Support the Arctic Sea Ice Forum and Blog

Author Topic: The 2017 melting season  (Read 1389104 times)

Tigertown

  • Nilas ice
  • Posts: 1676
    • View Profile
  • Liked: 21
  • Likes Given: 17
Re: The 2017 melting season
« Reply #3850 on: August 18, 2017, 03:29:46 AM »
Whether a picture is worth a thousand words, I don't know, but this one ought to be worth a right smart of them.
"....and the appointed time came for God to bring to ruin those ruining the earth." Revelation 11:18.

Ice Shieldz

  • Frazil ice
  • Posts: 249
    • View Profile
  • Liked: 59
  • Likes Given: 58
Re: The 2017 melting season
« Reply #3851 on: August 18, 2017, 03:36:47 AM »
Assuming this smoke settles on the ice, would its presence increase insolation related melt next melt season?

TerryM

  • First-year ice
  • Posts: 6002
    • View Profile
  • Liked: 895
  • Likes Given: 5
Re: The 2017 melting season
« Reply #3852 on: August 18, 2017, 03:46:58 AM »
See http://muenchow.cms.udel.edu/classes/Arctic/05_Ekman.pdf
or look up Ekman pumping on wikipedia

Understanding Ekman pumping and the Beaufort high is the key to understanding the melting patterns we have seen in recent years on the Alaskan side of the Arctic ocean. There have been multiple papers on Alaskan coastal upwelling in recent years. It has been increasing.
As bolded
Terry

A-Team

  • Young ice
  • Posts: 2775
    • View Profile
  • Liked: 720
  • Likes Given: 35
Re: The 2017 melting season
« Reply #3853 on: August 18, 2017, 04:00:04 AM »
Dispersion is more appropriate than divergence for scattering of floes; the latter is calculated separately for the ice pack at DTU along with vorticity. Gradient, divergence and curl: these were spoken for 150 years ago in the current context (applied physics). We have gone around and around on this before.

The lower animation below looks at this puzzling persistent polynya along the 120th meridian north of 80º (yellow star). It first shows up around June 23rd on the UH 3k concentration map and has persisted since, drifting south along with the ice pack.

The WorldView overlay (snatched from @zlabe for Aug 16th) shows quite a large feature consisting of open water with some scattered floes. The GEBCO bathymetry overlay shows that the polynya formed and resides over water some 3200 m deep; there is no association with continental shelf or Atlantic water along the break, nor with Lomonosov Ridge.

I would say further it has nothing to do mid-ocean tides nor with the Gakkel Ridge divergent plate spreading center nor warm water upwelling from its weak hydrothermal vents and sporadic pyroclastic volcanism far to the west.

Perhaps the polynya formed by happenstantial pack shifts or local cyclonic winds and is maintained by rigid motion of the surrounding ice. However that isn't plausible if a polynya forms in the same spot in multiple recent years. That could get murky depending on the extent of other ice loss in the region; Aug 2016 at WorldView was too cloudy at this lat,lon to form me to an opinion.

Is this the only such persistent open feature or just one we have seized upon among dozens, mostly because of its scale? And to say it repeats in earlier years, how good a locational and temporal match need that be?

Hycom flashes some low thickness pink at the approximate location for the first 11 days of August but it is not entirely convincing as the direction of movement seems slightly off. The polynya is not apparent on Piomas, per wip's July 1st through mid-August.
« Last Edit: August 18, 2017, 03:57:20 PM by A-Team »

Tigertown

  • Nilas ice
  • Posts: 1676
    • View Profile
  • Liked: 21
  • Likes Given: 17
Re: The 2017 melting season
« Reply #3854 on: August 18, 2017, 04:26:35 AM »
Assuming this smoke settles on the ice, would its presence increase insolation related melt next melt season?
You gotta think it would at some point in time next year. Probably not by itself, but with a little help from some other factor that exposes it again. That factor could be a number of things, rain being one.
"....and the appointed time came for God to bring to ruin those ruining the earth." Revelation 11:18.

Rob Dekker

  • Nilas ice
  • Posts: 2386
    • View Profile
  • Liked: 118
  • Likes Given: 119
Re: The 2017 melting season
« Reply #3855 on: August 18, 2017, 05:49:55 AM »
The lower animation below looks at this puzzling persistent polynya along the 120th meridian north of 80º (yellow star). It first shows up around June 23rd on the UH 3k concentration map and has persisted since, drifting south along with the ice pack.

The WorldView overlay (snatched from @zlabe for Aug 16th) shows quite a large feature consisting of open water with some scattered floes. The GEBCO bathymetry overlay shows that the polynya formed and resides over water some 3200 m deep; there is no association with continental shelf or Atlantic water along the break, nor with Lomonosov Ridge.

I would say further it has nothing to do mid-ocean tides nor with the Gakkel Ridge divergent plate spreading center nor warm water upwelling from its weak hydrothermal vents and sporadic pyroclastic volcanism far to the southwest.

Perhaps the polynya formed by happenstantial pack shifts or local cyclonic winds and is maintained by rigid motion of the surrounding ice. However that isn't plausible if a polynya forms in the same spot in multiple recent years. That could get murky depending on the extent of other ice loss in the region; Aug 2016 was too cloudy at this lat,lon to form me to an opinion.

Hycom flashes some low thickness pink at the approximate location for the first 11 days of August but it is not entirely convincing as the direction of movement seems slightly off. The polynya is not apparent on Piomas, though wip's mid-July animation seems the latest.

Ah. The Laptev triangle.
Indeed this is a puzzling feature.
Prior years it showed up as the 'Laptev bite' pretty much in the same place. About 120E/80N.

Thanks A-team for ruling out a lot of different possible causes for this feature. Your arguments make sense.

I would like to propose one theory that anyone may shoot down with any reasonable argument :
The feature shows up in the Laptev side of the Eurasian basin. That is where deep (under the halocline) warm Atlantic water current makes a U-turn :



The Laptev Triangle shows up in the center of that U-turn.
So here is my theory : Coriolis forces push matter to the right in the Northern Hemisphere, but also (less known) UP if it moves East and DOWN if it moves west.
https://en.wikipedia.org/wiki/Coriolis_force

So could it be that while that Atlantic water goes through its U-turn (moving East), that it gets pushed up a little bit ?
If so, some of that warm Atlantic water may end up above the halocline and cause more bottom-melt than in other places, which leads to a polynia later in the melting season (now).
« Last Edit: August 18, 2017, 06:07:23 AM by Rob Dekker »
This is our planet. This is our time.
Let's not waste either.

miki

  • Frazil ice
  • Posts: 138
    • View Profile
  • Liked: 44
  • Likes Given: 198
Re: The 2017 melting season
« Reply #3856 on: August 18, 2017, 05:55:53 AM »
As VAK was saying a while ago:

http://forum.arctic-sea-ice.net/index.php/topic,1834.msg125402.html#msg125402

The explanation for the current Laptev polyna is here: Even back in early 2000's when the Laptev Sea to north area was covered by very strong MYI, there appeared a tunnelling water current beneath sea ice that weakened it from that line. The sea ice began splitting down from the riparian deltas across the sea all the way to Canada. I believe that the shallow Siberian sea bed may also have additional subterranean rivers transport of water which takes water north. It could also be the collision of riparian discharges to saline oceanic water that causes turbulence that extracts heat from underlying warmer water source. Even a very thick and hard MYI could not prevent ice weakening and breaking in this area in 2000's, so the Laptev polnya isn't a miracle.  ;)

Does anyone have an explanation for the Laptev polyna? Considering how mobile the ice appears to be, I'm surprised not just that a hole would appear way off in the pack, but how persistent it is.

JMP

  • Frazil ice
  • Posts: 110
    • View Profile
  • Liked: 17
  • Likes Given: 61
Re: The 2017 melting season
« Reply #3857 on: August 18, 2017, 06:13:40 AM »
See http://muenchow.cms.udel.edu/classes/Arctic/05_Ekman.pdf
or look up Ekman pumping on wikipedia

Understanding Ekman pumping and the Beaufort high is the key to understanding the melting patterns we have seen in recent years on the Alaskan side of the Arctic ocean. There have been multiple papers on Alaskan coastal upwelling in recent years. It has been increasing.
As bolded
Terry
Yes. (For me) AMAZING information in those graphs/images.   Thank you! FOoW.

Lord M Vader

  • Nilas ice
  • Posts: 1333
    • View Profile
  • Liked: 48
  • Likes Given: 29
Re: The 2017 melting season
« Reply #3858 on: August 18, 2017, 11:36:53 AM »
The most recent runs from ECMWF and GFS indicates more high pressure dominated weather as the melting season is getting close to the end. If this forecast had been in July and not the second half of August the sea ice would have faced seriously melting.

Of importance for the freezing season is how thick the snow cover onto the remaining ice is. Any one here who can answer that question?

As the PIOMAS shows that the volume is higher than at the same time back in 2012 it should give the Arctic respit if the upcoming winter gets colder than last two years.

F.Tnioli

  • Grease ice
  • Posts: 769
    • View Profile
  • Liked: 147
  • Likes Given: 38
Re: The 2017 melting season
« Reply #3859 on: August 18, 2017, 12:39:08 PM »
Great paper! The physical state of the ice is unlike anything we have ever seen, pulverized and highly mobile. This paper helps explain some of what we are seeing. It also has brought us back on topic.

Thank you.
Yes, "pulverized and highly mobile" is the thing i often shorten just to the term "soup", see.

P.S. One is glad to be of service. o7
To everyone: before posting in a melting season topic, please be sure to know contents of this moderator's post: https://forum.arctic-sea-ice.net/index.php/topic,3017.msg261893.html#msg261893 . Thanks!

Gray-Wolf

  • Grease ice
  • Posts: 897
    • View Profile
  • Liked: 123
  • Likes Given: 342
Re: The 2017 melting season
« Reply #3860 on: August 18, 2017, 06:15:32 PM »

As the PIOMAS shows that the volume is higher than at the same time back in 2012 it should give the Arctic respit if the upcoming winter gets colder than last two years.

Let's not forget that the wrong type of weather over winter can lead to serious losses of volume via export ( with thinner , late formed ice replacing those losses?). If we see another winter of storms then we might expect a lot of ice from the Atlantic side of the basin to migrate toward Fram and oblivion?

I spent too many years only looking at 'summer' and melt season to notice just how winter was conditioning the ice for loss with older ice, piled up against the north shore of the CA and Greenland making its way , via the trans Arctic Drift, toward Fram. We also has the 'crackopalypse' late winter events continually fracturing the floes ( and then glueing them back together with weak , late formed , ice meaning rapid breakup occurred during mid melt season leaving us with very mobile small floes which were then subject to mechanical weathering with ever windy day/storm.
KOYAANISQATSI

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

Sterks

  • Guest
Re: The 2017 melting season
« Reply #3861 on: August 18, 2017, 07:34:50 PM »
The most recent runs from ECMWF and GFS indicates more high pressure dominated weather as the melting season is getting close to the end. If this forecast had been in July and not the second half of August the sea ice would have faced seriously melting.

As my mother would have said in her tongue this weather, now, does not bring "Ni chicha ni limoná" for the first days but looks interesting in the longer range, with potential for compaction, like wrapping up things.
In 20 days tops, this is over.

gregcharles

  • New ice
  • Posts: 95
    • View Profile
  • Liked: 11
  • Likes Given: 2
Re: The 2017 melting season
« Reply #3862 on: August 18, 2017, 11:40:14 PM »
In 20 days tops, this is over.

This ... being the melting season? So you predict the minimum at September 7 or earlier? It would surprise me if it were quite that early, but we'll see.

A-Team

  • Young ice
  • Posts: 2775
    • View Profile
  • Liked: 720
  • Likes Given: 35
Re: The 2017 melting season
« Reply #3863 on: August 19, 2017, 12:46:23 AM »
Quote
propose theory that the feature shows up in the Laptev side because that's where deep (under the halocline) warm Atlantic water current makes a U-turn.
The kaleidoscopic animation below looks for the 80º/120º polynya during the first 15 days of August for the six years 2012-2017. Here 2017 is outlined in yellow and earlier years go CW (ie with 2016 to 2017's right and 2012 to its left.) UH AMSR2 began serving on 01 Aug 2012 so it's not feasible to back go further.

The 6.25 km resolution is shown. Using the 3.125 version, UH really is calling the center of the polynya as open water, not just real low sea ice concentration (lower two images). The far left color tile (darkest blue) on their palette matches known expanses of open water, as it should.

A case could be made that 2012 and perhaps 2013 had a persistent polynya in a fairly similar place to 2017's. However there's little support for the polynya occurring every year, which restricts the space of possible explanations.
« Last Edit: August 19, 2017, 03:16:28 PM by A-Team »

oren

  • Moderator
  • First-year ice
  • Posts: 6821
    • View Profile
  • Liked: 2504
  • Likes Given: 2254
Re: The 2017 melting season
« Reply #3864 on: August 19, 2017, 12:50:10 AM »
Wonderful animation A-Team (ditto for many of your other graphics and animations...)

Neven

  • Administrator
  • First-year ice
  • Posts: 7822
    • View Profile
    • Arctic Sea Ice Blog
  • Liked: 1140
  • Likes Given: 546
Re: The 2017 melting season
« Reply #3865 on: August 19, 2017, 12:58:25 AM »
Picture yourself in a boat on a river
With tangerine trees and marmalade skies
Somebody calls you, you answer quite slowly
A girl with kaleidoscope eyes

 ;)

Very nice, A-Team!
Il faut comparer, comparer, comparer, et cultiver notre jardin

Sterks

  • Guest
Re: The 2017 melting season
« Reply #3866 on: August 19, 2017, 12:59:10 AM »
In 20 days tops, this is over.

This ... being the melting season? So you predict the minimum at September 7 or earlier? It would surprise me if it were quite that early, but we'll see.
Based on what ECMWF, I am inclined to believe so, if the strong dipole pulling air from Laptev and oriented towards the CAA comes to happen. It would be a nice compacting event in 5-7 days from now.
I don't think there is momentum to melt much more of the ESS arm but there may be some compacting there too.
And before all that the Beaufort vestige and the NWP ice will lose ice.
Loses before Sep guaranteed.
But then... Everything seems compacted toward high latitudes (except the arm that wont melt, if so very slowly).
I may well be very wrong or missing much.

Jim Hunt

  • Young ice
  • Posts: 4894
  • Stay Home, Save Lives
    • View Profile
    • The Arctic sea ice Great White Con
  • Liked: 535
  • Likes Given: 52
Re: The 2017 melting season
« Reply #3867 on: August 19, 2017, 12:01:12 PM »
Picture yourself in a boat on a river

Picture yourself on a boat in the Central Arctic. Some gaps are opening up along Pen Hadow's route towards the North Pole:

http://GreatWhiteCon.info/2017/07/pen-hadows-arctic-mission-to-sail-to-the-north-pole/#Aug-18
Reality is merely an illusion, albeit a very persistent one - Albert Einstein

Daniel B.

  • Grease ice
  • Posts: 659
    • View Profile
  • Liked: 3
  • Likes Given: 29
Re: The 2017 melting season
« Reply #3868 on: August 19, 2017, 01:54:19 PM »
In 20 days tops, this is over.

This ... being the melting season? So you predict the minimum at September 7 or earlier? It would surprise me if it were quite that early, but we'll see.
Sept. 7 is not that early.  I believe last year the minimum occurred on that date, and 2015 was a day later.  Later dates are the exception.  With a colder Atlantic and snows in Greenland, I would tend to agree with that date, if not earlier.

Jim Hunt

  • Young ice
  • Posts: 4894
  • Stay Home, Save Lives
    • View Profile
    • The Arctic sea ice Great White Con
  • Liked: 535
  • Likes Given: 52
Re: The 2017 melting season
« Reply #3869 on: August 19, 2017, 02:23:15 PM »
Sept. 7 is not that early. I believe last year the minimum occurred on that date.

That does rather depend on which is your favourite extent metric out of the many available?

http://GreatWhiteCon.info/2016/09/the-2016-arctic-sea-ice-metric-minima/#Milestones

This one's mine:

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

Pi26

  • New ice
  • Posts: 41
    • View Profile
  • Liked: 0
  • Likes Given: 0
Re: The 2017 melting season
« Reply #3870 on: August 19, 2017, 02:50:38 PM »
In 20 days tops, this is over.

Sept. 7 is not that early.  I believe last year the minimum occurred on that date, and 2015 was a day later.  Later dates are the exception.  With a colder Atlantic and snows in Greenland, I would tend to agree with that date, if not earlier.



I prefer to look at the refreeze on november 5 to see how last melting season really did, because the first quarter of freezing season also shows how much heat was left in water.
I am most afraid of the energy capacity chucki has to discharge (while melting season or even much later)
« Last Edit: August 19, 2017, 04:20:56 PM by Pi26 »

Pavel

  • Frazil ice
  • Posts: 255
    • View Profile
  • Liked: 46
  • Likes Given: 9
Re: The 2017 melting season
« Reply #3871 on: August 19, 2017, 03:10:12 PM »


I prefer to look at the refreeze on november 5 to see how last melting season really did, because the first quarter of freezing season also shows how much heat was left in water.
The volume decrease this summer is slow not only due to lack of heat but because energy was spent to heat the ocean and not to melt ice. No strong storms occurred and less deeper ocean heat have mixed up with surface waters. Another point is that Pacific side overheated. Despite the Atlantic side is colder but it should struggle to refreeze cause the freezing momentum is weak over there

Pi26

  • New ice
  • Posts: 41
    • View Profile
  • Liked: 0
  • Likes Given: 0
Re: The 2017 melting season
« Reply #3872 on: August 19, 2017, 04:54:27 PM »
I mean once again very old and important "extend" from north of greenland here goes around the corner to south.

« Last Edit: August 19, 2017, 05:06:24 PM by Pi26 »

Albatross

  • New ice
  • Posts: 4
    • View Profile
  • Liked: 0
  • Likes Given: 0
Re: The 2017 melting season
« Reply #3873 on: August 19, 2017, 05:18:16 PM »
Would it be safe to say that one of the NW passage routes is now open/navigable?

Jim Hunt

  • Young ice
  • Posts: 4894
  • Stay Home, Save Lives
    • View Profile
    • The Arctic sea ice Great White Con
  • Liked: 535
  • Likes Given: 52
Re: The 2017 melting season
« Reply #3874 on: August 19, 2017, 06:13:00 PM »
Would it be safe to say that one of the NW passage routes is now open/navigable?

I very much doubt it, unless you count icebreakers:

http://GreatWhiteCon.info/2017/07/the-northwest-passage-in-2017/
« Last Edit: August 19, 2017, 06:18:13 PM by Jim Hunt »
Reality is merely an illusion, albeit a very persistent one - Albert Einstein

Gray-Wolf

  • Grease ice
  • Posts: 897
    • View Profile
  • Liked: 123
  • Likes Given: 342
Re: The 2017 melting season
« Reply #3875 on: August 19, 2017, 06:56:31 PM »
Plea for help guys! I need to trace a link to one our our member discussing the current 15% or more measure for extent/area with NSIDC ? I believe we had a Email reply along the lines that they knew there were issues with the measure once the pack became dispersed in the central regions ( and not the peripheries).
The site has a number of die hard deniers who do not put much stead in the fine work that folk do here nor the expert analysis we are given on a daily basis ( BFTV used to post there but the nonsense must have become too much for him!).
Thanks in advance if anyone recalls or can point me to the EMail reply! :)
KOYAANISQATSI

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

numerobis

  • Grease ice
  • Posts: 837
    • View Profile
  • Liked: 16
  • Likes Given: 3
Re: The 2017 melting season
« Reply #3876 on: August 19, 2017, 07:16:13 PM »
The northwest passage is just a few more days of favorable winds from opening -- or a few days of unfavorable winds from staying closed this year.

The green parts of the map you can cross without an icebreaker; yellow if you're brace (or stupid); orange not so much, red definitely not. You couldn't crunch through any of the ice without an icebreaker, it's quite thick.

Pi26

  • New ice
  • Posts: 41
    • View Profile
  • Liked: 0
  • Likes Given: 0
Re: The 2017 melting season
« Reply #3877 on: August 19, 2017, 08:40:35 PM »
Would it be safe to say that one of the NW passage routes is now open/navigable?

 ;D

A-Team

  • Young ice
  • Posts: 2775
    • View Profile
  • Liked: 720
  • Likes Given: 35
Re: The 2017 melting season
« Reply #3878 on: August 19, 2017, 08:48:19 PM »
Quote
I prefer to look at the refreeze on november 5 to see how last melting season really did, how much heat was left in water [and/or came in with Atlantic Waters] ... the Atlantic side is colder but it should struggle to refreeze cause the freezing momentum is weak
Right. While insolation provides negligible heat to the Arctic Ocean ice towards the end of August,  sea water has far greater heat capacity and thermal conductivity than air -- and never mind local clouds, Atlantic Waters come up from the Gulf of Mexico.

North of the Barents and east to the Laptev, breakdown of stratification is not so much wind-dependent on mixing as on roughness induced tidal turbulence, especially over the Yermak Plateau (per many studies, eg N-ICE2015).

There's been confusion up-forum citing studies from the late 1990's, here's the 2017's to look at, both free full text:

https://tinyurl.com/yctkrnlb
https://tinyurl.com/y758r27n 

Quote
I Polyakov et al April 2017 write: Arctic sea-ice loss is a leading indicator of climate change and can be attributed, in large part, to atmospheric forcing. Here, we show that recent ice reductions, weakening of the halocline and shoaling of the intermediate-depth Atlantic Water layer in the eastern Eurasian Basin have increased winter ventilation in the ocean interior, making this region structurally similar to that of the western Eurasian Basin [~Svalbard].

The associated enhanced release of oceanic heat has reduced winter sea-ice formation at a rate now comparable to losses from atmospheric thermodynamic forcing, thus explaining the recent reduction in sea-ice cover in the eastern Eurasian Basin. This encroaching atlantification of the Eurasian Basin represents an essential step toward a new Arctic climate state, with a substantially greater role for Atlantic inflows.
The open water minimum in the Arctic Ocean proper was reached on 07 Sep 2016 using pixel count areas in UH AMSR2, which at 3 km resolution is a great improvement over 25 km resolution. (Open water is far easier to determine by satellite than accurate mid-range concentrations. Pixels in the PS projection deviate only by a few percent from equal-area north of 70º, so negligibly in subtractive comparisons.)

It's important not to throw in Greenland Sea ice, as NSIDC does for their 10 Sep 16 minimum. It should be subtracted, not added -- never in the satellite record has this ice made its way back into the Arctic Ocean. (Summer 2017 has seen little Fram export so it is somewhat moot this year.)

For inter-year comparison and current year prediction, it also makes sense not to include 'Barents Boundary' ice that lies south of the continental shelf bathymetric break, ice which is probably going to melt regardless of clouds, cool air or low wind. Atlantification hasn't gone away, it's just been smothered (temporarily masked) by ever-incoming ice.

The animation below determines this boundary using a 7 day AMSR2 average centered on the 2016 minimum; the resulting mask can then be applied as a future-driven correction to current data.

The noteworthy development this summer has been a steady push of ice up against and through this line of islands. While no one has a clue to the winds or weather beyond D5 (Aug 24th), ice models that use forecasts see this cyclonic push continuing.

Indeed, the a worse-case scenario for ice loss on the Atlantic side (3rd frame, 2nd animation) could see quite a bit of ice move into the thinning/melting zone over the next month, even as elsewhere the refreeze season had begun (as in in fall 2016). This suggests a more nuanced (regionally hybrid) definition of 'minimum' would more accurately characterize the situation.
2016    IB+CAA  Bering  Green   Open Water

09 01   263333   6136   9173   278642
09 02   270160   6136   9173   285469
09 03   269975   6136   9173   285284
09 04   269383   6136   9173   284692
09 05   268931   6136   9173   284240
09 06   272316   6136   9173   287625
09 07   273760   6136   9173   289069 *
09 08   270858   6136   9173   286167
09 09   270580   6136   9173   285889
09 10   267496   6136   9173   282805
09 11   265534   6136   9173   280843
09 12   260439   6136   9173   275748
09 13   257114   6136   9173   272423
09 14   257850   6136   9173   273159
09 15   257601   6136   9173   272910
09 16   255402   6136   9173   270711
09 17   254694   6136   9173   270003
« Last Edit: August 19, 2017, 10:18:56 PM by A-Team »

Pavel

  • Frazil ice
  • Posts: 255
    • View Profile
  • Liked: 46
  • Likes Given: 9
Re: The 2017 melting season
« Reply #3879 on: August 20, 2017, 10:20:18 AM »
The death ring is getting closer to the Pole.


Jim Hunt

  • Young ice
  • Posts: 4894
  • Stay Home, Save Lives
    • View Profile
    • The Arctic sea ice Great White Con
  • Liked: 535
  • Likes Given: 52
Re: The 2017 melting season
« Reply #3881 on: August 20, 2017, 02:27:09 PM »
NW Passage definitely open.

Not according to the most recent CIS map it isn't:
Reality is merely an illusion, albeit a very persistent one - Albert Einstein

ghoti

  • Grease ice
  • Posts: 767
    • View Profile
  • Liked: 12
  • Likes Given: 15
Re: The 2017 melting season
« Reply #3882 on: August 20, 2017, 04:17:31 PM »
Near real time images of the ice state in the passage can be seen at

https://canadac3.ca/en/expedition/live-feed/ and followed on the map at
https://canadac3.ca/en/expedition/expedition-map/

They are entering the Prince Regent Inlet on the way to Fort Ross now (August 20 14:00 UTC)

Ice is melting out but still an issue .

Edit: Of course as soon as I posted this they anchored in almost ice free water to take a field trip to the bird sanctuary on Leopold Island.
« Last Edit: August 20, 2017, 05:51:35 PM by ghoti »

Killian

  • Frazil ice
  • Posts: 299
    • View Profile
  • Liked: 62
  • Likes Given: 8
Re: The 2017 melting season
« Reply #3883 on: August 20, 2017, 06:53:38 PM »
NW Passage definitely open.

Not according to the most recent CIS map it isn't:

Really? You look at models over ice itself? Shirley, you're joking, Captain. Where in the image I posted is there solid ice land-to-land without a break? We don't need a 13 ft. aluminum fishing boat getting through to call it open, I'd think.

YMMV.

Jim Hunt

  • Young ice
  • Posts: 4894
  • Stay Home, Save Lives
    • View Profile
    • The Arctic sea ice Great White Con
  • Liked: 535
  • Likes Given: 52
Re: The 2017 melting season
« Reply #3884 on: August 20, 2017, 09:56:16 PM »
Really? You look at models over ice itself?

No Killian. I look at the ice charts kindly provided by the Canadian Ice Service.

Quote
YMMV.

Take it up with the CIS. And actually that's an image I posted:

http://forum.arctic-sea-ice.net/index.php/topic,762.msg125874.html#msg125874
Reality is merely an illusion, albeit a very persistent one - Albert Einstein

magnamentis

  • Guest
Re: The 2017 melting season
« Reply #3885 on: August 20, 2017, 10:50:28 PM »
Really? You look at models over ice itself?

No Killian. I look at the ice charts kindly provided by the Canadian Ice Service.

Quote
YMMV.

Take it up with the CIS. And actually that's an image I posted:

http://forum.arctic-sea-ice.net/index.php/topic,762.msg125874.html#msg125874

those are on the safe side, it's about money once again, liability, eventual rescue costs etc.
IMO NWP is navigable looking at all the info that is floating around but the official status by canadian ice service is a bit about covering their back.

silkman

  • Frazil ice
  • Posts: 365
    • View Profile
  • Liked: 57
  • Likes Given: 10
Re: The 2017 melting season
« Reply #3886 on: August 20, 2017, 11:04:21 PM »
Here are hourly Webcam images from the Shackleton archive for August 20 while it was sailing through the Franklin Strait:

https://legacy.bas.ac.uk/webcams/archive/cam.php?cam=1&date=2017-08-20%2014:03:03&position=7

I'm no expert but I'd venture to suggest that this supports the view that the Canadian Ice Service is playing it safe.

Unfortunately Sailwx is having a bit of a meltdown and has miraculously transported the ship back to the Antarctic but the air temperature where it actually is were well above freezing and the water temperature would favour melt. Scroll down for the table of data.

http://www.sailwx.info/shiptrack/shipposition.phtml?call=ZDLS1
« Last Edit: August 20, 2017, 11:10:34 PM by silkman »

ghoti

  • Grease ice
  • Posts: 767
    • View Profile
  • Liked: 12
  • Likes Given: 15
Re: The 2017 melting season
« Reply #3887 on: August 20, 2017, 11:06:21 PM »
Plus do we really think the CIS is more accurate than all the various measures of ice extent and area we contrast daily? Is the CIS magically better than Environment Canada's weather forecast?

We compare Modis "visible" images to images off the occasional transiting boats and the one buoy and they never match.

So I'd say when a boat goes through we know the passage is open. Until then we just speculate. The ice has melted enough this year that with the right wind you could sail through.

A-Team

  • Young ice
  • Posts: 2775
    • View Profile
  • Liked: 720
  • Likes Given: 35
Re: The 2017 melting season
« Reply #3888 on: August 21, 2017, 12:53:09 AM »
The first animation overlays the persistent triangular polynya, now centered at 81.3ºN, 121.2ºE, over Piomas of the same date, 15 Aug 17, as provided by wipneus. Note the polynya is large enough at 18,900 km2 (2nd animation) and 718 pixels (2-3 grid cells) to show up at the resolution of Piomas but it does not. How is the ice thickness calculated for a region that's half open water (see up-forum)?

The 3rd animation looks a visible vs passive radar for the last 31 days -- it's been quite cloudy over the polynya so WorldView only gets an occasional clear view. (By looking at Aqua and Suomi as well, some of the cloudy Terra views could have been replaced by clearer scenes.)
« Last Edit: August 21, 2017, 02:00:14 AM by A-Team »

Killian

  • Frazil ice
  • Posts: 299
    • View Profile
  • Liked: 62
  • Likes Given: 8
Re: The 2017 melting season
« Reply #3889 on: August 21, 2017, 01:42:45 AM »
Really? You look at models over ice itself?

No Killian. I look at the ice charts kindly provided by the Canadian Ice Service.

Quote
YMMV.

Take it up with the CIS. And actually that's an image I posted:


those are on the safe side, it's about money once again, liability, eventual rescue costs etc.
IMO NWP is navigable looking at all the info that is floating around but the official status by canadian ice service is a bit about covering their back.

Seems this is a bit OT here, so let this be my last on this here. We can chat over at the NWP thread, if more is needed.

Navigability is about being able to make it through the ice, period. All the other things you mention are about risk, thus *willingness* to go through the ice. The latter is irrelevant to discussions of the ice. And, there is always someone willing to do it.

Ships *can* get through, without icebreakers, IMO, so it *is* open. Simple as that.

Cheers

Jim Hunt

  • Young ice
  • Posts: 4894
  • Stay Home, Save Lives
    • View Profile
    • The Arctic sea ice Great White Con
  • Liked: 535
  • Likes Given: 52
Re: The 2017 melting season
« Reply #3890 on: August 21, 2017, 10:39:49 AM »
Ships *can* get through, without icebreakers, IMO, so it *is* open. Simple as that.

They can? IYHO?



Here you go:

http://forum.arctic-sea-ice.net/index.php/topic,762.msg125975.html#msg125975
Reality is merely an illusion, albeit a very persistent one - Albert Einstein

subgeometer

  • Frazil ice
  • Posts: 362
    • View Profile
    • All in the Name of Liberty
  • Liked: 112
  • Likes Given: 71
Re: The 2017 melting season
« Reply #3891 on: August 21, 2017, 01:50:48 PM »
DMI are showing a fairly large area of recently ice free water in the Northern Beaufort with a 4C+ anomaly. If its not an artefact it looks like warm water has been coming to the surface there also

F.Tnioli

  • Grease ice
  • Posts: 769
    • View Profile
  • Liked: 147
  • Likes Given: 38
Re: The 2017 melting season
« Reply #3892 on: August 21, 2017, 04:27:12 PM »
Ships *can* get through, without icebreakers, IMO, so it *is* open. Simple as that.

They can? IYHO?



Here you go:

http://forum.arctic-sea-ice.net/index.php/topic,762.msg125975.html#msg125975
I think that mutually acceptable definition of the "ship" term is to be mentioned before you'd start to throw gloves at each other, gentlemen? :)

There are many ships which are not ice-breakers which can, nonetheless, navigate through relatively thick ice. So many that they are, in fact, divided into specific ice classes, and there are even few separate classifications for such (not just one). So, i'm with Killian on this one.
To everyone: before posting in a melting season topic, please be sure to know contents of this moderator's post: https://forum.arctic-sea-ice.net/index.php/topic,3017.msg261893.html#msg261893 . Thanks!

gerontocrat

  • Multi-year ice
  • Posts: 10882
    • View Profile
  • Liked: 4032
  • Likes Given: 31
Re: The 2017 melting season
« Reply #3893 on: August 21, 2017, 04:43:03 PM »
I am waiting for a clapped out vessel full up of nasty stuff operated by a shonky outfit to boldly go where such a heap of junk should not.
"Para a Causa do Povo a Luta Continua!"
"And that's all I'm going to say about that". Forrest Gump
"Damn, I wanted to see what happened next" (Epitaph)

Jim Hunt

  • Young ice
  • Posts: 4894
  • Stay Home, Save Lives
    • View Profile
    • The Arctic sea ice Great White Con
  • Liked: 535
  • Likes Given: 52
Re: The 2017 melting season
« Reply #3894 on: August 21, 2017, 07:06:40 PM »
I am waiting for a clapped out vessel full up of nasty stuff operated by a shonky outfit to boldly go where such a heap of junk should not.

Does the Crystal Serenity fit that description?
Reality is merely an illusion, albeit a very persistent one - Albert Einstein

Sterks

  • Guest
Re: The 2017 melting season
« Reply #3895 on: August 21, 2017, 07:45:29 PM »
I am waiting for a clapped out vessel full up of nasty stuff operated by a shonky outfit to boldly go where such a heap of junk should not.

Does the Crystal Serenity fit that description?
Lol actually

gerontocrat

  • Multi-year ice
  • Posts: 10882
    • View Profile
  • Liked: 4032
  • Likes Given: 31
Re: The 2017 melting season
« Reply #3896 on: August 21, 2017, 08:10:06 PM »
I am waiting for a clapped out vessel full up of nasty stuff operated by a shonky outfit to boldly go where such a heap of junk should not.

Does the Crystal Serenity fit that description?
Lol actually
The "Costa Concordia". The apparently best run ship can run aground, let alone a tramp riding on a hope and a prayer.
A genuine old sea dog once told me "the ocean is not the danger, it is the coast".
"Para a Causa do Povo a Luta Continua!"
"And that's all I'm going to say about that". Forrest Gump
"Damn, I wanted to see what happened next" (Epitaph)

A-Team

  • Young ice
  • Posts: 2775
    • View Profile
  • Liked: 720
  • Likes Given: 35
Re: The 2017 melting season
« Reply #3897 on: August 21, 2017, 08:30:53 PM »
Quote
DMI shows recently ice free water in the Northern Beaufort with a 4C+ anomaly... looks like warm water has been coming to the surface there also
Seems like subg's circled spot has been there two days now, even as SSTAs change at other locations. The anomalies are fairly noisy though as seen in their daily differences, 2nd animation. It might not take much to get a flash melt going along this periphery. Note too DMI’s SSTA seems to be picking up a temperature for open water in the persistent polynya above.
« Last Edit: August 22, 2017, 01:06:25 AM by A-Team »

oren

  • Moderator
  • First-year ice
  • Posts: 6821
    • View Profile
  • Liked: 2504
  • Likes Given: 2254
Re: The 2017 melting season
« Reply #3898 on: August 21, 2017, 11:36:10 PM »
I've been wondering for a while what's up with the ESS bulge that survived thus far in the face of a very early opening of the ESS, and major advances on the Chukchi CAB front recently. My take is that it could soon disappear despite its longevity up to this point.
The animation shows the bulge in the last 3 weeks. It's been shrinking and melting, but managed to advance south in the last week, into what should be warm waters.
According to PIOMAS the ice in the bulge is relatively thin.
And finally, forecasts for the coming week show winds from the south and rising temps (second animation).
Temps in Pevek, on the ESS shore, reach 15oc when the winds blow from the south and east, lending credence to the possibility of high temps over the ESS should the forecast wind direction materialize.
Pevek Synop report

Sterks

  • Guest
Re: The 2017 melting season
« Reply #3899 on: August 22, 2017, 12:21:25 AM »
Fantastic animations ATeam and Oren, thank you.
The Chukchi side of the ESS bulge is being affected by the usual waters from Bering. Not coincidence most of the ice pack shapes get a deep bite East and North of Wrangel Island thse last years.

Winds are detrimental this time of the year: from South they compact and bring ocean heat via atmosphere, from the North they push the ice to uncomfortable areas.
Always cause vertical and wave mixing.
Not much wind lately or in the forecasts, perhaps enough to "pack up things" a little before coldness takes over, as the blow you mention over ESS, oren, also Laptev and Beaufort sea. The "unpacking" or dispersion goes toward Barents, expect Atlantic waters melt out the exported ice.