Support the Arctic Sea Ice Forum and Blog

Author Topic: The 2017 melting season  (Read 1119728 times)

Buddy

  • Young ice
  • Posts: 3325
  • Go DUCKS!!
    • View Profile
  • Liked: 40
  • Likes Given: 26
Re: The 2017 melting season
« Reply #450 on: March 27, 2017, 09:17:23 PM »
Quote
<snip; this off-topic rant has been copied and pasted to the 2017 sea ice extent and area data thread, next time I will just delete it; N.>

I actually started to put it there.....wasn't SURE where it should actually go, since it relates to both Arctic and Antarctic.

My bad.....
FOX (RT) News....."The Trump Channel.....where truth and journalism are dead."

seaicesailor

  • Guest
Re: The 2017 melting season
« Reply #451 on: March 27, 2017, 09:20:45 PM »
BTW when I said absence of cracks in the American side I meant mostly the Beaufort sea. As seen in that pic posted by A4R, north of the CAA and Greenland is a complete different story, but the danger there is not so much insolation but mobility of the ice toward the Atlantic ocean as explained by A4R.
Well, insolation too, eventually   :-\

slow wing

  • Grease ice
  • Posts: 766
    • View Profile
  • Liked: 129
  • Likes Given: 355
Re: The 2017 melting season
« Reply #452 on: March 27, 2017, 10:05:16 PM »
SeaIceSailor,

  My guess at the reason why there are no visible cracks in the Beaufort Sea at the moment is because it has been under fairly constant compression over at least the past month. So the lack of cracks probably doesn't speak much to the quality, or otherwise, of the ice there.

Tigertown

  • Nilas ice
  • Posts: 1647
    • View Profile
  • Liked: 2
  • Likes Given: 0
Re: The 2017 melting season
« Reply #453 on: March 28, 2017, 04:38:05 AM »
It seems a little quiet today except in the ESS and the Bering Sea.

romett1

  • Frazil ice
  • Posts: 221
    • View Profile
  • Liked: 4
  • Likes Given: 0
Re: The 2017 melting season
« Reply #454 on: March 28, 2017, 11:12:06 AM »
Latest GFS anomalies until next Tuesday (Climate Reanalyzer).
Kara, Laptev and ESS still anomalously warm, also Beaufort warmer than usual.

johnm33

  • Nilas ice
  • Posts: 1255
    • View Profile
  • Liked: 61
  • Likes Given: 34
Re: The 2017 melting season
« Reply #455 on: March 28, 2017, 11:18:47 AM »
"Beaufort" There's enough movement to generate cracks, but no durable cracks, looks like the ice is soft either on a small or large scale, no tensile strength. The extensive red on Nullschool suggests plenty of small cracks, and it's all close to -1.8 so rapidly refreezing where sea is exposed, thickening too, so perhaps in a couple of weeks we'll see cracks. https://www7320.nrlssc.navy.mil/hycomARC/beaufort.html   https://earth.nullschool.net/#current/ocean/surface/currents/overlay=sea_surface_temp_anomaly/orthographic=-37.81,87.19,1336/loc=-132.662,74.328

Jim Hunt

  • Young ice
  • Posts: 4077
    • View Profile
    • The Arctic sea ice Great White Con
  • Liked: 134
  • Likes Given: 22
Re: The 2017 melting season
« Reply #456 on: March 28, 2017, 11:25:49 AM »
An excellent view of the recently refrozen sea ice in the East Siberian Sea this morning, courtesy of the Terra satellite:

http://GreatWhiteCon.info/2017/03/facts-about-the-arctic-in-march-2017/#comment-220587
Reality is merely an illusion, albeit a very persistent one - Albert Einstein

Tigertown

  • Nilas ice
  • Posts: 1647
    • View Profile
  • Liked: 2
  • Likes Given: 0
Re: The 2017 melting season
« Reply #457 on: March 28, 2017, 11:33:36 AM »
Latest GFS anomalies until next Tuesday (Climate Reanalyzer).
Kara, Laptev and ESS still anomalously warm, also Beaufort warmer than usual.
It is good to know what the average anomalies over the whole Arctic are running, but does anyone know what they are peaking at? I can only make out the color shades to a limited degree.
Looks like around +18oC....

TheUAoB

  • New ice
  • Posts: 9
    • View Profile
  • Liked: 0
  • Likes Given: 0
Re: The 2017 melting season
« Reply #458 on: March 28, 2017, 11:41:31 AM »
"Beaufort" There's enough movement to generate cracks, but no durable cracks, looks like the ice is soft either on a small or large scale, no tensile strength. The extensive red on Nullschool suggests plenty of small cracks, and it's all close to -1.8 so rapidly refreezing where sea is exposed, thickening too, so perhaps in a couple of weeks we'll see cracks.
Since sea-ice melts/freezes at -1.8C, if the air temperature is clamped to -1.8C, to me, that implies the enthalpy of sea-water/ice is maintaining the temperature.  Water in cracks will likely freeze over for a while, but I can't imagine much if any thickening occurring under those conditions except through ridging.

Gray-Wolf

  • Grease ice
  • Posts: 791
    • View Profile
  • Liked: 46
  • Likes Given: 149
Re: The 2017 melting season
« Reply #459 on: March 28, 2017, 12:59:42 PM »
I have to think that this lack of fragmentation is a 'Thing'? I've been watching out for the type of fragmentation/'Crackopalypse' event to occur from late Jan onward and nothing, on the scale of recent past winters, has occurred in Beaufort?

My only clue is watching the Trans Arctic Drift, above Greenland, where we know there is 'thick, older ice, and see what is happening there? To me that areas shows the type of 'fragmentation' that I had been kind of expecting to occur across Beaufort. I have to think that the pressures are present to drive the type of 'crackopalypse event' we have seen at recent winters end but the new grown ice behaves differently to the type of 'conglomeration of varying sizes of floe glued together by FY ice' that had been present across Beaufort in previous years??

If Pancake ice is the seed for this ice than it may well have the ability to move like chain mail and absorb motion?

 Like the movement of ball pool balls compared to sheets of Styrofoam?
« Last Edit: March 28, 2017, 01:04:55 PM by Gray-Wolf »
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

johnm33

  • Nilas ice
  • Posts: 1255
    • View Profile
  • Liked: 61
  • Likes Given: 34
Re: The 2017 melting season
« Reply #460 on: March 28, 2017, 01:13:32 PM »
"Beaufort" There's enough movement to generate cracks, but no durable cracks, looks like the ice is soft either on a small or large scale, no tensile strength. The extensive red on Nullschool suggests plenty of small cracks, and it's all close to -1.8 so rapidly refreezing where sea is exposed, thickening too, so perhaps in a couple of weeks we'll see cracks.
Since sea-ice melts/freezes at -1.8C, if the air temperature is clamped to -1.8C, to me, that implies the enthalpy of sea-water/ice is maintaining the temperature.  Water in cracks will likely freeze over for a while, but I can't imagine much if any thickening occurring under those conditions except through ridging.
Just to be clear I'm assuming the red, in the link above, indicates cracks exposing the sea surface, the anomoly is .3C so -1.5C sst, the airs much colder. http://www.meteociel.fr/modeles/gfse_cartes.php?ech=6&code=0&mode=9&carte=1  and the thickening spreads from the CAA so I guess that's where durable cracks will appear. We'll see.


Apocalypse4Real

  • Frazil ice
  • Posts: 370
    • View Profile
  • Liked: 5
  • Likes Given: 1
Re: The 2017 melting season
« Reply #461 on: March 28, 2017, 03:38:16 PM »
Fracturing is occurring in the Beaufort as well as the CAB. Note the attached. It may be that the entire pack is becoming more mobile due to thinner ice and wind effects.

seaicesailor

  • Guest
Re: The 2017 melting season
« Reply #462 on: March 28, 2017, 05:13:11 PM »
ACNFS Hycom Sea ice drift predicted from today to Apr 2.
The situation reminds a bit to Spring 2014, with the ice drifting away from Laptev sea coasts persistently, and a lot of transport toward the Atlantic.

DrTskoul

  • Nilas ice
  • Posts: 1402
    • View Profile
  • Liked: 175
  • Likes Given: 59
Re: The 2017 melting season
« Reply #463 on: March 28, 2017, 05:19:26 PM »
Yikes.  Somebody close the doors, the draft is killing us...

oren

  • Young ice
  • Posts: 4173
    • View Profile
  • Liked: 670
  • Likes Given: 1190
Re: The 2017 melting season
« Reply #464 on: March 28, 2017, 05:32:00 PM »
johnm33's wonderful animation tells it all, the Beaufort is thickening and seems to be compacting as well, plus there is almost no gyre, I am guessing this is why it's not fracturing, while all the old ice in the CAB is tearing apart and spilling down the Fram.
I wonder if the Beaufort will manage to start late this year - I doubt it but it's becoming a possibility. Might balance the Beaufort's lack of MYI and high vulnerability to early meltout.

seaicesailor

  • Guest
Re: The 2017 melting season
« Reply #465 on: March 28, 2017, 05:47:11 PM »
If PIOMAS captures well all the melting that has been going on west of Svalbard, I don't think the volume increase will be in the high range.

romett1

  • Frazil ice
  • Posts: 221
    • View Profile
  • Liked: 4
  • Likes Given: 0
Re: The 2017 melting season
« Reply #466 on: March 28, 2017, 06:37:50 PM »
If PIOMAS captures well all the melting that has been going on west of Svalbard, I don't think the volume increase will be in the high range.

What seemed to be a decent block 120 km long and about 50 km wide at widest point, disappeared in just couple of days. Of course it's not surprising, as the warm current has been there for a very long time.

seaicesailor

  • Guest
Re: The 2017 melting season
« Reply #467 on: March 28, 2017, 06:50:07 PM »
If PIOMAS captures well all the melting that has been going on west of Svalbard, I don't think the volume increase will be in the high range.

What seemed to be a decent block 120 km long and about 50 km wide at widest point, disappeared in just couple of days. Of course it's not surprising, as the warm current has been there for a very long time.
Yes, and I wonder how permanent this is (the warm currents this strong). Can the ice affect the currents somehow in short term? I would say no but locally they may force the salty water sink in a more southernly location permitting the ice pack extend more... or just the opposite reinforce them for this summer (after all more sinking is one of the engines that drives more water from South)
« Last Edit: March 28, 2017, 06:56:59 PM by seaicesailor »

JimboOmega

  • Frazil ice
  • Posts: 140
    • View Profile
  • Liked: 2
  • Likes Given: 0
Re: The 2017 melting season
« Reply #468 on: March 28, 2017, 08:48:49 PM »
It seems a little quiet today except in the ESS and the Bering Sea.


Are those melt ponds (in the ESS)? In March? It's been anomalously warm... but not that (above freezing) warm. Right?

Neven

  • Administrator
  • First-year ice
  • *****
  • Posts: 7017
    • View Profile
    • Arctic Sea Ice Blog
  • Liked: 600
  • Likes Given: 398
Re: The 2017 melting season
« Reply #469 on: March 28, 2017, 10:10:07 PM »
Here's an update to that animation of the sea ice retreat from the southwestern shore of Novaya Zemlya (Kara Sea). Things haven't moved much for the past couple of days, and things might stay that way for a while longer, as this region seems to remain in the centre of a low-pressure area for the coming week.
Il faut comparer, comparer, comparer, et cultiver notre jardin

Tor Bejnar

  • Young ice
  • Posts: 2908
    • View Profile
  • Liked: 252
  • Likes Given: 145
Re: The 2017 melting season
« Reply #470 on: March 29, 2017, 01:09:58 AM »
The longer that bit of water remains ice-free, the less likely ice will re-cover it, as
1) the open water is prone to solar gain
2) the end of the (local) freezing season approaches.

I'm sure the surface re-freezing remains a possibility, though.  (It's still cold out there!)
Arctic ice is healthy for children and other living things.

VeliAlbertKallio

  • Frazil ice
  • Posts: 145
    • View Profile
    • Sea Research Society (SRS)
  • Liked: 17
  • Likes Given: 37
Re: The 2017 melting season
« Reply #471 on: March 29, 2017, 01:17:37 AM »
As per animation, the continued southward drift from the Baffin Bay remains one of the sea ice leaking points from the Arctic joining the Fram Strait, the Barentz Sea and the Kara Sea for rapid and early loss of sea ice. The Baffin Bay sea ice loss contribution may not be continuous, but it impacts the onset of darkening and melting of Greenland once sun gets stronger. It suggests me that the area is rapidly clearing from ice by sea ice transport - which is probably early.

ACNFS Hycom Sea ice drift predicted from today to Apr 2.
The situation reminds a bit to Spring 2014, with the ice drifting away from Laptev sea coasts persistently, and a lot of transport toward the Atlantic.

romett1

  • Frazil ice
  • Posts: 221
    • View Profile
  • Liked: 4
  • Likes Given: 0
Re: The 2017 melting season
« Reply #472 on: March 29, 2017, 11:54:57 AM »
Latest GFS anomalies until next Wednesday (Climate Reanalyzer). Added 5-day forecast, which is still red all the way from Kara Sea to Beaufort.

iceman

  • Frazil ice
  • Posts: 282
    • View Profile
  • Liked: 6
  • Likes Given: 17
Re: The 2017 melting season
« Reply #473 on: March 29, 2017, 12:13:14 PM »
The longer that bit of water remains ice-free, the less likely ice will re-cover it, as
1) the open water is prone to solar gain
2) the end of the (local) freezing season approaches.

I'm sure the surface re-freezing remains a possibility, though.  (It's still cold out there!)

I question whether the insolation anomaly in Kara is greater than the heat loss from open water to atmosphere.  If the latter is especially large, any refreeze could persist longer than usual.
     In contrast, the low ice cover in Okhotsk looks to heavily favor insolation at that lower latitude and this time of year.  But the excess heat gain there won't have much effect on the central Arctic.

Tor Bejnar

  • Young ice
  • Posts: 2908
    • View Profile
  • Liked: 252
  • Likes Given: 145
Re: The 2017 melting season
« Reply #474 on: March 29, 2017, 12:46:20 PM »
Thanks, iceman, for adding that important piece of the puzzle.
Arctic ice is healthy for children and other living things.

Neven

  • Administrator
  • First-year ice
  • *****
  • Posts: 7017
    • View Profile
    • Arctic Sea Ice Blog
  • Liked: 600
  • Likes Given: 398
Re: The 2017 melting season
« Reply #475 on: March 29, 2017, 02:06:53 PM »
Slightly more movement in the past two days in the Kara...
Il faut comparer, comparer, comparer, et cultiver notre jardin

oren

  • Young ice
  • Posts: 4173
    • View Profile
  • Liked: 670
  • Likes Given: 1190
Re: The 2017 melting season
« Reply #476 on: March 29, 2017, 05:33:24 PM »
Latest GFS anomalies until next Wednesday (Climate Reanalyzer). Added 5-day forecast, which is still red all the way from Kara Sea to Beaufort.
romett1, thanks for posting the GFS anomalies+forecast. It seems that every time I look at the table the forecast a few days out shows the anomaly lessening. But every time you post an update the anomaly stays high. Is it just my imagination? Or is the GFS underestimating the forecast anomaly?

romett1

  • Frazil ice
  • Posts: 221
    • View Profile
  • Liked: 4
  • Likes Given: 0
Re: The 2017 melting season
« Reply #477 on: March 29, 2017, 06:11:45 PM »
Latest GFS anomalies until next Wednesday (Climate Reanalyzer). Added 5-day forecast, which is still red all the way from Kara Sea to Beaufort.
romett1, thanks for posting the GFS anomalies+forecast. It seems that every time I look at the table the forecast a few days out shows the anomaly lessening. But every time you post an update the anomaly stays high. Is it just my imagination? Or is the GFS underestimating the forecast anomaly?

I have noticed same thing. I guess they are slightly conservative about days 6 and 7 and updating higher, when they feel more confident.
I hope the table is useful for forum readers, I was bit worried about CFS April - May long-term forecast (posted by FishOutofWater).

Lord M Vader

  • Nilas ice
  • Posts: 1248
    • View Profile
  • Liked: 18
  • Likes Given: 15
Re: The 2017 melting season
« Reply #478 on: March 29, 2017, 06:13:37 PM »
Not only is there movement in Kara, but also in the ice export through FJL and Fram. The remaining thick ice will be under fire for a while!

Tigertown

  • Nilas ice
  • Posts: 1647
    • View Profile
  • Liked: 2
  • Likes Given: 0
Re: The 2017 melting season
« Reply #479 on: March 29, 2017, 06:19:21 PM »
Latest GFS anomalies until next Wednesday (Climate Reanalyzer). Added 5-day forecast, which is still red all the way from Kara Sea to Beaufort.
romett1, thanks for posting the GFS anomalies+forecast. It seems that every time I look at the table the forecast a few days out shows the anomaly lessening. But every time you post an update the anomaly stays high. Is it just my imagination? Or is the GFS underestimating the forecast anomaly?
One concern, which may or may not have a bearing on the matter:
I think they take the average from the whole Arctic circle, which can be a little deceptive. You might find a +20oC anomaly in an area over the ocean and sea ice, but it might be really cold in another area, which could even be over land. This drops the average, which then fails to represent how detrimental the anomaly is to the ice. A good fix is posting the map along with the table. Neven is always pointing out that there are many people dropping in on this thread, so it is especially good for them to comprehend this, as I am sure the regulars here don't need it to be explained. BTW, good job romett1.

JimboOmega

  • Frazil ice
  • Posts: 140
    • View Profile
  • Liked: 2
  • Likes Given: 0
Re: The 2017 melting season
« Reply #480 on: March 29, 2017, 06:47:28 PM »
When it comes to these temperature anomalies... which I've been watching since at least November... I really have to wonder how much they matter this time of year (over ice, in particular).

If there's a patch of the arctic where normally it is -40 C/F, but instead due to huge anomalies it is -10 C, so what? It doesn't melt, melt ponds don't happen... I feel like the thermodynamics don't change...  until it gets above freezing.

Do we expect anything to come of these high anomalies, where temperatures still stay below freezing?

Peter Ellis

  • Grease ice
  • Posts: 616
    • View Profile
  • Liked: 33
  • Likes Given: 10
Re: The 2017 melting season
« Reply #481 on: March 29, 2017, 06:56:39 PM »
Yes, ice fails to thicken as much as normal if the temperature is not low enough.

DrTskoul

  • Nilas ice
  • Posts: 1402
    • View Profile
  • Liked: 175
  • Likes Given: 59
Re: The 2017 melting season
« Reply #482 on: March 29, 2017, 07:47:54 PM »
When it comes to these temperature anomalies... which I've been watching since at least November... I really have to wonder how much they matter this time of year (over ice, in particular).

If there's a patch of the arctic where normally it is -40 C/F, but instead due to huge anomalies it is -10 C, so what? It doesn't melt, melt ponds don't happen... I feel like the thermodynamics don't change...  until it gets above freezing.

Do we expect anything to come of these high anomalies, where temperatures still stay below freezing?

Heat flux out of the ice ( if we assume linear force formulation -  flux proportional to ΔT) is a quarter roughly compare to normal... it takes four times as long to thicken at the same level..

Lord M Vader

  • Nilas ice
  • Posts: 1248
    • View Profile
  • Liked: 18
  • Likes Given: 15
Re: The 2017 melting season
« Reply #483 on: March 29, 2017, 07:56:13 PM »
While this stuff might belong to the frezzing thread, I think it's a valuable view for the upcoming melting season.

Here is Zack Labe's tweet from today which shows how the temperature anomalies for October to December have evolved from 1979 and onward. Hat tip to him! :) I think we'll see a shift in the future to March being the coldest month during winter as polar amplification will continue and worsen.


Andre

  • New ice
  • Posts: 59
    • View Profile
  • Liked: 0
  • Likes Given: 0
Re: The 2017 melting season
« Reply #484 on: March 29, 2017, 08:24:26 PM »
romett1, thanks for posting the GFS anomalies+forecast. It seems that every time I look at the table the forecast a few days out shows the anomaly lessening. But every time you post an update the anomaly stays high. Is it just my imagination? Or is the GFS underestimating the forecast anomaly?

Fully agreed! I really enjoy your regular contribution romett1 and hope you will keep it up. It is easy to lose sight of the daily values, when watching the animation, which makes me appreciate your concise table format even more! Thanks for the regular updates!

jdallen

  • Young ice
  • Posts: 3003
    • View Profile
  • Liked: 174
  • Likes Given: 168
Re: The 2017 melting season
« Reply #485 on: March 29, 2017, 11:16:58 PM »
When it comes to these temperature anomalies... which I've been watching since at least November... I really have to wonder how much they matter this time of year (over ice, in particular).

If there's a patch of the arctic where normally it is -40 C/F, but instead due to huge anomalies it is -10 C, so what? It doesn't melt, melt ponds don't happen... I feel like the thermodynamics don't change...  until it gets above freezing.

Do we expect anything to come of these high anomalies, where temperatures still stay below freezing?

Heat flux out of the ice ( if we assume linear force formulation -  flux proportional to ΔT) is a quarter roughly compare to normal... it takes four times as long to thicken at the same level..


... presuming enthalpy remains constant.  The problem is, we have heat flow from depth, such that below a given temperature threshold, the ice won't thicken at all, because heat is replenished at the water/ice interface faster than it can be transferred out of the ice to atmosphere.  At -10C, ice more than 1M thick will actually start melting from the bottom, given enough time.
This space for Rent.

Neven

  • Administrator
  • First-year ice
  • *****
  • Posts: 7017
    • View Profile
    • Arctic Sea Ice Blog
  • Liked: 600
  • Likes Given: 398
Re: The 2017 melting season
« Reply #486 on: March 29, 2017, 11:43:52 PM »
Do we expect anything to come of these high anomalies, where temperatures still stay below freezing?

Yes, earlier melt onset due to downwelling longwave radiation (see here). Or pre-pre-conditioning, as sea ice sailor called it earlier today (half-kiddingly, but aptly).
Il faut comparer, comparer, comparer, et cultiver notre jardin

DrTskoul

  • Nilas ice
  • Posts: 1402
    • View Profile
  • Liked: 175
  • Likes Given: 59
Re: The 2017 melting season
« Reply #487 on: March 29, 2017, 11:53:18 PM »
When it comes to these temperature anomalies... which I've been watching since at least November... I really have to wonder how much they matter this time of year (over ice, in particular).

If there's a patch of the arctic where normally it is -40 C/F, but instead due to huge anomalies it is -10 C, so what? It doesn't melt, melt ponds don't happen... I feel like the thermodynamics don't change...  until it gets above freezing.

Do we expect anything to come of these high anomalies, where temperatures still stay below freezing?

Heat flux out of the ice ( if we assume linear force formulation -  flux proportional to ΔT) is a quarter roughly compare to normal... it takes four times as long to thicken at the same level..


... presuming enthalpy remains constant.  The problem is, we have heat flow from depth, such that below a given temperature threshold, the ice won't thicken at all, because heat is replenished at the water/ice interface faster than it can be transferred out of the ice to atmosphere.  At -10C, ice more than 1M thick will actually start melting from the bottom, given enough time.

The implicit assumption was the bottom was at equilibrium... if not then absolutely it can melt. The same way that ice does not initially form until air temperature is below -10...

dosibl

  • New ice
  • Posts: 42
    • View Profile
  • Liked: 2
  • Likes Given: 0
Re: The 2017 melting season
« Reply #488 on: March 30, 2017, 12:06:36 AM »
I've been watching the Hycom CICE thickness plots (https://www7320.nrlssc.navy.mil/hycomARC/arctic.html) while I wait for the next PIOMAS update, so I decided to download all the images and try to extract some data from them.

For each day I get the total number of colored pixels, as well as the thickness associated with that color (ranging from 0 to 5 meters). With those numbers its pretty straightforward to graph total thickness as well as average thickness.

Right now the numbers are for all ice shown in the image, I'm hoping to eventually produce the numbers by region, I'm particularly interested to see the overall percentage of ice that is in the Fram.

misfratz

  • New ice
  • Posts: 35
    • View Profile
  • Liked: 1
  • Likes Given: 0
Re: The 2017 melting season
« Reply #489 on: March 30, 2017, 12:32:58 AM »
Latest GFS anomalies until next Wednesday (Climate Reanalyzer). Added 5-day forecast, which is still red all the way from Kara Sea to Beaufort.
romett1, thanks for posting the GFS anomalies+forecast. It seems that every time I look at the table the forecast a few days out shows the anomaly lessening. But every time you post an update the anomaly stays high. Is it just my imagination? Or is the GFS underestimating the forecast anomaly?
I have noticed same thing. I guess they are slightly conservative about days 6 and 7 and updating higher, when they feel more confident.
I hope the table is useful for forum readers, I was bit worried about CFS April - May long-term forecast (posted by FishOutofWater).
Just a note about the forecast - these figures will be purely from the model, with no human intervention, so it's not a matter of the human forecasters becoming more confident.

If the model has a climatological bias to colder temperatures then you would expect that to become established during the course of the forecast. An example of the sort of thing would be if, say, the cloud forcing was too strong to produce too much cooling. It will take a few days for the model to diverge from the reality of the initial conditions to its biased model climatology.

Normally modelling groups publish papers on major model upgrades, so you might be able to find out whether this model has a climatological cold bias over the Arctic.

ipexnet

  • New ice
  • Posts: 5
    • View Profile
  • Liked: 0
  • Likes Given: 0
Re: The 2017 melting season
« Reply #490 on: March 30, 2017, 01:17:36 AM »
When it comes to these temperature anomalies... which I've been watching since at least November... I really have to wonder how much they matter this time of year (over ice, in particular).

If there's a patch of the arctic where normally it is -40 C/F, but instead due to huge anomalies it is -10 C, so what? It doesn't melt, melt ponds don't happen... I feel like the thermodynamics don't change...  until it gets above freezing.

Do we expect anything to come of these high anomalies, where temperatures still stay below freezing?

More Energy = Less Ice

LRC1962

  • Frazil ice
  • Posts: 431
    • View Profile
  • Liked: 5
  • Likes Given: 1
Re: The 2017 melting season
« Reply #491 on: March 30, 2017, 02:08:08 AM »
When it comes to these temperature anomalies... which I've been watching since at least November... I really have to wonder how much they matter this time of year (over ice, in particular).

If there's a patch of the arctic where normally it is -40 C/F, but instead due to huge anomalies it is -10 C, so what? It doesn't melt, melt ponds don't happen... I feel like the thermodynamics don't change...  until it gets above freezing.

Do we expect anything to come of these high anomalies, where temperatures still stay below freezing?

More Energy = Less Ice
A simple mind example. Take 2 freezers and 2 cows. Set one freezer at -10 and one at -40. Put one cow (both same size and weight) in each freezer. The cow in the freezer set at -10 will take much longer to freeze and even when it is totally frozen, a much shorter time to thaw then the one set at -40.
Now the Arctic is a much more complex system then a freezer because you have a lot of kinetic energy involved also, but I do think that does help get the point across that you can be frozen and then you can be really frozen.
"All truth passes through three stages: First, it is ridiculed; Second,  it is violently opposed; and Third, it is accepted as self-evident."
       - Arthur Schopenhauer

Shared Humanity

  • Young ice
  • Posts: 3813
    • View Profile
  • Liked: 316
  • Likes Given: 37
Re: The 2017 melting season
« Reply #492 on: March 30, 2017, 02:34:02 AM »
When it comes to these temperature anomalies... which I've been watching since at least November... I really have to wonder how much they matter this time of year (over ice, in particular).

If there's a patch of the arctic where normally it is -40 C/F, but instead due to huge anomalies it is -10 C, so what? It doesn't melt, melt ponds don't happen... I feel like the thermodynamics don't change...  until it gets above freezing.

Do we expect anything to come of these high anomalies, where temperatures still stay below freezing?

More Energy = Less Ice

Simple and to the point.

subgeometer

  • Frazil ice
  • Posts: 338
    • View Profile
    • All in the Name of Liberty
  • Liked: 90
  • Likes Given: 63
Re: The 2017 melting season
« Reply #493 on: March 30, 2017, 04:04:57 AM »
These cracks or shears or whatever are spreading and getting worse. They have no respect for the NP region either. Only the the thick, robust, durable, mighty, 93 cm ice in the Beaufort stands a chance against these. ;)


Hee''s an animation of the ESS from March 11-29 where the Bremen Thin Ice map at https://seaice.uni-bremen.de/thin-ice-thickness/ has been showing a persistent region of thin ice. Despite the ice pushing away from the Eurasian coast it's not apparently thickening up much else where, and the ongoing heatwave on the Eusaian side will not allow much new ice growth

Tigertown

  • Nilas ice
  • Posts: 1647
    • View Profile
  • Liked: 2
  • Likes Given: 0
Re: The 2017 melting season
« Reply #494 on: March 30, 2017, 04:55:13 AM »
JAXA volume sitting all alone now for this year, well below former years. This chart has been trending about 1,000 to 1,200 km3 below PIOMAS. I am sure we are all looking forward to the next PIOMAS update, though maybe a little anxiously.

Tigertown

  • Nilas ice
  • Posts: 1647
    • View Profile
  • Liked: 2
  • Likes Given: 0
Re: The 2017 melting season
« Reply #495 on: March 30, 2017, 05:55:51 AM »
So much for no cracks in the Beaufort.(first pic.)
BTW: Finally got that hole at the NP fixed.(second pic.)  ;)

jdallen

  • Young ice
  • Posts: 3003
    • View Profile
  • Liked: 174
  • Likes Given: 168
« Last Edit: March 30, 2017, 08:03:48 AM by jdallen »
This space for Rent.


romett1

  • Frazil ice
  • Posts: 221
    • View Profile
  • Liked: 4
  • Likes Given: 0
Re: The 2017 melting season
« Reply #498 on: March 30, 2017, 09:41:01 AM »
Thanks for the good words. Latest GFS anomalies until next Thursday (Climate Reanalyzer).
Added 5-day forecast, still red all the way from Kara Sea to Beaufort.
Also noticed that Kara Sea near Novaya Zemlya (where there is open water) is quite windy Mar 30 - Apr 6.

Tigertown

  • Nilas ice
  • Posts: 1647
    • View Profile
  • Liked: 2
  • Likes Given: 0
Re: The 2017 melting season
« Reply #499 on: March 30, 2017, 04:42:31 PM »
The Bering Sea ice has been holding the extent up for a while now, even inflating it some, but is getting really thin and dispersed now.
CLICK IMAGE PLEASE