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When will the Arctic Extent dip below 1,000,000 Km^2

2018-2019
12 (17.9%)
2020-2025
21 (31.3%)
2026-2030
13 (19.4%)
2031-2040
15 (22.4%)
2041-2060
2 (3%)
2061-2080
0 (0%)
2081-2099
1 (1.5%)
2100-beyond
3 (4.5%)

Total Members Voted: 64

Voting closed: July 27, 2018, 07:46:32 AM

Author Topic: When will the Arctic Go Ice Free?  (Read 140043 times)

Archimid

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Re: When will the Arctic Go Ice Free?
« Reply #800 on: July 25, 2019, 02:55:23 PM »
Quote
Despite this massive departure from normal, the appropriate conclusion seems to me to be it recovers in just a few years (~8).

If we assume 1980-2000 climate, ignore clouds, atmospheric disruptions and pretend the world will remain static to the disruption caused by an ice less, warming Arctic Ocean, like in the models, then sure. Hysteresis is only temporal and local.

That we are basing our risk assessment for climate change based on an idealized model with serious inconsistencies is plain wrong.
I am an energy reservoir seemingly intent on lowering entropy for self preservation.

Archimid

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Re: When will the Arctic Go Ice Free?
« Reply #801 on: July 25, 2019, 03:06:20 PM »
Quote
"modified ocean temperature" means this is where they did the extra large departures from normal:

Which they did only once, to simulate the missing heat that the models are not reflecting. On the BOE that followed the first BOE they didn't add the heat, even when the circumstances were the same. Thus the first BOE is faked and heat is added to better represent reality. This first BOE produced a natural BOE is not faked but the heat correction is not added. Instead the bias of the model is left to take over with 1980 climate and restore the ice.

I bet you that if the heat was added in the second BOE (to compensate for the model's flaw) the third year would also produce a BOE.

If a 2010's reference run was used instead of 1980-2000 they likely won't need to add extra heat.
I am an energy reservoir seemingly intent on lowering entropy for self preservation.

crandles

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Re: When will the Arctic Go Ice Free?
« Reply #802 on: July 25, 2019, 03:29:23 PM »
Quote
Despite this massive departure from normal, the appropriate conclusion seems to me to be it recovers in just a few years (~8).

If we assume 1980-2000 climate, ignore clouds, atmospheric disruptions and pretend the world will remain static to the disruption caused by an ice less, warming Arctic Ocean, like in the models, then sure. Hysteresis is only temporal and local.

That we are basing our risk assessment for climate change based on an idealized model with serious inconsistencies is plain wrong.

You assumed 1980-2000 climate in your rough estimation, the model used didn't.
You ignored clouds, the model used didn't. (maybe rather parameterised but they are included in models)

Models are imperfect, they attempts to include all the important dynamics as far as they can. Yes there are possibilities that things considered unimportant might interact to create import effects that are then missed by the model or the necessary simplifications are just a bit too simple. However they are the best that we have got.

.

What "serious inconsistencies"?

1 July being stated as maximal effect? I agree this looks odd, but you are not yet at the point of being able to say it is a 'serious inconsistency'. We simply don't understand it and there are various possibilities:

It might be the paper pushing what has actually been done, or
it might be we simply don't understand something.

Even if the paper is pushing what has actually been done, it doesn't mean it has any effect on the papers conclusions.

.

If models are the best we have got, why do you assert that using them is plain wrong?

crandles

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Re: When will the Arctic Go Ice Free?
« Reply #803 on: July 25, 2019, 03:37:08 PM »
Quote
"modified ocean temperature" means this is where they did the extra large departures from normal:

Which they did only once, to simulate the missing heat that the models are not reflecting. On the BOE that followed the first BOE they didn't add the heat, even when the circumstances were the same. Thus the first BOE is faked and heat is added to better represent reality. This first BOE produced a natural BOE is not faked but the heat correction is not added. Instead the bias of the model is left to take over with 1980 climate and restore the ice.

I bet you that if the heat was added in the second BOE (to compensate for the model's flaw) the third year would also produce a BOE.

If a 2010's reference run was used instead of 1980-2000 they likely won't need to add extra heat.

The reason they added the heat is explained:
Quote
The preceding experiments were somewhat unrealistic because although the ice was removed, the ocean was still in a state compatible with ice cover.

This isn't a model flaw that means the extra heat needs to be added every year. It is a massively overdone effect to ensure the ocean state being compatible with ice cover is not causing too much rapid ice formation that stops the albedo feedback that they want to introduce to see how much effect that sudden introduction of albedo feedback has.

Archimid

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Re: When will the Arctic Go Ice Free?
« Reply #804 on: July 25, 2019, 05:22:06 PM »
Quote
This isn't a model flaw that means the extra heat needs to be added every year. It is a massively overdone effect to ensure the ocean state being compatible with ice cover is not causing too much rapid ice formation that stops the albedo feedback that they want to introduce to see how much effect that sudden introduction of albedo feedback has.

Crandles,  the bold part is wrong. It is not a massively exaggerated number.They took the values of the model runs of the time calculated a number for the whole Arctic. Bet ya peanuts to dollars that the number they used is too low relative with recent temperatures.

FTA:

Quote
The preceding experiments were somewhat unrealistic because although the ice was removed, the ocean was still in a state compatible with ice cover. Hence, in the following experiments the ocean temperature will be modified to examine an ice‐free situation in the real world where an ice anomaly is connected with an ocean heat anomaly. Where and how should the ocean temperature be modified to simulate a realistic ice‐free situation? To answer this question the annual cycle of the ocean is analysed in the transitional zone with seasonal sea ice (not shown). The uppermost 200 m of the polar oceans are affected by seasonal changes in the HadCM3 run. A maximum ocean temperature of about 3°C is reached in areas which are seasonally covered by sea ice. Based on these findings two further sensitivity experiments are performed in which the initial global sea ice is removed and the ocean temperature of the uppermost 200 m (10 model levels) is artificially increased to a minimum value of 3°C on March 1st and September 1st, respectively.

And then this:

Quote
The initial salinity and ocean circulation remain the same as in the Ctrl run.

Quite literally, we are betting our lives on weak assumptions.
 
Quote
You assumed 1980-2000 climate in your rough estimation, the model used didn't.

That's what they used.

Quote
A 20‐year run is used as the reference run (called “Ctrl” in the following) beginning from a standard HadCM3 state taken from the control run, which has greenhouse gas forcing appropriate to pre‐industrial levels. Thus, these 20 years are stable with respect to atmospheric and sea ice parameters.

Quote
The green area represents the observed mean ice area for the period 1980 to 2000

Had they used more recent, CO2 forced data the result would probably change.

Quote
You ignored clouds, the model used didn't. (maybe rather parameterised but they are included in models)

Bet ya the model parameters pale in comparison with the clouds experienced during the last few years.  I used the old average to give you the biggest benefit of doubt. If I had use more recent years, as I should have, your case becomes even worse.


Quote
What "serious inconsistencies"?

The fact that a BOE faked under 1980's climate without co2 forcing and with no variation of the rest of the climate produces 2 consecutive BOEs under these darling scenarios, yet the conclusion of the paper is that we can safely assume hysteresis won't happen.

Quote
If models are the best we have got, why do you assert that using them is plain wrong?

I'm not asserting such thing. I'm using them myself, but I'm using them not as a bible  with an ultimate truth, but as microcosm of reality that they are. All models are wrong, some are useful.

These models are right, but the conclusion of the authors are highly misleading. These models say  that when a BOE happens in a world that does not change and is incapable of supporting a BOE, hysteresis is temporary. That is a very bad sign for when the world actually does support a BOE.

These models give the first hints of hysteresis and warrant a much closer look. Yet they are being used to pretend there will be no hysteresis.
I am an energy reservoir seemingly intent on lowering entropy for self preservation.

crandles

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Re: When will the Arctic Go Ice Free?
« Reply #805 on: July 25, 2019, 05:53:42 PM »

Quote
You assumed 1980-2000 climate in your rough estimation, the model used didn't.

That's what they used.

Quote
A 20‐year run is used as the reference run (called “Ctrl” in the following) beginning from a standard HadCM3 state taken from the control run, which has greenhouse gas forcing appropriate to pre‐industrial levels. Thus, these 20 years are stable with respect to atmospheric and sea ice parameters.


Sorry, yes you are right. I was confusing the two papers.

Quote
The green area represents the observed mean ice area for the period 1980 to 2000.

1980 to 2000 is observations.

They are using "greenhouse gas forcing appropriate to pre‐industrial levels", which I imagine you find rather alarming. Perhaps it would be rather concerning if Tietsche et al hadn't redone it with more modern & realistic climate following A1B emission scenario.

crandles

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Re: When will the Arctic Go Ice Free?
« Reply #806 on: July 25, 2019, 06:06:15 PM »
These models are right, but the conclusion of the authors are highly misleading. These models say  that when a BOE happens in a world that does not change and is incapable of supporting a BOE, hysteresis is temporary. That is a very bad sign for when the world actually does support a BOE.

These models give the first hints of hysteresis and warrant a much closer look. Yet they are being used to pretend there will be no hysteresis.

What first hints of hysteresis? They are being given enormous perturbation, after which some deviation from normal are expected but the question is whether they settle down into the same state or some different state. Do you see noticeably different states that the models settle down to?

Phil.

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Re: When will the Arctic Go Ice Free?
« Reply #807 on: July 25, 2019, 06:45:01 PM »
The paper I linked to elsewhere: https://advances.sciencemag.org/content/4/8/eaat6773
shows that if there is open surface water in the Chukchi and close by the thermocline will be effected which could have profound effects on the subsequent freezing season.  That could well be a cause of hysteresis, the disappearance of the deep cold water in the north of the Bering Sea could be the start.

philopek

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Re: When will the Arctic Go Ice Free?
« Reply #808 on: July 25, 2019, 07:00:31 PM »
Quote
You do know that there are no "sources" of cold?

Of course there are sources of cold. If I have a glass of warm water and I need a source of cold I just go get some ice and throw it in.
<Snippage>

OK, while creative, not really A Thing.

You don't really have "sources of cold" any more than you have "sources of vaccuum".  What "cold" indicates is a difference in enthalpy - net heat content components of a system, and thanks to the laws of thermodynamics heat will attempt to equilibrate across it - thus your ice cubes melting. 

There wasn't any "cold source" here, just the heat of varying levels being redistributed.

This does bring me to a point which I feel people have been overlooking.  It unfortunately is one for which we probably have the least instrumentation for - net enthalpy of the Arctic ocean and surrounding seas.

*This* will be the key factor in the tipping point.

Insolation year over year is virtually constant.  How much heat is retained or lost is a factor of our GHG levels and import from outside the Arctic during the refreeze.  There is in fact a calculable maximum possible loss which can be determined via calculation of black body radiation per square meter.  That can go up, but only if the temperature of the atmosphere goes up.

Further, once you have ice, and then snow cover, the rate of heat flow out of the ocean goes down again. Temperature drops and decreases the flow out of the atmosphere - or the heat source changes by way of the thermal gradient driving more import of heat into the arctic via broad scale convective atmospheric circulation from lower latitudes.  When that happens - as we've been starting to see, possibly as far back as the 1990s - the imported heat replaces the losses which normally would come out of the ocean, and enthalpy increases. 

So it has been for several years also that I've started becoming a much closer student of winter refreeze and weather conditions, and to a lesser degree have been trying to better understand the changing dynamics of current and salinity.  I have a very long way to go.

These I think more than summer melt are the real players - behind the scenes, pulling the levers of the secondary stuff we focus a lot of our attention on.

So again, when a BoE occurs, a great deal else will need to have happened to make it possible.  The net sum of those changes will already be driving, have been driving climate changes which are not reversible without our finding a way to dump petajules of heat out of the ecosystem. 

The state of the ice will be a side effect of that, and while no doubt a BoE will help dump more heat into an already overwhelmed system, it will be stacking it on top of an already monumental pile.  Absent of this any BoE is simply an anomaly which the system would swallow and then rapidly return to where it was previously. 

In a small way, that is *exactly* what we saw in 2012.  We were all convinced in 2013 that the End Was Nigh, and there were lots of scary moments which ended in... a bounce back.  The heat content of the system at the time is exactly why that happened.  If the area loss was the key to tipping the system over, that should have done it, but it didn't.  To be clear, I'm not trying to minimize the cascading effect of 2012, which was huge, but rather to put it into what I think is correct context.  In that regard, I think if we want to understand the most key drivers behind 2019, we need to go well past 2012, probably at least another decade, possibly two in order to find the build up which led us to where we are now.

So right you are witnessing the history of previous winters playing out.  There is excitement, driven in part by weather, much as in 2012, but again, now as then I think it is the heat the system started with in May that is the hidden power behind what is playing out now.

(Edit:  Looking for papers on Arctic Ocean heat content, I found this, which helps partially illustrate where I was trying to take my point.

https://advances.sciencemag.org/content/4/8/eaat6773

)

One of the very best posts i've seen in years, a real pleasure, full of knowledge, facts and understanding.

Archimid

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Re: When will the Arctic Go Ice Free?
« Reply #809 on: July 25, 2019, 07:19:32 PM »

1980 to 2000 is observations.

And the control runs match the observations. The model climate is one similar to the 1980 to 2000 climate.

Quote
They are using "greenhouse gas forcing appropriate to pre‐industrial levels", which I imagine you find rather alarming. Perhaps it would be rather concerning if Tietsche et al hadn't redone it with more modern & realistic climate following A1B emission scenario.

Realistic?

Quote
In this reference run, annual mean surface air temperature in the Arctic rises from −14°C in the 1900s to −4°C in the 2090s. Arctic sea‐ice extent declines, and the Arctic Ocean is typically ice‐free by the end of summer from 2070 onward

The first ice free arctic ocean will occur much sooner than 2070.

Quote
The start date is chosen such that the effect of the perturbation is maximal: starting from ice‐free conditions earlier in the year leads to immediate re‐freezing, and hence both earlier and later start dates imply shorter exposure of open water to sunlight, and a less pronounced ice–albedo effect.

This is a fundamental flaw of this model. With no ice over the Arctic, there is no reason for refreeze to commence during June. During June the ice dictates the sea and wind surface temperatures. Except for the deep ocean and Greenland, there is no other heatsink. However because of the nature of the perturbation, the appearance of a heat sinks is given.

Quote
As shown by Serreze et al. [2007], heat transport into the Arctic Ocean by advection of warm water and export of sea ice is only between 4 and 7 Wm−2 (March and August mean, respectively). Our model shows comparable results for oceanic heat transport into the Arctic.

...

Hence, we find that anomalies in oceanic heat transport into the Arctic are unimportant for the observed recovery of the Arctic energy budget.

[21] Consequently, the oceanic heat content anomaly is determined by the remaining two factors: (i) the latent heat anomaly induced by the initial conditions of the experiment and (ii) the surface heat flux anomaly.

Those are not the only two factors that remain, but the factor I'm about to mention was not evident at the time of this paper. Heat transport by air, facilitated by the breakdown of the atmospheric currents that we are already witnessing and accompanying clouds.

In fact the paper counts on the exact opposite.

Quote
Atmospheric heat content and lateral heat transport are not significantly affected

What we are seeing is the hemisphere bombard the arctic with heat at levels never seen before. Lateral heat transport is increasing tremendously. This model assumes lateral heat is insignificant.

We need newer models that better describe the changes happening in the arctic. Risk assessment and planetary level decisions are being made with unrealistic models, incomplete models.
I am an energy reservoir seemingly intent on lowering entropy for self preservation.

DrTskoul

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Re: When will the Arctic Go Ice Free?
« Reply #810 on: July 25, 2019, 07:47:14 PM »
Regarding rebound years, we have seen the following feedback:

Low area -> warm ocean in the fall releasing heat and humidity -> enhanced snow fall that diminishes melting momentum next year and gives a chance for ice to grow again. This leads to a few year as of fluctuations until weather patterns are favorable again and a crash is again imminent. Parallel to that, we have the steady climb of the heat absorbed into the global system. The increase heat can lead to less snowfall and less of a rebound during the rebound years making the next crash come sooner. At some point you will be seeing a first year ice pack diminishing and increasing to its maximum in an annual cycle. I believe the first BOE event will be followed by a large rebound that will take a few years to resolve until the next bigger crash. And then we will be oscillating between BOE and no BOE, until the heat is enough and the number of days and weeks in BOE increase beyond a threshold. All and all we are talking for a few decades before we reach that point .. maybe 1 maybe 2. The system does not seem to have faster dynamic than this ( as observed in the last 20 years).

Archimid

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Re: When will the Arctic Go Ice Free?
« Reply #811 on: July 25, 2019, 07:58:53 PM »
Regarding rebound years, we have seen the following feedback:

Low area -> warm ocean in the fall releasing heat and humidity -> enhanced snow fall that diminishes melting momentum next year and gives a chance for ice to grow again. This leads to a few year as of fluctuations until weather patterns are favorable again and a crash is again imminent. Parallel to that, we have the steady climb of the heat absorbed into the global system. The increase heat can lead to less snowfall and less of a rebound during the rebound years making the next crash come sooner. At some point you will be seeing a first year ice pack diminishing and increasing to its maximum in an annual cycle. I believe the first BOE event will be followed by a large rebound that will take a few years to resolve until the next bigger crash. And then we will be oscillating between BOE and no BOE, until the heat is enough and the number of days and weeks in BOE increase beyond a threshold. All and all we are talking for a few decades before we reach that point .. maybe 1 maybe 2. The system does not seem to have faster dynamic than this ( as observed in the last 20 years).

Pretty much this. I would add the disturbances to the atmosphere resulting in strong heat intrusions and the potential for abrupt loss due to super el niño like events to bring the time frame a few years closer than 10-20 years.  All this pending the results of this season and the behavior of winter.
I am an energy reservoir seemingly intent on lowering entropy for self preservation.

Aleph_Null

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Re: When will the Arctic Go Ice Free?
« Reply #812 on: July 25, 2019, 08:30:56 PM »
We need newer models that better describe the changes happening in the arctic. Risk assessment and planetary level decisions are being made with unrealistic models, incomplete models.

Presumably models get more difficult to construct as climate systems deconstruct.

Shared Humanity

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Re: When will the Arctic Go Ice Free?
« Reply #813 on: July 25, 2019, 10:57:12 PM »
Just finished an exhausting forced march through this thread since my last visit. That's 40 minutes of my life I will never get back. When I would stumble upon a comment that actually had content, I struggled to connect with it due to the morass of detritus that preceded it.

Tom_Mazanec

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Re: When will the Arctic Go Ice Free?
« Reply #814 on: July 26, 2019, 12:22:32 AM »
SHARKS (CROSSED OUT) MONGEESE (SIC) WITH FRICKIN LASER BEAMS ATTACHED TO THEIR HEADS

binntho

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Re: When will the Arctic Go Ice Free?
« Reply #815 on: July 26, 2019, 06:58:19 AM »
<snip>
<Snippage>
<sninp>

One of the very best posts i've seen in years, a real pleasure, full of knowledge, facts and understanding.
Agree.
because a thing is eloquently expressed it should not be taken to be as necessarily true
St. Augustine, Confessions V, 6

crandles

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Re: When will the Arctic Go Ice Free?
« Reply #816 on: July 26, 2019, 03:52:14 PM »
Copied posts on Tietsche et al 2011 and Schroeder & Connolley to
https://forum.arctic-sea-ice.net/index.php/topic,2818.0.html

Lets continue any discussion of this there.


Lou

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Re: When will the Arctic Go Ice Free?
« Reply #817 on: July 26, 2019, 09:36:15 PM »
The only thing that makes any sense to me is to start with the idea of what is going to happen to AGW in general and AGW in the Arctic in particular in the immediate future, i.e. the next 5 to 10 years. And that looks pretty grim to me. How you stick that into a curve is beyond me. I don't have a few cray computers to help me out, either.

I agree with virtually everything you've said in this topic, but the part above about trying to come up with a curve that models reality, prompted me to emerge from the shadows for a moment...

While I'm not at all optimistic that the first BOE will trigger a social/cultural change, as in making us wake up and leap into action, I assign it a non-zero probability, perhaps 5%.  Since I think the first BOE in recorded history is inevitable and will not trigger a massive, catastrophic tipping point, I'm hoping it happens sooner rather than later.  Call it a lottery ticket approach.

But I think it's also fair to say that part of the reason I don't expect the first BOE to have a huge social impact is that I think it will not mark the beginning of an age of yearly BOEs.  As the underlying trend of Arctic sea ice declining continues, it means we need less extreme weather every year to cause a BOE.  As I type this, there's considerable discussion on this board about the current hair raising conditions in the Arctic, yet the strong consensus is that we might challenge 2012, but won't come near a BOE this year.  I agree. 

But eventually we'll see the underlying trend plus the chaos of weather combining to deliver a BOE.  And the BOE+1 melt season is highly unlikely to see the same weather, so there won't be back-to-back BOEs.  We might not even see the second one for several years after the first.  And we all can guess how the deniers will spin that -- at least until the trend reaches a point where average weather results in a BOE, then we'll have one roughly one year in two.

oren

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Re: When will the Arctic Go Ice Free?
« Reply #818 on: July 27, 2019, 01:25:13 PM »
Well said Lou. First BOE will in all probability be an outlier, just like 2012 was in its time. But a few years to a decade after that it could become the norm.

Shared Humanity

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Re: When will the Arctic Go Ice Free?
« Reply #819 on: July 27, 2019, 05:42:51 PM »
As has been pointed out here by persons far brighter than me, 2007, 2010 and, to a lesser extent, 2012 melt seasons destroyed a lot of thick, old MYI which is reflected in the volume chart below. This destruction of thick ice established a new baseline for final volume and extent for the melt seasons that followed as the resulting minimums driven by weather fluctuate up and down. For us to approach a BOE, we need another huge melt season to destroy much of the thick MYI that remains. Despite being a strong melt season, 2019 is not the melt season we fear.

If you look at the volume chart below, 2007 destroyed 2.6 thousand km3 and 2010 another 2.2 thousand km3. With current volume minimums now bouncing around at 4.5 thousand km3, I actually believe we will need two spectacular melt seasons to arrive at our 1st BOE. I don't think this will happen until after 2030.
« Last Edit: July 27, 2019, 06:32:01 PM by Shared Humanity »

Shared Humanity

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Re: When will the Arctic Go Ice Free?
« Reply #820 on: July 27, 2019, 05:51:35 PM »
That 1st BOE will actually only occur if we combine a disastrous freeze season with the perfect melt season. This is why I visit this site daily all year long.

For me the question is...

What are the characteristics of the disastrous freeze season which will then set up the perfect melt season?

philopek

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Re: When will the Arctic Go Ice Free?
« Reply #821 on: July 27, 2019, 05:57:02 PM »
That 1st BOE will actually only occur if we combine a disastrous freeze season with the perfect melt season. This is why I visit this site daily all year long.

For me the question is...

What are the characteristics of the disastrous freeze season which will then set up the perfect melt season?

I think, while not every melting season is bad for the ice, almost every one of the last 3 freezing seasons have been very bad, bad enough to allow for a new record melt or record minimum, given the melting season's gonna shake hands with the preceding freezing seasons.

This is perhaps emphasized by the almost permanently above average temperatures in winter for the last few years, resulting in many less than average freezing days.


oren

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Re: When will the Arctic Go Ice Free?
« Reply #822 on: July 27, 2019, 05:58:36 PM »
I would say a disastrous freezing season will combine 2016's very late and thin refreeze, with 2019's winter-long transport of MYI to the Fram.

kassy

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Re: When will the Arctic Go Ice Free?
« Reply #823 on: July 27, 2019, 06:18:31 PM »
This is why i watch every winter now. There is always a lot of not freezing in the refreeze thread.
 
Þetta minnismerki er til vitnis um að við vitum hvað er að gerast og hvað þarf að gera. Aðeins þú veist hvort við gerðum eitthvað.

petm

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Re: When will the Arctic Go Ice Free?
« Reply #824 on: July 27, 2019, 06:19:27 PM »
My guess is that to go ice free will take something more dramatic and more permanent than simply a perfect storm of circumstances in one year (freeze + melt). It will look more like a state change and will result in the melt (and freeze) not conforming to previous patterns. E.g., It could be caused by a halocline collapse. I have no idea how many years it will be until something like this will occur.

philopek

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Re: When will the Arctic Go Ice Free?
« Reply #825 on: July 27, 2019, 06:21:12 PM »
I would say a disastrous freezing season will combine 2016's very late and thin refreeze, with 2019's winter-long transport of MYI to the Fram.

2016 already ended with the lowest volume ever in the following spring, hence wile what you describe is of course even worse, one of the two would be enough.

Only because the following summer in 2016 was not perfect from July onward, does not mean that winter was not bad enough for the ice.

Shared Humanity

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Re: When will the Arctic Go Ice Free?
« Reply #826 on: July 27, 2019, 06:22:40 PM »
My guess is that to go ice free will take something more dramatic and more permanent than simply a perfect storm of circumstances in one year (freeze + melt). It will look more like a state change and will result in the melt (and freeze) not conforming to previous patterns. E.g., It could be caused by a halocline collapse. I have no idea how many years it will be until something like this will occur.

I like this but wouldn't a halocline collapse more readily if a freeze season is so slow as to allow late fall and early winter storms to churn open waters and mix layers?

philopek

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Re: When will the Arctic Go Ice Free?
« Reply #827 on: July 27, 2019, 06:25:08 PM »
My guess is that to go ice free will take something more dramatic and more permanent than simply a perfect storm of circumstances in one year (freeze + melt). It will look more like a state change and will result in the melt (and freeze) not conforming to previous patterns. E.g., It could be caused by a halocline collapse. I have no idea how many years it will be until something like this will occur.

You are correct because this is the "when... ice free?" thread, but the question was for the perfect melt season which does not automatically imply an ice free arctic. 2012 for example was a perfect melting season (on the bad side) and did not go ice-free.

So my reply was solely related to the question as it was posed and i forgot the name of the thread. Therefore I think your reply takes better account of how the question was meant.

 8)

Shared Humanity

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Re: When will the Arctic Go Ice Free?
« Reply #828 on: July 27, 2019, 06:26:40 PM »
This is why i watch every winter now. There is always a lot of not freezing in the refreeze thread.

Agreed...

Shared Humanity

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Re: When will the Arctic Go Ice Free?
« Reply #829 on: July 27, 2019, 06:28:12 PM »
My guess is that to go ice free will take something more dramatic and more permanent than simply a perfect storm of circumstances in one year (freeze + melt). It will look more like a state change and will result in the melt (and freeze) not conforming to previous patterns. E.g., It could be caused by a halocline collapse. I have no idea how many years it will be until something like this will occur.

Do you have ideas as to what might drive this state change or what other state changes might come into play? I actually think this might be the key. I think exploring this idea of state change could provide some real insight into what we should be watching for and would be a good direction for this thread.
« Last Edit: July 27, 2019, 06:34:35 PM by Shared Humanity »

kassy

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Re: When will the Arctic Go Ice Free?
« Reply #830 on: July 27, 2019, 06:31:05 PM »
We should see the situation deteriorate in the edge seas yoy. Atlantification, Pacification. Whatever that does to the gyre after a couple of bad years.

Open water over the deep seas would be worse especially if conditions line up?

Should be plenty of forum years in it...i hope.
Þetta minnismerki er til vitnis um að við vitum hvað er að gerast og hvað þarf að gera. Aðeins þú veist hvort við gerðum eitthvað.

Shared Humanity

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Re: When will the Arctic Go Ice Free?
« Reply #831 on: July 27, 2019, 06:37:51 PM »
We should see the situation deteriorate in the edge seas yoy. Atlantification, Pacification. Whatever that does to the gyre after a couple of bad years.

Open water over the deep seas would be worse especially if conditions line up?

Should be plenty of forum years in it...i hope.

I believe one of us here has been tracking this metric, essentially measuring the lengthening of the "ice free" state for individual seas.

Rich

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Re: When will the Arctic Go Ice Free?
« Reply #832 on: July 27, 2019, 07:03:40 PM »
That 1st BOE will actually only occur if we combine a disastrous freeze season with the perfect melt season. This is why I visit this site daily all year long.

For me the question is...

What are the characteristics of the disastrous freeze season which will then set up the perfect melt season?

I think, while not every melting season is bad for the ice, almost every one of the last 3 freezing seasons have been very bad, bad enough to allow for a new record melt or record minimum, given the melting season's gonna shake hands with the preceding freezing seasons.


The last 5 freezing season's are all in the top 6 all-time from the he standpoint of lowest maxima.

This is similar to the phenomena where we see nightime low temperatures breaking far more heat records than daytime temperatures.

The reasons are similar. At night and during the Arctic winter, the signature impact of GHG's predominates. That signature impact is the trapping / retention of outgoing infrared radiation.

From a messaging standpoint, this should be the headline event for those trying to demonstrate that AGW is progressing and getting worse. It's clear and simple cause and effect that deniers have a harder time to refute.

Unfortunately, human beings prefer the drama and mythology of the big event and we place more emphasis on the yearly minimum and BOE which are much more a function of weather whims.

We need to understand our propensity to look for collapse porn in the way of things like a BOE and realize it's poor messaging to create hype around things that are rarely happening.

To philopek's comment on the main thread. I don't think I know what is going to happen this year and I am one of the people actually rooting for a record as a way to attract attention.

I merely think it is very unenlightened to place any emphasis whatsoever on record minimums and BOE's. There's no obvious upside to that when we can see the maximum predictably and reliably shrinking.

It's a tall order. Minimums make headlines and collapse porn appeals to base levels of human nature.

It also appeals to deniers who can say that alarmists keep pointing to the records and BOE's that don't materialize.

The unpopular message that I'm trying to get through is that we're practicing a lot of alarmism in ASIF. If may be fun and exciting, but it's not effective.


Shared Humanity

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Re: When will the Arctic Go Ice Free?
« Reply #833 on: July 27, 2019, 07:18:52 PM »
The last 5 freezing season's are all in the top 6 all-time from the he standpoint of lowest maxima.

This is similar to the phenomena where we see nightime low temperatures breaking far more heat records than daytime temperatures.

The reasons are similar. At night and during the Arctic winter, the signature impact of GHG's predominates. That signature impact is the trapping / retention of outgoing infrared radiation.


From a messaging standpoint, this should be the headline event for those trying to demonstrate that AGW is progressing and getting worse. It's clear and simple cause and effect that deniers have a harder time to refute.

Unfortunately, human beings prefer the drama and mythology of the big event and we place more emphasis on the yearly minimum and BOE which are much more a function of weather whims.

We need to understand our propensity to look for collapse porn in the way of things like a BOE and realize it's poor messaging to create hype around things that are rarely happening.

To philopek's comment on the main thread. I don't think I know what is going to happen this year and I am one of the people actually rooting for a record as a way to attract attention.

I merely think it is very unenlightened to place any emphasis whatsoever on record minimums and BOE's. There's no obvious upside to that when we can see the maximum predictably and reliably shrinking.

It's a tall order. Minimums make headlines and collapse porn appeals to base levels of human nature.

It also appeals to deniers who can say that alarmists keep pointing to the records and BOE's that don't materialize.

The unpopular message that I'm trying to get through is that we're practicing a lot of alarmism in ASIF. If may be fun and exciting, but it's not effective.


I'll keep this short. Please don't be offended. The 1st part of this comment (bolded) was spot on. The italicized portion was unnecessary and off topic IMHO.

No need to respond.

petm

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Re: When will the Arctic Go Ice Free?
« Reply #834 on: July 27, 2019, 07:19:51 PM »
Do you have ideas as to what might drive this state change

This would be my first guess: https://science.sciencemag.org/content/356/6335/285.full .

However, there are so many unknowns I'd also say it's difficult to predict but, if we keep our eyes open, we'll "know it when we see it".

Tor Bejnar

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Re: When will the Arctic Go Ice Free?
« Reply #835 on: July 27, 2019, 07:20:53 PM »
That's 2018-19 winter-long transport ...

I would say a disastrous freezing season will combine 2016's very late and thin refreeze, with 2019's winter-long transport of MYI to the Fram.
Arctic ice is healthy for children and other living things.

Shared Humanity

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Re: When will the Arctic Go Ice Free?
« Reply #836 on: July 27, 2019, 07:22:45 PM »
Do you have ideas as to what might drive this state change

This would be my first guess: https://science.sciencemag.org/content/356/6335/285.full .

However, there are so many unknowns I'd also say it's difficult to predict but, if we keep our eyes open, we'll "know it when we see it".

Thank you for that link...great read.

(Graphic is from article.)

petm

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Re: When will the Arctic Go Ice Free?
« Reply #837 on: July 27, 2019, 08:12:02 PM »
Thank you for that link...great read.

Welcome. You might also be interested in this recent review: https://iopscience.iop.org/article/10.1088/1748-9326/aade56/meta

Shared Humanity

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Re: When will the Arctic Go Ice Free?
« Reply #838 on: July 27, 2019, 08:50:13 PM »
Realize this shows how little I know but I now understand the distinction between the Eurasian and Amerasian basins which are separated by the Lomonosov ridge.

I am a slow learner but once I learn something, it usually sticks.

Rich

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Re: When will the Arctic Go Ice Free?
« Reply #839 on: July 27, 2019, 09:08:00 PM »
The last 5 freezing season's are all in the top 6 all-time from the he standpoint of lowest maxima.

This is similar to the phenomena where we see nightime low temperatures breaking far more heat records than daytime temperatures.

The reasons are similar. At night and during the Arctic winter, the signature impact of GHG's predominates. That signature impact is the trapping / retention of outgoing infrared radiation.


From a messaging standpoint, this should be the headline event for those trying to demonstrate that AGW is progressing and getting worse. It's clear and simple cause and effect that deniers have a harder time to refute.

Unfortunately, human beings prefer the drama and mythology of the big event and we place more emphasis on the yearly minimum and BOE which are much more a function of weather whims.

We need to understand our propensity to look for collapse porn in the way of things like a BOE and realize it's poor messaging to create hype around things that are rarely happening.

To philopek's comment on the main thread. I don't think I know what is going to happen this year and I am one of the people actually rooting for a record as a way to attract attention.

I merely think it is very unenlightened to place any emphasis whatsoever on record minimums and BOE's. There's no obvious upside to that when we can see the maximum predictably and reliably shrinking.

It's a tall order. Minimums make headlines and collapse porn appeals to base levels of human nature.

It also appeals to deniers who can say that alarmists keep pointing to the records and BOE's that don't materialize.

The unpopular message that I'm trying to get through is that we're practicing a lot of alarmism in ASIF. If may be fun and exciting, but it's not effective.


I'll keep this short. Please don't be offended. The 1st part of this comment (bolded) was spot on. The italicized portion was unnecessary and off topic IMHO.



I'm trying to get at the point of the benefit of the question and the benefit of the answer to the question. 

I'm not easily offended so no worries there.

Also trying to kill two birds with one stone and answer an OT question that philopek asked of me in the main thread.

Cheers.

oren

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Re: When will the Arctic Go Ice Free?
« Reply #840 on: July 27, 2019, 09:44:46 PM »
We should see the situation deteriorate in the edge seas yoy. Atlantification, Pacification. Whatever that does to the gyre after a couple of bad years.

Open water over the deep seas would be worse especially if conditions line up?

Should be plenty of forum years in it...i hope.

I believe one of us here has been tracking this metric, essentially measuring the lengthening of the "ice free" state for individual seas.
Indeed, I did some analysis for the Chukchi (a year ago?), and Gerontocrat made a slightly different and much more comprehensive analysis for all the seas.
I hope to revisit at some piint.

TeaPotty

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Re: When will the Arctic Go Ice Free?
« Reply #841 on: July 28, 2019, 12:09:22 AM »
New research relevant to this thread:
Loss of Arctic's Reflective Sea Ice Will Advance Global Warming by 25 Years
https://scripps.ucsd.edu/news/research-highlight-loss-arctics-reflective-sea-ice-will-advance-global-warming-25-years

Quote
Losing the remaining Arctic sea ice and its ability to reflect incoming solar energy back to space would be equivalent to adding one trillion tons of CO2 to the atmosphere... this roughly equates to 25 years of global CO2 emissions.

The authors of the study conclude that the loss of sea ice will add a globally-averaged 0.7 watts per square meter (W/m2) of solar heating to the Earth system, 0.21 W/m2 of which has already occurred between 1979 and 2016... equivalent to an increase in CO2 concentration from 400 to 456.7 parts per million... It would advance global warming by 25 years

nanning

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Re: When will the Arctic Go Ice Free?
« Reply #842 on: July 28, 2019, 06:49:11 AM »
Thank you for that great article TeaPotty. The anti-science government hasn't reached the Scripps institution it seems :).
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Archimid

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Re: When will the Arctic Go Ice Free?
« Reply #843 on: July 28, 2019, 01:26:54 PM »
Any links to free full text?
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DrTskoul

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Re: When will the Arctic Go Ice Free?
« Reply #844 on: July 28, 2019, 01:44:33 PM »

Archimid

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Re: When will the Arctic Go Ice Free?
« Reply #845 on: July 28, 2019, 02:43:43 PM »
Not it.
I am an energy reservoir seemingly intent on lowering entropy for self preservation.

DrTskoul

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Re: When will the Arctic Go Ice Free?
« Reply #846 on: July 28, 2019, 02:46:16 PM »
Not it.

The article I quoted Is " The results were published June 20 in the journal Geophysical Research Letters. In “Radiative Heating of an Ice-Free Arctic Ocean,” former Scripps graduate student Kristina Pistone "

Archimid

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Re: When will the Arctic Go Ice Free?
« Reply #847 on: July 28, 2019, 03:34:09 PM »
Not free. I followed your link, had to log in ( give information) and then directly request access to the paper. Haven't received it yet.

Here is the abstract of the paper:
Quote
During recent decades, there has been dramatic Arctic sea ice retreat. This has reduced the top‐of‐atmosphere albedo, adding more solar energy to the climate system. There is substantial uncertainty regarding how much ice retreat and associated solar heating will occur in the future. This is relevant to future climate projections, including the timescale for reaching global warming stabilization targets. Here we use satellite observations to estimate the amount of solar energy that would be added in the worst‐case scenario of a complete disappearance of Arctic sea ice throughout the sunlit part of the year. Assuming constant cloudiness, we calculate a global radiative heating of 0.71 W/m2 relative to the 1979 baseline state. This is equivalent to the effect of one trillion tons of CO2 emissions. These results suggest that the additional heating due to complete Arctic sea ice loss would hasten global warming by an estimated 25 years.

From here:

https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2019GL082914
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binntho

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Re: When will the Arctic Go Ice Free?
« Reply #848 on: July 28, 2019, 04:12:30 PM »
Not free. I followed your link, had to log in ( give information) and then directly request access to the paper. Haven't received it yet.
I had a similar experince the other day, and haven't yet received the paper I asked for.

But I did receive a notice that my name (which is extremely unusual and not shared with anybody else) appears in a "peer-reviewed" article from the Theological department of the University of Iceland! Apparently, in this paper on the decline of religion in Iceland, I and a couple of fellow culprits were named as examples of "extremely loud and obnoxious atheists".
because a thing is eloquently expressed it should not be taken to be as necessarily true
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petm

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Re: When will the Arctic Go Ice Free?
« Reply #849 on: July 28, 2019, 04:22:51 PM »
For the free full text try this:
http://eisenman.ucsd.edu/papers/Pistone-Eisenman-Ramanathan-2019.pdf

(NB: In general, use Google Scholar to search for free versions.)