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Messages - jdallen

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1
Arctic sea ice / Re: Latest PIOMAS update (June 2019)
« on: November 04, 2019, 05:40:03 PM »
PIOMAS Volume as at 31 October 2019   6.518  km3 '000
The standard graphs and tables as I use for the JAXA extent data are attached.

Volume gain in October mostly well below average, a bit above average gain in the last week.

2019 volume is still 3rd lowest in the satellite record, by 101 km3 above 2012, and only 33 km3 above 2016, and less than 2018 by 709 km3.
_______________________________________________________________
The last table is a look at projections to the next maximum. Far too early to take it seriously.

Volume is what I will be watching most closely this season.  Already cross-referencing from the Polarstern expedition thread, we've already seen hints that we may have been overestimating it.

2
Arctic sea ice / Re: 2019 sea ice area and extent data
« on: November 04, 2019, 05:37:20 PM »
JAXA ARCTIC SEA ICE EXTENT :- 7,804,258 km2(November 2, 2019)

Am I seeing a persistent gradual reduction in daily extent gain, and will that reduction continue?

<snippage>
For the last 40 years sea ice decline in winter has been a lot less than in the summer. So eventually 2019 sea ice extent would play catch-up to get closer to the trend values. I did not expect it to happen this quickly.

Will these 10 days of very high extent gains continue? 
Or will extent gains return to the average or even below?

2016 as I recall had a huge spike in cyclonic activity along the east coast of both Asia and North America which I think was key in slowing the refreeze.  I think for that reason 2016 will persist as an anomaly for some time, much as 2012 has.

Absent that vigorous activity, I do think the rapid extent gains will continue over the colder near-continental seas in particular - ESS, Laptev, Kara, CAA, Hudson, and Okhotsk.  However once that real estate is used up, I think we quite possibly will see a stall as the heat content in the Pacific side in particular is so huge that even without imported heat from further south it will resist freezing and provide its own local feedbacks to slow heat loss as well.

3
This is the 10hpa forecast as long as they make it (GFS). NO SPLIT AT ALL.

I hope your other data and musings are more exact

that's a different attribute at a different level.  no bite on the attitude.

https://www.wetterzentrale.de/en/topkarten.php?map=2&model=gfs&var=39&run=18&time=252&lid=OP&h=1&mv=0&tr=3#mapref

Posing a question, as I have no rigorous understanding as yet of the dynamics here.

Would it perhaps be implied here that there is increasing turbulence resulting in disconnections in behavior between layers of atmosphere? 

Or, if the apparent disconnections is purely coincidental, is what we are seeing evidence of increased turbulence and increased disruption of existing patterns?

4
Arctic sea ice / Re: When will the Arctic Go Ice Free?
« on: October 11, 2019, 06:35:55 AM »
jdallen:
The choice was between Hillary and the Donald.
<snippage>


And Trump is aggressively pursuing a policy that will lead to the deaths of billions this century
<snippage>

<sadly disappointed head shake>
This is by definition a question of faith(s), and impossible to argue over rationally.

Now back to the question posed by this thread...

Indeed!

<snippage>
     FWIW, the September 2019 IPCC cryosphere report shows Extent becoming asymptotic at about 10% of the 2000 level around 2070. 
<more snippage>

I've been slowly arriving at a similar conclusion, as a result of a confluence of factors we've covered all over the forums.  Key among them are total system enthalpy, ocean enthalpy, the dynamics of seasonal changes in the radiative energy budget... but other things like just the nature of ocean surface dynamics and the physical chemistry of water come in to play as well.

I think before that last 10% or so disappears for good, there will need to be a lot more support for atmospheric heating at high latitudes.  Along the way, this will create conditions for stupendous storms at much higher latitude than we've ever imagined. 

The drop off insolation at the end of the melt season will be like a vaccuum collapsing with everything rushing in to fill it.  I think we'll see more continuous flow out of the tropics all the way to the Arctic, with no Ferrel or Arctic cells to speak of long before the ice fully disappears consistently in the summer.

5
Arctic sea ice / Re: When will the Arctic Go Ice Free?
« on: October 10, 2019, 07:21:53 AM »
I get your point, Glen, but I vote as if my soul depends on it.
That's why this pro-life voter voted for Kasich in the Primary but Trump in the election (and hated it)>
Tom, for someone so intelligent, I have a very hard time squaring that with such complete foolishness.

He is actively working for the destruction of our environment.  How could you?

6
Arctic sea ice / Re: The 2019/2020 freezing season
« on: October 07, 2019, 08:44:40 AM »
Still trying to understand how the *warmest* August on record, according to awesome +70N 925hPa temps chart produced by Zack Labe, led to such a poor loss of ice extent. No convincing explanation so far....
I am convinced that we had normal melting conditions in 2019.

WTF? Normal melting conditions? With warmest August, 2nd warmes June and 3rd warmest July (and it was quite sunny for a good part of the summer as well)? How can you call that normal? Based on temps, ice should have crashed to nil, but it held up very well, so I have the same question as the original poster: i wonder why we did not lose more ice?

My answers are:
- the GAC of 2012 was truly a powerful and rare phenomenon and simple warm weather is not enough to repeat it
- the Central Pack is really hard to crack
- the Arctic is a mystery :)
Your answers are good, especially the third.

When the melting momentum hit a wall in early August I commented then that we were missing something key in our understanding of what drives the melt.  They key things that stand out in my mind now are:

  • Lack of comprehensive understanding of salinity, heat and movement of water under the ice
  • Underestimating the effect of high latitude and other conditions affecting refraction that reduce heat uptake.
  • Strong support for ice retention around the emerging "cold poles" - though that pretty much failed completely by July on the Siberian side.
There's far more, no doubt, but that's what jumps out at me now.

I will be watching a number of things now on the refreeze.  As others noticed, we are seeing regular cyclical massive intrusions of heat and moisture all the way into the central basin, which themselves show no sign of diminishing.

I think the refreeze of the peripheral central seas (ESS, Chukchi and Laptev in particular) will be strongly retarded.  I think the Beaufort and CAA will actually refreeze fairly fast, in keeping with the development of the "cold pole" over northern Canada and Greenland.  I think they will catch up rapidly once we reach mid to late November, and I think continued intrusions of heat will offset what would normally be heat lost from those seas.  That heat retention will play a key role in how much thickening we see late in the refreeze season.

I will be watching the CAB with considerable interest and am overjoyed by the over-winter expedition being carried out.  My prediction of what's ahead is that we will see much higher than typical snowfall, which we know is a very two edged sword.  Next spring it will protect the ice.  However, if it stacks up too high and too fast, it will seriously impede the very necessary lost of heat out of the arctic basin we need to preserve the ice.

I'm tentatively thinking were going to see conditions much like 2016-2017, with serious drops in FDD's and anemic volume growth, much of which won't happen until after northern hemisphere snowfall locks in colder temperature over the continents.

It will be an interesting season.

(Post script - various models have the remnants of typhoon HAGABIS blowing back up into a *very* powerful storm in the Bering in a few days.  That could seriously disturb weather on the Pacific side of the basin.  Worth keeping track of, I think.)

7
Arctic sea ice / Re: September predictions challenge 2019
« on: October 05, 2019, 08:59:00 AM »
*That* must be what happened.  I'll take the honorary victory.

8
Arctic sea ice / Re: The 2019 melting season
« on: September 12, 2019, 09:15:20 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
This makes a big assumption - that system behavior will be consistent as we reach that limit.

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

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

The ice in the CAB and along the CAA by dint of higher latitude appears less influenced by the effects of insolation and atmospheric heat.  It is also *somewhat* protected by the deeper waters of the central basin.

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

I think we may see quite a number of years like this - following the pattern of post 2012 - with the ice retreating to the high-latitude bastion we see.

We *could* see a weather driven event driving a season below 2012, but am leaning more and more to a conclusion that this would be anomalous rather than a signal of impending BoE.

I think we need a lot more data on changes in Arctic ocean enthalpy changes, as I'm thinking that and attendant changes in water column structure are what will drive us to a BoE.

9
Arctic sea ice / Re: When will the Arctic Go Ice Free?
« on: September 12, 2019, 08:49:08 PM »
Except that your graph shows anomalies throughout the year.  While volume has continued dropping at other times of the year, that cannot be said for the Sept. minima.  Check what others posters have presented regarding volume at minimum.

The whole point was that I think anomalies through the year is a better indicator than minima.
Based on my expectations of 2019 extrapolated from conditions, and the current surprising (higher than I expected) numbers, I'm thinking there may be sense to this hypothesis.

10
Arctic sea ice / Re: The 2019 melting season
« on: September 05, 2019, 06:53:41 PM »
Dorian's track:

https://www.nhc.noaa.gov/refresh/graphics_at5+shtml/151958.shtml?cone#contents

It will be interesting to see what effect of heat inputs from two hurricanes and (currently) two additional tropical disturbances will be in about a weeks time.

There may be no effect except to hinder freezing.  It is possible the heat may permit bottom melt to continue with a resulting late minimum.  I don't expect the numbers to be dramatic.  If melt does continue it will likely be at a trickle of 10-15K/day; at least that's my expectation.

11
Arctic sea ice / Re: The 2019 melting season
« on: September 05, 2019, 05:12:24 PM »
And the hole that's been appearing in the Lincoln Sea is as large as I've seen it.


I am no expert and I have only been following the Arctic for the last 7 or 8 years but I have never seen the Lincoln Sea in this poor of a condition.
+1
I agree - it's astonishing.

Here's how it *should* look.

12
Arctic sea ice / Re: 2019 sea ice area and extent data
« on: August 27, 2019, 11:38:07 PM »
Considering momentum, heat in the water and everything else, the slowdown over the last week is nothing short of astonishing to me.

I really didn't expect to be wrong concluding extent this year would drop under 4 million KM2, but am happy that it appears it won't.

As I said elsewhere, seems there's a factor we are missing somehow.

13
Arctic sea ice / Re: The 2019 melting season
« on: August 19, 2019, 07:56:49 AM »
Anyway... Here's an updated version of the five day forecast. There's been an interesting development over the CAA, where that storm that smached itself to pieces on the Alaskan coast is reorganising itself on the other side over the CAA. 976 hPa is pretty low, and it seems to be strengthening. This could get interesting in the coming days!
976hPa is a serious storm, especially in contrast to the high pressure domes elsewhere over the region.

Depending on location and duration, this could stir up some heat from depth.

14
Arctic sea ice / Re: The 2019 melting season
« on: August 15, 2019, 09:23:13 AM »
Weather forecast for the next 4 days.
This is so cool... :D
Thanks PETM!
I ended it with the smiley face that's still in the forecast... ;)

It looks like the southern part of the CAA will melt out, and the state of the Eurasian side of the ice + forecast suggests significant losses on the way.

How much of the northern CAA will hold out?

Will this wind finally drive the ice off of the Atlantic Islands where they've held on stubbornly all season? And will that result in any retreat of the ice along the Atlantic side where positive concentration anomalies are high?

Will the Beaufort be able to swallow all of the ice being pushed into its waters?

Any crystal ball owners out there?
We are now past the peak of insolation, and the remaining ice is for the most part above latitudes that will receive significant insolation between now as the equinox.

Heat blowing in from the continents will have a minimal effect, as it isn't accompanied by significant insolation or long-wave radiation.

All hinges now on bottom melt, and to a certain degree, on how much heat is pulled from depth by wind.

I think a 2nd place finish is pretty close to being "in the bag".  I'm doubtful that we will pass 2012 - *UNLESS* the melt season continues into late September, driven by bottom melt.

Unfortunately, that store of heat - what's already in the water - is an aspect of the Arctic we probably have the least information on.  We can only wait and see what transpires.

15
Arctic sea ice / Re: The 2019 melting season
« on: August 12, 2019, 05:19:19 AM »
A new high pressure system could be entering the arctic in 5 days from now. 1040 hPa is quite high right?

https://earth.nullschool.net/#2019/08/16/1800Z/wind/surface/level/overlay=mean_sea_level_pressure/orthographic=-37.55,98.87,1500/loc=-172.775,66.338
High pressure in 5 days, if widespread, not so much a problem for the ice. Insolation is dropping like a stone.

However, 1040 PA combined with a low someplace else... potential trouble for the ice.  Especially as this high is over the Chukchi and with 40+pa gradient could shove ice out of the main basin into "superheated" waters of the Beaufort.

16
Arctic sea ice / Re: The 2019 melting season
« on: August 11, 2019, 09:48:06 PM »
This ice has been hammered by high pressure for many weeks now, and it looks like it's in really bad shape. I don't see how all this can survive the high temperatures of the coming week. The surface temperature at this moment is 3.5°C.
The actual heat that can be transferred at this point I don't think overall will make that much of a difference.  Unless there's a lot of moisture in the advection, the heat content of the air is insufficient by itself to cause a lot of melt.

As insolation above 80 now is *also* starting to drop off rapidly that leaves just that heat already captured in the upper layers of ocean to do the work.

To that point, I think the danger to the pack right now is less the direct heat being delivered by advection, and more that it will interfere with the exchange balance, preventing loss to start from the ocean out of the atmosphere.

So, two $64 questions - how much heat has been captured, and how much of it will get pulled to the surface?

17
Arctic sea ice / Re: 2019 sea ice area and extent data
« on: August 11, 2019, 08:26:23 AM »
NSIDC Total Area as at 9 August 2019 (5 day trailing average)  3,570,381 km2

The 7 day turnaround has stopped.
On 8 August area loss collapsed.
On this day area loss collapsed even more.

Fascinating.  The collapse is running counter to everything we tend to expect from the current conditions. Consider for example the SST map from Climate Reanalyzer below. Consider also the current circulation and weather conditions.  What is happening is completely counter-intuitive.  It suggests we are missing some major factor.

18
Arctic sea ice / Re: "Stupid" Questions :o
« on: August 11, 2019, 08:14:53 AM »
The climate changed wildly throughout the Pleistocene and they did fine.

NOPE

El Cid:
There were about two dozen ice age cycles in the Pleistocene similar in speed and amplitude. When humans reached Australia there was an extinction event. When they reached the Western Hemisphere there was an extinction event. But in Africa where they had the most time to adapt to our hunting they did relatively well, and somewhat so in Eurasia.
There is still a lot of debate around the topic.  While H. Sapiens no doubt had an effect, they aren't the universal answer, and even in "new" territory like the Western Hemisphere and Australia, there are species for which that answer doesn't make sense.

It also doesn't make sense for many of the extinctions in Asia and Europe, where humanity and the megafauna *did* co-evolve.

Climate played a role as well.

19
Arctic sea ice / Re: The 2019 melting season
« on: August 04, 2019, 08:44:28 AM »
The heat can mostly move through conduction
You mean convection I assume?
Nope. Conduction.  No convection through the halocline unless wave action stirs things up.

20
Arctic sea ice / Re: meaningless freezingseason/melting season chatter.
« on: August 01, 2019, 07:19:58 AM »
sh wrote: "For me to believe year round BOE, someone would need to explain to me what conditions would prevent portions of the Arctic Ocean from freezing in the long, dark Arctic winter."

I can think of a few factors that could come into play, some of which we have already witnessed:
Well the sea around Svalbard (and even a couple of hundred km to the north at times) does not freeze in winter in spite of there being a long dark Arctic winter there. On the Atlantic front, we quite often see Ice-free conditions through winter in (admittedly) small areas north of 80 degrees.

So a warmer North-Atlantic current that stretches ever further north along the surface, particularly if coupled with clouds during winter, might well keep a very large part of the Arctic ocean ice free all year round.
Much depends on salinity and total system heat present.

Greenland still presents a serious "cold pole" as does Siberia/Yakutsk.  As long as we see snowfall over these regions, I think at the very least, near shore and the CAB north of the dropoff at Nansen basin will probably continue to freeze seasonally through the end of the century.

21
Arctic sea ice / Re: The caa-greenland mega crack
« on: August 01, 2019, 07:11:59 AM »
Aslan - on the topic of benches, the crack actually offers an explanation that doesn't require a full melt out of the basin.  Factor in post melt elastic rebound and you have a working theory for how they got there.
I'm a bit suspicious here - I don't think a crack of 10 to 20 km, even occurring every year, can explain beach formation. Waves inshore would be very small and insignificant, espcecally since the crack seems to form mainly when offshore winds are strong and persistent.

The beach ridges described in the literature above seem quite substantial, indicating a large wave fetch in onshore winds.
Agree 10-20 is not sufficient.  100-200 would be. 

Also consider, what are those benches cut in? Bedrock or sediment?  If sediment, it could have been frozen; we've seen how even modest surf has been chewing up permafrost along the Alaskan coast.

Like I said though, its the core of a hypothesis, which could be tested.

22
Arctic sea ice / Re: The 2019 melting season
« on: July 30, 2019, 07:23:17 AM »
What a difference 2 weeks makes.
Beaufort, 76.62, -165.12 upper right, 72.41, -140.43 lower left.  Somewhere between 600 & 700,000km2.

(Edit) Keep in mind this is "relatively" low latitude.  Insolation in two weeks will not be dropping like a rock here  the way it will north of 80.  Most of the ice in the 7/29 image, if not all, should be gone, unless it is replaced by export from the CAB or CAA.

23
Arctic sea ice / Re: 2019 sea ice area and extent data
« on: July 29, 2019, 07:12:40 PM »
Attached is a graph showing cumulative losses from August 1st to the minimum.

Despite starting with a lower extent each decade, the area lost is increasing each decade. 
    ....

This is quite significant. For volume, anomaly charts suggest the trend leans opposite. (I haven't scrutinized the data, which appear highly variable by year.) If so, the combination implies a shrinking but resistant end-of-season blob over time.
I think latitude counts for a lot as the pack has shrunk.  It is also pulled North which means that the angle of incidence changes more rapidly and dramatically during the melt.  In short, while peak insulation is high, the timeframe is short, and what can practically be captured is less.

Lower latitude ice has longer timeframes to capture heat, and that capture over time will be more consistent.

At high latitude my hunch is increases in loss will be driven more by net increases in system heat over time, primarily imported from elsewhere.

24
Consequences / Re: Wildfires
« on: July 28, 2019, 10:53:47 AM »
The sheer scale of this years fires is just boggling.  *Millions* of KM2 seriously affected by smoke...

7/25/2019 Worldview capture with a few added notations for reference.

25
Arctic sea ice / Re: The 2019 melting season
« on: July 27, 2019, 06:04:27 AM »
Take your pick. dmi, hycom jul3-25 and piomas jul3-15
DMI is garbage
All are consistent with themselves.

As such, year over year, they provide metrics for comparison with their previous states, which in and of itself is useful in understanding how the system is changing.

26
The Baltic is small and surrounded by land so not a good example of what would happen over the arctic seas?
And shallow, brackish, and a lot further south.

27

You have consistently sucked the air out of the room bickering with *multiple* people.  You've wrapped yourself in a heroic banner and pretty much declared you are on a crusade to sort us all out, and the rest of us need to get behind you to help push. That will not endear you to the myriad of researchers and citizen scientists here who have been studying (and continue to be) the Arctic for decades.


Thank you for your comment.

I certainly don't see myself as a hero. I am throwing a desperate Hail Mary as I watch the future get subsumed.

With all due respect to the people who spend their lives researching the Arctic, and becoming experts, I thank them. They and countless others have performed a great service in educating people.

At this point we have a surplus of information available to anyone interested. Civilization is not going over the precipice because of a lack of scientific understanding.

We are going under as a result of social inertia. At this point it's probably a lot more important to understand the bystander effect than Albedo Warming Potential.

AGW is primarily a social science problem at this point. This is a community which you claim is"terrified" of AGW, but there is very little discussion of what we do about it.

We're all watching it happen. No accountability to each other. Committed perhaps to adding to unnecessary surplus of understanding that we're screwed.

Twice this year, > 1M kids skipped school on the same day to protest climate change and the world moved on with hardly a pause. Are we with them or are we quiet bystanders?

It's interesting that even in a community that is mostly accepting of the risk of AGW and terrified, that the social construct of our obligation to do anything about it is taboo.

If you want to understand why the world can't embrace the mission of fighting AGW, maybe we can start by understanding why ASIF can't embrace it as a mission.
What is within us that prevents us from joining those kids?

We're not fighting. We're bystanding. We're throwing out surplus science and largely spectating.

It's all fucking madness. I'm not a hero. I'm alone. I'm outraged. I study history. I'm all too familiar with how easy it is for good people to do nothing when evil arises.
Rich;

There are places for discussion about action, and there are places for discussion about research - which puts tools in the hands of people like you and me to take our arguments to the street.

These forums are dedicated to science, for the most part, but we *do* have active discussions about action.

Because of this, you also miss the the fact, the virtual certainty that most of us *are* taking action, across multiple venues to address climate change.

Some like Neven and myself are working hard to reduce our and our families personal carbon foot print.

We all contribute to the discussions here trying to understand AND BETTER ARTICULATE exactly what is going on in the environment.  Discussions and research products here have frequently been picked up in mass media and significantly contribute to public understanding.

Contributions here have prompted new research by scientists studying the Arctic.  *Tell* me that isn't important?!

Do not think for one moment that the scientific discussion here isn't helping.

Similarly, do not assume that forum members are not actively pursuing remedies to climate change elsewhere - whether lobbying our governments, educating people about the science, contributing to environmental organizations or taking direct action themselves. (edit: Some of us may also actually be actively running as or supporting candidates for political office in an effort to directly change policy...)

It's all going on, Rich.  We just don't talk about it here for the most part, because "this" isn't the appropriate forum for those discussions.

There *is* a place for the dialog you want to have.  It even exists here in other threads:

https://forum.arctic-sea-ice.net/index.php/board,16.0.html

You will find people there very willing to engage you on exactly the topics you are describing.

Most of the posting you do in the Arctic Sea Ice threads really isn't helping, and in fact is making things harder.

For the sake of coherence, please consider moving your concerns there and reduce the amount of noise and friction being generated in the Arctic Sea Ice threads. 


28
Lightening rod ? .. or arsehole ?

Whatever works for you b.c.

As a practitioner of sarcasm, contempt and one upsmanship, I would think you would be grateful for my presence here. I'm here to compliment your sweet spot.

If there were no vehicles for smart ass comments, how would you fit in here?
Finally a place where a comment on this is appropriate.

Rich, the biggest problem I think people have is a lot of the posting you have done hasn't been about the ice, or climate change, but rather about Rich.

You have consistently sucked the air out of the room bickering with *multiple* people.  You've wrapped yourself in a heroic banner and pretty much declared you are on a crusade to sort us all out, and the rest of us need to get behind you to help push. That will not endear you to the myriad of researchers and citizen scientists here who have been studying (and continue to be) the Arctic for decades.

Your actual goals are completely lost in the process.

We relate to your fear. I think its safe to say the posters here are terrified for the future. I acknowledge yours, which is legitimate and justified.

Don't let it or your ego get in the way of the discussions.

29
Arctic sea ice / Re: When will the Arctic Go Ice Free?
« on: July 25, 2019, 09:25:43 AM »
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 petajoules 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 now 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

)

30
Arctic sea ice / Re: When will the Arctic Go Ice Free?
« on: July 23, 2019, 11:45:18 PM »
This thread has taken one helluva nosedive recently.
It is the roar of frustration and fear, which I in every way understand, and which is in every way understandable.

I have great sympathy for Teapotty and Archimid. 

Any differences I have with them are nuance of detail, much like whether the curtains will burn before or after the windows blow out of the burning house we find ourselves in.

I don't discredit their feelings.  In fact, for the most part, I share them.

31
Arctic sea ice / Re: The 2019 melting season
« on: July 22, 2019, 11:03:16 PM »
I'm not yet sold on the hype of the upcoming weather forecast.
2-3 C, 2m over the ice is really warm. Means there's a significant temperature gradient above the ice and thus heat transfer from the air to the ice<snip>
Let's keep in mind that 2-3C is the max, not the average for the 10 day forecast period.
There's a lot more than just air temperature in play here.  Wind will prompt movement and retrieval of heat from depth to the surface.  Wave action will have a mechanical effect on the ice.  Ice could be exported to peripheral regions with much higher SST's than where it sits currently.

The weather is striking the pack with a heated hammer; what remains is where, how hard, and where do the chips fly.


Quote
The cool thing about being new to this is learning a lot.

Good!

(Edit:  And echoing werther, much of the damage has already been done.)

32
Arctic sea ice / Re: When will the Arctic Go Ice Free?
« on: July 22, 2019, 10:35:15 PM »
<various snippages>
I did not say that a BOE is a huge danger. On the contrary, I think I made it abundantly clear that I think a BOE is a non-event.

The ongoing loss of Arctic Ice is not a BOE, and it is the ongoing and continuing loss of Arctic Ice that is already having dangerous effects and will only get worse as more ice is loss. Irregardless of an eventual BOE.
On this, I have to say I'm in concord with binntho.  For all of our wrangling over what is an entirely symbolic metric threshold (1000km3 of ice), it is an effect, rather than a cause.

That cause - general heating of the Arctic climate - is already generating cascading failures in the biome and through teleconnections wreaking havoc all across the northern hemisphere.  One need go no further than news of massive animal die offs, massive floods, crushing heat waves, and images of half of Siberia under wood smoke to validate this.

This will no doubt scale with time, but reaching the specific above mentioned threshold will not mark nor prompt any abrupt transition that isn't already well underway, nor already having pronounced effects on the world.

The rest of it - the personal charges of denialism et. al. - are value judgements, and are really out of place here.

Gentle sentients, can we please return to the discussion of science rather than tearing at each other?

33
Arctic sea ice / Re: When will the Arctic Go Ice Free?
« on: July 21, 2019, 11:09:25 PM »
Umm, I don't really believe this graph as the green and purple trend lines don't cross in future and with continues GHG emissions I believe they will. Also sorry about the trendlind being extended outside the range they are meant to apply to which makes graph horribly messy.

<snippage>

These need more data to verify, but so far the data suggests what?
I think the problem lies in the fact we are trying to collapse probability in a 3 dimensional system over time down to 1 absolute scalar value.

I think what we need is something like the "probability of melt" map we've seen elsewhere on the forum, where we evaluate each section of the map in turn over time.

Then I'd say we can stack probabilities to something more sensible.

34
Arctic sea ice / Re: When will the Arctic Go Ice Free?
« on: July 21, 2019, 10:09:21 PM »
Actually, the regional PIOMAS data that Wipneus posts starts on the year 2000. I merely used the whole data set. Where did you get regional PIOMAS from 1979?

It's on the piomas site, I just downloaded it

Archmid's CAB excludes the peripheral seas. Your PIOMAS data includes them.
For the sake of identifying trends, the peripheral seas very much need to be left out, as even before the current decline, they tended to melt out entirely over the melt season and buffer the numbers in ways that mask the actual shift in system behavior.

Archmid's arguments are very persuasive, and match my more anecdotal evaluation of what we are seeing.  I think the leveling off or even slight de-acceleration in the rate of volume decline is an "asymptotic" effect.  Namely, we are now approaching "hard" limits of the system, much like a descending pendulum starting to scrape a surface.  That suggests to me we've already made one non-reversible transition in system state.

The question now to be answered is how long it will stay in this current state before tipping into the next one - which would be where we see regular BoE's.

My own sense is that it will happen sometime in the next ten years, which I evaluate in terms of probabilities. 

This year I think is the 2nd (after 2016) where there was a non-zero probability of a BoE.  I don't think it will happen this year, but there is still good reason to believe 2019 will challenge 2012 for the low extent record.  I think we are seeing a cumulative increase in potential for it moving forward.  Pick your number - 1%, 2%, 5% (mine) or higher, I think that will stack up as enthalpy in the region and globe as a whole continues to stack up and pass key "non-tangible" thresholds which govern climate state. 

When it comes, it will likely be sudden and still a surprise, even though we are looking for it.

35
Arctic sea ice / Re: When will the Arctic Go Ice Free?
« on: July 16, 2019, 03:07:44 AM »
I've been ruminating on this a bit...

For all of a BoE marking some sort of milestone in the Arctic, the impact of reduced summer (and Winter...) ice coverage is already making itself felt.  In short, the difference between 2 million km2 extent and 1 million km2 extent won't be that significant from the standpoint of its effect on climate.

We're already seeing dire changes to the ecosystem and major impacts to year-round atmospheric circulation.  I'm not seeing that changing much with a BoE, except on ramp up, in the manner of degree.

36
Arctic sea ice / Re: "Stupid" Questions :o
« on: July 15, 2019, 10:13:50 PM »
<snip>
<snip>
<snip>
I'm interested in exploring the relationship / correlation between water temp and depth. If you're game we can try that. If not, also OK.

The flow of geothermal heat is pretty consistent, and very, very small... on the order of only 87 MILLIwatts per square meter.  You'll get some higher concentrations in active geothermal/volcanic zones, but that's the average over all.

That's the reason why you get 100s of meters of permafrost in Arctic zones because the heat flow is to low to prevent it from forming until reaching a depth where the thermal balance is reached between water freezing and heat loss.  If the Arctic were in permanent darkness (e.g. if the Earth were tidally locked with the sun), that freezing zone would extend down through most of the crust.

What keeps things locking up further during Polar night is heat flows from outside of the region bringing in heat to offset loss from the top of the atmosphere.

Permafrost on ocean shelves like the ESS is actually an artifact left over from the last glaciation, when the shelves in question were exposed.  Clathrates which have formed do so naturally, and can form at fairly high temperatures, as pressure is a factor in their formation - there's actually a lot of them at depth in the Gulf of Mexico for example, as you have methane release, low temperatures and very high pressure..

The melting of both (clathrates and sub-sea level permafrost) is driven much more by heat carried by water on the shelves, captured during the melt season, or imported by currents, and is understandably low considering the usual low temperature of sea water, which is low enough that pure water ice won't melt if it is protected against intrusion by salt.

So, all in all, you really aren't going to get any heat input from Geothermal sources in the Arctic worth mentioning as contributers to any melt we see.

37
Arctic sea ice / Re: When will the Arctic Go Ice Free?
« on: July 11, 2019, 09:35:52 PM »
Find me a paper that describes what happens after the first BOE...
That seems to be very uncertain. The IPCC states "with high confidence" that there will be no hysteresis ...
<snippage>
I think we're already seeing hysteresis with changes in feedback and increased uptake of heat, not to mention the extermination of ice more than 4 years old.  It would take generations of pre-1980's weather to restore the pack to the state it was in before 2010, much less earlier.

38
Arctic sea ice / Re: The 2019 melting season
« on: July 09, 2019, 10:04:34 PM »
If the GFS 384 hour prog verifies 2012 will likely take a solid lead over 2019, but I doubt the air over this Arctic will be as cool as the forecast output below.
If there is one thing I'd bet my mortgage on not happening it's whatever the the GFS is showing at hour 384...
Me too, and Judah Cohen too. To add to the confusion, tweet 3h ago:
All in all, we're trying to predict how the pot is going to boil.  The climate system's primary drivers have been staggered, and volatility is increasing as a result.  With near-shore land temperatures consistently well above historical maximums region wide, with more heat and moisture being pumped into them from lower latitudes, its no surprise models are vacillating like they have been.

The gradient between land and sea temperatures has become both narrow and steep simultaneously.

Pure chaos ramping up.

39
Arctic sea ice / Re: The 2019 melting season
« on: July 09, 2019, 09:52:58 PM »
<snip>
<snip>
The ice front is now hundreds of kilometers offshore. It's the temperature there that counts.

It's still going to melt at 1-2C above freezing, but not at the same rate that we've been losing ice recently.
<snip>

Actually, it starts melting at -1.8C.  By the time your sea water reaches 0c, your bottom melt rate is measured in multiple cm/day, more so if you are at 1-2C ... which much of the Beaufort has reached.

There's even more heat at depth, even in the Beaufort, so if things get stirred up, because of the current loosely consolidated state of the pack, that will permit Ekman pumping to bring a lot of that to the surface.

There's also the question of longwave radiation, which even with clouds, at this level of insolation, will continue to drop prodigious amounts of energy on to the ice.

The momentum is already there, thanks to June and the first part of July.  There will remain enough energy to maintain velocity.  I think the best we can hope for is that it doesn't *accelerate*, which it would were June conditions to persist.

40
Arctic sea ice / Re: The 2019 melting season
« on: July 05, 2019, 09:47:46 PM »
Currently it's 21C at the weather station at Niuqsuk Airport, just east of Barrow,  with the dewpoint at 11C, with the breeze blowing straight out onto the sea
Those dewpoints mean the ice will be literally sweating the moisture out of the air even without rainfall, with the attendant transfer of heat.  Same applies to any open water as well, assuming SSTs of around zero.

41
Arctic sea ice / Re: The 2019 melting season
« on: July 04, 2019, 09:09:24 PM »
That is not a real chart of july 3rd. It would mean a BOE within two weeks.

this is:https://seaice.uni-bremen.de/data/amsr2/today/Arctic_AMSR2_nic.png
The truth is somewhere between in this case I think.

We know there is a substantial amount of MYI spread out in that "thin" area shown.  Over the winter, it was divided, and divided again, with spaces between filled in with ice which now is rapidly being converted to soup... that's what the consistent 100K+ drops in area are telling me, especially when coupled with far more modest drops and occasional increases in extent.

It certainly isn't going to flatline in a BoE, but I'm expecting CAPIE to make a hole in the floor.  It could lead to this paradoxical outcome... 2nd - 4th lowest annual extent while having lowest annual area.

42
Arctic sea ice / Re: 2019 sea ice area and extent data
« on: July 04, 2019, 08:52:40 PM »
NSIDC area appears to now be the lowest on record:

https://cryospherecomputing.tk/
I guess Tealight is using one day daily data while I use 5 day trailing average, 2-3 days behind, which is around 300k at this time of year. The regional sea area files provided by NSIDC at https://nsidc.org/arcticseaicenews/sea-ice-tools/ are all 5 day data.

I stick with NSIDC for area in total and by individual sea for consistency.

The data does show how 2019, 2012 and 2016 are in a very narrow band so far.
I prefer 5 day data as well, as it reduces noise from volatility and I think is better at illuminating trends.

That all three years are in such a narrow band is very indicative in itself, and quite alarming.

43
Arctic sea ice / Re: 2019 sea ice area and extent data
« on: July 04, 2019, 08:49:35 PM »
Compactness now also lowest on record:
Ironic, considering some of the discussions around dispersion and 2019's supposed lack thereof...

44
Arctic sea ice / Re: The 2019 melting season
« on: July 03, 2019, 03:35:27 AM »
If HYCOM is anywhere near correct it looks like we could easily lose 1M KM^2 of area this coming week... that kind of collapse would put 2012 to shame.
Don't think it will be that much, but I think the steady march of 90-110K daily losses will continue plodding along.  We'll lose ground to 2012 during that time.

However, I think the state of the ice is such, that once 2012 trails off, we will continue plodding along with those 90-110K losses through July and possibly well into August.

If we go seriously low this year, I think it will be via a long whimper rather than a BANG.

45
Arctic sea ice / Re: The 2019 melting season
« on: July 02, 2019, 07:59:31 PM »
It seems unusual to me the wind coming from south Asia to the Bering Strait. I don't see the normal jet stream. Instead, a flow south to north. It is coming a lot of heat to the Arctic, with this wind pattern?

https://earth.nullschool.net/#current/wind/isobaric/700hPa/orthographic=-212.00,61.11,316
That may be about the clearest most succinct example of the breakdown of the Hadley/Ferrell/Polar cell circulation I've seen yet.

Tropics straight to the Arctic.

46
Arctic sea ice / Re: The 2019 melting season
« on: July 02, 2019, 12:52:40 AM »
 Wouldn't cheer yet.  There is 2-3cm of rain forecast to fall under a bunch of these clouds on the Pacific side.

47
Arctic sea ice / Re: The 2019 melting season
« on: June 30, 2019, 09:19:28 AM »
Check out post 2802 which is documenting a 5'+ surge.
What happens when a continuous 5' wall of water hits the ice? My default mental image is that the water goes over the top and floods it. As fast as the water might work it's way through any cracks in the ice, it i ifs is replaced by the continuing surge behind it.
<snippage>
The ice will bob up and down on the water and there may be some splashing but there will be no tsunami inundation. There will be a current develop, but substantially less than the wind speed.

Five foot waves will put the larger floes under stress and  probably break them  up. The wind and wave motion will cause some layer mixing, and possibly accelerate melting. There will be compaction or dispersion depending on the wind direction.
<more snippage>
Your insulting language is unnecessary.

Sorry you feel insulted, but Pragma's assessment is fundamentally correct; any surge would simply lift the ice rather than overtop it.  Your experience in Miami notwithstanding, what happens with surge in a storm there really doesn't apply to the Arctic pack.  Any overflow would be limited to a few 10's of meters of extent, if that, and would rapidly disperse.

The slope of the surge won't be such that it will cause any serious mechanical damage to floes.  Wave action attendant with a storm will.

48
Arctic sea ice / Re: The 2019 melting season
« on: June 30, 2019, 07:32:39 AM »
Slater map should be deleted, and just the graph kept. This is the only way to avoid confusion, and I never did get what value that map adds.
I *very* much disagree.

The Slater map captures the quintessential uncertainty and variability of the melt season.  I actually consider it to be one of the best models we have available.

You need to keep in mind, it is not explicitly predictive; its not meant to be.  It instead measures potential.

So please explain how the Slater Map works. In theory, if we get the worst possible weather every day, s BOE is still within the realm of potential.

How is the Slater Map anything other than a guess as to what the weather will do the rest of the season?

As a former CPA / auditior, I'm open minded but bringing a perspective of professional skepticism.
It *is* a guess, and an educated one.

Over the years we've tried out all kinds of very specific metrics in an effort to create/find the "one true measure" that will reliably predict in May what the ice will look like in September, and from those metrics extrapolated the prompt demise of the ice, frequently.

Pretty much every year we've failed spectacularly - 2013 stands out very much in this regard.

We've gotten better, and those of us who've been around for a while have become far more circumspect in our predictions, and far less certain of what might appear to others to be "reliable" metrics.

So in fact, the behavior of the system on the whole has just *1* factor that is consistently predictable year over year, month over month and day over day:  The amount of insolation that strikes the upper atmosphere.  The net enthalpy present in the Arctic Ocean is a second factor that *approaches* insolation in reliability, but we really don't have a clear handle on it because of our lack of sensors measuring it.  And while it's moderately predictable, the rate in which that heat will be exchanged with the ice definitely is *not*.

The rest of it - albedo, precipitation, cloud cover, atmospheric circulation, air temperature, inflow of extra-polar sea water into the peripheral seas and basins, export of ice and ice quality,  to name the most obvious - is decidedly not predictable, in spite of the incredible efforts of folks building models like the GFS and ECMWF have put into them.  The best windows we have pretty much still fuzz out about 120 hours into the future.

So to look through a glass darkly, one of our best approaches is to stack uncertainty.  We sum the various potentials to see where they are in their swing to sense where the state of a specific location will be further in the future.  And Zack's tool has actually done a reasonably good job of that.

As a metaphor, I'll leave you with one of my favorite graphics to illustrate variability.  Just imagine each of the factors above to be a leg in this pendulum, each of which year over year, month over month, day over day, can change in length, and who's period can shift in velocity.

https://revolution-computing.typepad.com/.a/6a010534b1db25970b0192aa7aa4a6970d-pi

Edit: It occurs to me that you could take another approach to Labe's map.  That is this, that he *is* predicting the reciprocal losses of ice relative to his coverage prediction.  To wit, where he has a 10% potential for ice remaining in a given location, across *all* of those locations, his model is expecting 90% of the ice to disappear during the time frame specified.

So, overall, eyeballing areas, he's expecting something like 2/3rds of the ice to disappear in the next 50 days.

49
Arctic sea ice / Re: The 2019 melting season
« on: June 30, 2019, 06:39:13 AM »
Slater map should be deleted, and just the graph kept. This is the only way to avoid confusion, and I never did get what value that map adds.
I *very* much disagree.

The Slater map captures the quintessential uncertainty and variability of the melt season.  I actually consider it to be one of the best models we have available.

You need to keep in mind, it is not explicitly predictive; its not meant to be.  It instead measures potential.

50
Arctic sea ice / Re: The 2019 melting season
« on: June 28, 2019, 09:15:53 AM »
I think that this dispersed ash probably did make it to the upper troposphere and maybe the lower stratosphere

I read it went (only) 13km high.
... and ash is far less important than SO2.  The most recent eruption wasn't anywhere near a scale sufficient to affect climate.

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