled open water reaching into the Pacific side of the Arctic for at least a few weeks as that ice had to melt.

This year, we don't have that luxury. The lack of ice in Okhotsk/Bering is also threatening in that its usual persistence tempers the airmasses advected north during the melt season (at least, through June or so). With most of the ice already gone or set to vanish by 5/15, we should see the melt season begin much sooner than normal across the Siberian Seas, and potentially Beaufort as well.

On the flip side, this should keep relative cold along the Atlantic-facing ice (Baffin, Barentz, Hudson). But this will only add to transport into these regions, which will likely melt out by summer's end anyways, IMO setting us up for a record low situation come September. If any region is looking somewhat solid, I would say it is the CAA, though this will also be prone to flushing as the ice structure disintegrates and the garlic press begins to activate.

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Re: The 2017 melting season
« Reply #1071 on: May 03, 2017, 10:41:56 PM »
things change from season to season mostly based on wind and weather patterns in general. the information which part of the alps got more or less snow which year is nice to know but has no value as to climate development.

each year we have to read through various this year but last year and that year statements while in my opinion this is chatting, nothing wrong about it but does not provide any useful input when it comes to a better understanding of the system and eventually finding a few things we can do that not only work but are realistic.

just to avoid any misunderstanding, of course it would help if everyone would stop heating in winter and stop driving cars with ICEs but it's not yet a realistic scenario, hence a waste of words and energy, while preparing for a switch to EVs is feasible and will ultimately lead to achieve that goal through the backdoor.

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Re: The 2017 melting season
« Reply #1072 on: May 03, 2017, 11:01:49 PM »
Expectations of early surface melting are important, given we have  a half of the Arctic that is more vulnerable and thin than ever and the other sinking down like the Titanic. Thank you to the nice five comments in a row and to M&M for putting the contra-punctal colouration

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Re: The 2017 melting season
« Reply #1073 on: May 03, 2017, 11:33:43 PM »
This is so important, isn't it  crucial if early surface melting and if arctic dipole emerges to initiate early melting of the Pacific side?
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Csnavywx

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Re: The 2017 melting season
« Reply #1074 on: May 03, 2017, 11:57:11 PM »
To roll foward FoW's post:







Some strong hints at a +DA pattern as the record-setting NAO block retrogrades into central and northwestern Canada. Pretty bad timing if that's the case as it could easily initiate early surface melting if temperature advection is strong enough.

bbr2314

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Re: The 2017 melting season
« Reply #1075 on: May 04, 2017, 12:27:32 AM »
To roll foward FoW's post:







Some strong hints at a +DA pattern as the record-setting NAO block retrogrades into central and northwestern Canada. Pretty bad timing if that's the case as it could easily initiate early surface melting if temperature advection is strong enough.
Equally important in these maps is the ending of winter across NE Asia (Siberia, etc). I think the GFS has problems with reducing snowcover prematurely, but even with that issue, the other models also seem to be hinting at ridging developing into Central Asia, which would likely begin pumping heat into/across Siberia.

As the Siberian snowpack gets smoked into oblivion, it becomes much easier for ridging to pump heat directly into the Arctic, without any sort of moderation. This is similar to what's about to happen over Okhotsk/Bering, but the sheer scale/size of Siberia means that once it goes snow-free, the warmth's ability to attack directly into the Arctic becomes much greater. I would think this is why the anomalies begin spiking fairly dramatically towards D10+.

While snow depth remains fairly high in areas adjacent to the peripheral seas, southern reaches of Siberia are currently at a major loss in terms of extent, and with area already plunging over there, it should only be a matter of time before those blues evaporate into the atmosphere & are deposited over the Arctic as rain.

Areas of snowcover I could see persisting abnormally long include Quebec and the northern reaches of Scandinavia/far NW Russia, as these seem to be the favored dumping grounds for the cold up north given its inability to remain in place this year (and also, the heat ridging that I believe will soon predominate over the Pac/Asian side of the Arctic should favor lingering cold in these areas). But since the ice near these areas is first-year and will melt anyways, that does little good.

It should also be noted that Iceland is very red on these maps as well, perhaps it is not exactly chicken and egg re: NATL blocking, but I would imagine an anomalously early snow-free Iceland certainly does not hurt ridging potential for the NATL/Greenland.

Lastly, it should be noted that we have bits of green over very low-latitude areas, including Japan, Iran, Turkey, SE Europe, and the southern Rockies. All of these regions are quite elevated, and while they will ultimately lose snowcover, this seems to be yet another indicator of the Arctic's increasing inability to retain cold, and consequent late-season snowfall in areas where it should not be happening. We have now seen killing snows & frosts damage crops across much of southern Europe as well as the western Great Plains of the US -- it is not the raw warming that will do civilization in, but the increasingly rapid and as-yet-unpredictable swings between anomalous heat and cold weather.

« Last Edit: May 04, 2017, 12:32:33 AM by bbr2314 »

VeliAlbertKallio

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Re: The 2017 melting season
« Reply #1076 on: May 04, 2017, 02:19:48 AM »
Global Weather Logistics animates broad front of Arctic air moving over North Atlantic. Strong eastward winds north of Greenland turning to south over the Fram Strait on 7th May: http://globalweatherlogistics.com/seaiceforecasting/gfs.850mb.temps.arctic.html   
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Re: The 2017 melting season
« Reply #1077 on: May 04, 2017, 10:06:49 AM »
Strong eastward winds north of Greenland turning to south over the Fram Strait on 7th May:
Strong winds over Fram Strait also forecasted by GFS. Here is animation May 7 - May 8 (Climate Reanalyzer). Losing some of the thickest ice again.

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Re: The 2017 melting season
« Reply #1078 on: May 04, 2017, 11:26:43 AM »
NSIDC April overview is out, pretty dramatic overview of conditions over Lincoln Sea (where ice is usually thick and old). "The group noted that the ice was unusually broken up and reduced to rubble, with few large multi-year floes, forcing the pilots to land on refrozen leads that at times were only 70 centimeters (28 inches) thick. Pilots remarked that they had never seen the ice look like this". https://nsidc.org/arcticseaicenews/

F.Tnioli

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Re: The 2017 melting season
« Reply #1079 on: May 04, 2017, 02:05:50 PM »
I think it is important to note that the ice in Okhotsk/Bering is seemingly at record lows at the moment.

Last year's Beaufort melt was very bad, but it was not catastrophic in the way that this year could be, due to the gyre pushing relatively thick ice into the pathway of the Bering Strait, which stalled open water reaching into the Pacific side of the Arctic for at least a few weeks as that ice had to melt.

This year, we don't have that luxury. The lack of ice in Okhotsk/Bering is also threatening in that its usual persistence tempers the airmasses advected north during the melt season (at least, through June or so). With most of the ice already gone or set to vanish by 5/15, we should see the melt season begin much sooner than normal across the Siberian Seas, and potentially Beaufort as well.

On the flip side, this should keep relative cold along the Atlantic-facing ice (Baffin, Barentz, Hudson). But this will only add to transport into these regions, which will likely melt out by summer's end anyways, IMO setting us up for a record low situation come September. If any region is looking somewhat solid, I would say it is the CAA, though this will also be prone to flushing as the ice structure disintegrates and the garlic press begins to activate.
I generally concur, just one thing about CAA: me thinks, with conditions like this, transport outta CAA is likely to play much bigger role than it ever did. Nothing fancy backing this up, just general considerations about stronger winds being likely, as well as more open water places for the ice to go around CAA.

appended:

...

each year we have to read through various this year but last year and that year statements while in my opinion this is chatting, nothing wrong about it but does not provide any useful input when it comes to a better understanding of the system and eventually finding a few things we can do that not only work but are realistic.

just to avoid any misunderstanding, of course it would help if everyone would stop heating in winter and stop driving cars with ICEs but it's not yet a realistic scenario, hence a waste of words and energy, while preparing for a switch to EVs is feasible and will ultimately lead to achieve that goal through the backdoor.
Better understanding of the system - must include understanding of upstream emissions, for example note here how black and red prevails. Same things in black and light-blue will prevail into the future globally. And then you may be interested to read this paper, and would you please pay special attention to 3rd and 4th bars in figure 5, this is reality of the matter for now and decades to come, given the above. See?

And also, can we wrap this up at this exact point, because this goes way off-topic, please? At least, i definitely will go no further.

P.S. I hesitated to post this one, too; but after a while, inner scientist defeated inner model citizen, and i went for it...
« Last Edit: May 04, 2017, 02:42:54 PM by F.Tnioli »
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iceman

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Re: The 2017 melting season
« Reply #1080 on: May 04, 2017, 02:57:18 PM »
Mean annual volume export between 2003-2008 was 2,600 km^3

http://onlinelibrary.wiley.com/doi/10.1029/2009GL039591/full

I would be very surprised if that much ice was exported this year due to the anomalous thin ice (compared to the pre-2007 period)
@ Jai, thanks good to know. Where can we find more recent years? One other thing to consider is the higher ratio of 2016-17 thick ice which resided or resides closer to the fram. With continued export, one might surmise that the rate at which volume drops would be significant relative to our already diminished volume.
Concur with both point and counterpoint.  2017 already looks high w.r.t. export in proportion to current-year volume, and this coming week won't help.
     A scarier trend in 2017, if we had the data, would be: absolute (not relative) volume that does *not* get exported via Fram Strait.

Credit: National Snow and Ice Data Center

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Re: The 2017 melting season
« Reply #1081 on: May 04, 2017, 03:32:38 PM »
Not sure which thread to post this in, but is this unusual? Is it relevant to Arctic?
Today's jet stream:
https://media.giphy.com/media/xUPGcoh39ZKjSAlIju/giphy.gif




(from: https://earth.nullschool.net/#current/wind/isobaric/500hPa/orthographic=-62.81,40.95,555 )

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Re: The 2017 melting season
« Reply #1082 on: May 04, 2017, 03:35:23 PM »

I generally concur, just one thing about CAA: me thinks, with conditions like this, transport outta CAA is likely to play much bigger role than it ever did. Nothing fancy backing this up, just general considerations about stronger winds being likely, as well as more open water places for the ice to go around CAA.

appended:

Better understanding of the system - must include understanding of upstream emissions, for example note here how black and red prevails. Same things in black and light-blue will prevail into the future globally. And then you may be interested to read this paper, and would you please pay special attention to 3rd and 4th bars in figure 5, this is reality of the matter for now and decades to come, given the above. See?

And also, can we wrap this up at this exact point, because this goes way off-topic, please? At least, i definitely will go no further.

P.S. I hesitated to post this one, too; but after a while, inner scientist defeated inner model citizen, and i went for it...

absolutely, well said and specifically yes to more mobile ice hence impact is greater, no doubt about that, while it was not where i was headed with my sub-par english (at least when compared to my german skills LOL), sorry for any misunderstanding that it might have caused, in short: +1
« Last Edit: May 04, 2017, 03:42:06 PM by magnamentis »

F.Tnioli

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Re: The 2017 melting season
« Reply #1083 on: May 04, 2017, 05:19:23 PM »
This one caught my eye in one of nearby threads, posted yesterday:



Is this real? Can there be any much error?
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Re: The 2017 melting season
« Reply #1084 on: May 04, 2017, 06:41:53 PM »
This one caught my eye in one of nearby threads, posted yesterday:



Is this real? Can there be any much error?
It is most definitely real and also explains why volume is at a record low.

Models are now emphasizing a sustained period of warmth across the Pacific side of the Arctic beginning shortly and extending/worsening indefinitely.

I have already mentioned how I believe this is connected to the very early melt of Bering/Okhotsk, and it appears that the ramifications of ^ will result in the same occurring over Chuchki/ESS, and potentially the Beaufort as well.

If you look at HYCOM/PIOMAS it is apparent that while there is a slight barrier of 2-3M ridged ice between Beaufort and Pacific inflows, this is totally absent along the Chuchki front. Last year saw some extremely thick ice in between the inflows & both peripheral seas, something we are almost lacking completely this year.

If we see sustained warmth as the models are now indicating, the ramifications will be quite dire for several reasons.

1) With the Bering already mostly ice-free, there is vastly heightened potential for Pacific inflows to push much farther into the Arctic than they ever have before. On PIOMAS the only year with ice thicknesses anywhere near 2017's in the aforementioned regions appears to be 2011.

2) With ice thicknesses already at record lows in the Chuchki/ESS, any heat intrusions have the potential to rapidly melt the little amounts of ice that currently exist. HYCOM and satellite already show areas of low concentration in these peripheral seas. If we see extended heat through to 6/1, we may be dealing with large portions of these areas taking up an unprecedented amount of solar insolation at the peak of summertime. Normally this energy would go into melting the ice, not warming up the water.

3) Increased Pacific inflow is likely to destroy the structural integrity (or whatever minimal amount remains) across Beaufort/the CAA. Beaufort's ice thickness is again at unprecedented low levels, though somewhat thicker than Chuchki/ESS. But it could and IMO likely will melt out completely this year, and as Chuchki/ESS melt out, the increasing areas of open water will likely lend themselves to heat intrusions of mounting substance from several perspectives.

4) The above directly relates to the fate of the ice in the CAA in that the fracturing of the Beaufort/ice adjacent to the CAA will allow the garlic press to activate *way* ahead of when it had in recent years. This means we could see much more freshwater and thick ice flush into Baffin Bay and, ultimately, this would disrupt AMOC circulation to a greater extent than we have seen in recent years.

5) Finally, the increased open water in peripheral seas during the height of NHEM insolation means that as cyclones drift north from Siberia during the summertime, they will likely intensify beyond levels previously seen, enhancing export out of the FRAM, at least while there is still ice to export. Besides enhancing export, heat transport into the Arctic is also likely to continue increasing. And as we enter late July and August, the sheer area of the Arctic Ocean that will be ice-free means that we are likely to see GACs far worse than the repeat events of last summer.

If the above holds to be true, last year may in fact have been the last instance of meaningful September sea ice. The PIOMAS maps are absolutely terrifying, not just because of the record-low volume, but because of where the worst anomalies are situated and what they entail for solar insolation during the months of June, July, and August. The situation is likely to result in superficial gains in Atlantic ice extent (as well as substantial freshwater export) continuing for a month or two, but this will all melt out by September anyways.


Hyperion

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Re: The 2017 melting season
« Reply #1085 on: May 04, 2017, 10:27:16 PM »
Not sure which thread to post this in, but is this unusual? Is it relevant to Arctic?
Today's jet stream:
https://media.giphy.com/media/xUPGcoh39ZKjSAlIju/giphy.gif




(from: https://earth.nullschool.net/#current/wind/isobaric/500hPa/orthographic=-62.81,40.95,555 )
Unusual? Seems less and less so all the time. That equatorial east to west flow is symptomatic of strong pile to equator flows at high altitude. What seems to be happening of late is big low level flows going from one hemisphere to another. A few weeks ago when cyclone cook was in the house the big high in th arctic coupled up and from Alaska to Antarctica the whole Pacific basin lower level airmass got drawn. Some seemed to return at the top of the troposphere, but massive deep southern ocean lows seem to be punching a hole in the roof of the night and returning it via the stratosphere. Generating a massive trade winds belt at 10 hpa 30+ km altitude. The flows reversed about a week ago with up to 1056hpa in a massive high over Antarctica and low pressure predominant in the Arctic. Now with a few cyclones popping up in the sth pacific and pressure buildin Gain in the arctic the pendulum appears to be swinging. With the absolute ratsnest the jets have become perhaps we shouldnt be surprised that cyclones at 20 degrees sthe like the central pacific one get captured by mr ferell so quickly as a jet flow whips up and arond them from the pole. Making them into the dreaded hybrids. Still feeding on tropic moisture dragged in at low level. And polar cold. But I am mouth wide open a this active planetry dual hemisphere single cell pan-atmospheric single cell behaviour. If this becomes more usual my questions are... Will it prove to be an oscillation sloshing one way and the other on a period of a couple of weeks as lately or some other. Potentially setting up big ocean pumping. Or be predominant as a seasonal flow from one hemisphere pole to the other. Sharing heat from the summer with the pole in  the dark. https://earth.nullschool.net/#current/wind/isobaric/250hPa/overlay=temp/winkel3=-166.96,15.64,226/loc=-162.898,-8.084     

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Neven

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Re: The 2017 melting season
« Reply #1086 on: May 05, 2017, 12:13:59 AM »
Rutgers has updated the April NH snow cover anomaly graph:
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VeliAlbertKallio

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Re: The 2017 melting season
« Reply #1087 on: May 05, 2017, 03:30:17 AM »
While the tropical Hadley Cells have been expanding northwards across the Mediterranean, the Polar Cells have been expanding southwards due to sea ice reduced ocean reducing the mid-winter panning over the Arctic Ocean and surrounding areas - leading to inflated polar hot air balloon situation where the fire rises from the increasingly open ocean. As the polar panning of cold air has reduced, the tightness of the vortex has weakened leading to entanglement with mid lattitued air masses. As the polar cell expanded from the north, and the equatorial Hadley Cells  expanded north, the mid latitude cells are being squeezed out from the latitudes between them.

Sadly, this process will continue with Hadley Cells pushing Sahara towards north across the Mediterranean Sea to the Central Europe and the inflated polar cell starting to collide with it. The cell eventually becomes chaotic as the accrual of coriolis effect contorts the south-to-north air flow into a meandering and irregularly ending river of air. How many years ahead of us Coriolis Cell formation is, depends on when the Arctic Ocean loses its sea ice cover. We ain't there yet...

Not sure which thread to post this in, but is this unusual? Is it relevant to Arctic?
Today's jet stream:
https://media.giphy.com/media/xUPGcoh39ZKjSAlIju/giphy.gif




(from: https://earth.nullschool.net/#current/wind/isobaric/500hPa/orthographic=-62.81,40.95,555 )
Unusual? Seems less and less so all the time. That equatorial east to west flow is symptomatic of strong pile to equator flows at high altitude. What seems to be happening of late is big low level flows going from one hemisphere to another. A few weeks ago when cyclone cook was in the house the big high in th arctic coupled up and from Alaska to Antarctica the whole Pacific basin lower level airmass got drawn. Some seemed to return at the top of the troposphere, but massive deep southern ocean lows seem to be punching a hole in the roof of the night and returning it via the stratosphere. Generating a massive trade winds belt at 10 hpa 30+ km altitude. The flows reversed about a week ago with up to 1056hpa in a massive high over Antarctica and low pressure predominant in the Arctic. Now with a few cyclones popping up in the sth pacific and pressure buildin Gain in the arctic the pendulum appears to be swinging. With the absolute ratsnest the jets have become perhaps we shouldnt be surprised that cyclones at 20 degrees sthe like the central pacific one get captured by mr ferell so quickly as a jet flow whips up and arond them from the pole. Making them into the dreaded hybrids. Still feeding on tropic moisture dragged in at low level. And polar cold. But I am mouth wide open a this active planetry dual hemisphere single cell pan-atmospheric single cell behaviour. If this becomes more usual my questions are... Will it prove to be an oscillation sloshing one way and the other on a period of a couple of weeks as lately or some other. Potentially setting up big ocean pumping. Or be predominant as a seasonal flow from one hemisphere pole to the other. Sharing heat from the summer with the pole in  the dark. https://earth.nullschool.net/#current/wind/isobaric/250hPa/overlay=temp/winkel3=-166.96,15.64,226/loc=-162.898,-8.084   
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Re: The 2017 melting season
« Reply #1088 on: May 05, 2017, 03:53:37 AM »
Neven,

I do not understand how to interpret the latitudinal figures along the bottom of your graph.. (no apology I'm learning) I appreciate the training wheels.
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Tor Bejnar

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Re: The 2017 melting season
« Reply #1089 on: May 05, 2017, 04:09:21 AM »
H2O world:  those are years: 68=1968, etc.
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Re: The 2017 melting season
« Reply #1090 on: May 05, 2017, 07:58:30 AM »
Rutgers has updated the April NH snow cover anomaly graph:

Land snow cover may be the only metric to give us some hope for the upcoming melting season.
Unfortunately, April land snow cover is rather poorly correlated to September SIE.
We'll have to wait until June until decent correlation appears.
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oren

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Re: The 2017 melting season
« Reply #1091 on: May 05, 2017, 08:27:43 AM »
Update from SMOS, thickness of <0.5m ice around the Arctic.
https://seaice.uni-bremen.de/thin-ice-thickness/

seaice.de

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Re: The 2017 melting season
« Reply #1092 on: May 05, 2017, 10:16:16 AM »
Update from SMOS, thickness of <0.5m ice around the Arctic.

Well, you should be careful with this kind of data. The possible maximal thickness, that can be estimated depends on temperature (and salinity) of the ice. See plot below, taken from [1].

Usually the SMOS ice thickness product becomes very unreliable after around April 15. This is the reason why the UH product is not available after this date. By the way, a validation has shown, that "UH product performs better in comparison with the UB product" [2]. Therefore, you might consider to have a look at the UH data available at [3].

[1] http://www.the-cryosphere.net/8/997/2014/tc-8-997-2014.html
[2] http://www.seaice.de/Kaleschke_RSE_2016_final.pdf
[3] http://icdc.cen.uni-hamburg.de/1/daten/cryosphere/l3c-smos-sit.html

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Re: The 2017 melting season
« Reply #1093 on: May 05, 2017, 10:35:57 AM »
Stunning aprupt upwards movement of the Extent Graph of Bremen...  :o



And a huge crack north of Canada appeared yesterday:
« Last Edit: May 05, 2017, 11:00:29 AM by nicibiene »
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Neven

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Re: The 2017 melting season
« Reply #1094 on: May 05, 2017, 10:43:23 AM »
Yes, and it seems almost half the ice has been occupied by grey aliens:
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subgeometer

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Re: The 2017 melting season
« Reply #1095 on: May 05, 2017, 10:53:52 AM »
Stunning aprupt upwards movement of the Extent Graph of Bremen...  :o



pretty dramatic hey. Their map has a lot of missing data today as well

But the reality is not a lot better, here are a couple of worldview animations of the ESS from april 30 to may 5, a wide view and a closer one of the region from70.6260°, 178.126V to 70.5408°, 173.1176°

You can see floes drifting and rotatingat different speeds according to the local ice concentration eg with the 2 large floes at top left of the wide view

 This is part of the area forecast by GFS to see above zero temps starting about 4 days out and intensifying. I don't know how significant it is but a modest low is forecast to form in the area and proceed across the basin to the pole bringing snow and rain in its wake

F.Tnioli

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Re: The 2017 melting season
« Reply #1096 on: May 05, 2017, 01:21:11 PM »
...
2) With ice thicknesses already at record lows in the Chuchki/ESS, any heat intrusions have the potential to rapidly melt the little amounts of ice that currently exist. HYCOM and satellite already show areas of low concentration in these peripheral seas. If we see extended heat through to 6/1, we may be dealing with large portions of these areas taking up an unprecedented amount of solar insolation at the peak of summertime. Normally this energy would go into melting the ice, not warming up the water.
...
The state of summer-time ESS ice cover is my biggest concern for a few years now, and for the reason other than mere acceleration of further polar amplification per se. I was like mighty happy to see ESS standing better than most other regions last season, for example. But now...

There is that well known Shakhova et al work, about ~50Gt CH4 release out of ESS. This is the big thing there IMO. Obviously there are dire long term ramifications (to say the least), but in terms of this topic, short-term effects are of on-topic relevance: high local CH4 concentrations during max insolation times will cause additional significant accumulation of heat near the surface, and that will do things not in just ESS area itself, but also other parts of the Arctic through air and water currents. There are recent-years' in-situ measurements for CH4 in numerous spots of the region showing CH4 over-saturation in the water column and massive local CH4 concentrations increase in the air as well, but so far mainly autumn-times, when there is not much (if any) sunlight to make CH4' massive short-term GHG efficiency matter any much. And most of the extra CH4 gets much dispersed around NH in winter times, plus some is converted to CO2 during that time as well, so next summer-time sees little of the emission left in the air (so far). Getting the ESS' seabed directly warmed up by sunlight during June intensively should produce substantial CH4 emissions summer-time, i suspect. Might be the "game changer" for the season - not sure if this one will have enough of the "oomph" this season (who can be?), but can't be sure that won't happen either. What you think?
« Last Edit: May 05, 2017, 01:29:56 PM by F.Tnioli »
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Re: The 2017 melting season
« Reply #1097 on: May 05, 2017, 01:48:02 PM »
Now that the methane release has begun, it is continuous.  Subsea releases don't stop, but accumulate beneath the ice, releasing through any cracks that open up.

There is nothing that will stop the releases short of HSZ equilibrium, which is not even in the cards for now.

Would be interesting to know how these spring releases from beneath the ice affects melting.
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F.Tnioli

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Re: The 2017 melting season
« Reply #1098 on: May 05, 2017, 01:53:14 PM »
...
Sadly, this process will continue with Hadley Cells pushing Sahara towards north across the Mediterranean Sea to the Central Europe and the inflated polar cell starting to collide with it. ...
Which pretty much desertifies Central Europe, eh. Side remark: beautifully, your logic correlates perfectly with Aiguo Dai's (et al) PDSI calculations and maps for higher global temps, by the way, which were done some years ago. Corrected version of said maps can be previewed here, see figure 11 (d), (e), (f). Based on IPCC AR4, so generally we can expect faster pace than those maps demonstrate, too.
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F.Tnioli

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Re: The 2017 melting season
« Reply #1099 on: May 05, 2017, 02:08:54 PM »
Now that the methane release has begun, it is continuous.  Subsea releases don't stop, but accumulate beneath the ice, releasing through any cracks that open up.

There is nothing that will stop the releases short of HSZ equilibrium, which is not even in the cards for now.

Would be interesting to know how these spring releases from beneath the ice affects melting.
They don't exactly "stop", but intensity still varies through seasons. I believe late-spring and summer-time (so far) were times when minimum amounts of CH4 were being released, which was (so far) quite very fortunate circumstance for the ACI in terms of how resistant it is to summer melting processes.

But most importantly for the matter we discuss here, i think, is the fact that much of CH4 which does not escape water column very shortly after being released from the seabed - does not survive "under the ice" much long, because most of it apparently turns into CO2 rather quick. Heck, i've even seen some paper last year about CH4-eating micro-biota blooming in the Arctic waters, if memory serves. Highest local air CH4 concentrations are observed during autumn and lately winter times, when CH4 can still escape water column pretty fast - but not in late spring / early summer. Yet the latter would be exactly the case if much of CH4 released during all the winter and early-spring times would be ready to go from water column into the athmosphere the moment some cracks in the ice would allow it to. At least, this is how i understand it. Please correct me if i'm wrong somewhere.
« Last Edit: May 05, 2017, 02:27:29 PM by F.Tnioli »
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