The 2019 melting season

[uniquorn]

The latest NSIDC "quick look" sea ice age map:

Thanks Jim. Animation for (most of) this melting season from week ending mar25-sep2
edit: ani removed as it is reposted downthread

[Jim Hunt]

Thanks Jim. Animation for (most of) this melting season from week ending mar25-sep2

My pleasure Oren!

Note in particular all the red stuff disappearing down the Nares Strait this year.

[Freegrass]

I  think it will require more import of oceanic heat - from the Atlantic side in particular - to push the system out of the state I think it may have settled into.

Where would this heat come from? As the Gulf Stream slows down, less heat will get transported into the arctic, no?

"We see a cooling southeast of Greenland, although everywhere else on the globe you see a warming," said Levke Caesar, a scientist at the Potsdam Institute for Climate Impact Research in Germany and co-author of a study that found the current to be 15% weaker. "When the circulation slows down, we have less heat transport to that region."

https://phys.org/news/2019-08-gulf-stream-seas-hotter-florida.html

[RoxTheGeologist]

This makes a big assumption - that system behavior will be consistent as we reach that limit.

Based on the surprising end of season slowdown this year, I'm not sure that's safe. I'm still mulling hypotheses for what we are seeing and why the dynamics are not falling more in line with your assumptions. 

"Blue Ocean" is a boundary condition, and the retreat of the ice to where it stands now - post 2007 - suggests to me that the dynamics for the ice north of 80 are significantly different from those of the peripheral seas, which is were most significant visible changes in the Arctic have unfolded.

This is my thought too; that there isn't enough insolation to melt the ice N of 80°N with the current FDD thickness increase, even in a sunny year. To melt the ice there has to be less FDDs. Increased oceanic heat isn't going to effect the high Arctic sea ice while vertical mixing is prohibited by the halocline. The latter isn't likely to disappear completely because of the input of fresh water from rivers and ice melt. Mixing can occur during big storms, but they seem to be rare in the summer. If that's the case, then seeing the high Arctic ice free is likely to require a warm, cloudy winter as well as a bright summer.

Did I just state the obvious?

[Archimid]

The obvious is nice this day and age.

[Niall Dollard]

This is my thought too; that there isn't enough insolation to melt the ice N of 80°N with the current FDD thickness increase, even in a sunny year.

At the end of July, I said as much, while the melt season thread was in full rampant flow.

From a discussion point of view, this seemed to be too controversial at the time and the discussion was taken off to another thread and died a death.

It is a pity that the melting season thread, at certain times of the year, can be a discouraging place to raise a different point of view.

 

[Espen]

This is my thought too; that there isn't enough insolation to melt the ice N of 80°N with the current FDD thickness increase, even in a sunny year.

At the end of July, I said as much, while the melt season thread was in full rampant flow.

From a discussion point of view, this seemed to be too controversial at the time and the discussion was taken off to another thread and died a death.

It is a pity that the melting season thread, at certain times of the year, can be a discouraging place to raise a different point of view.

 

The subject of sea ice extent/area/volume is now more related to gaming, unfortunately?

[selfservingalias]

had me fooled (if it isnt related to gaming)

[Aleph_Null]

The subject of sea ice extent/area/volume is now more related to gaming, unfortunately?

I appreciate your irreverence. At some point, it seems, instrumentation will (inevitably?) encounter difficulties with scads of scattered ice, and the numbers may seem academic to people checking out Worldview when the clouds clear over the Pole.

[oren]

This makes a big assumption - that system behavior will be consistent as we reach that limit.

Based on the surprising end of season slowdown this year, I'm not sure that's safe. I'm still mulling hypotheses for what we are seeing and why the dynamics are not falling more in line with your assumptions. 

"Blue Ocean" is a boundary condition, and the retreat of the ice to where it stands now - post 2007 - suggests to me that the dynamics for the ice north of 80 are significantly different from those of the peripheral seas, which is were most significant visible changes in the Arctic have unfolded.

This is my thought too; that there isn't enough insolation to melt the ice N of 80°N with the current FDD thickness increase, even in a sunny year. To melt the ice there has to be less FDDs. Increased oceanic heat isn't going to effect the high Arctic sea ice while vertical mixing is prohibited by the halocline. The latter isn't likely to disappear completely because of the input of fresh water from rivers and ice melt. Mixing can occur during big storms, but they seem to be rare in the summer. If that's the case, then seeing the high Arctic ice free is likely to require a warm, cloudy winter as well as a bright summer.

Did I just state the obvious?

This is true but ignores the effects of export. Some years, including 2019, see constant export out of the >80^o region, which effectively reduces thickness and lowers the threshold of heat required for meltout.

[Aluminium]

September 8-12.

2018.

[El Cid]

As we are preparing for the freezing season, I think it is useful to take a look at current SST anomalies. I present 2019/09/10 SST anomalies vs the composite of 2016 and 2012 on the same day.

The obvious takeaways:

- The Chukchi/Bering region is very hot and will likely delay freezing very long (thereby probably creating nice curves in the jetstream over Alaska and pushing cold air into the Hudson/Great Lakes region in Nov/Dec)
- The Barents is cold, probably due to the big amount of old ice that was pushed there during 2019. I don't know what to make of it really, as that sea is basically, mostly ice free and I do not think that will change this year. We'll see

[SimonF92]

Cold Eastern-Beaufort? Is that an artefact? Seems odd given the conditions there this melt season

[Shared Humanity]

Cold Eastern-Beaufort? Is that an artefact? Seems odd given the conditions there this melt season

Ice has been  imported from the cab and melting in this area of the Beaufort all season.

[SimonF92]

Cold Eastern-Beaufort? Is that an artefact? Seems odd given the conditions there this melt season

Ice has been  imported from the cab and melting in this area of the Beaufort all season.

Didn't the same thing happen in 2012 and 2016?

[SMN444]

The obvious takeaways:

- The Chukchi/Bering region is very hot and will likely delay freezing very long (thereby probably creating nice curves in the jetstream over Alaska and pushing cold air into the Hudson/Great Lakes region in Nov/Dec)

Will this alteration in the jetstream also tend to push ice into the CAA 'garlic press' or will the surface winds be disconnected from the jetstream?

[harpy]

Thanks Jim. Animation for (most of) this melting season from week ending mar25-sep2

My pleasure Oren!

Note in particular all the red stuff disappearing down the Nares Strait this year.

Thanks for pointing that out.

[El Cid]

The obvious takeaways:

- The Chukchi/Bering region is very hot and will likely delay freezing very long (thereby probably creating nice curves in the jetstream over Alaska and pushing cold air into the Hudson/Great Lakes region in Nov/Dec)

Will this alteration in the jetstream also tend to push ice into the CAA 'garlic press' or will the surface winds be disconnected from the jetstream?

Someone more qualified than me should answer that question because it seems an easy one but I am afraid that it is more comlicated than it seems, involving many variables

[Freegrass]

If this high pressure system doesn't compact the ice in the coming days, I think the melting season will be over.

Last 24h + Five day Forecast

Wind @ Surface
12 - 18 september 3 pm UTC

Use pause function and slider to go frame by frame.

[Shared Humanity]

Cold Eastern-Beaufort? Is that an artefact? Seems odd given the conditions there this melt season

Ice has been  imported from the cab and melting in this area of the Beaufort all season.

Didn't the same thing happen in 2012 and 2016?

The current cold anomaly is exactly where there is a finger of ice that is melting.

[Aleph_Null]

Aluminium + IWPD @ 850hPa (hindcast/forecast acquired 9/12 from Nullschool)

[subgeometer]

I have the chance to use a decent internet connection occasionally at the moment, so I've bodged a fix to my download script and begun downloading a bunch of sequences from Worldview to compile some movies with ffmpeg as I get to know the relevant encoding settings.

Here's a movie of most of the basin from May until the 11th(I was careless and missed the southern Beaufort and the Alaska coast). I'm not sure it will display here but should play fine on most any system. Hopefully the 15MB file size doesn't exceed a limit, if so I'll try resizing from 720 to 360p

Edit: that plays nicely on my barebones system after a considerable lag downloading, and reducing(naively) to 360p only gets file size down a few MB. It should be possible to get something like this down to half the size or a bit less  without any noticeable image quality loss or resorting to keyframing - I'll keep playing around

[subgeometer]

Another movie,( at a more reasonable 7MB) of the relentless conveyor feeding ice into the Beaufort Sea from 24-May through to 13 september. I should have gone a few weeks further back to breakup, and when I have time I'll grab the remaining frames to do so

[slow wing]

13 September is another of the dates on Neven's excellent year-to-year sea ice map comparison

It's easy to see that 2019 is one of the years with the lowest ice extent although that's qualitative.
(I have to admit that 2007 looks about as low as 2012 to me at a first glance, although we know 2012 is actually far lower.)

[sark]

September 16-17 Break will be stronger than expected.  This is the 2nd time in September that is verifying and both indicated by GFS at +15 days.  A third blocking pattern is predicted before the end of the month.  But then?

1st was Sept 5-7
2nd will be 16-17
3rd possible before month end

The third block is continually over Canada and displaced from the North Pole although quite energetic feature.  Being displaced it does not orient as a symmetrical quadrupole in the Arctic, but it is still arriving from both the Pacific and Atlantic basins simultaneously.

The idea that the 3rd Polar Front Break in September is kept out of the central Arctic after the preceeding 5 months of tropical air reaching the North Pole from both sides of the Earth simultaneously

LOL what is happening?

[sark]

Not to mention,  I finally found a place for 500mb Vector Windspeed

[Pavel]

The land snow cover extent start to increase. One can expect more precipitation and snow in the fall/winter due to extra open water and higher SSTs in the Arctic Ocean

[sailor]

September 8-12.

With the forecasted winds the tendency to squeeze the pack at both pacific and Atlantic side (pack dislodging now from Svalbard) will even strengthen. I guess the melting season keeps kicking the can for a few days into next week.

[Jim Hunt]

A "low bandwidth" animation of Arctic sea ice age since the 2015 minimum:

[Aleph_Null]

See the Nullschool Animations thread: https://forum.arctic-sea-ice.net/index.php/topic,2905.0.html

Hindcast: 9/10 to 9/14, Forecast: 9/14 to 9/18.
Wind + IWPD @ 850hPa [Instantaneous Wind Power Density: air density ρ, wind velocity v: ½ρv3]

[Jim Hunt]

JAXA/ViSHOP extent has fallen (just!) below the 2007 minimum:

http://GreatWhiteCon.info/2019/09/the-2019-arctic-sea-ice-metric-minima/#Sep-14

[Jim Hunt]

See the Nullschool Animations thread

A hopefully helpful hint for you:

https://forum.arctic-sea-ice.net/index.php/topic,2905.msg228498.html#msg228498

[Aleph_Null]

A hopefully helpful hint for you...

As you responded here, so will I. I'm not sure I understand you clearly. Do you mean to suggest that I post too many large files to the main thread? I've made every effort to be as economical with every byte as I can (unlike some here). The products I post in this thread have not been too large for many users.

I think this one, and the Aluminium+IWPD animation posted earlier, are of general interest and they're intended to expand viewership, frankly. Everything else goes in Nullschool Animations. Is that okay?

[Jim Hunt]

Is that okay?

If I were you I'd ask b.c. that question:

https://forum.arctic-sea-ice.net/index.php/topic,2791.msg228461.html#msg228461

[Aleph_Null]

If I were you I'd ask b.c. that question

With all due respect, I just did. Sorry to return to an OT matter, but you can take your response to the Nullschool Animations thread if you don't want the subject of what should be posted here cluttering up this thread.

I work pretty darn hard at what I do, and only post the 5 MB one here in the main thread every two days, where it's been one of the most viewed pieces. Say so if you don't want it here. Stop hinting.

[Jim Hunt]

NSIDC extent has also (barely) reached a new low for the year:

[Jim Hunt]

With all due respect, I just did.

What was his answer?

I work pretty darn hard at what I do,

I don't doubt it. However have you ever considered following Freegrass's illustrious example and employing the services of YouTube?

[gandul]

If I were you I'd ask b.c. that question

With all due respect, I just did. Sorry to return to an OT matter, but you can take your response to the Nullschool Animations thread if you don't want the subject of what should be posted here cluttering up this thread.

I work pretty darn hard at what I do, and only post the 5 MB one here in the main thread every two days, where it's been one of the most viewed pieces. Say so if you don't want it here. Stop hinting.

Be careful with answering Jim Hunt, you seem a candid poster and he's the worst troll if he wants to.

From my side, a 5 MB every two days is perfect. And I can't pay the Fibre service. Many false fariseos around, ignore.

[Thomas Barlow]

What's that?  4th lowest on record?

http://nsidc.org/arcticseaicenews/charctic-interactive-sea-ice-graph/

[Jim Hunt]

Be careful with answering Jim Hunt, you seem a candid poster and he's the worst troll if he wants to.

Especially if your name is Donald Trump!

http://GreatWhiteCon.info/2019/09/ship-of-fools-iii-escapes-arctic-sea-ice/#comment-289052

[Jim Hunt]

What's that?  4th lowest on record?

Yup, and currently 3rd lowest for JAXA/ViSHOP extent.

[be cause]

If I were you I'd ask b.c. that question

With all due respect, I just did.

 I only post the 5 MB one here in the main thread every two days, where it's been one of the most viewed pieces.

 Sorry Aleph Null .. with all due respect .. you just didn't !

 your posts are 'most viewed' as everyone who opens the page becomes one of your autoviewers whither they want to or not . Gaining views by force is unfair . I have now paid 4 times to see your latest post . Where do my invoices go ?
It should be noted that in a poll earlier this year only 1 person voted for self loading/playing posts on the forum . Who was that ?

Sorry to see Jim declared a troll .. I would like to thank him for years of dedicated and informed posting . Never needed to post numbskull.. sorry nullskool gifs .
  I never saw what NS brought to the table beyond prettifying hard information at a big cost in kbs . I saw no-one complain of it lacking on ASIF before this summer's deluge of data demanding posts
 

 and the melting season continues .. the bottom is hard to reach .. b.c.

 

[Aleph_Null]

Sorry to see Jim declared a troll

Me too. That "troll" talk goes nowhere and is unnecessary, imho. Your concern means everything to me (of course I asked you right up there, and you just answered), so I'll find some way to drastically cut back on the size of the hindcast/forecast version I post here. But in order for there to be equity, shouldn't there be some common standard of what is acceptable? There's a case to be made that visual content can convey useful information for many visitors.

Can I have a clean conscience if I limit mp4's posted here to 2.5 MB, every couple of days? Several in this thread have posted far more.

[Tom_Mazanec]

I too have been called a troll, so I know how that feels.

[be cause]

we are all trolls in someones eyes ..

it is not size that matters .. it is the viewers right to choose what they view that I consider so important . I would much rather click and play a gif of 15,000 kb than visit a page 10 times and have to pay to not see 10 or 20 gifs of any size every time I drop by . I don't understand why this is so hard to appreciate/understand .. b,c,


and the ice is still melting ! 

[gerontocrat]

........ this summer's deluge of data demanding posts
 

This problem has come up before - you can reduce the unwanted by altering your profile to reduce the messages displayed per page.

The default is 50, reducing to say, 25 (or even less), is supposed to reduce the load on your device. It does mean having to click onto the next page more often. (

see attached (you don't get the arrow)
_______________________________________
I have to say that if I've got a gif of more than a few hundred kb I deliberately make them more than 700 pixcels height and / or width. That stops the autoload.  For smaller image size on gifs I was reducing the number of loops, but then some people moaned because they wanted more.

I wonder if DungeonMaster could disable autoload - i.e. force "click to start" ?

[Jim Hunt]

I too have been called a troll, so I know how that feels.

I've been called much worse things than "troll" over the years:

http://GreatWhiteCon.info/2015/02/the-great-white-con-2015-new-einstein-award/

ROFL

Now back to the remains of the 2019 melting season....

[blumenkraft]

I too have been called a troll, so I know how that feels.

I've been called much worse things than "troll" over the years:

None of you both deserves to be called that!

[El Cid]

Please, please, pretty please, post these nullschool animations on the nullschool thread - as had been said before many times, they usually have no added value whatsoever. They look gooood, and are animated, and have all sorts of nice colors but frankly a simple meteorological chart gives you a much better picture of what is going on.
Besides, posting a forecast every day is totally unnecessary. Rarely do important changes happen that necessitate posting a new forecast. Yes, sometimes interesting phenomena come up (eg. a huge warm/cold intrusion, big ridging, extreme wind, etc) but surely not every day...

[Aleph_Null]

I don't understand why this is so hard to appreciate/understand.

Now I'm stuck OT, but it feels disrespectful for me to continue posting mp4's given that you view it as inexplicable. Animated gifs are roughly 3 times larger for the content I prepare. It's possible to respectfully disagree with you about larger files being preferable.