Support the Arctic Sea Ice Forum and Blog

Author Topic: The 2015 melting season  (Read 1847190 times)

Rubikscube

  • Frazil ice
  • Posts: 254
    • View Profile
  • Liked: 5
  • Likes Given: 4
Re: The 2015 melting season
« Reply #1350 on: June 17, 2015, 04:13:05 PM »
I have checked back to see the reanalysis maps for the snow data, and they do line up reasonably well with the former forecasts. You're being very uncharitable to assume that I never even looked and to equate this to denialism, but just to give one example (upper image is forecast with 7-day lead time, lower image is reanalysis):

Thank you very much. Sorry for my harsh response, but some snow cover forecasts have seemingly been overestimating the snow melting quite grossly so when you only post longterm forecasts I start suspecting you are picking cherries. I see now that you have to reason to do so either, the reanalysis aligns remarkably well with the 7 day forecast.
« Last Edit: June 17, 2015, 04:21:50 PM by Rubikscube »

Nightvid Cole

  • Frazil ice
  • Posts: 437
    • View Profile
  • Liked: 5
  • Likes Given: 0
Re: The 2015 melting season
« Reply #1351 on: June 17, 2015, 04:31:19 PM »
I have checked back to see the reanalysis maps for the snow data, and they do line up reasonably well with the former forecasts. You're being very uncharitable to assume that I never even looked and to equate this to denialism, but just to give one example (upper image is forecast with 7-day lead time, lower image is reanalysis):

Thank you very much. Sorry for my harsh response, but some snow cover forecasts have seemingly been overestimating the snow melting quite grossly so when you only post longterm forecasts I start suspecting you are picking cherries. I see now that you have to reason to do so either, the reanalysis aligns remarkably well with the 7 day forecast.

No harm done.  :)

Neven

  • Administrator
  • First-year ice
  • Posts: 7781
    • View Profile
    • Arctic Sea Ice Blog
  • Liked: 1145
  • Likes Given: 537
Re: The 2015 melting season
« Reply #1352 on: June 17, 2015, 05:43:05 PM »
With the massive CT SIA drop of 340K, CAPIE is now starting to look more 'normal':
« Last Edit: June 17, 2015, 05:50:59 PM by Neven »
Il faut comparer, comparer, comparer, et cultiver notre jardin

jdallen

  • Young ice
  • Posts: 3256
    • View Profile
  • Liked: 535
  • Likes Given: 208
Re: The 2015 melting season
« Reply #1353 on: June 17, 2015, 06:30:06 PM »
Things are looking quite blocky.

http://mp1.met.psu.edu/~fxg1/CMCNA_0z/hgtcomp.html
How so 'Blocky'?

My untrained eye seems to see multiple possible points of entry of warmer moister air from lower latitudes.
This space for Rent.

OnlyInItForNares

  • New ice
  • Posts: 1
    • View Profile
  • Liked: 0
  • Likes Given: 0
Re: The 2015 melting season
« Reply #1354 on: June 17, 2015, 06:52:42 PM »

JayW

  • Grease ice
  • Posts: 605
    • View Profile
  • Liked: 224
  • Likes Given: 282
Re: The 2015 melting season
« Reply #1355 on: June 17, 2015, 09:45:55 PM »
Things are looking quite blocky.

http://mp1.met.psu.edu/~fxg1/CMCNA_0z/hgtcomp.html
How so 'Blocky'?

My untrained eye seems to see multiple possible points of entry of warmer moister air from lower latitudes.

I'm looking at the high over low configurations (rex block) one around the Bering/Alaska area and one around Greenland. But, I don't feel like blocky regimes necessary preclude warm air intrusions, in fact I think of them as over amplified patterns, but I'm a hack.   :D

http://mp1.met.psu.edu/~fxg1/ECMWF_12z/hgtcomp.html
"To defy the laws of tradition, is a crusade only of the brave" - Les Claypool

Rubikscube

  • Frazil ice
  • Posts: 254
    • View Profile
  • Liked: 5
  • Likes Given: 4
Re: The 2015 melting season
« Reply #1356 on: June 17, 2015, 09:48:11 PM »
These are the 2002-2014 average (2012 excluded), 2015 vs average and 2015 vs 2012 ice concentration maps for 16th June.

Most of the negative anomaly is actually in Kara sea and notice as well the anomalies north of Franz Joseph and Severnaya Zemlya. 2015 is also ahead in Chukchi and Beaufort although the gap is not extraordinary. Laptev is lagging behind still (but the anomaly south of the New Siberian island is probably not very indicative at this stage of the season) and Baffin ever more so with a significant patch of positive 100% anomaly. Lots of ice east of Greenland too.

2012 is significantly ahead of 2015 at this stage, as one could expect looking at the number. The difference can of course be made up for during the course of the season, but crucial regions like Beaufort and Laptev have apparently gotten a rather massive head start.

Nightvid Cole

  • Frazil ice
  • Posts: 437
    • View Profile
  • Liked: 5
  • Likes Given: 0
Re: The 2015 melting season
« Reply #1357 on: June 18, 2015, 02:23:25 AM »
These are the 2002-2014 average (2012 excluded), 2015 vs average and 2015 vs 2012 ice concentration maps for 16th June.

Most of the negative anomaly is actually in Kara sea and notice as well the anomalies north of Franz Joseph and Severnaya Zemlya. 2015 is also ahead in Chukchi and Beaufort although the gap is not extraordinary. Laptev is lagging behind still (but the anomaly south of the New Siberian island is probably not very indicative at this stage of the season) and Baffin ever more so with a significant patch of positive 100% anomaly. Lots of ice east of Greenland too.

2012 is significantly ahead of 2015 at this stage, as one could expect looking at the number. The difference can of course be made up for during the course of the season, but crucial regions like Beaufort and Laptev have apparently gotten a rather massive head start.

Ok, I'll admit, I am completely stumped as to why there is such a large contradiction between sources of data this year. Both DMI and NSIDC concentration maps seem to show concentration dropping into the central Arctic, suggesting significant melt pond coverage. Yet, in some noticeable enigma, your source doesn't have it.

My best guess is that your source uses AMSR2 and is picking up cloud cover again. In that case we should not conclude that this year is behind 2012.

But if this is not the case, I give up. I will drop out of making any and all predictions until late July if we can't straighten up this bizarre contradiction, or until the sources agree with each other for at least 5-7 consecutive days.

It's very difficult to try to analyze this flustering of a situation.  :-\
« Last Edit: June 18, 2015, 02:29:29 AM by Nightvid Cole »

Juan C. García

  • Nilas ice
  • Posts: 2163
    • View Profile
  • Liked: 1039
  • Likes Given: 762
Re: The 2015 melting season
« Reply #1358 on: June 18, 2015, 03:04:35 AM »
Nullschool says that temperature at the Arctic is from 0.1ºC to 4.9ºC
How much reliable is nullschool?
Where I can learn to use it?
Which is the best answer to Sep-2012 ASI lost (compared to 1979-2000)?
50% [NSIDC Extent] or
73% [PIOMAS Volume]

Volume is harder to measure than extent, but 3-dimensional space is real, 2D's hide ~50% thickness gone.
-> IPCC/NSIDC trends [based on extent] underestimate the real speed of ASI lost.

sedziobs

  • Frazil ice
  • Posts: 395
    • View Profile
  • Liked: 63
  • Likes Given: 12
Re: The 2015 melting season
« Reply #1359 on: June 18, 2015, 03:44:53 AM »
Nullschool uses GFS, so it ostensibly has similar reliability.

There's some helpful info on the "about" page: http://earth.nullschool.net/about.html

Juan C. García

  • Nilas ice
  • Posts: 2163
    • View Profile
  • Liked: 1039
  • Likes Given: 762
Re: The 2015 melting season
« Reply #1360 on: June 18, 2015, 04:22:44 AM »
Nullschool uses GFS, so it ostensibly has similar reliability.

There's some helpful info on the "about" page: http://earth.nullschool.net/about.html

Thank you sedziobs  ;)
Which is the best answer to Sep-2012 ASI lost (compared to 1979-2000)?
50% [NSIDC Extent] or
73% [PIOMAS Volume]

Volume is harder to measure than extent, but 3-dimensional space is real, 2D's hide ~50% thickness gone.
-> IPCC/NSIDC trends [based on extent] underestimate the real speed of ASI lost.

epiphyte

  • Frazil ice
  • Posts: 385
    • View Profile
  • Liked: 20
  • Likes Given: 19
Re: The 2015 melting season
« Reply #1361 on: June 18, 2015, 05:27:26 AM »
Nullschool uses GFS, so it ostensibly has similar reliability.

There's some helpful info on the "about" page: http://earth.nullschool.net/about.html

Once you get the hang of it it's a really handy visualization tool.

One of the things I've been trying to do this year is to figure out where under the cloud cover there is precipitation going on, and whether it is rain or snow. Until nullschool came along that was not clear to me at all... but now, by flipping between the temperature and TPW (precipitable water) displays on the surface , 1000 and 850mb, with the wind speed and direction overlayed, it's easier to get a good feel for where moisture is being picked up and dropped off and whether it's likely to be liquid when it hits the surface.

To keep on topic I'd mention that to me it least it appears that it's been raining and/or rain/wet snow mix in places in and to the North of Beaufort + Chuchki,  and then not really ponding so much as just darkening the surface. Don't know whether I'm reading it right, or what it means, but I'm guessing it's not good news for the ice in those areas.


sedziobs

  • Frazil ice
  • Posts: 395
    • View Profile
  • Liked: 63
  • Likes Given: 12
Re: The 2015 melting season
« Reply #1362 on: June 18, 2015, 05:47:23 AM »
The Laptev shores had been cool until recently.  This current weather is about as bad as it gets for the ice.

Edit: 54F is 12C.

cesium62

  • Frazil ice
  • Posts: 291
    • View Profile
  • Liked: 11
  • Likes Given: 1
Re: The 2015 melting season
« Reply #1363 on: June 18, 2015, 08:12:52 AM »
2012 is significantly ahead of 2015 at this stage

Are we integrating red vs blue dots by eyeball, or do we have a pixel by pixel integration?

F.Tnioli

  • Grease ice
  • Posts: 767
    • View Profile
  • Liked: 148
  • Likes Given: 36
Re: The 2015 melting season
« Reply #1364 on: June 18, 2015, 09:38:49 AM »
Is there any webcams or recent stills from any buoys in the ESS (ice/ocean is what i'd like to see, how it looks like there right now)? Couldn't find any with a quick search... Getting old may be...  :(
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!

seaicesailor

  • Guest
Re: The 2015 melting season
« Reply #1365 on: June 18, 2015, 09:42:21 AM »
2012 is significantly ahead of 2015 at this stage

Are we integrating red vs blue dots by eyeball, or do we have a pixel by pixel integration?

For integrated values, Wipneus numbers confirm so.
There is though an important qualitative difference with 2014 and is that there is already a melt front in Beaufort and very warm  open water behind it (McKenzie river and low albedo).

2015 has all 2012 fronts open. It's way behind sure.

F.Tnioli

  • Grease ice
  • Posts: 767
    • View Profile
  • Liked: 148
  • Likes Given: 36
Re: The 2015 melting season
« Reply #1366 on: June 18, 2015, 10:13:42 AM »
...
2015 has all 2012 fronts open. It's way behind sure.
Sarcasm detected.  ;D

Cryosphere today has the area number dropping down like mad last few days. Exactly as expected it'd be, some ~week ago, in this very topic, yep. ~340k lost in one day - frankly, i think this might be quite a record for a daily loss. In 2012, the meanest June's daily ice area loss (in CT numbers) was ~270k...
« Last Edit: June 18, 2015, 10:41:38 AM 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!

Siffy

  • Frazil ice
  • Posts: 179
    • View Profile
  • Liked: 0
  • Likes Given: 0
Re: The 2015 melting season
« Reply #1367 on: June 18, 2015, 10:42:07 AM »


Just noticed this on the EOSDIS page. Looks like cracking in the ice and movement in the Nares Strait.

If you toggle the date you can see the crack move to the south looks like the ice there might push through the ice to the south?

oren

  • Moderator
  • First-year ice
  • Posts: 6530
    • View Profile
  • Liked: 2419
  • Likes Given: 2103
Re: The 2015 melting season
« Reply #1368 on: June 18, 2015, 12:14:30 PM »


Just noticed this on the EOSDIS page. Looks like cracking in the ice and movement in the Nares Strait.

If you toggle the date you can see the crack move to the south looks like the ice there might push through the ice to the south?

There's a closeup of this crack in the Nares Strait thread in the Greenland section.

slow wing

  • Grease ice
  • Posts: 819
    • View Profile
  • Liked: 156
  • Likes Given: 506
Re: The 2015 melting season
« Reply #1369 on: June 18, 2015, 12:49:03 PM »
One of the things I've been trying to do this year is to figure out where under the cloud cover there is precipitation going on, and whether it is rain or snow. Until nullschool came along that was not clear to me at all...
Are you familiar with the Climate Reanalyser displays?
Can see the places with rain and snow here...
http://cci-reanalyzer.org/Forecasts/
Choose
1) "Arctic" as Region
2) "Precipitation & Clouds" as Parameter
That is actually forecasts. Nearest to current is 3 hours in the future.

I haven't yet found the same information on the current weather display. It should be there? Am I missing choosing the correct parameters?


F.Tnioli

  • Grease ice
  • Posts: 767
    • View Profile
  • Liked: 148
  • Likes Given: 36
Re: The 2015 melting season
« Reply #1370 on: June 18, 2015, 01:35:35 PM »
Well, the link says "forecasts", so naturally it's about forecasts. It also has http://cci-reanalyzer.org/DailySummary/ , would it do?
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!

slow wing

  • Grease ice
  • Posts: 819
    • View Profile
  • Liked: 156
  • Likes Given: 506
Re: The 2015 melting season
« Reply #1371 on: June 18, 2015, 01:48:15 PM »
Oh yes, now I see "precipitation & clouds" also on that current weather link.

Shared Humanity

  • Guest
Re: The 2015 melting season
« Reply #1372 on: June 18, 2015, 02:08:07 PM »
These are the 2002-2014 average (2012 excluded), 2015 vs average and 2015 vs 2012 ice concentration maps for 16th June.

Most of the negative anomaly is actually in Kara sea and notice as well the anomalies north of Franz Joseph and Severnaya Zemlya. 2015 is also ahead in Chukchi and Beaufort although the gap is not extraordinary. Laptev is lagging behind still (but the anomaly south of the New Siberian island is probably not very indicative at this stage of the season) and Baffin ever more so with a significant patch of positive 100% anomaly. Lots of ice east of Greenland too.

2012 is significantly ahead of 2015 at this stage, as one could expect looking at the number. The difference can of course be made up for during the course of the season, but crucial regions like Beaufort and Laptev have apparently gotten a rather massive head start.

What is really fascinating to me about the negative anomalies is occurring in the Baffin, CAA and Hudson. This area had a brutally cold winter which you think would have caused the ice to be resilient during this melt season. Even more peculiar......the negative anomalies are in the northern regions of the Baffin and Hudson. What could be causing this?

Could heavy snow, caused by the early onset of winter, driven heavy snow accumulation in the northern regions, insulating the ice from the cold?

F.Tnioli

  • Grease ice
  • Posts: 767
    • View Profile
  • Liked: 148
  • Likes Given: 36
Re: The 2015 melting season
« Reply #1373 on: June 18, 2015, 02:16:10 PM »
...
Could heavy snow, caused by the early onset of winter, driven heavy snow accumulation in the northern regions, insulating the ice from the cold?
Definitely. I believe every extra cm of snow acts much better than every extra 1 cm of ice in terms of insulation from freezing air above. Thicker snow cover = much thinner ice.

What i do not know is whether some instruments could be affected by lower layers of snow cover. Pressed into relatively dense substance by the weight of higher layers of snow cover during relatively long time (some ~8 months?), could some instruments pick those lower ("near ice") layers of snow cover as "ice" erratically? How negligible or significant is that effect if it exists at all? What about possible water content? I imagine, much like in "aquafiers" found in southern (iirc) Greenland some 10...40 meters below the icesheet surface which were said to be the size of Ireland, containing liquid water "between" ice crystals, - it perhaps is possible that heavy "wet" snowfall during autumn 2014 could perhaps lead to lower levels of snow cover to remain "wet" for quite some time (days to few weeks?), insulated by upper relatively thick layers of fresh snow (ditto "heavy" snowfall), and later freeze into a strange "mix" - half snow, half bigger-pieces ice...
« Last Edit: June 18, 2015, 02:29:44 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!

plinius

  • Frazil ice
  • Posts: 403
    • View Profile
  • Liked: 0
  • Likes Given: 0
Re: The 2015 melting season
« Reply #1374 on: June 18, 2015, 03:00:27 PM »
There are numbers...
http://onlinelibrary.wiley.com/doi/10.1029/2000JC000409/abstract

1cm of snow insulates like something like 5-20cm of ice. Would also imply that 10 cm of snow kill probably about 50-100cm of equilibrium ice thickness.
There were also papers (I think including Schellnhuber as author) dealing with the effect of early snow.

Nightvid Cole

  • Frazil ice
  • Posts: 437
    • View Profile
  • Liked: 5
  • Likes Given: 0
Re: The 2015 melting season
« Reply #1375 on: June 18, 2015, 03:08:20 PM »
00z ECMWF shows the current cyclone over the central Arctic moving over to the southwestern CAA in 24 hours, only to be replaced by another cyclone, which will do roughly the same. It isn't until +96h or even +120h (6/22 or 6/23, respectively) that the Arctic will be cyclone-free enough to limit cloud interference with the observations. At that point, all sources, visible and microwave, should agree on the dropping ice concentration and extensive melt ponding in the CAB.

So I predict large areas of "red"/"light purple" in the CAB on the CT map for 6/23. Actually even on 6/22 we should see it, though the Beaufort Sea may appear to have a higher concentration due to the cloud cover associated with the cyclone.

Cloud cover away from the cyclones should be thin enough to not affect the SSMIS data significantly. AMSR2 may still be impacted somewhat.
« Last Edit: June 18, 2015, 03:14:10 PM by Nightvid Cole »

seaicesailor

  • Guest
Re: The 2015 melting season
« Reply #1376 on: June 18, 2015, 03:10:45 PM »
...
2015 has all 2012 fronts open. It's way behind sure.
Sarcasm detected.  ;D

Cryosphere today has the area number dropping down like mad last few days. Exactly as expected it'd be, some ~week ago, in this very topic, yep. ~340k lost in one day - frankly, i think this might be quite a record for a daily loss. In 2012, the meanest June's daily ice area loss (in CT numbers) was ~270k...

It was not intentionally sarcastic . . . althought it also makes sense in a sarcastic way.

There were larger, monster CT area drops in 2008. See below from another thread:

A quick glance at my CT SIA spreadsheet tells me a drop this big (300K+) hasn't happened since 2008. Impressive indeed.
That's correct. For the record, there were two monster single-day drops that year: 396k in late April, and 437k in early May. The largest one-day decrease since then was 287k in the first week of June last year.

seaicesailor

  • Guest
Re: The 2015 melting season
« Reply #1377 on: June 18, 2015, 03:14:44 PM »
00z ECMWF shows the current cyclone over the central Arctic moving over to the southwestern CAA in 24 hours, only to be replaced by another cyclone, which will do roughly the same. It isn't until +96h or even +120h (6/22 or 6/23, respectively) that the Arctic will be cyclone-free enough to limit cloud interference with the observations. At that point, all sources, visible and microwave, should agree on the dropping ice concentration and extensive melt ponding in the CAB.

So I predict large areas of "red"/"light purple" in the CAB on the CT map for 6/23.

That is indeed within the range of reliable forecasts. Also, from MODIS these past days I could see large areas with open skies (maybe not continuously) in the Pacific side of the Arctic

Metamemesis

  • New ice
  • Posts: 38
    • View Profile
  • Liked: 1
  • Likes Given: 1
Re: The 2015 melting season
« Reply #1378 on: June 18, 2015, 03:25:23 PM »
One of the things I've been trying to do this year is to figure out where under the cloud cover there is precipitation going on, and whether it is rain or snow. Until nullschool came along that was not clear to me at all...
Are you familiar with the Climate Reanalyser displays?
Can see the places with rain and snow here...
http://cci-reanalyzer.org/Forecasts/
Choose
1) "Arctic" as Region
2) "Precipitation & Clouds" as Parameter
That is actually forecasts. Nearest to current is 3 hours in the future.

I haven't yet found the same information on the current weather display. It should be there? Am I missing choosing the correct parameters?

I had been looking for a good visual display of precipitation, so thanks for the link. I normally use Nullschool, too. Wasn't quite prepared for the Reanalyzer images, though: rain forecast over the CAB (6 days out, so not a strong forecast).

« Last Edit: June 18, 2015, 03:57:25 PM by Metamemesis »

F.Tnioli

  • Grease ice
  • Posts: 767
    • View Profile
  • Liked: 148
  • Likes Given: 36
Re: The 2015 melting season
« Reply #1379 on: June 18, 2015, 03:34:47 PM »
There are numbers...
http://onlinelibrary.wiley.com/doi/10.1029/2000JC000409/abstract

1cm of snow insulates like something like 5-20cm of ice. Would also imply that 10 cm of snow kill probably about 50-100cm of equilibrium ice thickness.
There were also papers (I think including Schellnhuber as author) dealing with the effect of early snow.
Thanks, Plinius.

I think that that "5...20cm" is much dependant on the state of the snow. Fresh upper "dry" snow with lots of air - here we go, 20; dense thick possibly partially filled with frozen "moisture" snow at the bottom - some weeks/months after it fell in a wet state right on top of the thin fresh ice, - here we go, 5 or perhaps even less. That's why it's so large (4 times) difference; should be quite similar to density, i guess. I have 1st-hand experience going through (literally) all kinds of snow with my  own hands (ok, usually i used a shovel, whatever :D ), and i sure can tell you that a big shovel full of fresh "upper" snow is times lighter (my weight) than same shovel full of thick "near ground" snow. Thermal conductivity should correspond to that.
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!

F.Tnioli

  • Grease ice
  • Posts: 767
    • View Profile
  • Liked: 148
  • Likes Given: 36
Re: The 2015 melting season
« Reply #1380 on: June 18, 2015, 03:43:37 PM »
...

There were larger, monster CT area drops in 2008. See below from another thread:

A quick glance at my CT SIA spreadsheet tells me a drop this big (300K+) hasn't happened since 2008. Impressive indeed.
That's correct. For the record, there were two monster single-day drops that year: 396k in late April, and 437k in early May. The largest one-day decrease since then was 287k in the first week of June last year.
~400k is a record for April/May daily loss, yes, but for June, 340k does seem like a record in terms of this single month (June). Which was and still is my point; we don't get so much insolation in April nor in May as we do in June, which is why i think spring records for daily loss and June/July ones - are of different nature, the latter being much more important for the melt season as a whole.
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!

Rubikscube

  • Frazil ice
  • Posts: 254
    • View Profile
  • Liked: 5
  • Likes Given: 4
Re: The 2015 melting season
« Reply #1381 on: June 18, 2015, 04:05:09 PM »
Ok, I'll admit, I am completely stumped as to why there is such a large contradiction between sources of data this year. Both DMI and NSIDC concentration maps seem to show concentration dropping into the central Arctic, suggesting significant melt pond coverage. Yet, in some noticeable enigma, your source doesn't have it.

My best guess is that your source uses AMSR2 and is picking up cloud cover again. In that case we should not conclude that this year is behind 2012.

I've been bit sloppy specifying my sources lately, but I'm allways using the standard 2,5x2,5 grid products provided by Uni-Bremen (a caveat is that I go straight to the TIFF files and not the more accurate HDFs since don't know how to properly attend for its vast amount of numerical data). This means 2002-2011 is AMSR-E and 2013-2015 is AMSR2. 2012 is only available in SSMIS until late July, and comparing an SSMIS to an AMSR2 might perhaps be a more dubious exercise, but Uni-Bremen at least doesn't provide any alternatives.

It is worth noticing that the color scale that I use in my delta maps somewhat exaggerate small differences (5-50%). My initial idea was to emphasize melt ponding and put a distinct line at 50% difference, but it probably makes the difference to 2012 look more brutal than it really is as well. Please let me know if you think my color scale is misleading and want me to adjust it.

Are we integrating red vs blue dots by eyeball, or do we have a pixel by pixel integration?

There are many different sources providing area and extent numbers, most notably Wipneus. I don't have the skill to engage is such activities either, so this only serves as a year-to-year visual comparison.

What is really fascinating to me about the negative anomalies is occurring in the Baffin, CAA and Hudson. This area had a brutally cold winter which you think would have caused the ice to be resilient during this melt season. Even more peculiar......the negative anomalies are in the northern regions of the Baffin and Hudson. What could be causing this?

I think an unusual wind setup with lots of cold air flowing south from CAA is the most likely answer.

johnm33

  • Guest
Re: The 2015 melting season
« Reply #1382 on: June 18, 2015, 04:21:59 PM »
 North Baffin and Hudson have both been undermined by sea flowing through from the north all winter, has to have played some part in the melt.
 http://www7320.nrlssc.navy.mil/GLBhycomcice1-12/navo/arcticsss_nowcast_anim365d.gif

F.Tnioli

  • Grease ice
  • Posts: 767
    • View Profile
  • Liked: 148
  • Likes Given: 36
Re: The 2015 melting season
« Reply #1383 on: June 18, 2015, 04:49:09 PM »
Thanks alot, Vergent!

Meanwhile, CT updated the area number. After jaw-droppin' 340k we get lazy 70k. Huh. I scared 'em numbers to get back in line?  8)

P.S. What's with snow cover getting quite noticeable bump upwards 06.16 2015 in the above animation? Looks strange. But man, darn fast there, that 2015. Darn fast.

P.P.S. Oops, Vergent's post gone while i was adding the P.S. here! Straaange...  :o Neat animations for sure, it had. Please re-post if possible, Vergent.
« Last Edit: June 18, 2015, 04:56:20 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!

Vergent

  • Grease ice
  • Posts: 573
    • View Profile
  • Liked: 2
  • Likes Given: 2
Re: The 2015 melting season
« Reply #1384 on: June 18, 2015, 05:15:59 PM »
Arctic ice snow cover June 1 - 22 and the consequent melt June 22 - Sept. 11:

2012;



2013;



2014;



2015;


Verg 8)
« Last Edit: June 18, 2015, 05:30:59 PM by Vergent »

Bob Wallace

  • Young ice
  • Posts: 3855
    • View Profile
  • Liked: 43
  • Likes Given: 5
Re: The 2015 melting season
« Reply #1385 on: June 18, 2015, 05:21:33 PM »
Nice images Vergent.  How about a bit of a pause on the first and last frames?

And how about composites of the first and last frames?  Smaller versions of all four years in a single frame.

The days speed past faster than I can store them in memory.

Vergent

  • Grease ice
  • Posts: 573
    • View Profile
  • Liked: 2
  • Likes Given: 2
Re: The 2015 melting season
« Reply #1386 on: June 18, 2015, 05:35:50 PM »
Nice images Vergent.  How about a bit of a pause on the first and last frames?

And how about composites of the first and last frames?  Smaller versions of all four years in a single frame.

The days speed past faster than I can store them in memory.

Help yourself!

http://thredds.met.no/thredds/godiva2/godiva2.html?server=http://thredds.met.no/thredds/wms/topaz/dataset-topaz4-arc-myoceanv2-be

Click on the "+". Choose "north polar..." Then choose from the menu on the left(click on "arctic ocean physics.." to expand the menu.

Verg

edit: you need to switch from "north polar.." to another view and back when you change data sets. otherwise , you just get a blank.
« Last Edit: June 18, 2015, 06:29:18 PM by Vergent »

Nightvid Cole

  • Frazil ice
  • Posts: 437
    • View Profile
  • Liked: 5
  • Likes Given: 0
Re: The 2015 melting season
« Reply #1387 on: June 18, 2015, 06:02:31 PM »
Vergent, excellent job with the animations!* The data speaks for itself - it is not alarmist, rather, it's alarming!

*It would be better to include the colorbars/scales than to omit them.

Nightvid Cole

  • Frazil ice
  • Posts: 437
    • View Profile
  • Liked: 5
  • Likes Given: 0
Re: The 2015 melting season
« Reply #1388 on: June 18, 2015, 06:07:39 PM »
Ok, I'll admit, I am completely stumped as to why there is such a large contradiction between sources of data this year. Both DMI and NSIDC concentration maps seem to show concentration dropping into the central Arctic, suggesting significant melt pond coverage. Yet, in some noticeable enigma, your source doesn't have it.

My best guess is that your source uses AMSR2 and is picking up cloud cover again. In that case we should not conclude that this year is behind 2012.

I've been bit sloppy specifying my sources lately, but I'm allways using the standard 2,5x2,5 grid products provided by Uni-Bremen (a caveat is that I go straight to the TIFF files and not the more accurate HDFs since don't know how to properly attend for its vast amount of numerical data). This means 2002-2011 is AMSR-E and 2013-2015 is AMSR2. 2012 is only available in SSMIS until late July, and comparing an SSMIS to an AMSR2 might perhaps be a more dubious exercise, but Uni-Bremen at least doesn't provide any alternatives.

It is worth noticing that the color scale that I use in my delta maps somewhat exaggerate small differences (5-50%). My initial idea was to emphasize melt ponding and put a distinct line at 50% difference, but it probably makes the difference to 2012 look more brutal than it really is as well. Please let me know if you think my color scale is misleading and want me to adjust it.

I don't think the color scale is unreasonable.

Vergent

  • Grease ice
  • Posts: 573
    • View Profile
  • Liked: 2
  • Likes Given: 2
Re: The 2015 melting season
« Reply #1389 on: June 18, 2015, 06:12:30 PM »
Vergent, excellent job with the animations!* The data speaks for itself - it is not alarmist, rather, it's alarming!

*It would be better to include the colorbars/scales than to omit them.

I've had trouble with their permalinks breaking in the past, and unfortunately transferring the image to Imgur the scale doesn't come along. The snow depth scale is from 0.02(2 cm) to 1 meter, the concentration scale is 0 - 1.

Verg
 

Nick_Naylor

  • Frazil ice
  • Posts: 291
    • View Profile
  • Liked: 0
  • Likes Given: 0
Re: The 2015 melting season
« Reply #1390 on: June 18, 2015, 06:21:12 PM »
It should be interesting to see what becomes of this crack in the ESS as the cyclone tries to open it up over the next few days.

Edit: Seems this browser won't allow attachments, but here's a link:
https://earthdata.nasa.gov/labs/worldview/?p=arctic&l=MODIS_Aqua_CorrectedReflectance_TrueColor(hidden),MODIS_Terra_CorrectedReflectance_TrueColor,Reference_Labels,Reference_Features(hidden),Coastlines&t=2015-06-18&v=-1364852.3681705137,1237539.2461799774,93323.63182948623,1916451.2461799774

seaicesailor

  • Guest
Re: The 2015 melting season
« Reply #1391 on: June 18, 2015, 06:52:29 PM »
It should be interesting to see what becomes of this crack in the ESS as the cyclone tries to open it up over the next few days.

Edit: Seems this browser won't allow attachments, but here's a link:
https://earthdata.nasa.gov/labs/worldview/?p=arctic&l=MODIS_Aqua_CorrectedReflectance_TrueColor(hidden),MODIS_Terra_CorrectedReflectance_TrueColor,Reference_Labels,Reference_Features(hidden),Coastlines&t=2015-06-18&v=-1364852.3681705137,1237539.2461799774,93323.63182948623,1916451.2461799774

The ESS edge is about to open up, not only along that crack! That is a qualitative advantage wrt 2012, along with snow data Vergent shows. Still, there is more MYI; clouds or lack thereof will  determine how this goes

jdallen

  • Young ice
  • Posts: 3256
    • View Profile
  • Liked: 535
  • Likes Given: 208
Re: The 2015 melting season
« Reply #1392 on: June 18, 2015, 07:07:21 PM »
It should be interesting to see what becomes of this crack in the ESS as the cyclone tries to open it up over the next few days.

Edit: Seems this browser won't allow attachments, but here's a link:
https://earthdata.nasa.gov/labs/worldview/?p=arctic&l=MODIS_Aqua_CorrectedReflectance_TrueColor(hidden),MODIS_Terra_CorrectedReflectance_TrueColor,Reference_Labels,Reference_Features(hidden),Coastlines&t=2015-06-18&v=-1364852.3681705137,1237539.2461799774,93323.63182948623,1916451.2461799774

The ESS edge is about to open up, not only along that crack! That is a qualitative advantage wrt 2012, along with snow data Vergent shows. Still, there is more MYI; clouds or lack thereof will  determine how this goes
The apparent sunlight and low albedo is more worrisome to me. The ice looks to have wall-to-wall melt ponding, and the heat flowing off the continent and sunlight could strip as much as 10cm/day or more off the top of it. Iirc that ice started under 2m thick. Much of it should be gone by the end of the 1st week of July if not sooner.
This space for Rent.

Laurent

  • Young ice
  • Posts: 2538
    • View Profile
  • Liked: 6
  • Likes Given: 35
Re: The 2015 melting season
« Reply #1393 on: June 18, 2015, 07:38:57 PM »
Eye balling the albedo near the Barentz sea seems low. There is that spot (see the image between Chukchi and ESS) that shows a very low albedo ( http://1.usa.gov/1dMCFg1)  certainly some algual blum.

http://www.weather-forecast.com/maps/Arctic?symbols=none&type=prec

Weather forecast doesn't not show any snow ! Climate reanalyser does ?
http://www.weather-forecast.com/maps/Arctic?symbols=none&type=prec
http://cci-reanalyzer.org/Forecasts/

Vergent

  • Grease ice
  • Posts: 573
    • View Profile
  • Liked: 2
  • Likes Given: 2
Re: The 2015 melting season
« Reply #1394 on: June 18, 2015, 08:51:40 PM »


The last data import was Monday, so this may not reflect the snow/rain if it was not forecast. Will post  next Monday when it will be primarily observation based.

Verg 

ChrisReynolds

  • Nilas ice
  • Posts: 1714
    • View Profile
    • Dosbat
  • Liked: 2
  • Likes Given: 0
Re: The 2015 melting season
« Reply #1395 on: June 18, 2015, 08:59:03 PM »
HYCOM makes me think we may be seeing a crash this year.
http://dosbat.blogspot.co.uk/2015/06/are-we-facing-crash-in-2015.html

But I want to see what the rest of this month brings before deciding either way.

Neven

  • Administrator
  • First-year ice
  • Posts: 7781
    • View Profile
    • Arctic Sea Ice Blog
  • Liked: 1145
  • Likes Given: 537
Re: The 2015 melting season
« Reply #1396 on: June 18, 2015, 09:33:07 PM »
I'll be using this comparison map for next month's assessment of melt ponds, but here's a sneak preview showing temperature anomalies and average sea level pressure for the June 1-15 period:



Not as 'hot' as 2011 or 2012, but definitely not as cool as 2013 and 2014. When it comes to SLP, there's a beautiful Dipole-ish division between high and low, smack down the middle of the prime meridian. But again, the Arctic isn't dominated by clear sky high-pressure areas like in 2011 and 2012.
Il faut comparer, comparer, comparer, et cultiver notre jardin

seaicesailor

  • Guest
Re: The 2015 melting season
« Reply #1397 on: June 18, 2015, 11:49:38 PM »
HYCOM makes me think we may be seeing a crash this year.
http://dosbat.blogspot.co.uk/2015/06/are-we-facing-crash-in-2015.html

But I want to see what the rest of this month brings before deciding either way.

Great post and comments, thx.
That (probable) thinning in ESS is scary indeed. BTW the same model predicts Beaufort MYI approach the coast, and get thinner. Open waters are warming up enough perhaps, plus insolation?

jdallen

  • Young ice
  • Posts: 3256
    • View Profile
  • Liked: 535
  • Likes Given: 208
Re: The 2015 melting season
« Reply #1398 on: June 19, 2015, 01:49:06 AM »
HYCOM makes me think we may be seeing a crash this year.
http://dosbat.blogspot.co.uk/2015/06/are-we-facing-crash-in-2015.html

But I want to see what the rest of this month brings before deciding either way.

Great post and comments, thx.
That (probable) thinning in ESS is scary indeed. BTW the same model predicts Beaufort MYI approach the coast, and get thinner. Open waters are warming up enough perhaps, plus insolation?
Perhaps.

On my mind is the distribution of ice, by volume.

We have been taking comfort from the fact that volume rebounded in 2013/14.  What we may be overlooking is the distribution of that volume is highly asymmetric.

We have coverage in the ESS, Laptev, Chukchi and Kara, but not the volume it needs to survive.  We have volume in the CAB, but also know *that*ice is not uniform. Winter and current export through the Fram has thinned ice north and east of the Barents considerably. Most of our saved volume is in the CAB, and I'd  wager over half that is smashed up within 400 KM of the CAA.  That certainly won't melt out, and we may see disconnected "islands" of MYI surviving in the CAB and Beaufort.  Trace out where you see ice 1.75 or thinner, and I suspect that will be close to showing us what will disappear. We may still end up with more volume and area than 2012, but less extent.

Another thought to ponder; heat continued well into October last season, with peripheral melt happening after minimum even as portions of the CAB started re freezing.  Will increased seasonal heat and El Niño conspire to extend the active melt for a later minimum? 

I'm in Chris Reynolds camp; one good smash is all it would take to change the story being played out.

My metaphor for you - it's like watching a high wire walker trying to cross Niagra falls in a windstorm without either pole or net. Getting to the other side (of the melt season)  intact is more a matter of luck than it is dependent on the current state of things.

One good gust (smash)....

This space for Rent.

seaicesailor

  • Guest
Re: The 2015 melting season
« Reply #1399 on: June 19, 2015, 02:54:53 AM »
 I will try my first gif


Not well tuned  :(
Its 40 days or so of Beaufort front evolution form MODIS

I see a few interesting things but its so late, took so long, tomorrow.

Edit: fixed link thx Vergent
« Last Edit: June 19, 2015, 03:50:41 AM by seaicesailor »