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Messages - subgeometer

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1
Arctic sea ice / Re: The 2019 melting season
« on: September 21, 2019, 11:27:31 PM »
I was away for a few days, but it took me about 5 seconds to decide it would be good to call the minimum. The 2019/2020 freezing season thread is open.

Thanks for all the contributions. There is plenty of signal between the noise for historians to make note of, 500 years from now.  ;)

2
Arctic sea ice / Re: The 2019 melting season
« on: September 14, 2019, 01:09:52 PM »
A "low bandwidth" animation of Arctic sea ice age since the 2015 minimum:




3
Arctic sea ice / Re: The 2019 melting season
« on: September 03, 2019, 08:46:09 PM »
Make sure that you select the option "area weight grids: yes" to get proper area weighting.  If you don't select that option, the calculation is skewed toward the high latitudes (just like in the DMI 80N temperature graph).
Thanks for clarifying.

4
Arctic sea ice / Re: The 2019 melting season
« on: September 01, 2019, 02:38:10 PM »


I'm happy to discuss this somewhere else! Just let me know where...

Anywhere but here...

5
Arctic sea ice / Re: The 2019 melting season
« on: August 29, 2019, 05:42:38 PM »
That graphic of ice movement vectors overlaying the U. Hamburg ice map is most useful in showing that the stall in extent drop has not been caused by a stall in melting. Bottom melting has continued while the ice has been dispersed by the weather for the past week. The apparent stall isn't really good news for sea ice. The ice volume is still very low as we shall soon see in PIOMAS.

This melting season has been very interesting and complicated.

I think we are going to see one more period of extent drops. There is too much heat in the Arctic ocean for bottom melting to stop in the next week, so don't call the melting season over just yet.

6
Arctic sea ice / Re: The 2019 melting season
« on: August 26, 2019, 02:55:32 AM »
I just have one very scientific thing to say ... the ice looks like Shit!

The Laptev and Beaufort are getting hammered.  The extent in Beaufort is going up, but the ice that is getting flushed into the south Beaufort is the last of the multi year 5+ ice. 

This year is unlikely to break records for extent (although it is still too early to rule that out for certain) but, the ice going into the freezing season is going to be about the worst it has ever been. 

Just play around on Worldview for a few minutes.  It looks terrible.

7
Thanks for the update. The race is over for the first place at minimum. But 2019 can take the lead again in the fall

8
Arctic sea ice / Re: The 2019 melting season
« on: August 19, 2019, 06:57:04 PM »
Am I going crazy or is there a LOT of ice being exported thru the Fram and Svalbard right now? I feel like not that long ago the area was *somewhat* surrounded by blue water (except north) and now I see lots of ice being pushed into the region. Maybe I'm confused or misread what I saw earlier.

9
Arctic sea ice / Re: The 2019 melting season
« on: August 18, 2019, 08:59:10 PM »
Let's wave goodbye to the off-topic subject.

10
Arctic sea ice / Re: The 2019 melting season
« on: August 18, 2019, 06:33:35 PM »
While ice was exported to Fram and Beaufort, it was replenished a lot of the time from the ESS and Laptev. In addition, the CAA CAB crack was some of the missing ice, and the big holes that appear in the CAB on any cloud-free image are the rest.

11
Arctic sea ice / Re: The 2019 melting season
« on: August 16, 2019, 11:36:49 PM »
The 850 mPa above overlaid with latest AMSR2 concentration using a very rudimenrary tool...
It seems the ESS corner is going to suffer most the heat but the winds will be stronger at Laptev. In any case, it is a swift beat to all this peripheral ice.

12
Arctic sea ice / Re: The 2019 melting season
« on: August 12, 2019, 01:37:20 AM »
I am amazed how easily the human is deceived and can "see" patterns with minimal data....

Canals on Mars.

13
Arctic sea ice / Re: The 2019 melting season
« on: August 10, 2019, 12:25:44 AM »
You contradict yourself.
Why would you expect the Central Basin to continue behaving as it has when its' neighbors are nearly gone?

Because the "neighbors" basically disappear every year now.

What % of the ice volume at year end is in the CAB? 80-90%?

This year is a great example. The periphery is getting crushed, CAB area is higher than the 2010's average. For the most part, SST's are stalled where the water transitions from shallow to deep.

The $64K question is how do you get sustained heat to the pole w/o warm SST's? You need freak weather as in 2012. That can certainly happen, but we can't predict it. Freak winds can also do the trick, but also not predictable.

The first BOE could come 50 years from now. There's simply no conclusive evidence that we can extrapolate the past losses of the shallow Arctic to future losses in the deep Arctic. Two different animals.
It all sounds nice but not supported by facts:
The Beaufort, ESS, Laptev and Chukchi all trend toward earlier meltout, which does matter to the CAB.
In 2000-2003 CAB volume at minimum was around 8500 km3, while in 2012 it reached 3500 km3, and several years came in at around 4000 km3. With such a change in 10-15 years, what makes you think the rest will take 50 years?
If it takes freak 2012 weather to melt the CAB, how did 2016 match 2012 CAB area? Or even go lower according to NSIDC?
Why do the Laptev Bite and the Beaufort meltout occur early over deep waters, while the shallow ESS normally holds out longer?

14
Arctic sea ice / Re: The 2019 melting season
« on: August 02, 2019, 07:00:00 PM »
Playing around with the Slider long term options. Here are a few days of weather (M10 band) in the Arctic.

Is this kind of thing any useful for anyone?

15
Arctic sea ice / Re: The 2019 melting season
« on: August 02, 2019, 04:17:35 PM »
...
2019 definitely appears to be one of the worst years on this date. How bad will this melt season end up compared to previous worst years? Too early to tell?
Yes, too early. I see that unusually large amount of ice is now in the state which allows quick and massive melt under GAC-like conditions, by either low thickness, high fragmentation or both. In the same time i see large amounts of ice which are just barely enough thickness to survive if it'll be not too much wind and not too much insolation. I.e., the season arrived to the point where weather decides unusually much. And since "usual" is already pretty much - yep, too early to tell.

16
Arctic sea ice / Re: The 2019 melting season
« on: August 02, 2019, 03:35:00 PM »
Can we stay focused on the melt season?

17
Arctic sea ice / Re: The 2019 melting season
« on: August 02, 2019, 06:26:52 AM »
July 28 - August 1.

2018.

18
Arctic sea ice / Re: The 2019 melting season
« on: August 02, 2019, 05:52:03 AM »
With approx 40 days till the end of the melt season, all cards are still on the deck.

19
Arctic sea ice / Re: The 2019 melting season
« on: July 26, 2019, 01:58:31 PM »
Guys,guys!

We know why Neven is away and you want him to come back to this???

Take a chill pill, kiss and make up .and lets move on please?

20
Arctic sea ice / Re: The 2019 melting season
« on: July 26, 2019, 08:52:01 AM »
My lord, dipole starts setting up and people are getting their hackles up over 5-day averages. Relax. WAA just started in earnest today. It's gonna take a couple of days for that to show up in earnest on the rolling area averages.

This is going to look pretty silly by Monday.

21
Arctic sea ice / Re: The 2019 melting season
« on: July 23, 2019, 03:52:59 PM »
The incoming weather pattern is amazing.  OMG it's EXCITING.

The pattern brings a devestating combination of weather, climate, and geological processes.

That are currently expected to ramp up and wind down over roughly a 10 day period.

Peaking over roughly 6-7 days.


1.  MASSIVE amounts of solar insolation.  This is absolutely off the charts.  Models show a massive ridge developing over the next 48 hours over the Canadian basin.  This ridge over the Arctic will be centered over the Canadian basin especially Western Canadian basin and it is absolutely a monster. 

SOLAR INSOLATION AT THE NORTH POLE IS STILL ABOUT 460W/m2 and it drops to around 430W/M2 by August 1st and 400W/M2 around the 7th of August.

So this is really the very end of any impact solar insolation is going to have on this season directly in the Canadian basin.

And as we are currently riding melt momentum to maintain progressing as the most destructive melt season in modern human record keeping.

The weather has decided to ABRUPTLY cancel the mostly cloudy atmospherically benign/good for ice pattern and REPLACE it with a MONSTER DIPOLE

This isn't some 4-7 day slow change.   Where yeah the mass fields look good for melt but the cold air takes forever to scour out or the high pressure ridges are dirty and low clouds/fog run rampant.

No this EXPLOSION OF POWER is

BEYOND NUCLEAR FISSION
BEYOND NUCLEAR FUSION
BEYOND SUPERNOVA EXPLOSION

NO THIS IS SOMEWHERE BETWEEN OG BIG BANG AND MULTIVERSE BIG BANG.


2.  SSTS ARE  NEAR RECORD, AT RECORDS, AND MOSTLY ABOVE RECORD TERRITORY ALL OVER THE ARCTIC BASIN AT LARGE.

ENUF SAID...

3.  THE LONG FETCH KING KONG BUNDY'S HUGE BALL SACK OF HEAT SMASHING IT ALL!


WE COULD TAKE A BIG LEAD ON 2012 THEN 2012 WILL WILL PLAY CATCHUP ONCE THE GAC HITS.

ANYWAYS...


I SAID THAT IS WHAT YOU NEEDED TO GET A NEW RECORD JONALU TO CHANCE THIS IS PRETTY FREAKING EXCITING AS THIS IS A BEAST PATTERN CHANGE

22
Arctic sea ice / Re: The 2019 melting season
« on: July 22, 2019, 01:19:53 PM »
Perhaps more of a worry is that the low concentration area is at the tip of the atlantic current, here shown using mercator salinity at 34m. Note also the lower concentration area above the current further west.
edit: forgot scale

23
PIOMAS has updated the gridded thickness data to the 15th of this month. Volume calculated from this was 8.77 [1000km3]. That is the lowest for the day, with quite a margin.

Here is the animation.

Neven, web-master: I can't seem to modify the top post anymore to change the subject of this thread to the latest update.

24
Arctic sea ice / Re: The 2019 melting season
« on: July 21, 2019, 10:09:21 PM »
I suspect the worst pattern for ice at this time of year is the dipole pattern with low pressure in the ESS and high pressure over the CAA and Greenland. It favors the export of sea ice, the mixing of ocean heat with ice and intense melting of ice in the passages of the CAA.

25
Arctic sea ice / Re: The 2019 melting season
« on: July 21, 2019, 12:44:20 PM »
It's beginning to appear that the solid white area on this map is possibly the approximate region that will be ice-covered at minimum. Can anyone estimate the area?


That looks like an overly optimistic scenario to me regarding the Atlantic side and CAA.

26
Arctic sea ice / Re: The 2019 melting season
« on: July 17, 2019, 07:32:02 PM »
Take your time with family, Neven. I'm so sorry about your loss. We'll carry on here.

27
Arctic sea ice / Re: The 2019 melting season
« on: July 16, 2019, 06:17:19 AM »
Maybe I misunderstood him, but I thought he was talking about the ESS.  I don’t think there are any glaciers over there calving ice bergs, but I’m happy to be corrected if I’m wrong.  🤔

28
Arctic sea ice / Re: The 2019 melting season
« on: July 15, 2019, 10:30:18 PM »
When this season is over and we can compare what happened to what we expected, will that help us predict 2020 better?

I doubt it.

29
Arctic sea ice / Re: The 2019 melting season
« on: July 11, 2019, 09:47:25 PM »
You guys are completely overestimating how hard it is for the ice in the cab to melt north of 80 degrees north.

We haven't had that peak Insolation hit the CAB

A new record is unlikely.
Almost all ice North of 80 in the Laptev side is the FYI. It can melt out even if it Will stay in the High Arctic. Also we'll have early melt of the peripheral seas, the highest SST, more killing zones for the CAB ice that Will drift to the south. The melting season can Last longer due to the Ocean extra heat accumulated + more possibility of strong storms

30
Arctic sea ice / Re: The 2019 melting season
« on: July 10, 2019, 12:08:09 AM »
For those interested in anecdotal evidence of what happened in 2012 around this time, I can highly recommend my own writings (someone has to do it) on the ASIB at the time: ASI 2012 Update 6: piggy bank

It corroborates a lot of what friv is saying.

31
Arctic sea ice / Re: The 2019 melting season
« on: July 09, 2019, 10:02:56 PM »
XXX-rated Pole Hole showing up on 12z EURO

For when is the forecast, who is making it, and how trustworthy is this source? I've never seen this map before.

32
Arctic sea ice / Re: The 2019 melting season
« on: July 09, 2019, 06:47:06 PM »
PS what was the source by chance?
I really like the source - pogodaiklimat - because it has graphs of the past and not just a forecast like most weather sites. It compares with daily climatology. It shows a whole month at a time. And archives the graphs of past months and years that you can access at the bottom of the page.
Downsides are that it's in Russian (Google translate to the rescue), and only covers Russia and ex-soviet states, world big cities and the USA (but not Northern Canada or Greenland).

Here are my bookmarks plus a few others I managed to find now thanks to your question.
www.pogodaiklimat.ru/monitor.php?id=21432   Kotelny Island
http://www.pogodaiklimat.ru/monitor.php?id=21824  Tiksi
http://www.pogodaiklimat.ru/monitor.php?id=25051  Pevek
http://www.pogodaiklimat.ru/monitor3.php?id=PABR  Barrow
http://www.pogodaiklimat.ru/monitor.php?id=21982  Wrangel Island
http://www.pogodaiklimat.ru/monitor.php?id=20069  Vize island (Kara/CAB/Barents border)
http://www.pogodaiklimat.ru/monitor.php?id=20046  Heiss Island (Franz Josef Land)

33
Arctic sea ice / Re: The 2019 melting season
« on: July 09, 2019, 04:32:54 AM »
The GFS is trending towards a cool Arctic

Does that mean cyclones, or cool and calm?

I’m totally confused too.  I think the take home message is that this is an expert interpreting long term model results.  His interpretations are accurate, but long term models suck so we will wait and see what happens.  😝

34
Arctic sea ice / Re: The 2019 melting season
« on: July 08, 2019, 10:52:42 PM »
I've opened a special thread to specifically discuss the differences between 2012 and 2019. Be sure to read the rules, and please, post lots of maps, graphs and satellite images that show these differences.

Of course, you can post them here as well.

35
Arctic sea ice / Re: The 2019 melting season
« on: July 08, 2019, 09:14:37 PM »
In the meantime...Slater's model is pretty much unchanged the past few days.

Expected extent on Aug 27,2019: 4,31 M sq km

NSIDC extent on the same day of

2012: 3,94
2016: 4,77
2007: 4,83
2017: 5,00

Based on this, unless something extreme happens In July/Aug (superheat and or a big cyclone), it still looks like 2nd place for 2019.
What did the Slater model predict on this date for August 27, 2012? I'm betting that the prediction was more than 4.31Msqkm.

36
Arctic sea ice / Re: The 2019 melting season
« on: July 08, 2019, 02:13:50 PM »
A big P.S. also to my post, beyond the fact that June 2019 was abysmal, I wanted to show also, even though it was not explicitly state, that Sun input is increasing bigly in Arctic, with an increase of 1 W/m² in June every four years. It could perhaps have been better to wait MERRA, but the topic was brought again in this discussion so go. But even more importantly, no matter if 2019 is at record or not, we are witnessing the effect of increase Sun input, with Chukchi, Beaufort and Bering running like bats out of hell after records. Of course, it is a progressive state change, but I fear we are nearer and nearer to the point that Bering sea will be perennially open, and even Chucki sea looks to be already in bad state for a good refreeze this winter. If ocean is warm enough, I think that it could supply enough moisture to create a positive feedback with longwave radiation. The warmer, the moister, the moister, the less heat can escape to space. And the warmer, the longer it takes to cool down, and if heat is not able to radiate back to space, it will take even longer. And if a melt season can give hand to the next like it was almost the case last three years, Sun input in summer is going to go trough the roof, etc... Up to now, Arctic was more or less able to erase its memory of the latest melt season during winter, but when I see the SSTs going trough the roof and Arctic pounded by relentless warmth and sun, and the last 3 years, I fear we are reaching the point where it is no longer the case.

37
Arctic sea ice / Re: The 2019 melting season
« on: July 08, 2019, 01:43:15 PM »
...
I think what is missing here is a discussion of the impact of increased solar irradiance.
...

Are you talking about the reduced albedo, low cloud cover, something else?

Looking at only solar irradiance I believe we are at a solar minimum right now with a lower irradiance than in 2012 and most of the rest of this decade (even then that difference is tiny).

The low solar minimum that the earth is presently experiencing is not the key issue that I am talking about. Rather, the key issue is the amount of solar energy entering the system as a result of reduced albedo in the arctic. This difference far offsets the difference in energy coming from the sun due to the solar cycle.

I broadly agree, I have also the feeling that incoming solar radiation is probably a bit an understate factor. It is of course a know fact, and a spoken one, that lower albedo implies a greater heat accumulation. But perhaps that the big train of heat ready to ram us is not fully acknowledge. By the way this is why I'm back here, at ASIF. I'm like a vulture, when I smell the good fragrance of a water bath I am here.

So to continue this discussion, I will try something (each word of this sentence is important XD ). NCEP/NCAR Reanalysis is easier to manipulate and is update with a lag of a few days only. So I already us it, but radiations data are not as good as other dataset. Good enough to say something about big trend and to beat some dead horses, but probably not good enough for details -like the exact magnitude of the June 2019 crash-. MERRA is probably better but will not be available until mid or late July for the month of June. As already state, solar heat input in June above 70°N is a big factor : https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2016JD025819
With MERRA data up to June 2018 I am going to back up this claim and give some order of magnitude, and with reanalysis up to June 2019 I am going to show that this year things are worst than worse. I will update the analysis when June 2019 data from MERRA will be available in late July -when nobody will no longer care as sea ice extent will be many thousands squared kilometers below 2012 and the crash will be beyond obvious XD -. Perhaps MERRA datas are going to show a little miracle, against the reanalysis, but is not really likely.

I am going to use two different flux. With MERRA, I am using net downward flux at surface (SWGNT for short). State an other way, it is the solar input wich is really accumulating at surface. The part of the Sun wich is not absorbed can be reflected by atmosphere and surface, wich is going back to space as a outgoing shortwave radiation (RSR for Reflected Sun Radiation). And Sun can also be absorbed by atmosphere. I stick with SWGNT cause looking at RSR implies giving weight to heat absorbed by atmoshere, but I don't think this part of the flux is really important. Its variations year over year are not as important, and heat absorbed by atmosphere is probably going to be mixed all over the hemisphere in a few days (as a side note, aerosols and soots -also known as black C- implies that Sun is more easily captured by the atmosphere, wich also have implications for global warming. But, looking only at sea ice year over year, the Sun captured by the atmosphere is not looking like a big factor). So, with MERRA dataset, is is going to be SWGNT. But Reanalysis as not an easy dataset for this flux. I could be possible to mix surface albedo with the downward shortwave flux at surface, but it is starting to look a bit too shaky, given the accuracy of reanalysis. So, with this lad, I am sticking with shortwave outgoing flux at TOA (RSR in the state paper above). Of course, the higher the heat absorbed by the surface, the lesser the heat making an escape to space. As a consequences, many graphs are going to have a left hand y axis, and a reversed right hand y axis. So far, the brains already hurts XD

The first graph is September SIE and SWGNT. The latter is reversed, meaning that the more the Sun is absorbed at surface in June, the less ice survived in September. Correlation is looking quite good, so let's check this.

The two datasets are quite correlated, with a decrease of the September SIE of 1 million square kilometers if absorbed radiation increase by 7 or 8 W/m². It should be note also that extrapolating the trend brings plausible results, with a zero SIE if June heat input is up to around 150 W/m². Definitively in the realm of possibilities.

So now that we have checked we are able to replicate the results of the above study, and that sea ice is screwed if Arctic is pounded by Sun in June, let's look at what the reanalysis is saying about June 2019. Was it bad, or worse than worst ? Short answer, acording to reanalysis June 2019 is abysmal. Values from reanalysis for outgoing solar flux at TOA are correlated with values from MERRA for solar input at surface. Correlation is not so bad (R² 0.45), but 2019 is not a record low point (caramba ^^). This said, it is looking like reanalysis is not going down enough. What I'm going to do is to artificially increase the trend for USWRF. Not for the pleasure of making things looking worst, but because, without MERRA data for June yet, we can only guess what happened. And an educated guess will be that reanalysis is to shy (not a surprise here...). Correlation is improved (R² 0.55) and 2019 is to the basement. Again, this is not intended to manipulate data to prove that June 2019 is a nightmare, but it is really because it is quite probable that reanalysis is not going down enough. Correlation with September SIE is also vastly improved (R² up to 0.43, from 0.20 with bulk values). Again, it is not a surprise that adding a trend to a datset to compare it with a dataset -SIE- where the trend is overwhelming everything vastly improves the correlation -if the slope of a dataset is way higher than its variability, we can correlated it with about any dataset having also a big slope-. But I do think this as a physical meaning.

I let you also the values for SWGNT in June in W/m², and with a conversion to "how many meters of ice could be melt by such and heat input ?" to give a sense of the energy in play.

   SWGNT      Thickness elt
1980   107   0.90
1981   109   0.92
1982   103   0.87
1983   103   0.87
1984   108   0.92
1985   113   0.96
1986   99   0.84
1987   108   0.91
1988   109   0.92
1989   99   0.84
1990   117   1.00
1991   111   0.94
1992   102   0.87
1993   116   0.99
1994   108   0.92
1995   109   0.93
1996   100   0.85
1997   109   0.92
1998   114   0.97
1999   102   0.87
2000   112   0.95
2001   114   0.97
2002   112   0.95
2003   108   0.92
2004   107   0.91
2005   113   0.96
2006   107   0.90
2007   118   1.00
2008   117   0.99
2009   111   0.94
2010   115   0.97
2011   117   0.99
2012   118   1.00
2013   109   0.92
2014   112   0.95
2015   113   0.96
2016   113   0.96
2017   116   0.99
2018   108   0.91



So, if I am not fooling myself, if I did not make any basic calc errors, etc... June 2019 has sucked up a lot of Sun, and probably is the leading horse in this race. Put in another way : die sea ice, die ! And see you again when MERRA will update.

38
Arctic sea ice / Re: Latest PIOMAS update (July 2019)
« on: July 06, 2019, 08:25:12 AM »
Awesome, Wip, thanks a lot. You received five likes from me, and I wish I could give you more.  :)

39
Arctic sea ice / Re: Latest PIOMAS update (July 2019)
« on: July 06, 2019, 07:59:25 AM »
Thickness map, comparisons with previous years and their diff's.

You certainly want to click these to read the very small fonts (and even then...).

40
Arctic sea ice / Re: 2019 sea ice area and extent data
« on: July 05, 2019, 10:31:15 AM »
magnamentis, I would appreciate it if you refrain from dumping on PIOMAS, ADS-NIPR, etc. These interruptions in daily data reporting are very annoying, but there's no hidden agenda.

41
Arctic sea ice / Re: The 2019 melting season
« on: July 01, 2019, 04:07:04 PM »
Despite all of the hyperbole and wish casting, 2019 will not be in the top 3 lowest sea ice minimums on record in area or extent. We may not end up in the top 5 in a sea ice area metric (looking at UH AMSR2 and NSIDC daily data and extrapolating).

Wow, I didn't know you could predict the weather that far out, WD88!

Is it okay if I ban you if you are wrong, come September?  :)

42
Arctic sea ice / Re: The 2019 melting season
« on: June 28, 2019, 06:19:56 PM »
The 12z gfs drops a sizeable but weak low pressure system into the CAB around day 7.

This would finally bring some relief to the basin.


Edit.  It quickly dies in the far Southern CAB.

The earlier gfs runs did this.

But the ensembles kept the dipole going.

We'll see.  The models have been doing this for almost 2 weeks before dropping/curtailing it as we get closer.

43
Arctic sea ice / Re: The 2019 melting season
« on: June 27, 2019, 04:39:16 PM »
The GAC welled up heat stored in layers below the Arctic ocean's surface to melt large quantities of ice. Of course, it takes heat to melt ice. Yes, melting ice is a highly endothermic process. The comment you referred to was incorrect and should be disregarded.

Water is a very unusual liquid, it's extraordinarily strongly hydrogen bonded. It's a liquid at room temperature whereas most other compounds with a similar atomic weight are gaseous. When it freezes it forms covalent bonds, and it expands, and hence it's density goes down. Forming those bonds releases energy. When you break those bonds, you have to add energy. The same applies to the transition from liquid to gas, but this time you have to break all the hydrogen bonds that keep it as a  liquid, and that requires much more energy than the transition from solid to liquid.

I'd recommend reading the wiki on water and ice. There are whole journals dedicated to the research of water. Its fascinating stuff....well, I assume, to the other nerds on this forum....


44
Arctic sea ice / Re: The 2019 melting season
« on: June 26, 2019, 03:39:35 AM »
Is it just me, or does the main pack stretch out (while maintaining near 100% concentration) for many weeks (March & April), as a huge amount of ice is exported and melted in the Atlantic, before finally pulling away from the Russian coast (in early May)? I wonder what are the elastic properties of the pack -- does it actually stretch and contract at constant (max) concentration? -- and how such properties are being affected by the dramatic changes in ice characteristics (thickness, age, density, etc.) in recent years.
The pack does not actually stretch, as it is not cohesive, and ice is not stretchable anyway. What is really happening is that open water is created at the top of the "stretch", and due to the low wintertime temps the open water freezes, thus completing the ice cover and keeping constant max concentration. But this hides the process of effective thinning of the central pack, which this year has been extra-active.
When air temps rise above -10C or thereabouts, the open water has a much harder time keeping up, and eventually the mobile ice is seen to break away from the shore-fast ice.
This process can be seen in animations like this one posted by A-Team.

45
Arctic sea ice / Re: The 2019 melting season
« on: June 26, 2019, 02:00:34 AM »
This bullshit about June not being the most important month is just embarrassing.

Whatever.  Going to look stupid come August.



Also anyone who thinks the ice isn't heading into July in the worst shape we have ever seen it overall is clueless.

I'm sorry for the hard line language but there should be an intellectual integrity here but whatever.

As soon June 15th 2019 THIS YEAR WAS SECOND LOWEST VOLUME ON RECORD.

SINCE JUNE 15TH:

2012 VERSUS 2019.

NOT EVEN CLOSE.


A lot of times BBR can really go nuts with the hyperbole.  Way more than myself and others.  But his claims of 2019 being the worse off are dead on.

The only difference is the Western CAB and parts of the CAA in 2012 got hit good in a warm sunbath by now.

This year the ESS region has taken a bath in the heat.

Half of the Arctic is getting pulverized with solar max insolation and highly anomolous mid level temps.




46
Arctic sea ice / Re: The 2019 melting season
« on: June 26, 2019, 01:41:47 AM »
Check out Nullschool North Pacific SSTA from 4/27-6/21 (in weekly increments)  In addition to the obvious bespoke heat buildup in bearing sea - note the pacific northwest 'Blob' coming online. Most that research the blob's effects say that it is not necessarily a forcing agent on the jet-stream, because jet forcing primarily comes from tropical waters. However, the jury is still out as to the degree that the blob is responsible for maintaining the persistence of ridging/troughing in the wider area.

47
Arctic sea ice / Re: The 2019 melting season
« on: June 24, 2019, 08:32:34 PM »
Oh boy. So sorry, Sterks!  :-[

Not the first time i confuse them. But surely the last time.  :)

48
Arctic sea ice / Re: The 2019 melting season
« on: June 23, 2019, 06:18:47 AM »
I don't think it should be too surprising that we're losing area/extent only at a moderate pace. The Beaufort-Chukchi front opened early, was well retreated and most of the heat has been hitting places where the ice is thicker and that takes time to melt through and break up. The Beaufort sector will still melt out in July (as it did last year in cloudy and cooler conditions) and now it appears there will be a significant portion of the ESS-Laptev and part of the CAB that will follow.

The ess/laptev/chuchki/pacific side CAB has really taken a beating.

If there isn't a break in the ridging the pole could be ice free this September.


49
Arctic sea ice / Re: The 2019 melting season
« on: June 22, 2019, 05:26:54 PM »
Included is a 20 hour loop showing the impressive ridge.  As energy rotates around it, it will go through several anticyclonic wave breaks (evident already).  These often give numerical models difficulty.  As they "break" they generally result in a cyclone downstream, in this case the Beaufort/CAA region.   Again, very hard to predict, and should give anyone pause about buying model runs beyond hour 120, and temper expectations.  Just my two cents.  I'll go back to simple observations of interesting features.

http://rammb-slider.cira.colostate.edu/?sat=jpss&z=1&im=24&ts=1&st=0&et=0&speed=130&motion=loop&map=1&lat=0&opacity%5B0%5D=1&hidden%5B0%5D=0&pause=0&slider=-1&hide_controls=1&mouse_draw=0&follow_feature=0&follow_hide=0&s=rammb-slider&sec=northern_hemisphere&p%5B0%5D=band_m08&x=13964.6669921875&y=16288.22265625

50
Arctic sea ice / Re: The 2019 melting season
« on: June 21, 2019, 10:38:40 PM »
grixm, you may be a noob but you are spot on.

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