Support the Arctic Sea Ice Forum and Blog

Author Topic: The 2015 melting season  (Read 1825422 times)

Shared Humanity

  • Guest
Re: The 2015 melting season
« Reply #1850 on: July 06, 2015, 03:03:27 PM »
I am certainly not going to weigh in on which is more accurate but have these two models (Piomass and DMI) diverged to this extent in the past? If not, this is very likely due to the fact that some of the model assumptions are breaking down as a result of the entirely new regime in the cryosphere. This could be happening to either or perhaps both of the models.

Nick_Naylor

  • Frazil ice
  • Posts: 291
    • View Profile
  • Liked: 0
  • Likes Given: 0
Re: The 2015 melting season
« Reply #1851 on: July 06, 2015, 03:29:55 PM »
I wonder why bottom ~half of the picture was not transmitted.

I think I can see why they didn't show the full image . . .

F.Tnioli

  • Grease ice
  • Posts: 767
    • View Profile
  • Liked: 148
  • Likes Given: 36
Re: The 2015 melting season
« Reply #1852 on: July 06, 2015, 03:31:53 PM »
I am certainly not going to weigh in on which is more accurate but have these two models (Piomass and DMI) diverged to this extent in the past? If not, this is very likely due to the fact that some of the model assumptions are breaking down as a result of the entirely new regime in the cryosphere. This could be happening to either or perhaps both of the models.
Answer to your question was given by me in this very topic, today. Given that 2012 was quite unusual year with tons of melt overall, your assumption sounds only more reasonable, to me.

And one more strange thing about this year's massive disagreement between PIOMASS and DMI. Previous four years, despite all bumps and weathers, i see very fine agreement between those systems in terms of "places" for June melt. I.e., the year with most June melt is the same year in both models, the year with least mealt - the same, and all in between. Except this year, that is. Look:

ASI June volume loss, x1000 km^3:
2011: PIOMASS 6,7; DMI 8,7
2012: PIOMASS 7,3; DMI 10,4
2013: PIOMASS 6,6; DMI 8,0
2014: PIOMASS 5,7; DMI 6,4

I.e., 2012 is most ice lost, 2nd-most is 2011, 3rd-most is 2013, and least ice lost is 2014 - all that in BOTH models. But now we get:

2015: PIOMASS 6,2; DMI 9,2

Which is 4th place out of five years in PIOMASS, but 2nd place in DMI. This is exactly what i was talking few pages ago: models can have all sorts of varying assumptions, but usually their behaviour over time about reflecting one and same physical process - correlates in many detectable ways. This year's June, it doesn't. Which is why i said someone went nuts in either PIOMASS or DMI. That's of course figurative. Perhaps data is damaged within one of them, or there is intended unfair play, etc.

I hope, Neven, you do respect my dropped pants a tiny bit more now. :) There is logic in here observation, and i suspect you see it easily.
« Last Edit: July 06, 2015, 04:04:09 PM by F.Tnioli »
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!

Nightvid Cole

  • Frazil ice
  • Posts: 437
    • View Profile
  • Liked: 5
  • Likes Given: 0
Re: The 2015 melting season
« Reply #1853 on: July 06, 2015, 04:32:12 PM »
I wonder why bottom ~half of the picture was not transmitted.

I think I can see why they didn't show the full image . . .

Nice...

Neven

  • Administrator
  • First-year ice
  • Posts: 7756
    • View Profile
    • Arctic Sea Ice Blog
  • Liked: 1133
  • Likes Given: 521
Re: The 2015 melting season
« Reply #1854 on: July 06, 2015, 04:50:49 PM »
I hope, Neven, you do respect my dropped pants a tiny bit more now. :) There is logic in here observation, and i suspect you see it easily.

Why don't you keep your pants on, research some more, and then ask questions? Maybe the DMI model covers a larger region than PIOMAS for instance (hence the higher volume). PIOMAS is constrained by observations, how about the DMI model? Etc, etc...

I'm not very interested in difference between models. I'm interested in the difference between individual years, in any model or dataset, whether that be volume, concentration, temp, SLP, and so on.
Il faut comparer, comparer, comparer, et cultiver notre jardin

jdallen

  • Young ice
  • Posts: 3248
    • View Profile
  • Liked: 525
  • Likes Given: 206
Re: The 2015 melting season
« Reply #1855 on: July 06, 2015, 05:38:17 PM »
Two days from now...

1030-1035 hPa is serious shit. This melting season is simply 2014+heat. And now major insolation as well. I don't know, could this kill the 'rebound'?
As you said elsewhere, Neven, it does look like 2014 with heat; lots of it.  I recall last year around this time we were pretty disturbed by how things looked as well, and there was some discussion whether or not we were going to see a 2012 - level melt off.  Thankfully (I and others were wrong, and...), weather came to the rescue of the pack.

"Napkin-back" calculation suggests enough heat left after albedo loss to strip off 6CM of ice a day, more or less.  Bottom melt will be bonus.

Now it's just grinding out the time - just under half a meter of ice a week, more or less, as long as these conditions persist.

Lots of ice all across the Arctic is currently below 1.5M in thickness; possibly over half of it.

If this pattern persists, by the end of July we should see most of the pack as a discontinuous bowl of MYI ice cubes trying to resist the pounding its getting.

I wonder if this is the new pattern?
This space for Rent.

Laurent

  • Young ice
  • Posts: 2538
    • View Profile
  • Liked: 6
  • Likes Given: 35
Re: The 2015 melting season
« Reply #1856 on: July 06, 2015, 05:42:43 PM »
Comparing Hycom GLB and the reality (today)
It seems to me that it may be correct ! we will see that very soon...
The high pressure will favour Fram export and melt everywhere...
I am not playing the poll game because I just don't know what the result will be, we are living a tremendous moment if it is "The year"  (even if it is not) so let's enjoy the moment and gather all the data's available. We are not in the Arctic to see it but still, breath intently enjoy being alive, watch and share what is going on. It may not be this year, anyway I have no doubt it would be too fast and too soon.

mati

  • Frazil ice
  • Posts: 268
    • View Profile
  • Liked: 1
  • Likes Given: 0
Re: The 2015 melting season
« Reply #1857 on: July 06, 2015, 05:59:51 PM »
Svalbard - 16 C today :)
http://www.wunderground.com/personal-weather-station/dashboard?ID=ILONGYEA2

West coast of greenland - 16 C today :)
http://www.wunderground.com/personal-weather-station/dashboard?ID=IVESTGRN3

North CAB - alert - only 9C today
http://weather.gc.ca/city/pages/nu-22_metric_e.html

hudsons bay - attawapiskat - 18C
http://www.wunderground.com/personal-weather-station/dashboard?ID=MSWUIMNRAPT

(just cause i like every chance i get to say ottawapisscat)

Looks like the heat is on!!!!

EDIT: holy crap it was 17.3 C in alert yesterday???
and so it goes

ChrisReynolds

  • Nilas ice
  • Posts: 1714
    • View Profile
    • Dosbat
  • Liked: 1
  • Likes Given: 0
Re: The 2015 melting season
« Reply #1858 on: July 06, 2015, 07:58:57 PM »
JD Allen, Laurent,

I'm holding out hope that I'm wrong this year and we're about to see a big crash, or at least between 2007 and 2012. I've been watching Bremen AMSR2, and for the last 15 days there has been repeated appearance of low concentration (greys) across the Pacific half of the pack. Right where HYCOM-Arctic and PIOMAS show a lot of thinning over this month. Frankly though I find HYCOM-Global to be rather unbelievable.

Against the idea of a massive loss this year is the PIOMAS spring volume loss. I have calculated this using average anomaly of volume for the 7 day average centred on 20 April, and the minimum volume anomaly for June, the spring volume loss is the loss between those two figures. Here are the PIOMAS spring volume losses since 2000.

2000   0.099
2001   -0.031
2002   0.072
2003   0.219
2004   0.420
2005   -0.308
2006   0.226
2007   -2.033
2008   -0.802
2009   -1.199
2010   -3.169
2011   -3.228
2012   -4.176
2013   -2.278
2014   -2.258
2015   -2.348

This year the spring volume loss is over, minimum anomaly was reached on 23 June, as usual shortly after the summer solstice. PIOMAS volume losses for the rest of the season will be at less than average rate for the rest of the summer.

I think that the spring volume loss is the same process that causes the rapid early collapse of ice in the PIOMAS -1m experiment. The main driver being thinner ice in the Central Arctic with non negligible roles for Beaufort to Kara.

plinius

  • Frazil ice
  • Posts: 403
    • View Profile
  • Liked: 0
  • Likes Given: 0
Re: The 2015 melting season
« Reply #1859 on: July 07, 2015, 12:02:47 AM »
Concerning the navo/hycom/GLB/CICE issue:

As neven noticed earlier, there seems some weird boundary in the ice at 80 latitude.
Well, if you have a look at the sea surface salinity:
http://www7320.nrlssc.navy.mil/hycomARC/navo/arcticsss_nowcast_anim30d.gif

I would say that this is proof enough that something is going badly wrong in their code/assumptions. I'd suspect something going wrong in their radiation balance, perhaps some approximation on the day cycle?

One a side-not - nice finger of salty warm water penetrating into the Chukchi. If the ice does not melt out before that, it will wipe out the ice on its path.

seaicesailor

  • Guest
Re: The 2015 melting season
« Reply #1860 on: July 07, 2015, 04:56:22 AM »

Oops
How many 100s in area?

Frivolousz21

  • Nilas ice
  • Posts: 1845
  • Live in Belleville, IL..15 miles SE of St. Louis.
    • View Profile
  • Liked: 550
  • Likes Given: 6
Re: The 2015 melting season
« Reply #1861 on: July 07, 2015, 07:23:32 AM »
2013/14 is not close to 2015.

I look forward to a full clear scan of the Pacific side this week.

Regardless the point stands.

The animation below shows this.






And it's not even close.


Only 2012 had this kind of warmth during the first half of July.




This is going to end up a big time volume loss season.
I got a nickname for all my guns
a Desert Eagle that I call Big Pun
a two shot that I call Tupac
and a dirty pistol that love to crew hop
my TEC 9 Imma call T-Pain
my 3-8 snub Imma call Lil Wayne
machine gun named Missy so loud
it go e-e-e-e-ow e-e-e-e-e-e-blaow

oren

  • Moderator
  • First-year ice
  • Posts: 6313
    • View Profile
  • Liked: 2319
  • Likes Given: 1964
Re: The 2015 melting season
« Reply #1862 on: July 07, 2015, 07:56:18 AM »
Interesting to note that both 2013 and 2014 had Baffin and Hudson clear by this time, in spite of their poor melt elsewhere.

seaicesailor

  • Guest
Re: The 2015 melting season
« Reply #1863 on: July 07, 2015, 09:10:09 AM »
There is a lot of fire smoke over Chukchi. Can this be fooling the satellite into thinking there is lower concentration?

Anyway, the amount of smoke from record for in Alaska and Canada is impressive. It covers an area equivalent to Germany or so.

johnm33

  • Guest
Re: The 2015 melting season
« Reply #1864 on: July 07, 2015, 09:32:53 AM »
Concerning the navo/hycom/GLB/CICE issue:

As neven noticed earlier, there seems some weird boundary in the ice at 80 latitude.
Well, if you have a look at the sea surface salinity:
http://www7320.nrlssc.navy.mil/hycomARC/navo/arcticsss_nowcast_anim30d.gif

I would say that this is proof enough that something is going badly wrong in their code/assumptions. I'd suspect something going wrong in their radiation balance, perhaps some approximation on the day cycle?

One a side-not - nice finger of salty warm water penetrating into the Chukchi. If the ice does not melt out before that, it will wipe out the ice on its path.
Perhaps it's just energetically easier for the water to accelerate east and disappear through Peary channel [approx 80degN], and the archipelago generally, than for it to decelerate the 30kph per degree as it moves north. That less saline water has been flowing through to Hudson/Baffin all winter, through all available channels, maybe it has established a certain amount of inertia by now?
edit. It'll be interesting to see if that line moves north when the Nares arch finally breaks.
« Last Edit: July 07, 2015, 09:56:17 AM by johnm33 »

F.Tnioli

  • Grease ice
  • Posts: 767
    • View Profile
  • Liked: 148
  • Likes Given: 36
Re: The 2015 melting season
« Reply #1865 on: July 07, 2015, 09:36:35 AM »
...
I'm not very interested in difference between models. I'm interested in the difference between individual years, in any model or dataset, whether that be volume, concentration, temp, SLP, and so on.
So am i. However, in this June's volume loss case, PIOMASS says that this year is "nothing special", some 4th place outta 5 last years, rather close to 5th and 3rd with that. While DMI says it's a special year, 2nd outta 5 last years, rather far from 3rd with that. Big-time melt.

So tell me, if you're interested - quote - in the difference between individual years, in _any_ model, - then does it mean you're interested in DMI data for this June? Because if i read this literally, you are. Thing is, i have the feeling you are not. Their "weather" model being "wrong" for ice volume, or is it something else, or is my feeling incorrect? I'm quite lost here...
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!

Neven

  • Administrator
  • First-year ice
  • Posts: 7756
    • View Profile
    • Arctic Sea Ice Blog
  • Liked: 1133
  • Likes Given: 521
Re: The 2015 melting season
« Reply #1866 on: July 07, 2015, 10:42:59 AM »
So tell me, if you're interested - quote - in the difference between individual years, in _any_ model, - then does it mean you're interested in DMI data for this June? Because if i read this literally, you are. Thing is, i have the feeling you are not. Their "weather" model being "wrong" for ice volume, or is it something else, or is my feeling incorrect? I'm quite lost here...

I can't pay attention to everything, and I simply don't know how trustworthy DMI volume is, as I believe it's new and I have no idea what they're doing to come up with those modelled volume estimates.

There's a difference between PIOMAS and DMI modelled volume? Fine. Noted. Now, let's see how things play out, and then maybe next time we'll be able to better attribute reliability.
Il faut comparer, comparer, comparer, et cultiver notre jardin

plinius

  • Frazil ice
  • Posts: 403
    • View Profile
  • Liked: 0
  • Likes Given: 0
Re: The 2015 melting season
« Reply #1867 on: July 07, 2015, 10:54:18 AM »
Perhaps it's just energetically easier for the water to accelerate east and disappear through Peary channel [approx 80degN], and the archipelago generally, than for it to decelerate the 30kph per degree as it moves north. That less saline water has been flowing through to Hudson/Baffin all winter, through all available channels, maybe it has established a certain amount of inertia by now?
edit. It'll be interesting to see if that line moves north when the Nares arch finally breaks.

If you look at this again:
http://www7320.nrlssc.navy.mil/hycomARC/navo/arcticsss_nowcast_anim30d.gif

There is a perfect, circled boundary in the salinity near the end of the simulation. No way that this is caused by some natural current - those would be far slower and certainly not perfectly aligned with the 80 degree line (Coriolis forces by the way deflect _any_ current, so even if you had initially something flowing due west or east it would experience a force bending it south or north).
Must be something in the assumptions on melt.

Jim Hunt

  • Young ice
  • Posts: 4744
  • Stay Home, Save Lives
    • View Profile
    • The Arctic sea ice Great White Con
  • Liked: 507
  • Likes Given: 44
Re: The 2015 melting season
« Reply #1868 on: July 07, 2015, 10:56:04 AM »
Anyone for a swim? There's lots of open water where IMB 2015B used to be:

http://GreatWhiteCon.info/resources/arctic-sea-ice-images/summer-2015-images/#2015B
Reality is merely an illusion, albeit a very persistent one - Albert Einstein

seaicesailor

  • Guest
Re: The 2015 melting season
« Reply #1869 on: July 07, 2015, 11:24:39 AM »
Anyone for a swim? There's lots of open water where IMB 2015B used to be:



There is some haze visible from Canada and Alaska fires too.

Andreas T

  • Nilas ice
  • Posts: 1143
    • View Profile
  • Liked: 17
  • Likes Given: 4
Re: The 2015 melting season
« Reply #1870 on: July 07, 2015, 11:26:13 AM »
more open water can be seen in the vicinity from a higher vantage point. Location is IMB2015B from 5.7. (latest update)
 image is 6.7. (closest clear view) though less clear than today
« Last Edit: July 07, 2015, 11:33:10 AM by Andreas T »

johnm33

  • Guest
Re: The 2015 melting season
« Reply #1871 on: July 07, 2015, 11:55:04 AM »
Perhaps it's just energetically easier for the water to accelerate east and disappear through Peary channel [approx 80degN], and the archipelago generally, than for it to decelerate the 30kph per degree as it moves north. That less saline water has been flowing through to Hudson/Baffin all winter, through all available channels, maybe it has established a certain amount of inertia by now?
edit. It'll be interesting to see if that line moves north when the Nares arch finally breaks.

If you look at this again:
http://www7320.nrlssc.navy.mil/hycomARC/navo/arcticsss_nowcast_anim30d.gif

There is a perfect, circled boundary in the salinity near the end of the simulation. No way that this is caused by some natural current - those would be far slower and certainly not perfectly aligned with the 80 degree line (Coriolis forces by the way deflect _any_ current, so even if you had initially something flowing due west or east it would experience a force bending it south or north).
Must be something in the assumptions on melt.
Idealised the flow probably looks like a chain from above and a series of face down ps looping along, edgeways on, but given other forces at work more likely similar to the vortices on the far left of this


Frivolousz21

  • Nilas ice
  • Posts: 1845
  • Live in Belleville, IL..15 miles SE of St. Louis.
    • View Profile
  • Liked: 550
  • Likes Given: 6
Re: The 2015 melting season
« Reply #1872 on: July 07, 2015, 12:03:22 PM »
Every water entry point into the basin is now above normal. 

With explosive warmth being thrusted into the pacific side of the pack with Sun and epic WAA.






Truly near record warm airmass plunging into the central arctic. 






The ice is in really awful shape over a huge area of the Pacific side.

With concentrations running around 50%.  Half of the surface area is ocean.  Which equals very low albedo and huge energy uptake.
I got a nickname for all my guns
a Desert Eagle that I call Big Pun
a two shot that I call Tupac
and a dirty pistol that love to crew hop
my TEC 9 Imma call T-Pain
my 3-8 snub Imma call Lil Wayne
machine gun named Missy so loud
it go e-e-e-e-ow e-e-e-e-e-e-blaow

Frivolousz21

  • Nilas ice
  • Posts: 1845
  • Live in Belleville, IL..15 miles SE of St. Louis.
    • View Profile
  • Liked: 550
  • Likes Given: 6
Re: The 2015 melting season
« Reply #1873 on: July 07, 2015, 01:30:29 PM »
There is a lot of fire smoke over Chukchi. Can this be fooling the satellite into thinking there is lower concentration?

Anyway, the amount of smoke from record for in Alaska and Canada is impressive. It covers an area equivalent to Germany or so.

No.

I got a nickname for all my guns
a Desert Eagle that I call Big Pun
a two shot that I call Tupac
and a dirty pistol that love to crew hop
my TEC 9 Imma call T-Pain
my 3-8 snub Imma call Lil Wayne
machine gun named Missy so loud
it go e-e-e-e-ow e-e-e-e-e-e-blaow

Frivolousz21

  • Nilas ice
  • Posts: 1845
  • Live in Belleville, IL..15 miles SE of St. Louis.
    • View Profile
  • Liked: 550
  • Likes Given: 6
Re: The 2015 melting season
« Reply #1874 on: July 07, 2015, 01:44:19 PM »
 :P
Anyone for a swim? There's lots of open water where IMB 2015B used to be:

http://GreatWhiteCon.info/resources/arctic-sea-ice-images/summer-2015-images/#2015B

Wow that's at 76-77N.

Thats awful.  That has to be at least 3-4 miles wide.

And that water has small wave action.

Enough to keep the heat incoming moving into ice from the open water.

Currently a nasty fetch of 2-3C temps are plowing the Pacific side.

« Last Edit: July 07, 2015, 01:57:31 PM by Frivolousz21 »
I got a nickname for all my guns
a Desert Eagle that I call Big Pun
a two shot that I call Tupac
and a dirty pistol that love to crew hop
my TEC 9 Imma call T-Pain
my 3-8 snub Imma call Lil Wayne
machine gun named Missy so loud
it go e-e-e-e-ow e-e-e-e-e-e-blaow

Nightvid Cole

  • Frazil ice
  • Posts: 437
    • View Profile
  • Liked: 5
  • Likes Given: 0
Re: The 2015 melting season
« Reply #1875 on: July 07, 2015, 01:56:06 PM »
Ice concentration is now <85% across about half of the Arctic Ocean (horizontally scrollable image):

 

Buddy

  • Young ice
  • Posts: 3379
  • Go DUCKS!!
    • View Profile
  • Liked: 49
  • Likes Given: 34
Re: The 2015 melting season
« Reply #1876 on: July 07, 2015, 02:09:08 PM »
Quote
Ice concentration is now <85% across about half of the Arctic Ocean (horizontally scrollable image):

....And weakening QUICKLY over the past week.

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

Neven

  • Administrator
  • First-year ice
  • Posts: 7756
    • View Profile
    • Arctic Sea Ice Blog
  • Liked: 1133
  • Likes Given: 521
Re: The 2015 melting season
« Reply #1877 on: July 07, 2015, 02:16:58 PM »
I've summarized all the stuff here for the latest ASI update over on the blog: ASI 2015 update 4: massive heat.

Here's a close-up of the ECMWF forecast for the coming 6 days:



Below it I wrote:

Quote
In the last ASI update I said I use Caps Lock sparingly, but I'm going to use it again: This high-pressure area is HUGE, huge in size, huge in high pressure, huge in persistence. In fact, I can't remember many instances of an intense forecast like this one, and I've been watching the Arctic intently for 5 full years now. A HUGE part of the Arctic sea ice pack - and let's not forget the Greenland ice sheet (see this blog post by RobertScribbler) - is getting hit by a solar blast just two weeks after the solstice, and this will last days on end.
And the GFS temperature anomaly forecast:



Conclusion:

Quote
This melting season so far has been as slow as last year's, with little movement and transport of ice. But this time around there's much more heat in the system. The multi-year ice on the Pacific side of the Arctic has already had it tough so far, but is now suffering a major blow with open skies practically all over the Arctic bringing massive solar radiation and heat to the ice.

Unless weather conditions shift dramatically, I don't see how this year can end up as another rebound. In fact, if this keeps up, the uptick in volume and multi-year ice since 2012 will be obliterated. It is also looking increasingly likely that both the Northwestern Passage and the Northern Sea Route will open up this year.

But I'm getting ahead of myself, it's too soon to be drawing conclusions, with still two full months to go in this melting season. Nonetheless, I think it's safe to say there will be some hefty daily decreases in the coming week, which could be sustained for weeks to come if a lot of melting momentum is built up.

Enjoy the Arctic sea ice, it's the only Arctic sea ice you've got.
I didn't put in an animation of the SST anomalies in the past two weeks that shows the heat disappearing from and returning to the Pacific side of the Arctic, as well as a comparison with 2012, 2013 and 2014 around this time. That's the bonus below:
Il faut comparer, comparer, comparer, et cultiver notre jardin

Phil.

  • Frazil ice
  • Posts: 363
    • View Profile
  • Liked: 45
  • Likes Given: 1
Re: The 2015 melting season
« Reply #1878 on: July 07, 2015, 02:40:18 PM »
Anyone for a swim? There's lots of open water where IMB 2015B used to be:


From your images from buoy #9 I think I see ITB 59 in the distance sitting on top of some rubble ice.   :)

plinius

  • Frazil ice
  • Posts: 403
    • View Profile
  • Liked: 0
  • Likes Given: 0
Re: The 2015 melting season
« Reply #1879 on: July 07, 2015, 02:46:52 PM »
Beaufort now being pounded with warm storm. obuoys already ramped up to about 8 m/s winds. And this ablation stake
http://iabp.apl.washington.edu/camera2.jpg

is quite unlikely to see the end of the day.

seaicesailor

  • Guest
Re: The 2015 melting season
« Reply #1880 on: July 07, 2015, 03:16:41 PM »

[...]

Conclusion:

Quote
This melting season so far has been as slow as last year's, with little movement and transport of ice. But this time around there's much more heat in the system. The multi-year ice on the Pacific side of the Arctic has already had it tough so far, but is now suffering a major blow with open skies practically all over the Arctic bringing massive solar radiation and heat to the ice.


Neven, I enjoyed reading your post.

Next three of four days CICE model shows some movement, transport, and compaction. Then, not much for the rest of the week. We'll see what comes later. HYCOM CICE drift model is what looks to me most reliable of HYCOM CICE, but my evaluation is based on pure map-eyeballing. BTW you were absolutely right, June 30 PIOMAS ice volume of peripheral seas was greater than that for 2014, calculated by Chris Reynolds.





F.Tnioli

  • Grease ice
  • Posts: 767
    • View Profile
  • Liked: 148
  • Likes Given: 36
Re: The 2015 melting season
« Reply #1881 on: July 07, 2015, 03:34:46 PM »
I can't pay attention to everything, and I simply don't know how trustworthy DMI volume is, as I believe it's new and I have no idea what they're doing to come up with those modelled volume estimates.

There's a difference between PIOMAS and DMI modelled volume? Fine. Noted. Now, let's see how things play out, and then maybe next time we'll be able to better attribute reliability.
What's new? DMI's volume model? Barely. It's HYCOM CICE which they claim they run (some details here). Or is it DMI itself which is "new"? Doubt it. Founded 1872. Yep, not a typo - 143 years ago. I respect that.

Two persons directly responsible for HYCOM CICE running at DMI - are Mads Hvid Ribergaard and Jacob Woge Nielsen, i believe. The latter has published serious works about ocean surface physics and chemistry, and he's FIDE chess player with highest ELO 2239 - this means, he's seriously smart. The former does research in DMI since 1998, and looking at his face and degrees, i see one healthy and capable human being. It doesn't get any much better than this if we speak about who could properly implement and run HYCOM CICE, - both in terms of personalities and in terms of the whole scientific institution which runs the thing.

My question now - last few posts, - is NOT about difference between PIOMASS and DMI volumes in terms of absolute numbers. Rather, it is about why 2015 June volume loss is "similar to 2014 PIOMASS amount" in PIOMASS, but "much higher than 2014 DMI amount" in DMI. I don't have an answer to this. If i should stop asking about this, then please tell so, and then i'll stop asking about this. Cross my heart, hope to die! :)
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!

plinius

  • Frazil ice
  • Posts: 403
    • View Profile
  • Liked: 0
  • Likes Given: 0
Re: The 2015 melting season
« Reply #1882 on: July 07, 2015, 03:43:36 PM »
Your post an unsettling inability to divide facts, important facts, and feeling.
I am neither interested in someone's chess rating nor face when assessing a model.

Neven

  • Administrator
  • First-year ice
  • Posts: 7756
    • View Profile
    • Arctic Sea Ice Blog
  • Liked: 1133
  • Likes Given: 521
Re: The 2015 melting season
« Reply #1883 on: July 07, 2015, 03:48:56 PM »
My question now - last few posts, - is NOT about difference between PIOMASS and DMI volumes in terms of absolute numbers. Rather, it is about why 2015 June volume loss is "similar to 2014 PIOMASS amount" in PIOMASS, but "much higher than 2014 DMI amount" in DMI. I don't have an answer to this. If i should stop asking about this, then please tell so, and then i'll stop asking about this. Cross my heart, hope to die! :)

You can ask a thousand times, but when no one answers, chances are that no one knows and/or finds it interesting enough to ponder.

When I said the DMI volume stuff looked new to me, it's because I haven't noticed that map before this year. Maybe it was there already, but I haven't seen it. PIOMAS has been around for year, puts up different maps, shares data on and off their website for amateurs (like Chris Reynolds and Wipneus) to have a look at, etc, etc. So, I know PIOMAS. I don't DMI yet. I have looked enough at ACNFS and TOPAZ in the past to know that they are less reliable than PIOMAS (this can always change, of course).

First you have to figure out why there's a difference between PIOMAS and DMI. What input do they both use? What concentration data, what atmospheric data, etc? Do they cover the same area? What landmask do they use? Is the model constrained by observational data? There are probably many more questions, but I know nothing about models.

Once you know why they're different, you might be able to assess which one is more reliable. But this can also change from year to year.
Il faut comparer, comparer, comparer, et cultiver notre jardin

Jim Hunt

  • Young ice
  • Posts: 4744
  • Stay Home, Save Lives
    • View Profile
    • The Arctic sea ice Great White Con
  • Liked: 507
  • Likes Given: 44
Re: The 2015 melting season
« Reply #1884 on: July 07, 2015, 04:09:09 PM »
The view from the giant swimming pool where IMB 2015B used to be has changed. The wind and rain have set in:

http://GreatWhiteCon.info/resources/arctic-sea-ice-images/summer-2015-images/#IMB2015B

Would you describe those as ripples, or waves?

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

F.Tnioli

  • Grease ice
  • Posts: 767
    • View Profile
  • Liked: 148
  • Likes Given: 36
Re: The 2015 melting season
« Reply #1885 on: July 07, 2015, 04:24:10 PM »
Mostly wind waves, it looks to me. Rather small wind waves, but not ripples. Britannica says, ripples are waves with wavelength of, quote, "few centimeters or less". Not the case on the photo, afaict.
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!

Laurent

  • Young ice
  • Posts: 2538
    • View Profile
  • Liked: 6
  • Likes Given: 35
Re: The 2015 melting season
« Reply #1886 on: July 07, 2015, 04:28:20 PM »
Where do you get the webcam ? The official doesn't seem to work ?
http://imb.erdc.dren.mil/2015B.htm

plinius

  • Frazil ice
  • Posts: 403
    • View Profile
  • Liked: 0
  • Likes Given: 0
Re: The 2015 melting season
« Reply #1887 on: July 07, 2015, 04:37:22 PM »
The view from the giant swimming pool where IMB 2015B used to be has changed. The wind and rain have set in:

http://GreatWhiteCon.info/resources/arctic-sea-ice-images/summer-2015-images/#IMB2015B

Would you describe those as ripples, or waves?

Aren't ripples just waves still dominated by surface tension (consistent with Tiniolis quote from the EB)? In that case clearly "waves"!

F.Tnioli

  • Grease ice
  • Posts: 767
    • View Profile
  • Liked: 148
  • Likes Given: 36
Re: The 2015 melting season
« Reply #1888 on: July 07, 2015, 04:39:41 PM »
My question now - last few posts, - is NOT about difference between PIOMASS and DMI volumes in terms of absolute numbers. Rather, it is about why 2015 June volume loss is "similar to 2014 PIOMASS amount" in PIOMASS, but "much higher than 2014 DMI amount" in DMI. I don't have an answer to this. If i should stop asking about this, then please tell so, and then i'll stop asking about this. Cross my heart, hope to die! :)

You can ask a thousand times, ...

When I said the DMI volume stuff looked new to me, it's because I haven't noticed that map before this year. ...

First you have to figure out why there's a difference between PIOMAS and DMI. ...

Once you know why they're different, you might be able to assess which one is more reliable. But this can also change from year to year.
Oh, thanks! Thousands times is a bit overkill though. Just slightly overkill... ;D

My current assumption, the map was indeed made public less than a year ago, however data in it spans back to 2011, and while i do not know for sure, i suspect that they do have their own data that far back. One wouldn't expect any less from those guys in DMI.

No, i don't have to figure out what is "the" difference between PIOMASS and DMI. This would include noting every significant detail of both, which is practically impossible. Both have their know-hows they are not willing and/or not able to publish, i think. But it's not needed to define "the" difference to answer my question.

Enough, i think, would be to attempt to find what's unusual about this June's volume drop in PIOMASS in compare to previous years, and do the same within DMI, specifically looking for "less melt than expected it'd be, based on usual PIOMASS patterns" within PIOMASS, and "more melt than expected it'd be, based on usual DMI patterns" in DMI. It seems both things happened to some degree, otherwise we wouldn't have highest % disagreement between the two during last 5 years for June melt (even higher % than 2012, when DMI volume dataset was indeed "new"). So basically i know "what" i'd want to do to answer my own question, but i do not know every needed detail to "how" i am to do it.

Naaah, nevermind then.

P.S. I probably bored everyone to death already? Apologies, gentlemen. Inability to talk short is one of my quirks... Like Sartorius.
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!

Jim Hunt

  • Young ice
  • Posts: 4744
  • Stay Home, Save Lives
    • View Profile
    • The Arctic sea ice Great White Con
  • Liked: 507
  • Likes Given: 44
Re: The 2015 melting season
« Reply #1889 on: July 07, 2015, 04:41:37 PM »
Where do you get the webcam ? The official doesn't seem to work ?

They changed the URL. Click through my link above, or better still try this one:

http://iabp.apl.washington.edu/WEB_CAM/camera2/
« Last Edit: July 07, 2015, 05:00:46 PM by Jim Hunt »
Reality is merely an illusion, albeit a very persistent one - Albert Einstein

F.Tnioli

  • Grease ice
  • Posts: 767
    • View Profile
  • Liked: 148
  • Likes Given: 36
Re: The 2015 melting season
« Reply #1890 on: July 07, 2015, 04:43:44 PM »
...
Aren't ripples just waves still dominated by surface tension (consistent with Tiniolis quote from the EB)? In that case clearly "waves"!
Please do make an effort to not misspell my last name. It's awkward one, i know. But it's what it is. %)
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!

Tor Bejnar

  • Young ice
  • Posts: 3653
    • View Profile
  • Liked: 636
  • Likes Given: 410
Re: The 2015 melting season
« Reply #1891 on: July 07, 2015, 05:05:12 PM »
OT: During the first couple of years at my current job, I kept a record of typed misspellings of my name:  16 variations of "Bejnar" (Benjar and Benjnar being the most common misspellings) and half a dozen or so variations of "Tor" (Thor, Torr and Tom being the most common misspellings).  I imagine you may have a similar experience.

OnTopic: Water lapping at ice floes: heat moving to where there is the least of it.
Arctic ice is healthy for children and other living things.

Neven

  • Administrator
  • First-year ice
  • Posts: 7756
    • View Profile
    • Arctic Sea Ice Blog
  • Liked: 1133
  • Likes Given: 521
Re: The 2015 melting season
« Reply #1892 on: July 07, 2015, 05:13:41 PM »
P.S. I probably bored everyone to death already? Apologies, gentlemen. Inability to talk short is one of my quirks... Like Sartorius.

No problem.  ;D
Il faut comparer, comparer, comparer, et cultiver notre jardin

jdallen

  • Young ice
  • Posts: 3248
    • View Profile
  • Liked: 525
  • Likes Given: 206
Re: The 2015 melting season
« Reply #1893 on: July 07, 2015, 05:19:47 PM »
The view from the giant swimming pool where IMB 2015B used to be has changed. The wind and rain have set in:

http://GreatWhiteCon.info/resources/arctic-sea-ice-images/summer-2015-images/#IMB2015B

Would you describe those as ripples, or waves?

Thats... really bad.
This space for Rent.

Yuha

  • Frazil ice
  • Posts: 304
    • View Profile
  • Liked: 53
  • Likes Given: 25
Re: The 2015 melting season
« Reply #1894 on: July 07, 2015, 05:39:28 PM »
Beaufort now being pounded with warm storm. obuoys already ramped up to about 8 m/s winds. And this ablation stake
http://iabp.apl.washington.edu/camera2.jpg

is quite unlikely to see the end of the day.

If you compare the ablation stake yesterday (first image) and today (second image), it seems to be deeper today. Either the storm brought some fresh snow or the ice is so soft that the stake is digging itself deeper into the ice.



Tor Bejnar

  • Young ice
  • Posts: 3653
    • View Profile
  • Liked: 636
  • Likes Given: 410
Re: The 2015 melting season
« Reply #1895 on: July 07, 2015, 06:08:46 PM »
I think the stake is leaning more toward the camera today.  Note the changed difference between the distance between ice edge (on marker) and the ice melt ring (where marker disappears): ~32 cm yesterday to ~35 cm today.  If the stake was leaning more away from the camera today, we'd see more of the lowest white square, I think, not less.

The ice edge does not appear to have changed and the melt ring around the stake appears unchanged (so no edge erosion or new snow).  Of course, this analysis assumes the camera height and distance from stake have not changed!
Arctic ice is healthy for children and other living things.

Yuha

  • Frazil ice
  • Posts: 304
    • View Profile
  • Liked: 53
  • Likes Given: 25
Re: The 2015 melting season
« Reply #1896 on: July 07, 2015, 06:16:02 PM »
Conclusion:

Quote
This melting season so far has been as slow as last year's, with little movement and transport of ice.

The transport out of Fram has been slow for the last two or three weeks but it was much stronger during the first half of June. Overall, I think there has been more transport than last year.




Rubikscube

  • Frazil ice
  • Posts: 254
    • View Profile
  • Liked: 5
  • Likes Given: 4
Re: The 2015 melting season
« Reply #1897 on: July 07, 2015, 06:50:31 PM »
If you compare the ablation stake yesterday (first image) and today (second image), it seems to be deeper today. Either the storm brought some fresh snow or the ice is so soft that the stake is digging itself deeper into the ice.

Definitely about 10 cm of wet fresh snow, quite amazing with such 850 hPa temps even though it is 5 a.m. or something up there. The snow will help, but the wind and waves might do some damage. Wonder if this weather hits Buoy 12 which sits just to the north of this camera.

Neven

  • Administrator
  • First-year ice
  • Posts: 7756
    • View Profile
    • Arctic Sea Ice Blog
  • Liked: 1133
  • Likes Given: 521
Re: The 2015 melting season
« Reply #1898 on: July 07, 2015, 06:52:29 PM »
Conclusion:

Quote
This melting season so far has been as slow as last year's, with little movement and transport of ice.

The transport out of Fram has been slow for the last two or three weeks but it was much stronger during the first half of June. Overall, I think there has been more transport than last year.

You could be right, Yuha. It's difficult for me to quantify. I'm basing myself mainly on the fact that there hasn't been much of a Beaufort Gyre, etc.
Il faut comparer, comparer, comparer, et cultiver notre jardin

S.Pansa

  • Frazil ice
  • Posts: 170
    • View Profile
  • Liked: 42
  • Likes Given: 5
Re: The 2015 melting season
« Reply #1899 on: July 07, 2015, 07:05:20 PM »
If you compare the ablation stake yesterday (first image) and today (second image), it seems to be deeper today. Either the storm brought some fresh snow or the ice is so soft that the stake is digging itself deeper into the ice.

Definitely about 10 cm of wet fresh snow, quite amazing with such 850 hPa temps even though it is 5 a.m. or something up there. The snow will help, but the wind and waves might do some damage. Wonder if this weather hits Buoy 12 which sits just to the north of this camera.

Hmmm. I am pretty sure the stake is giving in, i.e sinks into the ice. Compare these two images

image 1
image 2