Support the Arctic Sea Ice Forum and Blog

Show Posts

This section allows you to view all posts made by this member. Note that you can only see posts made in areas you currently have access to.


Messages - VeganPeaceForAll

Pages: [1]
1
Arctic sea ice / Re: The 2020 melting season
« on: September 13, 2020, 09:15:50 AM »
It wouldn't be much of a rebound anyways when you consider how thin all of the ice is.

What good is 4 year old ice that's under a meter thick
It’s more resilient than FYI under a meter.

That difference is more academic than practical, at 1m.

Quote
Anyway, the notion that Western CAB ice is homogeneously under a meter thick is misleading.
I can imagine a field of mixed floes of different thickness, surviving tall  ridges, ... the closer to CAA the thicker and older in average.

*Mostly* true, I'll agree, but I think you are overstating  how much of that melange is actually MYI and of significant thickness.

Quote
The region between the NP and the Beaufort sea has suffered surface melting but has stayed relatively protected compared to the other side of the NP. It stayed substantially colder during July even when it was 24/7 under the sun.
Now this 1 millon km2 of extent has several years of being stretched, exported to Beaufort sea or the CAA channels until it completely melts. It is a region of slow turnover time compared to the Gyre or the ice on the transpolar drift. It is a buffer against abrupt apocalypse scenarios.
You are making an awful lot of assumptions there, in the face of evidence - like the melt out of thick, MYI north of Greenland this year - which don't support your rosy interpretation of the ice's survivability.

Other posters have pointed out that Transpolar drift is broken.  The Gyre is broken.  Pretty much every mechanism we are used to watching and basing assumptions on, is broken.

And then there is the raw question of how much what we see in models is diverging from what's actually visible where we have "feet on the ground".

The only buffer we have against "sudden apocalypse" scenarios is the weather. 1 million km2 of 1m thick MYI or the equivalent simply doesn't have the thermal inertia to stop an apocalypse if the weather isn't cooperative.

The net enthalpy in the system has exploded, between additional solar uptake, and the huge inputs implied by the salinity data we see around Atlantification, as well as less dramatic inputs through the Bering strait on the Pacific side.

At this point, it really all hinges on seasonal uptake and existing heat.  Not extent.  Not area.  Not thickness.

We burned through ~15,000 km3 worth of ice this season already.  The ice you are citing (1,000,000 km2 of more or less 1m thick MYI) would represent less than 7% of that.

Even if I'm generous, and assume say, an average of 3m thickness, (which is VERY generous), we are talking about less than 20% of what has been lost this season already (PIOMAS figures).

It's not a bastion.  It's barely a cushion.  At best, averaged out, it's about 4 weeks of melt.  That's how thin a margin the Arctic pack's survival hinges on.

So back to my point... even if you are correct about quantity, at this stage in the evolution of the Arctic, it is weather, not ice volume which will determine any given year if we can avoid a BoE. 

That's been true pretty much since 2012.  Many of us have been holding our breath every year since 2012 in fear of a BoE.  So far, we've lucked out.  Increasingly, the deck is being stacked against us.

Some years ago, during one or another poll, I indicated that I thought there wouldn't be a BoE until sometime after 2029, and probably not before 2050.  At this point, I'll be surprised if we make it to 2029 *without* a BoE.  MYI won't help prevent it.

Weather will be the determinant of the pack's survival, not the existing ice.

2
Arctic sea ice / Re: The 2020 melting season
« on: September 11, 2020, 06:19:12 PM »
I'm really surprised more are not taking about the storm hitting Alaska's north slope. While I don't think we will see any large losses/gains of ice in the next week or so, I think with the current stormy conditions the ice is certainly going to be put under some strain.

Plus, given the overall warmth of the surrounding seas/oceans, I suspect there is a whole lot of mixing and bottom melt still occurring.

3
Arctic sea ice / Re: The 2020 melting season
« on: September 08, 2020, 09:43:32 AM »
Longish meta discussion, perhaps crossing off topic, but hopefully useful exposition.

@jdallen Relax, ...<snip>...
It seems I ruffled some feathers.
My only personal criticism is the one you resolved. More on feather ruffling down post.
Quote
- I am not sure if there is any implication for future seasons ... <snip> ... But per Piomas, there is a lot of 1 to 2 meter ice in a region overlapping the NASA 4+y regiin.
This speaks to discussions both here and on other threads about ice quality and and how products we currently are relying on for data seem increasingly less accurate in how they characterize the state of the ice.

I would also hazard to say "a lot" is very much qualitative rather than quantitative, less scalar and more binary.
Quote
- <snip> the parochy has been cherishing this product <snip> it looks pretty convincing, <snip> I personally trust this product <snip>
I find "cherish" an odd word to apply here, as it suggests an attachment that really doesn't exist. "Looks convincing" is similarly perilous as it asks us make value judgments rather than evaluate what is presented critically.

Similarly, "trust" is really not relevant.  What is relevant, is how closely the model output matches what is actually present in the Arctic.  The Polarstern expedition even without presenting much of its detail, has already highlighted the fact that there is an increasing gap between what the models produce and what is actually present, and that not in a favorable direction.

Since joining the forum in 2013, I've become both much more conservative in my declarations, and less likely to draw conclusions from the output of a single data source.  To this point, any model I evaluate is being examined in context with others like it, which use different algorithms and frequently completely different sets of data.  For the most part, it is only when I see broad agreement across them that I will make strongly worded statements.  And recently, I've relied far more on what is directly observable (EOSDIS for example) rather than modeled information.

I'm not yet seeing how your assertion is borne out in that context, aside from the specific, narrow definition you are using to support your suggestion that ice may somehow be recovering.

"Recovery" is a provocative and very strong word to use, in the context of the discussions taking place here, and in view of other information sources that would not support its use.  What is also worth reflecting on is just how narrowly you are having to set your definitions to justify it.  As you frame it, 4 year old MYI which is only 1-2m thick is of equal value to what 4 year old MYI *used* to be - 3m thick or more for the most part, and far more robust than the scattering of dots the current maps present.  That in itself is what I suspect is provoking more than a few readers here.

I think that's a serious mistake in analysis, and very much overlooks context.  There are many explanations for what we are seeing in those graphics, but very few of them would justify the use of "Recovery" as a relevant and useful characterization.  It strikes me as being akin to sending out a press release when a fire has been put out on one wall of a building, while the blaze continues to intensify elsewhere.

Better would be to examine the model in context, and ask yourself or others a few more questions about it.  You may be able to avoid getting your ears boxed as thoroughly as mine were. 

4
Arctic sea ice / Re: The 2020 melting season
« on: September 08, 2020, 07:09:50 AM »
It wouldn't be much of a rebound anyways when you consider how thin all of the ice is.

What good is 4 year old ice that's under a meter thick

5
Arctic sea ice / Re: The 2020 melting season
« on: August 26, 2020, 10:58:02 PM »
...
  And does "go to the DMI thread" mean you'll delete this, after you got your opinion in there first. No-one else's allowed.
...

If you disagree with someone state it, and your reasons and evidence.  Don't try to attack them personally for any reason.  It's well established that discussions on specific topics, such as specific model accuracy, don't belong in the melting season thread.

Since you seem to have not read most of this years thread (or previous years) maybe give that a go to see what people have said about these things.

6
Arctic sea ice / Re: The 2020 melting season
« on: August 14, 2020, 09:44:45 PM »
New record?

Some folks have been wondering about the extent numbers slowdown, and scratching their heads over it.
<snip>
From the NASA age of ice map recently posted here, I would infer a recovery, if anything, of surviving 4+ year old ice. But nothing dramatic to observe an ice regime back to pre 2007, or unknown chart territory of any sort, anyway. A really warm season, that is. The CAB ice, compacted and uniform, will do a nice basis of two year ice and beyond in the coming years.
gandul, your choice of supporting evidence for this assertion looks perilously close to being cherry picked.

Compared to other data sources, it also looks counter-factual.

Consider:

https://seaice.uni-bremen.de/data/smos/png/20200813_hvnorth_rfi_l1c.png

And:

https://www7320.nrlssc.navy.mil/GLBhycomcice1-12/navo/arcticictnnowcast.gif

(note: - the HYCOM link is transient, and in the future, to reference the specific date you'd need to go through their archive)

Any talk of recovery sounds to me like whistling in the dark.  You need to marshal a lot more concrete evidence.

7
Arctic sea ice / Re: The 2020 melting season
« on: August 13, 2020, 08:16:11 AM »
2016 was when sea temps were generally the highest in the Arctic, so I compared 2020/08/10 to the same date in 2016.

You can see how extremely hot sea temperatures are on the Atlantic-Siberian side. This will have ramificiations in the fall (likely a very slow freezing season), but is also significant now, because the Atlantic side will likely be attacked heavily by bottom melt. The Beaufort-Chukchi region is already disintegrating quickly and then there is the Greenland gap. Because of the above I think 2020 will stll come out first with a big bang at the end

8
Arctic sea ice / Re: The 2020 melting season
« on: August 11, 2020, 11:29:43 AM »
Here are a couple of longer-term animations looking at the Lincoln Sea and the region north of Ellesmere, contrasting with the more northerly ice in the CAB.
The first animation tracks a specific floe since initial breakup at the edge of Lincoln. The floe has since been moving westward for 50 days, a rare behavior, until it breaks up in two following a hard bump against the Ellesmere coast. Towards the end of the animation it can be seen that the ice to the north and east appears gray and much lower quality that the ice near Ellesmere.

The second animation looks at the Lincoln Sea during spring and summer. It appears the region of the thickest ice - that was compacted and probably strengthened during winter - is delineated in red. In fitting with the movement of the specific floe from the first animation, it appears the thickest ice from the Lincoln Sea is now spread in a strip from Greenland to the north of Ellesmere. I would hazard a guess that the gray ice above that strip is much more vulnerable to melting out in the next month, though if it actually does so is anyone's guess.

If I am not mistaken, this gray ice originates from ice that entered the region during March, following massive export to the Fram as shown on previous Ascat animations. In April and May it was broken up and moved around, and since June it has been spreading west.

Click to animate both gifs.

Ascat animation showing Fram export from the west, available thanks to uniquorn in https://forum.arctic-sea-ice.net/index.php/topic,3017.msg269957.html#msg269957

9
Arctic sea ice / Re: The 2020 melting season
« on: July 31, 2020, 05:03:12 PM »
The progression of Chukchi and Beaufort has been obscured by cloudcover on satellite. However, as today's Bremen and EOSDIS imagery confirm, both seas have for all intents and purposes now disintegrated.

The Laptev and Atlantic fronts have undergone a similarly deceptive evolution over the past week or so. As winds have changed direction, the pack has dispersed back into the open waters that have now accumulated insolation. Mixing is ongoing. On the surface the melt front has optically advanced somewhat, maybe a few 10s of KMs at most. But in reality, the melt front is now stretching hundreds if not thousands of KM WITHIN the pack and CAB itself. Within this region, the ice is now melting from above and below, and it is also slowly dispersing.

Concentration drops behind the respective Maginot Lines of the Laptev & ATL will become apparent very soon, and will follow the dissolution of the Beaufort and Chukchi. As I have been harping about for a week or three now, there is some chance the collapse of the Lincoln Sea could link up with the Laptev front and the ATL front could slough off thereafter. That does not mean the broken floes in between it and the rest of the pack will not refreeze in September, but there is some chance it falls off into the FRAM and the floes do not refreeze and we have a halocline overturning / destabilization event in the entire ATL east of the Lomonosov Ridge.

If the Atlantic hurricane season to date is any indication, I think we are going to see major hurricane(s) turn poleward in August and September, and that may lead to the obliteration of this component of the icepack.

10
Arctic sea ice / Re: The 2020 melting season
« on: July 23, 2020, 10:03:58 AM »
[ADS NIPR VISHOP (JAXA)] Arctic Sea Ice Extent.

July 22nd, 2020:
     6,116,303 km2, a century drop of -117,789 km2.
     2020 is the lowest on record.
     Highlighted 2020 & the 4 years with a daily lowest min in Sept. (2012, 2019, 2016 & 2007).
     In the graph are today's 10 lowest years.

2020: -926K km2 versus 2012.   :P

Another 117k drop or above and we'll go dipping under 6,000,000km2, I feel like there might be more century drops, let's hope a high does not develop or a GAC because then the ice will be truly screwed.


It is looking like below 3 million km^2 is likely this year. If we had a GAC which i would not bet against with the crazy year we are having in 2020, we could go below 2 million KM^2! Setting the Arctic up for a BOE in the next few years  :o

11
Arctic sea ice / Re: The 2020 melting season
« on: July 13, 2020, 11:42:36 PM »
For those wondering about a slowdown, it's the old 2D vs 3D problem. To shrink fast in 2D one must have lots of very thin ice at any given day that can complete its meltout. But what happens when most of the ice has a typical thickness of FYI at about 1.5m-2m, maybe 1m-1.5m by now? The sun and heat melt the ice in 3D, while 2D shows no ice disappearing, thus an apparent slowdown. This is especially true when the sun is shining on the thicker middle of the pack, while clouds hide the more southern and thinner parts. But the damage is accumulated in 3D, and if the season is long and/or warm enough, will translate to 2D with a vengeance.
Of course the other factor is extent vs area, compaction will show huge extent drops, but is not necessarily melt, it could be just movement.

12
Arctic sea ice / Re: The 2020 melting season
« on: July 12, 2020, 09:52:45 PM »
As the GAAC insolation melts the CAB ice pack, the GAAC compacting forces will get find less resistance. Thus, if the GAAC continues for another month, there will be a large ice ball at the north pole for Santa to sit on (and no other ice).

13
Arctic sea ice / Re: The 2020 melting season
« on: July 12, 2020, 09:42:59 PM »
Looks like the melt-pond drainage phase is about over in the CAB and area will start decreasing steadily again. Area losses should start gradually accelerating should this blocking event continue to hold and thickness drops start taking their toll and increasing the in-situ open water fraction. Also, the open water front (especially from the Laptev) looks to advance bodily into the CAB soon, which will hasten the retreat.

14
Arctic sea ice / Re: HYCOM
« on: July 12, 2020, 01:02:09 AM »
Over the past few decades the loss of thick multi year sea ice, and the presence of more open water and larger waves has led to more ridging. Because Hycom has been updated and improved it is difficult to use it to analyze the changes in Arctic sea ice thickness over the years. The new version of Hycom is probably a better model than PIOMAS to understand what the ice is doing NOW but it is inferior for inter year comparisons that involve years before the change to the GLB - global model. The new GLB version is a major improvement that is hard to compare to the maps of the old Hycom.

15
Arctic sea ice / Re: The 2020 melting season
« on: July 09, 2020, 11:24:05 PM »
X amount of heat does not produce Y amount of area loss.
X amount of heat produces Z amount of volume loss.
Daily area loss reflect how much thin ice melts in a day. A larger amount of thicker ice may melt and no melt ponds required to slow area loss.

16
Arctic sea ice / Re: The 2020 melting season
« on: July 09, 2020, 06:54:45 PM »
I'm not really convinced melting has really slowed down much. It's still warm with a fair amount of sun...I just think it has to do with how scattered the whole pack is. There are open sections of water in so many portions along with some significant melt ponds pretty much at the pole. If/when a strong low forms I think it's going to cause some destruction.

17
Arctic sea ice / Re: The 2020 melting season
« on: July 07, 2020, 11:59:30 PM »

Look at all the beautiful ice saving BLUE sub zero temperatures in the Beaufort, Chuckchi and ESS from July 11th - 17th.

https://climatereanalyzer.org/wx/fcst/#gfs.arc-lea.t2

The high pressure is doing a fantastic job of keeping the infernal Siberian WAA away from the ice.

While the GFS 12Z from today does show cooler air coming into the CAA, Beaufort and eastern Chukchi from D3-10, that's pretty much it until after D10 (w/r/t 850mb). The rest of the arctic is dominated by WAA, and the total temp anomaly at 2m is pretty consistently averaging around 1C above normal during this period. From my perspective this is forecasting just slightly better overall conditions for the ice than what we're seeing right now, which is horrendous. As the high weakens around d6-7, warm air floods into the ESS, Laptev, western Chukchi and adjacent CAB. Prior to that there is significant positive temp anomalies associated with the HP (1st image).

I'm curious as to why you ignored all of this in favor of that you just posted? Were you just not aware? It just seems to me like your post is rather imbalanced and out-of-context.

18
Arctic sea ice / Re: The 2020 melting season
« on: July 07, 2020, 01:22:28 PM »
Asking good questions is well encouraged. It enables shy posters and lurkers to receive answers that otherwise they would have had to guess. Normally such questions should go in the questions thread or in subject-specific threads, but it is sometimes acceptable to post them in this thread as well, depending on context, and tone.
Asking repeat questions, in the main thread, in an adversarial tone, for which the answer has already been given and over which a consensus exists in the community, is ill-mannered and is seen as a way to preach rather than an innocent attempt to find answers.
Phoenix - your 850 hPa vs. surface temps question was an example of the latter.
Asking "Can someone explain what is insane with the forecast?" is perfectly acceptable and within context. I often wonder myself, though thanks to the efforts of knowledgeable posters I have learned some of the basics over the years. Had you stopped with that sentence, all would have been fine. But you didn't and are hereby warned, derailing this thread is not allowed and moderation will be swift. Note: If I had been up when the post was made I would have moved it elsewhere immediately, but it already garnered some responses so I will let it stay.

19
Arctic sea ice / Re: The 2020 melting season
« on: July 03, 2020, 08:26:06 PM »
Ice colouring blue/grey as far north as 87.5.

Only other year that had almost as far north colour change this early was...2012.

Edit: Image is from July 3

Perhaps further than that as the cutoff in visible is due to advection fog and low stratus. The widespread advection fog event over the past 2-3 days did a big number on the pack up there.

Roll back to the 29th on that sector and you'll see there's still some snow cover. The warm front (and associated advection fog) rolls in right afterwards and destroys virtually all of it, leaving behind ponded bare ice. Strong subsidence from the building ridge moves in right after that, clearing out even the low clouds and exposing it to full sun.

I've seen deep snowpacks virtually obliterated overnight by strong WAA and advection fog events. It generally takes very warm air aloft and dewpoints above freezing to do it. The combination of direct heat exchange and direct diabatic heat release from condensation of water vapor directly onto the snowpack has a devastating effect.

20
Arctic sea ice / Re: When will the Arctic Go Ice Free?
« on: June 30, 2020, 05:03:43 PM »
Quote
Volume will naturally taper off as it approaches zero, such that both area and volume (and thickness) reach zero simultaneously.
Why would volume naturally taper off as it approaches zero? Just to give area a respite?
It is the opposite. At a certain volume threshold the Arctic becomes practically ice-free. Once the typical thickness of CAB ice is melted during a melting season, area will crash, while some volume may be retained in very thick ice floes (pressure ridges and very old MYI).
As the freezing season becomes shorter and less powerful, and the melting season longer and more powerful, not forgetting the contribution of increased mobility and export, this inflection point is not too far off, probably a decade into the future.

21
Arctic sea ice / Re: The 2020 melting season
« on: June 12, 2020, 05:50:24 PM »
Everything looks terrible for the ice but it has before and little melt has resulted.

I think, Armageddon's Blade is ready and possibly waited for this message. :)

earth.nullschool.net, 16.06.2020 00:00 UTC, 850 hPa.

1. A WAA near the Lena Delta. Temperature is 7.4°C. Doesn't sound outstanding. But wind speed is 90 km/h.
2. What about water vapor? 29.72 kg/m2.
3. Though it's just one point. How big is this WAA? It's everywhere.
4. Weak clouds don't provide good protection from the Sun.

Water vapour has a high enthalpy of vaporisation. That heat can melt approximately 4x it's mass of ice as it condenses. High winds blowing over warm and wet Land is an effective way of transferring heat into the ice. In this case, each 10M3 of air can melt 1M3 of ice.



22
Arctic sea ice / Re: The 2020 melting season
« on: June 12, 2020, 05:43:47 PM »
Everything looks terrible for the ice but it has before and little melt has resulted. I think it will be another few years yet before decimation. This year will probably be 2nd or 3rd JAXA but ice melt will probably slow in the coming days just to confuse us all again


As long as the ice is not less than 20cm thick it always takes some time to see the 2-dimensional results of an ongoing melting process. Considering that there is something like average ice-thicknesses in given regions it will show once of a sudden and the day before it happens there will be many impatient people trying to convince us that what we see is not real or does not have the impact it should.


It will, there are no miracles in physics, there is that much ice and that much melt and once the ice has melted to a certain extent it will disintegrate on a large scale.


All this provided that the weather will not undergo a total change to it's current as well as it's forecasted conditions.

23
Arctic sea ice / Re: The 2020 melting season
« on: June 07, 2020, 08:23:35 AM »
Phoenix, this has to be said:

It would do you well with a bit more humility and a bit less confidence. You have latched onto your theory like it's the gospel. I have taken the time to patiently explain some of its shortcomings in the DHACSOO thread, to no avail it seems.

Specifically I have explained the DMI N 80 data is heavily weighted around the pole itself, and is not a true measure of temperatures north of 80. And that the added energy from AGW gets soaked up by the ice and is not showing in temperature readings, this does not mean AGW is irrelevant. And that the data shows Inner Basin volume during the melting season does matter, and the CAB is not the only thing we should care about, due to melt progress, ice mobility and other factors.
I am fine with people expecting crashes and with people expecting recoveries. However I am not fine with your excessive preaching that can intimidate others from posting, others who may dislike confrontation, dislike harsh criticism and feel less sure of their insights and contributions. Be warned I am losing my patience. And the numerous moderator reports I have received say my instincts are justified.

BTW, 2020 could be a recovery year, this wiill not mean your theory was sound.

24
Arctic sea ice / Re: The 2020 melting season
« on: June 06, 2020, 12:40:36 AM »

The low itself does not pull in the heat, its an Arctic low hence its own cold air blob and low thicknesses. The warmth comes in via a ridge over the ESS and Chukchi but there's uncertainty just how much heat comes in and how long it lasts for. E.g on the GFS it looks brief but some signs on the ECM it may last longer.

Nullschool uses the GFS and auto-updates, usually a ~4.5-5 day forecast. Haha yeah, on nullschool anyway, it cuts off right as its centered in the Chukchi with some decent winds, heat, and moisture. Looks like it could continue to some degree, has some winds coming off Alaska, could be the impetus to break open the Beaufort channel if the winds don't do it over the next few days. Could be the straw that breaks up some of that turquoise/dark coast ice in the ESS + Chukchi too, since that side of Eurasia heating up. We'll see.

Low pressure system over the next few days will probably help expand that body of water in the Laptev, and most of that "ice" on the inner Severnaya coast (island between Kara and Laptev) is basically just rubble pushed up against it, so likely to open up a bit in some fashion. Ice in more northern Laptev where winds are blowing might be worth paying attention to given the state of things.

Cyclone coming looks like it's going to be pretty effective. Kara tongue will continue to get beat up, Svalbard going to get it, we'll see what happens to the FJL ice. If the low pressure winds open up the inner Severnaya coast and the body of Laptev water expands, all the ice between the Laptev + Kara gets a lot more interesting pretty quick.

Will be an interesting next 5 days. Eurasia starting to heat, looks like warmth starts to peak over into the CAA a bit towards the end of it. Good northerlies heading down Baffin, Hudson gets a bit too. Atlantic may play a more important role this year.

25
Arctic sea ice / Re: The 2020 melting season
« on: May 23, 2020, 12:33:55 AM »
     
Stopped being lazy and checked and the low was heavily influenced that year because of the Mackenzie.  https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2013GL058956

     I haven't given much attention to the effect of river discharge on the Arctic sea ice.  While the warm outflow of a big river seemed important for impact on the ice near the river delta, it seemed too small to matter much to the big picture, e.g. heat content of the entire Arctic Ocean, or even to the entire Beaufort Sea.  But these statements from the paper linked by Error refute that:
     "The Mackenzie and other large rivers can transport an enormous amount of heat across immense continental watersheds into the Arctic Ocean"

     "...the volume of the total discharge over the 3 week period is equivalent to a layer thickness of 0.19 m of warm waters across the entire open water area of 316,000 km2"
     (ed.  The area of the Beaufort Sea is 178,000 km2)

      "The warmest waters were observed near the coast of the Mackenzie Delta, e.g., 13°C at 147 km, 10°C at 287 km, 8°C at 350 km, and 2°C as far as 456 km from the Mackenzie River mouth"

     "The Mackenzie River has an enormous watershed of 1.8 million km2 with the southern extent reaching to 52.2oN. This watershed is primarily within the continental climate regime, and the heat can be intense in summer when the maximum temperature may reach 32°C around latitude 53°N (e.g., Edmonton, Alberta, Canada). Fresh and warm Mackenzie waters reside in the surface layer with the attendant high thermal capacity thus contributing excessive heat to melt sea ice, most effectively when the sea ice cover has been fragmented "

     "In addition to the Mackenzie, there are a number of other large rivers that discharge into the Arctic Ocean. Notable are the Yukon, Ob, Yenisei, Lena, and Kolyma Rivers, each with its immense watershed under a continental climate regime providing massive discharge of warm waters into the Arctic Ocean or a peripheral sea to melt sea ice in spring and summer. "

     "This massive discharge carries an enormous heating power of 1.0 × 1019 J/yr for each 1°C of the warm river waters above freezing, equivalent to 2.5 gigaton of trinitrotoluene (TNT) per °C per year. "

     "In the summer melt season, warm river waters, for which the temperatures can be higher than 10°C, contribute directly to melting sea ice. In the fall season around the time of sea ice freezeup, surface waters cool while the halocline stratification insulates the surface from the deeper seawater, allowing more sea ice to grow. At the same time in the fall, rivers also start to freezeup, drastically reducing the river discharge. Thus, to be an effective insulator, the stratification needs to be persistent to maintain the surface layer consisting of a large mass of fresh river waters that already discharged into the Arctic Ocean earlier in the summer. Such maintenance of the stratification requires calm‐ocean conditions without significant mixing throughout the summer to fall freezeup. In summer 2012, the violent storm significantly enhanced ocean mixing that transported ocean heat upward and further contributed to sea ice melt "

26
Arctic sea ice / Re: The 2020 melting season
« on: May 13, 2020, 07:13:15 AM »
I agree with friv, and think one additional ingredient here is the amount of ice that will be sent down the death zone past Svalbard and out the Fram strait. We're looking at 4+ days of strong surface winds exporting ice. Just look at how packed the isobars are on this output and how well they are positioned to export ice.

That ain't no joke that is crazy you're going to see open water come in the kara or the laptev because of all this

Chiming in.

Add Ekman pumping.  The ice is far more mobile than previous years, so it will not prevent transfer of force from the wind to the water below.  We should see significant mixing of the column under those regions where the wind in this dipole are *already* at work.  The CAB immediately north of Svalbard will be shattered more thoroughly than we would normally see before July.

The High combined with the storm over Svalbard create a near perfect hammer and anvil to shatter the Arctic.  The only question remaining is just how severe the damage will be.

To underscore what Friv said earlier about albedo,  we are talking about conditions being created (dropping albedo from 85 down to 60) which will more than double the amount of insolation being captured by the ice.   It will be doing that about a month earlier than typical, during increasing insolation.

Certainly we've seen ice get beaten up with lowered albedo, but mostly that is happening after the solar peak in late June, so the ice is basically riding the end of a wave (diminishing insolation) after it's broken.

We may be about to see that equation shifted a full month, so that those late July conditions are reached in late June instead - at peak insolation. In short, the ice will be getting pulled into the "wave" of insolation just as it's breaking, with pretty serious consequences.

If that happens, it will be hard *not* to overtake the 2012 extent and area losses. 

27
Arctic sea ice / Re: The 2020 melting season
« on: April 11, 2020, 08:51:55 AM »
Once humans are diminished greatly, Earth's CO2 and pollution control mechanisms will kick in 10-fold, and ice-extent will grow.
We must evolve...in the real sense of the word.

Now that is a major misunderstanding. Even if we stopped emittin all Co2 today, warming would continue for at least decades as Co2 stays in the atmosphere for quite long:
https://www.yaleclimateconnections.org/2010/12/common-climate-misconceptions-atmospheric-carbon-dioxide/

It turns out that while much of the “pulse” of extra CO2 accumulating in the atmosphere would be absorbed over the next century if emissions miraculously were to end today, about 20 percent of that CO2 would remain for at least tens of thousands of years.

Each year the chance of a BOE is bigger and with no aerosols due to COVID19 and a snowless winter in Europe, and the state of the ice as shown upthread and wintertime export of multiyear ice, this year is a very strong contender I believe

28
Arctic sea ice / Re: The 2020 melting season
« on: March 27, 2020, 03:57:54 PM »
not to beat a dead horse, but
 
Export in a southerly direction through Fram is still huge. and the melt in the eastern GS is still beyond huge (see image), although the warm water influx from the Pacific seems to have slowed somewhat.

Although it's too early to quantify, this past solid month of export and melt may have crippled the arctic sea ice's prospect of surviving as a whole through summer

This export and melt so early in the season portend to the scary prospect of open water at the pole this Sept. imho


29
Arctic sea ice / Re: The 2019/2020 freezing season
« on: November 10, 2019, 07:34:11 AM »
I have spent many years lurking on this forum. Over the years I see little to give me hope that climate change will not devastate the Arctic and the planet as a whole.

I teach climate change in my classes at a community college in Southern California. In my feeble attempt to explain how these great dips of the jet stream that bring an Arctic blast to the eastern half of the USA can hurt the Arctic I use a freezer we have in the classroom. I open it up to let the cold out and ask them “When I close the door, how does the freezer make it cold again?” I tell them about condensers and heat exchangers.

 I ask them “How does the Arctic keep so cold when its freezer door is opening when the jet streams make these large dips?” My feeble answer is we have a season of dark in the Arctic that is the time when we generate all the cold in the Arctic freezer by a lack of energy input directly from the Sun. Without that energy,  some of the energy brought in during the season of light will radiate into the atmosphere and eventually into space and at some point reach a point where the energy levels have dropped enough to freeze water and form ice that seals any remaining heat energy in the waters below it. Once the waters are sealed off by the ice, energy in the air continues to loose heat energy into space and becomes ever colder. So as long as the period of dark is exporting/exchanging more heat than it imports during the season of light we will have a functioning Arctic Freezer.

When the Arctic experiences two things: 1) Importing more heat during the season of light than it had before, and 2) opening the Arctic Freezer door more often during the season of dark, the Arctic Freezer will become more and more strained until it is no longer capable of acting as a freezer.

Why I watch this forum is to try and understand the heat gain and heat loose in the Arctic.

30
Arctic sea ice / Re: The 2019/2020 freezing season
« on: September 26, 2019, 01:36:33 PM »
The "slush floes" that dominated large parts of the CAB (facing the Laptev and the Beaufort) managed to survive thanks to the poor melting weather in August. This saved the melting season, but also gave a jumpstart to the freezing season, as cold fresh water intermixed with spread floes can freeze very quickly. Thus the very quick rise in area in the CAB. The CAA has seen a similarly quick refreeze around the surviving ice. Now that this process is (probably) over, it's gonna be mighty interesting. I expect a relatively slow refreeze especially in the ESS and Chukchi, as this summer they have been ice free longer than usual, giving the surface water time to heat and especially to mix.

31
Arctic sea ice / Re: The 2019 melting season
« on: September 20, 2019, 08:22:43 PM »
      Nobody is saying the topic of changing weather dynamics is unimportant, just that this thread is narrowly focused on the 2019 melt season, not the bigger picture.  Likewise, the existentially important topic of the possible emergence of altered weather patterns will get more informed discussion by appearing in its own thread.  And as noted above, appearing as the main topic of a thread creates a focused archival record of the conversation on that particular topic.

    If your concern is that fewer people will see it there because we all congregate at the melting thread and that people won't make the effort to see another important topic discussed in a separate thread, all I can say is c'est la vie.  You can't make people care about something.  I think the overwhelming majority of ASIF visitors do care about the climate crisis or they wouldn't be here.  An active thread about weather dynamics would be a good addition.  But not good to hijack the thread focused on watching the ice melt.  Diluting the focus and therefore quality of the melting thread would do more harm than good.

You've missed the main points. What sark was noting is that the larger problem (destabilization of the atmosphere) is impacting this melt season.

Second, that this will get more extensive in succeeding seasons and we need to expect and look for that.

Third, there very much seems at least to be a view by some in this thread that this year (or any year's) ice melt is independent of the larger controlling dynamics. And this if true I find most concerning of all. It is akin to weather forecasters focusing on short term weather why also philosophically denying climate change. We cannot get stuck there.

Focusing on the near term local while excluding the impacts of larger causes and the larger causes themselves is a grievous mistake.

Sam


32
Arctic sea ice / Re: The 2019 melting season
« on: September 20, 2019, 04:37:25 PM »
if atmospheric talk of current changes with quick looks of the past and the future is off topic, might as well close the thread. 

While sark words are a bit cryptic they reflect exactly what we are seeing. Terra incognita. The unknown, the new. He follows it with actual data and animations. If it sounds scary, then you are understanding correctly. As a Daily null school checker for the last few years, his historic gifs are extremely useful for context.

Still, complaining and meta posts like this are the main pollutants of this thread this year. Real posts like killians daily predictions, freegrass and AN animations and now sark’s atmospheric posts are all on topic and real contributions.

33
Arctic sea ice / Re: 2019 sea ice area and extent data
« on: September 19, 2019, 09:00:39 AM »
with only 1 day after minimum with a not-so-large increase, I wouldn't call minimum yet personally. Yeah, it's possible, but we are in a fluctuating period. A drop today isn't unlikely

34
Arctic sea ice / Re: The 2019 melting season
« on: September 16, 2019, 07:34:48 PM »
Given the data that 2019 started the melt a week early is it thus perhaps that freezeing will perhaps be a week late thus giving a tiny push towards a lower extent than if freezeing began on October 1st?

Given that this year the permafrost is melting at a higher rate leading to increased methane with increased heat level retention.


35
Arctic sea ice / Re: The 2019 melting season
« on: September 16, 2019, 02:40:43 PM »
Updated full-size versions available in the Nullschool Animations thread:
https://forum.arctic-sea-ice.net/index.php/topic,2905.msg228895.html#msg228895

Hindcast: 9/12 to 9/16, Forecast: 9/16 to 9/20. Wind + IWPD @ 850hPa (tiny version)

36
Arctic sea ice / Re: The 2019 melting season
« on: September 16, 2019, 02:31:43 PM »
No wonder this melt-season keeps on pushing: the seas are hot! The picture shows 20190913 SST vs the average of 2016,17,18 on the same day. Refreeze will likely be very slow based on this

37
Arctic sea ice / Re: The 2019 melting season
« on: September 13, 2019, 10:52:42 AM »
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

38
Arctic sea ice / Re: The 2019 melting season
« on: September 12, 2019, 07:41:29 PM »
According to Jim's graphs, ice volume has decreased from 14.9 to 4.7 * 1000 cu. km from mid 80's to now
This represents approx 0.35 * 1000  cu km change / year  at time of minimum volume. Assuming a BOE occurs  when there is 15% of the 16,000,000 max in 1980 and an average thickness of remaining ice of 1 metre, the volume at a BOE would be 2.4 cu km
Therefore , at 0.35 * 1000 loss in vol / year , we could expect a BOE in (4.7-2.4)/0.35 = 6.6 years

39
Arctic sea ice / Re: 2019 sea ice area and extent data
« on: September 12, 2019, 05:54:04 PM »
NSIDC Total Area as at 11 September 2019 (5 day trailing average)  2,952,478   km2

Addendum


Once gain, it is the Beaufort, Chukchi, and ESS that refuse to let the melting season die.

And that bumpy ride in the Beaufort suggests that ice being exported from the CAB is still melting out. Much of this ice is MYI.

40
Arctic sea ice / Re: The 2019 melting season
« on: September 12, 2019, 01:43:44 PM »
...
On that note, how's that multi-year ice doing in 2019?
It's doing exceptionally well: practically all of it is in sea ice's heaven now. Gone to better world, it is. No more suffering from all the greenhouse effect, bottom melt, rains and melt ponds all over it. RIP, MYI.

NASA was kind enough to present 1984-2019 animation about it - see yourself, in which amount of ice 4+ years old is practically zero by July 2019.

41
Arctic sea ice / Re: The 2019 melting season
« on: September 11, 2019, 04:31:57 PM »
What's the official minimum then?

Currently, according to JAXA data, it is 4,158,349 km^2. Achieved on September 4th.

The extent data is misleading, at best.  The rank matters little - what matters is the sea ice thickness and the condition of the ice in general.

Unfortunately, the sea ice extent graphs are given the most attention rather than sea ice thickness and fragmentation (and sea surface temperature).

The sea ice extent is a dubious measurement, as highly fragmented slush should not be considered "extent", but it does seem to get included.  Therefore, the "extent" of the low quality single year ice of 2019 is compared against the "extent" of the multi year ice of, say 1995 - which is incorrect - it's comparing apples to oranges.

We need to be focusing on the multi year ice, sea ice thickness  - not the "extent" data.

On that note, how's that multi-year ice doing in 2019?

42
Arctic sea ice / Re: The 2019 melting season
« on: September 09, 2019, 02:54:50 PM »
If the mercator model is correct slush dispersion doesn't significantly affect SST yet. Depending on the weather, extent may follow 2018's slush path (brown) to meet 2012 (yellow).
amsr2-uhh overlaid at 60% transparency onto mercator SST, aug1-sep6
wipneus regional extent, CAB, sep6
piomas percentage of maximum by year, CAB, 2011-2019
edit:forgot scale
I have a feeling that that PIOMASS percentage-of-maximum graph has too little space on the right side, with - was it? - day 260 being the limit. I mean, my gut says _this_ year the minimum in terms of that particular metric could perhaps happen well past day 260. I wonder if you feel anyhow similar, sir.

43
Arctic sea ice / Re: The 2019 melting season
« on: September 08, 2019, 02:35:57 PM »
The models at Tropical Tidbits are coming into consensus on a high pressure system forming towards the Canadian side of the central Arctic basin by about 4 days from now and then intensifying.

That could potentially bring some compaction of the ice pack and a relatively late minimum extent date for this year.

To illustrate with an example, here is the latest NAVGEM 96h forecast:

44
Arctic sea ice / Re: The 2019 melting season
« on: September 08, 2019, 09:53:25 AM »
Wind + Temp @ Surface
The bottom melting continues almost everywhere and the slush in the Pacific side still be melting for some weeks.

45
Arctic sea ice / Re: The 2019 melting season
« on: September 04, 2019, 09:40:55 PM »
I've been watching Lingling and Dorian recently, and I'm interested that they both undergo extratropical transition and integrate their momentum into the jet stream around the same time:



Dorian and Lingling are the symmetrically opposite 968mb lows here. Their angular momentum seems to enhance a dipole pattern, and the timing of their momentum transfer will be critical to how it sets up here. Regardless of the exact configuration, it looks like this will split the initiating tropospheric polar vortex into two lobes and allow a major heat/moisture intrusion from the Pacific



As we enter peak hurricane season, it's important to remember that one of the major heat engines that moves heat from equator to pole are tropical cyclones, so watching their activity will be critical to see how the freezing season initiates (or fails to)

This to me indicates that the melting season is not over yet and way may see losses for the next two weeks. I would be stunned if the AO does not go negative again in the next two weeks, but then again I'm just a naive observer and not a pro meteorologist.

Edit: And after looking at this month's PIOMAS, I really wonder if this will push the Sept 15 update into first place.

46
Arctic sea ice / Re: The 2019 melting season
« on: September 04, 2019, 02:12:22 PM »
.......everywhere on the other side of the pole will struggle to drop below freezing, so bottom melt will continue.


Please elaborate your opinion why surface temps would impact bottom melt ?

IMO bottom melt can continue even though the surface fresh waters or waters with poor salinity can show some freezing.

THX

47
Arctic sea ice / Re: Latest PIOMAS update (September 2019)
« on: September 04, 2019, 09:38:48 AM »
Thanks for the update. The thickest remaining ice is now mooving to the  Fram strait. And 2019 has the highest AWP that one can expect the slow refreeze. I think 2019 Will take the 1st place again in October-November.

48
Arctic sea ice / Re: The 2019 melting season
« on: September 03, 2019, 09:26:29 AM »
Cloud free image of the CAA from Worldview, I think I'll frame it and put it on the wall.

More importantly there has been no Southward movement of ice from the CAB into the clear blue water in the last couple of days, despite a Northerly wind.

Wind is forecast to continue to from the North and strengthen for the next couple of days, also the Ice can stay mobile into early October, so there is still time for the CAB to populate the channels with floes.

However, if not, there will only be salty 1st year ice there, ready for an early breakup next year.

49
Arctic sea ice / Re: The 2019 melting season
« on: September 01, 2019, 05:51:40 AM »
The ice looks like shit!

Extent has an 85% margin of error. 

Regardless of where the extent numbers turn out this year, the actual amount of ice is about as low as it has ever been.  It is obvious to anyone who takes the time to study Worldview. 





50
Arctic sea ice / Re: The 2019 melting season
« on: August 31, 2019, 08:05:45 AM »
The Forecast is looking destructive on day five, with a 970 hPa storm popping up that's finding a lot of energy to feed on.

Pages: [1]