Support the Arctic Sea Ice Forum and Blog

Author Topic: The 2015 melting season  (Read 1846952 times)

12Patrick

  • Frazil ice
  • Posts: 140
    • View Profile
  • Liked: 0
  • Likes Given: 0
Re: The 2015 melting season
« Reply #2850 on: July 31, 2015, 10:45:20 AM »
Slow Wing


When it comes to compaction vs dispersal remember Ekman pumping. The Coriolis effect is very strong in Arctic waters turning everything toward the right.


Terry
Like the impeller on a centrifugal pump.

BornFromTheVoid

  • Nilas ice
  • Posts: 1264
    • View Profile
  • Liked: 596
  • Likes Given: 212
Re: The 2015 melting season
« Reply #2851 on: July 31, 2015, 11:47:40 AM »
I think we really need to keep an eye on the Atlantic side over the next week.

There is very little thick ice in the region, and what is there appears to be moving toward the Pacific sector. All the while there are some very mild SSTs about, easily capable of eating into the ice and providing warmth and moisture for additional melt from above.




The ECM shows high pressure dominating the region for the next week, generally steering warm, moist air from those high SSTs up over the thin ice, as well as toasty upper air values.




We've already seen a strong northward retreat of the ice here over the last few days, and this could very well continue or accelerating under the current regime.

I recently joined the twitter thing, where I post more analysis, pics and animations: @Icy_Samuel

slow wing

  • Grease ice
  • Posts: 819
    • View Profile
  • Liked: 156
  • Likes Given: 506
Re: The 2015 melting season
« Reply #2852 on: July 31, 2015, 12:29:10 PM »
Actually it is a great disperser for the ice by virtue of Coriolis (if he put the name to the force rightfully)
Would have thought it was centripetal force/effect. It also seems straightforward: the moving ice wants to continue travelling in a straight line rather than bending around in the circular path of the wind. So that will cause dispersion. Is there more to it?

iceman

  • Frazil ice
  • Posts: 285
    • View Profile
  • Liked: 7
  • Likes Given: 19
Re: The 2015 melting season
« Reply #2853 on: July 31, 2015, 12:34:12 PM »
<normally I'd let this stand, except when someone can't defend himself, sorry; N.>
« Last Edit: July 31, 2015, 03:15:22 PM by Neven »

seaicesailor

  • Guest
Re: The 2015 melting season
« Reply #2854 on: July 31, 2015, 12:47:26 PM »
Actually it is a great disperser for the ice by virtue of Coriolis (if he put the name to the force rightfully)
Would have thought it was centripetal force/effect. It also seems straightforward: the moving ice wants to continue travelling in a straight line rather than bending around in the circular path of the wind. So that will cause dispersion. Is there more to it?
Northern Hemisphere:

Low pressure anti-clockwise rotating winds drag ice. Ice deviates to the left right due to Coriolis. The streamlines therefore diverge in spiral fashion. Ocean water upwelling is forced. Why? Because pumping water up is required in order to fill in what otherwise would become void.

Even when low pressure surface winds converge in spiral toward the right left (since, for surface winds, pressure gradient is aided by surface friction to compensate Coriolis), ice drift deviation wrt wind toward the left right is even larger, because Coriolis force over ice dominates.

EDIT: Tried to make it correct

This is overly simplified but more or less correct. Not shared by all here.
« Last Edit: July 31, 2015, 02:17:34 PM by seaicesailor »

plinius

  • Frazil ice
  • Posts: 403
    • View Profile
  • Liked: 0
  • Likes Given: 0
Re: The 2015 melting season
« Reply #2855 on: July 31, 2015, 01:18:30 PM »
icesailor, I think you mixed up your hemispheres/hands.

Rubikscube

  • Frazil ice
  • Posts: 254
    • View Profile
  • Liked: 5
  • Likes Given: 4
Re: The 2015 melting season
« Reply #2856 on: July 31, 2015, 01:31:10 PM »
Its not just the ice north of CAA that is cracking up and leaving the shores, also some of the most resilient ice in between the islands is cracking up and exiting north. This picture is todays modis from Prince Gustav Adolf Sea (to the west) and Peary Channel, both areas which have always seen close to 100% concentration at minimum as far as satellite records go.
I don't know about 100% concentration at minimum, RC, but things cracked up completely back in 2010 and 2011 as well (and probably 2012 too, but I can't remember), with ice moving into the CAA from the CAB.

This year might be earlier though, and it's the way around now, ie ice moving from the CAA to the CAB.

Yes, the ice was pretty meshed up those years (most notably in 2011 I think), but it never left the building, not according to Uni-Bremen maps at least. I'm not sure if those channels will clear up this year either, but the chances are increasing. Note that the narrower channel in the bottom of your 2010 animation, Sverdrup Channel, has been partly or virtually ice free on several previous occasions.

As for the ice in Beaufort, I think everything south of 75N is toast. An ice pack suffering from such low concentration this far south in July simply cannot survive, not unless the import of ice from CAB reaches absurd levels. Just because the ice is stubborn MYI doesn't mean it is immortal.

DavidR

  • Grease ice
  • Posts: 736
    • View Profile
  • Liked: 33
  • Likes Given: 3
Re: The 2015 melting season
« Reply #2857 on: July 31, 2015, 01:51:35 PM »
Another beautiful sunny day in the Barents! There may not be much ice to melt but there is an awful lot of warming ocean under those clear skies.

https://earthdata.nasa.gov/labs/worldview/?p=arctic&l=MODIS_Aqua_CorrectedReflectance_TrueColor%28hidden%29,MODIS_Terra_CorrectedReflectance_TrueColor,Graticule,Coastlines&t=2015-07-31&v=-1114020.503589117,-745696.1840893566,2818139.496410883,1185567.8159106434

Over the next month that  warm water will  be attacking the CAB to  keep  extent  down!!
Toto, I've a feeling we're not in Kansas anymore

seaicesailor

  • Guest
Re: The 2015 melting season
« Reply #2858 on: July 31, 2015, 02:11:11 PM »
icesailor, I think you mixed up your hemispheres/hands.

Yeah probably I messed it up, I'll edit it.

seaicesailor

  • Guest
Re: The 2015 melting season
« Reply #2859 on: July 31, 2015, 02:20:19 PM »
icesailor, I think you mixed up your hemispheres/hands.
Corrections:

Northern Hemisphere:

Low pressure anti-clockwise rotating winds drag ice. Ice deviates to the left right due to Coriolis. The streamlines therefore diverge in spiral fashion. Ocean water upwelling is forced. Why? Because pumping water up is required in order to fill in what otherwise would become void.

Even when low pressure surface winds converge in spiral toward the right left (since, for surface winds, pressure gradient is aided by surface friction to compensate Coriolis), ice drift deviation wrt wind toward the left right is even larger, because Coriolis force over ice dominates.

This is overly simplified but more or less correct. Not shared by all here.

Nightvid Cole

  • Frazil ice
  • Posts: 437
    • View Profile
  • Liked: 5
  • Likes Given: 0
Re: The 2015 melting season
« Reply #2860 on: July 31, 2015, 03:01:45 PM »
Wipneus compactness is below 2012 right now, on all 3 metrics, indicating that "slush" has continued to take over the Arctic:


Neven

  • Administrator
  • First-year ice
  • Posts: 7777
    • View Profile
    • Arctic Sea Ice Blog
  • Liked: 1143
  • Likes Given: 537
Re: The 2015 melting season
« Reply #2861 on: July 31, 2015, 03:16:31 PM »
No general Ekman/Coriolis discussions! Stop it now! Go away to another thread!  ;D
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 #2862 on: July 31, 2015, 03:21:35 PM »
No general Ekman/Coriolis discussions! Stop it now! Go away to another thread!  ;D

;-) think that's all clarified, apart from that I admit to have found the past discussion invigorating.

Nightvid Cole

  • Frazil ice
  • Posts: 437
    • View Profile
  • Liked: 5
  • Likes Given: 0
Re: The 2015 melting season
« Reply #2863 on: July 31, 2015, 03:29:04 PM »
Witness the (first-ever) "Lomonosov Ridge channel", an expressway from Russia to Ellesmere Island:




JimD

  • Nilas ice
  • Posts: 2270
    • View Profile
  • Liked: 3
  • Likes Given: 0
Re: The 2015 melting season
« Reply #2864 on: July 31, 2015, 04:18:11 PM »
Wow that was fun...for a time there, before our recently departed departed, I was getting a whole new perspective on collapse dynamics  :P
We do not err because truth is difficult to see. It is visible at a glance. We err because this is more comfortable. Alexander Solzhenitsyn

How is it conceivable that all our technological progress - our very civilization - is like the axe in the hand of the pathological criminal? Albert Einstein

seaicesailor

  • Guest
Re: The 2015 melting season
« Reply #2865 on: July 31, 2015, 05:08:30 PM »
Since discussions on ice divergence are so frequent and end up being off-topic, I have opened the following thread. It is a kind invitation to people with knowledge on the problem, to explain, add links , ..., so that we can use that material as a reference  :)

Neven please let me know if it is ok, or requires any change

http://forum.arctic-sea-ice.net/index.php/topic,1344.0.html

« Last Edit: July 31, 2015, 08:03:02 PM by seaicesailor »

jdallen

  • Young ice
  • Posts: 3256
    • View Profile
  • Liked: 535
  • Likes Given: 208
Re: The 2015 melting season
« Reply #2866 on: July 31, 2015, 07:06:54 PM »
I think we really need to keep an eye on the Atlantic side over the next week.

There is very little thick ice in the region, and what is there appears to be moving toward the Pacific sector. All the while there are some very mild SSTs about, easily capable of eating into the ice and providing warmth and moisture for additional melt from above.
Concur. The heat in the Barents in particular is dangerous; I've been watching SSTs there for a bit. I'm sure they are responsible for the "knife edge" ice boundaries there near The islands.  That 4C+ anomaly is good to strip 15CM a day off any ice unfortunate to get swept over it.  As that is along the route taken by the remnants of the North Atlantic drift, that suggests considerable energy is being carried into the basin, at depth if not at the surface.
This space for Rent.

cesium62

  • Frazil ice
  • Posts: 291
    • View Profile
  • Liked: 11
  • Likes Given: 1
Re: The 2015 melting season
« Reply #2867 on: July 31, 2015, 07:33:19 PM »
Witness the (first-ever) "Lomonosov Ridge channel", an expressway from Russia to Ellesmere Island:

Sure you don't want to call that the Cole Channel?  ;-)

seaicesailor

  • Guest
Re: The 2015 melting season
« Reply #2868 on: July 31, 2015, 08:37:43 PM »
I think we really need to keep an eye on the Atlantic side over the next week.

There is very little thick ice in the region, and what is there appears to be moving toward the Pacific sector. All the while there are some very mild SSTs about, easily capable of eating into the ice and providing warmth and moisture for additional melt from above.
Concur. The heat in the Barents in particular is dangerous; I've been watching SSTs there for a bit. I'm sure they are responsible for the "knife edge" ice boundaries there near The islands.  That 4C+ anomaly is good to strip 15CM a day off any ice unfortunate to get swept over it.  As that is along the route taken by the remnants of the North Atlantic drift, that suggests considerable energy is being carried into the basin, at depth if not at the surface.

That region that is north of Kara/Laptev bite and reaches the Pole was thin in 2014 and all broken in 2013, but never melts out. 2012 even. Is there a year that did not resist?

Yet, there are dark marks that, now, to me, seem ice so thin that the ocean can be seen thru. And the fact, recalled here, that the Transpolar drift was off the charts past Winter.

More stuff to be christened this year.

Espen

  • Young ice
  • Posts: 3341
    • View Profile
  • Liked: 230
  • Likes Given: 1
Re: The 2015 melting season
« Reply #2869 on: July 31, 2015, 08:40:58 PM »
As we see in The Canadian Archipelago, where I see most of the until now "fast" ice will be gone during August, the same is seen in Northern Greenland in Danmark Fjord, Independence Fjord, Frederick E. Hyde Fjord, G. B Schley Fjord and maybe Hellefiskfjord the latter for the first time according to my memory, so instead of watching the big picture watch the details, something is very different this year!

http://rapidfire.sci.gsfc.nasa.gov/imagery/subsets/?subset=Arctic_r03c03.2015212.aqua.250m
Have a ice day!

Bruce Steele

  • Nilas ice
  • Posts: 1905
    • View Profile
  • Liked: 504
  • Likes Given: 26
Re: The 2015 melting season
« Reply #2870 on: July 31, 2015, 09:03:34 PM »
Nightvid Cole,  Neven posted a map in the comment section of the ASIB that looks like your
Lomonosov Ridge Channel .


The question whether (weather) July made up for a lack of preconditioning is a good one. What do the melt ponds look like now?
Well, like it says in the update CAPIE is relatively low, but there's a lot of dispersal in the Beaufort and Chukchi, so it's not just melt ponds. But 2012 als had quite a lot of dispersal, ie open water between floes, on the Siberian side of the Arctic by now (and then the cyclone came).

In fact, Wipneus' compactness graph (which in principle is much more accurate, because it uses area and extent from the same sources) has 2015 as lowest in all three measures: NSIDC SSMIS 25km, JAXA AMSR-2 10 km, and Uni Hamburg AMSR-2 3.125 km.

And then there's this, a map produced by the Japanese Arctic Data archive System, based on JAXA AMSR-2 data:



I don't know how reliable that map is, but it's interesting and can be compared to data from previous years.

Plenty of melting potential.

Posted by: Neven | July 31, 2015 at 08:35


Sorry about sending you off to search for the post. Maybe you could repost here with your Lomonosav Channel ... Side by side?

Neven

  • Administrator
  • First-year ice
  • Posts: 7777
    • View Profile
    • Arctic Sea Ice Blog
  • Liked: 1143
  • Likes Given: 537
Re: The 2015 melting season
« Reply #2871 on: July 31, 2015, 09:27:46 PM »
Here's the map, Bruce, Wipneus regularly posts them in his AMSR-2 thread (they can be found here):

Il faut comparer, comparer, comparer, et cultiver notre jardin

greatdying2

  • Grease ice
  • Posts: 574
    • View Profile
  • Liked: 0
  • Likes Given: 0
Re: The 2015 melting season
« Reply #2872 on: July 31, 2015, 11:46:51 PM »
Here's the map, Bruce
Regarding the Beaufort, this map is perhaps consistent with the DMI thickness map, which suggests that although extent decreases may have slowed a bit recently, thickness in the Beaufort has been taking a hit.

http://polarportal.dk/en/havisen-i-arktis/nbsp/sea-ice-extent/ (Click the "thickness and volume" tab.)
« Last Edit: August 01, 2015, 02:17:58 AM by greatdying2 »
The Permian–Triassic extinction event, a.k.a. the Great Dying, occurred about 250 million years ago and is the most severe known extinction event. Up to 96% of all marine species and 70% of terrestrial vertebrate species became extinct; it is also the only known mass extinction of insects.

greatdying2

  • Grease ice
  • Posts: 574
    • View Profile
  • Liked: 0
  • Likes Given: 0
Re: The 2015 melting season
« Reply #2873 on: July 31, 2015, 11:52:10 PM »
July 30
The Permian–Triassic extinction event, a.k.a. the Great Dying, occurred about 250 million years ago and is the most severe known extinction event. Up to 96% of all marine species and 70% of terrestrial vertebrate species became extinct; it is also the only known mass extinction of insects.

Neven

  • Administrator
  • First-year ice
  • Posts: 7777
    • View Profile
    • Arctic Sea Ice Blog
  • Liked: 1143
  • Likes Given: 537
Re: The 2015 melting season
« Reply #2874 on: August 01, 2015, 11:44:34 AM »
Okay, everyone, August polls are up for:

NSIDC September average sea ice extent

and

CT daily sea ice area minimum

I want at least 100 votes for the NSIDC SIE poll, so don't let me down.  :)
Il faut comparer, comparer, comparer, et cultiver notre jardin

12Patrick

  • Frazil ice
  • Posts: 140
    • View Profile
  • Liked: 0
  • Likes Given: 0
Re: The 2015 melting season
« Reply #2875 on: August 01, 2015, 02:49:08 PM »
How many sites track Arctic Sea Ice volume other than PIOMAS? Have the links to them?

Neven

  • Administrator
  • First-year ice
  • Posts: 7777
    • View Profile
    • Arctic Sea Ice Blog
  • Liked: 1143
  • Likes Given: 537
Re: The 2015 melting season
« Reply #2876 on: August 01, 2015, 02:55:51 PM »
Organisations that track volume and have daily maps up, are AFAIK DMI, TOPAZ, ADS and NRL. Maybe there's one or two more.
Il faut comparer, comparer, comparer, et cultiver notre jardin

12Patrick

  • Frazil ice
  • Posts: 140
    • View Profile
  • Liked: 0
  • Likes Given: 0
Re: The 2015 melting season
« Reply #2877 on: August 01, 2015, 02:59:15 PM »
Organisations that track volume and have daily maps up, are AFAIK DMI, TOPAZ, ADS and NRL. Maybe there's one or two more.

Thanks Neven I have to add those to my favorites list...

12Patrick

  • Frazil ice
  • Posts: 140
    • View Profile
  • Liked: 0
  • Likes Given: 0
Re: The 2015 melting season
« Reply #2878 on: August 01, 2015, 03:09:24 PM »
ADS link did not open...

Nightvid Cole

  • Frazil ice
  • Posts: 437
    • View Profile
  • Liked: 5
  • Likes Given: 0
Re: The 2015 melting season
« Reply #2879 on: August 01, 2015, 04:24:50 PM »
CAB has begun its area cliff sooner than 2012 (Wipneus area, taken from Arctic Sea Ice Graphs page): (orange = 2012, green = 2013, pink = 2014)




12Patrick

  • Frazil ice
  • Posts: 140
    • View Profile
  • Liked: 0
  • Likes Given: 0
Re: The 2015 melting season
« Reply #2880 on: August 02, 2015, 01:04:06 AM »
Is there a chart that shows extent loss per day for the past month in a numerical form?

greatdying2

  • Grease ice
  • Posts: 574
    • View Profile
  • Liked: 0
  • Likes Given: 0
Re: The 2015 melting season
« Reply #2881 on: August 02, 2015, 01:48:14 AM »
Tommy is gone and now Tommy's Gap is closing. Coincidence?  ???
The Permian–Triassic extinction event, a.k.a. the Great Dying, occurred about 250 million years ago and is the most severe known extinction event. Up to 96% of all marine species and 70% of terrestrial vertebrate species became extinct; it is also the only known mass extinction of insects.

Villabolo

  • New ice
  • Posts: 61
    • View Profile
    • Global Warming Basics
  • Liked: 14
  • Likes Given: 30
Re: The 2015 melting season
« Reply #2882 on: August 02, 2015, 02:06:01 AM »
Tommy is gone and now Tommy's Gap is closing. Coincidence?  ???

I'm sure he and his gap might do an encore next year.  :)

Lou

  • New ice
  • Posts: 13
    • View Profile
  • Liked: 12
  • Likes Given: 53
Re: The 2015 melting season
« Reply #2883 on: August 02, 2015, 02:42:45 AM »
Tommy is gone and now Tommy's Gap is closing. Coincidence?  ???

I'm sure he and his gap might do an encore next year.  :)

I've always liked the idea of naming climate change-related events after high profile deniers, e.g. the Inhofe Gap, etc.

DavidR

  • Grease ice
  • Posts: 736
    • View Profile
  • Liked: 33
  • Likes Given: 3
Re: The 2015 melting season
« Reply #2884 on: August 02, 2015, 02:48:45 AM »
Is there a chart that shows extent loss per day for the past month in a numerical form?
Not sure what  you  really  want Patrick but  if you take the files here you can make your own graphs.
NSIDC Extent:
ftp://sidads.colorado.edu/DATASETS/NOAA/G02135/north/daily/data/

CT Area:
http://arctic.atmos.uiuc.edu/cryosphere/timeseries.anom.1979-2008/
« Last Edit: August 02, 2015, 11:42:24 AM by DavidR »
Toto, I've a feeling we're not in Kansas anymore

12Patrick

  • Frazil ice
  • Posts: 140
    • View Profile
  • Liked: 0
  • Likes Given: 0
Re: The 2015 melting season
« Reply #2885 on: August 02, 2015, 03:13:09 AM »
Is there a chart that shows extent loss per day for the past month in a numerical form?
Not sure what  you  really  want Patrick but  if you take the files here you can make your own graphs.
NSIDC Extent:
ftp://sidads.colorado.edu/DATASETS/NOAA/G02135/north/daily/data/
CT Area:
http://arctic.atmos.uiuc.edu/cryosphere/timeseries.anom.1979-2008

Just a day by day chronology over the past 30 days of extent in numerical figures...

slow wing

  • Grease ice
  • Posts: 819
    • View Profile
  • Liked: 156
  • Likes Given: 506
Re: The 2015 melting season
« Reply #2886 on: August 02, 2015, 04:12:24 AM »
The U. Bremen map update shows the ice getting tossed around by the low pressure system that is about midpoint between the North Pole and the Alaskan coast. There are some really big holes in the Beaufort Sea ice pack now - 100 km scale.

On the Atlantic side, a high pressure system is nibbling away at the ice edge in front of Svalbard and off Greenland's Eastern coast.




Click on gif to flash through latest three maps...



12Patrick

  • Frazil ice
  • Posts: 140
    • View Profile
  • Liked: 0
  • Likes Given: 0
Re: The 2015 melting season
« Reply #2887 on: August 02, 2015, 05:03:20 AM »
The U. Bremen map update shows the ice getting tossed around by the low pressure system that is about midpoint between the North Pole and the Alaskan coast. There are some really big holes in the Beaufort Sea ice pack now - 100 km scale.

On the Atlantic side, a high pressure system is nibbling away at the ice edge in front of Svalbard and off Greenland's Eastern coast.




Click on gif to flash through latest three maps...
  I ran the 3 image loop and saw some noise up in the Sea Of Okhotsk and Bering Sea and was wondering if that noise is being added to the daily extent by accident?
« Last Edit: August 02, 2015, 05:09:34 AM by 12Patrick »

jdallen

  • Young ice
  • Posts: 3256
    • View Profile
  • Liked: 535
  • Likes Given: 208
Re: The 2015 melting season
« Reply #2888 on: August 02, 2015, 05:50:27 AM »
I ran the 3 image loop and saw some noise up in the Sea Of Okhotsk and Bering Sea and was wondering if that noise is being added to the daily extent by accident?

That happens a *lot* - general consensus is that it's surf or some thing similar that gets stirred up and fools the satellite sensors.

Its never significant, and typically disappears by the next day.  I suspect the folks running the analysis don't think its worth the trouble to try coding it out.  Personally, I tend to agree with them.
This space for Rent.

12Patrick

  • Frazil ice
  • Posts: 140
    • View Profile
  • Liked: 0
  • Likes Given: 0
Re: The 2015 melting season
« Reply #2889 on: August 02, 2015, 05:58:14 AM »
I ran the 3 image loop and saw some noise up in the Sea Of Okhotsk and Bering Sea and was wondering if that noise is being added to the daily extent by accident?

That happens a *lot* - general consensus is that it's surf or some thing similar that gets stirred up and fools the satellite sensors.

Its never significant, and typically disappears by the next day.  I suspect the folks running the analysis don't think its worth the trouble to try coding it out.  Personally, I tend to agree with them.
Could it be birds or schools of fish?

seaicesailor

  • Guest
Re: The 2015 melting season
« Reply #2890 on: August 02, 2015, 07:20:33 AM »
Is there a chart that shows extent loss per day for the past month in a numerical form?
Not sure what  you  really  want Patrick but  if you take the files here you can make your own graphs.
NSIDC Extent:
ftp://sidads.colorado.edu/DATASETS/NOAA/G02135/north/daily/data/
CT Area:
http://arctic.atmos.uiuc.edu/cryosphere/timeseries.anom.1979-2008

Just a day by day chronology over the past 30 days of extent in numerical figures...

ftp://sidads.colorado.edu/DATASETS/NOAA/G02135/north/daily/data/

I think the extent data link David gave you was broken, this one should work. The small "*_nrt.csv' file is current year data in csv format, and the big one " final" is historiical data.


jdallen

  • Young ice
  • Posts: 3256
    • View Profile
  • Liked: 535
  • Likes Given: 208
Re: The 2015 melting season
« Reply #2891 on: August 02, 2015, 08:21:34 AM »
I ran the 3 image loop and saw some noise up in the Sea Of Okhotsk and Bering Sea and was wondering if that noise is being added to the daily extent by accident?

That happens a *lot* - general consensus is that it's surf or some thing similar that gets stirred up and fools the satellite sensors.

Its never significant, and typically disappears by the next day.  I suspect the folks running the analysis don't think its worth the trouble to try coding it out.  Personally, I tend to agree with them.
Could it be birds or schools of fish?
*Extraordinarily* unlikely.  The largest schools or flocks ever seen would scarcely fill a pixel  at the resolution of these maps. 

No, its a weather phenomenon of some sort.
This space for Rent.

12Patrick

  • Frazil ice
  • Posts: 140
    • View Profile
  • Liked: 0
  • Likes Given: 0
Re: The 2015 melting season
« Reply #2892 on: August 02, 2015, 08:37:36 AM »
I ran the 3 image loop and saw some noise up in the Sea Of Okhotsk and Bering Sea and was wondering if that noise is being added to the daily extent by accident?

That happens a *lot* - general consensus is that it's surf or some thing similar that gets stirred up and fools the satellite sensors.

Its never significant, and typically disappears by the next day.  I suspect the folks running the analysis don't think its worth the trouble to try coding it out.  Personally, I tend to agree with them.
Could it be birds or schools of fish?
*Extraordinarily* unlikely.  The largest schools or flocks ever seen would scarcely fill a pixel  at the resolution of these maps. 

No, its a weather phenomenon of some sort.
Fog? Methane hydrates bubbling up?
« Last Edit: August 02, 2015, 08:58:22 AM by 12Patrick »

BornFromTheVoid

  • Nilas ice
  • Posts: 1264
    • View Profile
  • Liked: 596
  • Likes Given: 212
Re: The 2015 melting season
« Reply #2893 on: August 02, 2015, 09:39:50 AM »
The regions well away from the Arctic would be masked out in the area and extent calculation (or at least should be). The most likely cause of errors are weather (dense clouds and falling rain), mixed pixels and plain old noise.
It's definitely not fish or birds.
I recently joined the twitter thing, where I post more analysis, pics and animations: @Icy_Samuel

Nick Stokes

  • New ice
  • Posts: 3
    • View Profile
    • Moyhu
  • Liked: 0
  • Likes Given: 0
Re: The 2015 melting season
« Reply #2894 on: August 02, 2015, 09:46:18 AM »
12Patrick
  <i>"Is there a chart that shows extent loss per day for the past month in a numerical form?"</i>
 
  Yes, "http://www.moyhu.blogspot.com.au/p/latest-ice-and-temperature-data.html
  (scroll down for longer version). The JAXA original data are at
  https://ads.nipr.ac.jp/vishop/data/graph/plot_extent_n_v2.csv.
  NSIDC ftp://sidads.colorado.edu/DATASETS/NOAA/G02135/north/daily/data/NH_seaice_extent_nrt.csv.
 
 

Nick Stokes

  • New ice
  • Posts: 3
    • View Profile
    • Moyhu
  • Liked: 0
  • Likes Given: 0
Re: The 2015 melting season
« Reply #2895 on: August 02, 2015, 09:57:46 AM »

ChrisReynolds

  • Nilas ice
  • Posts: 1714
    • View Profile
    • Dosbat
  • Liked: 2
  • Likes Given: 0
Re: The 2015 melting season
« Reply #2896 on: August 02, 2015, 12:19:38 PM »
I ran the 3 image loop and saw some noise up in the Sea Of Okhotsk and Bering Sea and was wondering if that noise is being added to the daily extent by accident?

That happens a *lot* - general consensus is that it's surf or some thing similar that gets stirred up and fools the satellite sensors.

Its never significant, and typically disappears by the next day.  I suspect the folks running the analysis don't think its worth the trouble to try coding it out.  Personally, I tend to agree with them.
Could it be birds or schools of fish?
*Extraordinarily* unlikely.  The largest schools or flocks ever seen would scarcely fill a pixel  at the resolution of these maps. 

No, its a weather phenomenon of some sort.
Fog? Methane hydrates bubbling up?

No.

It's generally caused by land/ocean boundary issues and weather. Okhotsk and Bering show extent in the nrt data, but historically no extent at this time in summer in the final. Just disregard this and when the nrt data becomes final next year these stray pixcels will be removed.

ChrisReynolds

  • Nilas ice
  • Posts: 1714
    • View Profile
    • Dosbat
  • Liked: 2
  • Likes Given: 0
Re: The 2015 melting season
« Reply #2897 on: August 02, 2015, 02:34:50 PM »
July Blog post - How Low Can It Go...
http://dosbat.blogspot.co.uk/2015/08/july-status-how-low-can-it-go.html

I last used that title in mid August 2012, the only year PIOMAS has released data mid month!

Blink comparison. 31 July 2012 and 2015. Red line is 15 September 2012 ice edge.
« Last Edit: August 02, 2015, 06:27:19 PM by ChrisReynolds »

Quantum

  • New ice
  • Posts: 99
    • View Profile
  • Liked: 0
  • Likes Given: 0
Re: The 2015 melting season
« Reply #2898 on: August 02, 2015, 03:26:56 PM »
Hi everyone, still novice at this whole thing but I'd appreciate any criticism of my posts.
I've tried to insert an image from the ICON/DWD model for 24 hours from now (annotated)



There are two features of interest, there is a cold core low spinning over the arctic. Again, my view on this is that it isn't going to significantly harm the ice. The airmass is very cold underneath it, precipitation is solid and although there is an argument that clear skies are preferable (though I'm still not sure how cloud type comes into this) clear spells in this LP have to be preferable to near constant fog under a dirty high. Wind and waves would also be fairly low. There is an occluded front which I have labelled on the map, but since this low originated over the arctic the airmass difference bounded by the front is almost trivial so we are talking light snow. Also there is going to, surprisingly, be some accumulation (up to 5cm!) from this feature which can only be beneficial.

The 2nd feature is a 2ndry system that originated outside the arctic, the cold front labeled defines a very sharp boundary between very cold dry air and very warm moist air. Consequently this feature will give heavy snow on the arctic facing side and heavy rain in its warm sector. Wind and waves will accompany this LP aswell although the shot of warm air will not affect any still frozen sea ice (though will raise the SSTs).

Thankfully (contrary to previous forecasts) the 2ndry feature is not projected to move northward or develop significantly.

Buddy

  • Young ice
  • Posts: 3379
  • Go DUCKS!!
    • View Profile
  • Liked: 49
  • Likes Given: 34
Re: The 2015 melting season
« Reply #2899 on: August 02, 2015, 03:28:14 PM »
Quote
Blink comparison. 31 July 2012 and 2015. Red line is 15 September 2007 ice edge.

Chris....LOVE the "blink comparison".  It would be interesting to see where the two are at mid-month in August in a couple of weeks.

Interesting times.....

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