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Messages - Tor Bejnar

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1
Arctic sea ice / Re: AMSR2 Sea Ice Volume/Thickness
« on: December 09, 2018, 01:56:15 AM »
I've been brooding over PIOMAS volume data the last 3 days, following some discussion elsewhere about trends vs "weather" and the kind.

I'm staring here as I write at 4 graphs I derived from the PIOMAS data downloaded from the U.of Washington Polar Science center.  I'm pondering what it implies about past changes in the Arctic and what import it has for the future.

Let me back up for a moment and describe what I've done first, and why.

There's been a lot of discussion on the Arctic forums recently around three dimensions we use to evaluate Arctic system health.

In our discussions and arguments we've wrestled with the reality that two of those measures - extent and area, particularly as they appear at the end of melt season - have become increasingly difficult to evaluate to make a skillful determination of how the Arctic will look in a few years. Our discussion has shifted and expanded now to where over the last two years there has been much more tracking and examination of the annual refreeze.  This has given us some hints and generated quite a few more questions.

Roll back to what I'm doing now.  I'm using PIOMAS daily volume data going back to 1979 (http://psc.apl.uw.edu/data/)

My analysis is more empirical than theoretical.  At this moment I'm less interested in prediction than I am the data set.  I have a particular interest in volume as well. Unlike extent and area, it represents a far better proxy for key forces at work in the Arctic - heat exchange and total system enthalpy.

My second purpose is contrast volume changes with changes that have taken place during the time period in question and see if a pattern appears which follows or is affected by them.

Methods:

Simply digesting a raw and fairly substantial pile of data is unlikely to produce anything useful.  However, I don't want to fall into the trap of over-analyzing the information - while it is good to reduce "noise", over-processing values can remove meaningful signals it contains.  My approach to this is three fold.

1) Create a sample average from a meaningful but more controllable time frame.

Most analysis of this data has been around extreme endpoints in annual variation - the annual maximum extent/area/volume and corresponding minimum - which land on arbitrary dates and are very narrow samples.  For my work here, I've picked to arbitrary but significant dates March 21 (Day 80/81 of each year) and September 21 (Day 260/262).  I then averaged the daily volume for a time frame window which extends from two weeks before until two weeks after those dates to get what I call "Vernal" and "Autumnal" volume numbers for those dates.

My logic in doing this is this: Rather than use a metric which is volatile and fundamentally disconnected from other forces in play at the time they take place (annual minimum/maximum), I wanted to anchor the analysis to two specific points in them where we know predictable and measurable changes are taking place (the Spring and Fall equinoxes).  Further, to make the new metric sensitive to conditions during the specific year and season, rather than simply pluck out one number, an average over a near-term time frame would better incorporate and smooth other signals from forces in play at the time.

In addition to these two numbers, I also created a baseline value for tracking behavior on a broader time scale.  In this case, I created an annual average for each year, summarizing all volume measurements from January 1 to December 31 for each year in question.

2) Create a derivative average which further smooths the Vernal and Autumnal numbers over a wider time frame. 

In this case, I created a second data set from my spring and fall averages, starting with 1983, which is a simple 5 year running average of those numbers.  The goal here is to round off peaks and valleys without losing all of the signal they contain, and hopefully permit underlying trends to be more visible, and more importantly, better identify transitions in system behavior.

3) Create a third derivative/index to show system volatility.

At the start, these were actually the numbers I was most interested in. We've discussed this some on the forums, but the summary of my thought here is, this, and also may qualify as a hypothesis:  As the Arctic as a system approaches behavioral limits, the volatility of the system - the relative change against base values - will increase.

Again keeping it simple, I created three values for each year in question.  These were (a) The absolute difference between Vernal and Autumnal values (b) the Percent that value represented of the Vernal volume and (c) the Percent that value represented of the Annual volume as derived in (1) above.  I did this for both the raw and 5 year running averages of Vernal, Autumnal and Annual values.

Note: all values I used were rounded up to three decimals. I figured the significance of fractional cubic KM of ice were meaningless based on the confidence of the measurements.

Findings:

From raw data and graphic analysis by Jim Pettit, Zach Labe and many others it's already clear that sea ice volume has been declining steadily over the time period in question.  What isn't necessarily clear is the nuances of how those changes have taken place.

Both the smooth and averaged data clearly shows this trend. No surprises (nor were any expected).

However, annual seasonal loss has shown only a very modest increase - less than 10% over all - with an average of 14.242K KM3, median of 14.034K KM3 and deviation of 1.164K KM3.  Breaking the loss dataset in half shows the 2nd half loss rate only increasing by about 1000KM3, and 2nd half loss volatility actually declined slightly. The 5 year running averages are correspondingly closer.  This suggests strongly that large year to year variations in melt are not significant contributors to the reduction in volume over the period measured.

The first think that jumped out at me in particular in the averaged data, is I think I'm seeing two historical locations where I think there's a signal identifying a fundamental change in how the system behaves.  The first is in the 1990-1994 time frame. There I think spring, fall and yearly average graphs start a break in slope, falling into the glide path that takes us down hill to where we are now.  I'm not sure what the specific conditions were at the time, or, considering hysteresis, how far back we need to look for the trigger, but it strikes me that is a specific place in time and space we can point at where the system signals a change has taken place.

The second was the 2010-2013 time frame.  in that range all three measures - Annual average, spring and fall - flatten out.  As another interesting and possibly key item, annual loss intersects and then starts to follow the annual average curve.  I'm not sure what this means yet, but it sure looks like a strong signal.  Also, while the three major curves flatten, the *vernal* curve is still trending down.  I think the running 5 year equinox graph shows this the best.

My general take away - I think the graphs support another of my thoughts - that as the total energy available to the system increases (reduced ice), the overall volatility of its metrics will increase - especially area and extent - which actually are more derivative of this than volume.

I'll be interested to hear what other folks think.  If someone can point me in the right direction, I'll post the spreadsheet with my raw numbers someplace for people to tear apart.

 (P.S. - the average volume will be off a bit for 2018 as we haven't finished the year.  That said, we are far enough along it that the relative change is small enough to be negligible to my analysis.)

2
Arctic sea ice / Re: Arctic Image of the Day
« on: December 05, 2018, 04:19:37 PM »
Am I the only one that checks in with the webcam in Utqiagvik to see if the house on the left hand side of the image has its door wide open again?  It's cold up there.  Why is the damn door open so often?  Maybe we should call them to let them know?


3
Policy and solutions / Re: Tesla glory/failure
« on: November 29, 2018, 06:34:52 PM »
More Tesla jokes.....
Meanwhile, the Tesla 3 is NOT a joke & is better looking than all previous Teslas..... plus all other viable EVs of ANY brand, which is a delight to potential buyers who put $1000 on the line, two years previously. Tesla 3 is very efficient (tho I may hold out for a 64kWhr Ioniq). Tesla 3 has innovations other brands don't have, all backed up by in-house battery & solar cell energy productions. Those complaining about Tesla have to be short sellers.
Tesla colors have to get strong 3-D metal flake paints, like so many other brands also need.

4
Arctic sea ice / Re: The 2018/2019 freezing season
« on: November 25, 2018, 03:52:21 PM »
A comparison of Chukchi ice extent from 2015-2018, nov1-24 using amsr2-uhh.
The main ice edge for each year from 2015-2017 has been extracted using edge detect in imagej, then splitting the colour channels to remove some of the concentration data, so it should be seen only as a rough comparison.

5
Arctic sea ice / Re: 2018 sea ice area and extent data
« on: November 21, 2018, 04:04:44 PM »
Another interesting statistic to show the uniqueness of the current refreeze. The table shows the extent changes (JAXA) in the last 30 days (Oct 21 - Nov 20). 2018 is leading with a margin of over 400'000 km2 and the extent gain was over 1'000'000km2 higher than the 2010's average!

Another note I'd like to make is that the table considers all years from 1979-2018. Out of the years in the top 10, there are 4 from the 2010's, 4 from the 2000's and only 2 from before 2000. This shows that there are times of the year where the refreeze is actually going up, rather than down like the overall extent trend.

My theory, and please correct me if I'm wrong, is that this is the effect of the increased summer melt in the central seas. Especially the CAB, Laptev and Kara lose way more ice in summer than they did 20 years ago. But because of their northern and central location, they still refreeze 100% in winter anyway. But this (usually quite fast) freeze of those seas was around early October 20 years ago, it's now happening in late October and November. Therefore the upwards trend in October - November sea ice gain.

6
Policy and solutions / Re: Extinction Rebellion
« on: November 02, 2018, 12:48:07 PM »
Hi I am a longtime lurker. Inspired by a post on Jason Box's Twitter feed I was one of the 1000 people at the Declaration of Rebellion for Extinction Rebellion on Wednesday. It was a glorious autumn day and I felt privileged to be at the start of something so significant. https://mobile.twitter.com/extinctionr

7
Policy and solutions / Re: Tesla glory/failure
« on: October 29, 2018, 02:43:40 PM »
An interesting and well-written article by Paulo Santos, both short-side and not short-side.

And if you read the article carefully, you realise the gap between Tesla shorts and Tesla optimists.

Tesla shorts believe that Tesla is overvalued as a “car manufacturer”.  Yep I’d say that this is quite correct.  But, you see, Tesla is not “just” a car manufacturer.  Tesla manufactures the batteries for their vehicles but also for other energy sequestration projects including the smart home.  Tesla is in the process of manufacturing Semi’s which will become the leading EV  heavy vehicle in the world.  Tesla are also a vehicle software and processor manufacturer.

Over and above that they also have a charging station network.  If you think about it Tesla produces the cars and provides “gas” stations for the cars too.  They will do the same for Trucks.

Then if you factor Solar City into the mix, Tesla will provide the products to generate the “fuel” for the vehicles and provide home fuelling stations, on street fuelling station for the vehicles they produce.

Then the shorts value them as a “car manufacturer”.

Is it any wonder the markets are split right down the middle. Those who are investing for the future shape of Tesla are pricing it high.  Those who just want to make a quick buck and get out, potentially taking Tesla down with them, only value Tesla for what it cannot make a profit on today.

Solar City will, eventually, become a key critical pillar in the Tesla low emissions landscape.  Unless the shorts kill the company before they get there.

This is the core/crux of the problem between the shorts and the bulls on Tesla.  The bulls know what it is.  The shorts don’t care what it is, they just want to sell it as another failing car manufacturer and make a fast few billion on it.

8
Consequences / Re: Global Surface Air Temperatures
« on: October 23, 2018, 06:37:31 PM »
I must say, I dont understand the reasoning behind Hansen's graph. The minimums are compared with the latest reading, which is closer to the linear trend than then minimums (or course - since the minimums are below the trend and max are above... And we are currently in between). So drawing lines from the minimums to that end point will show steepening lines even if the minimums stay the same distance between the linear trend line.

Its geometry, or even mechanics. You have a line that runs underneath a pivot point, connect a sliding rod through a point attached to that lower line with the other end attached to that higher pivot point. Now slide the bottom point along the lower line and reproduce this exact graph.

I dont get it - but as a not particularly knowledgeable random person on the internet I'm happy to be proven wrong!

Edit: If the latest data point IS a minimum, and therefore a minimum higher than the others, that's surely just one point and not particularly evidence of a trend surely. Connecting those other points to this one still doesnt look valid scientifically.

9
Arctic background / Re: Arctic Maps
« on: October 06, 2018, 12:25:00 AM »
Reposted from Artic Cafe thread

Test your knowledge of the Arctic seas, basins and shelfs in this 100 piece puzzle i made of a map Uniquorn posted.

https://www.jigsawplanet.com/?rc=play&pid=0a4eb46199b7

10
The rest / Re: The Trump Presidency (was "Presidential Poll")
« on: September 27, 2018, 04:48:15 PM »


Some girls didn't need to be drugged to get into it. Ever been to Spring break in Florida folks?


The problem with Kavanaugh isn't that he drank and had sex in high school.  The problem is that he's shown himself to be the unrepentant product of rich white male entitled chauvinistic jock frat prep-school bro culture.

My educational trajectory put me into regular contact with this culture and its denizens for 10 - 15 years.  Sounds like a prison sentence.  I was more drawn to the anti-war hippie counter-culture types.  By the time I got to college, this youth culture was rapidly evaporating.  Pity.

The parties we've been reading about, the ones of Kavanaugh's youth, weren't notable for the alcohol and sex, they were notable for targeting women to intoxicate and, since they were then unable to give consent, gang-rape. 

He grew into respectability, but there's no sign he ever had any epiphany about the culture he came from.   We can see this in his paternalistic yet vigorous refusal to let a 17 year-old immigrant obtain medical care and abortion:

Brett Kavanaugh's One Abortion Case
https://www.aclu.org/blog/reproductive-freedom/abortion/brett-kavanaughs-one-abortion-case

This rich white entitled male bro culture is part of why so many Americans (and others around the world) suffer.  The stories that are now dogging Kavanaugh are broadly consistent with each other and with the toxic culture I observed during my educational years.  This is a segment of the entitled culture that refuses to take personal responsibility for our shared global environment.  As it ties in with sexuality and gender relations, we can see it in stories from the new movement unfolding now:

I couldn’t stop reading #WhyIDidntReportIt stories. Then I realized why.
https://www.washingtonpost.com/local/i-couldnt-stop-reading-whyididntreportit-stories-then-i-realized-why/2018/09/26/6dff450c-c109-11e8-90c9-23f963eea204_story.html?utm_term=.5fc2bd38a1e0

"In the last week, women and men who have experienced sexual abuse at the hands of others have started doing what they haven’t been able to for years and decades: admit something unfair and awful and damaging happened to them.

Just search for #WhyIDidntReportIt, or variations of that hashtag, and their stories will come barreling at you as confessionals, some containing only bits of details and others spilling out in their complete and painful-to-read messiness."

This chauvinistic, ultimately abusive culture is part of the problem.  Kavanaugh is an unrepentant product of it.

11
Arctic sea ice / Re: When will the Arctic Go Ice Free?
« on: July 30, 2018, 05:23:40 PM »
Btw-

The point here is that messing with high CO2 and CH4 levels is extremely dangerous. In gaming terms (and no thus isn't a game, that is the name used from studies that were developed during the Cold War), this is a "non zero sum game". And isn't the nice version where most or everyone wins. It is the nastiest version where nearly everyone loses.

Should we be so foolish as to push the Earth hard enough to trigger methane and tundra releases, the "game" is over. The Earth flips in a highly non-linear response to a wholly different environmental state - the hot Earth state. And in the long history of life on Earth, the greatest amount of time has been in either the hot Earth or cold Earth states. It has been relatively rare for the Earth to sit in a quasi stable condition between those two extremes.

The shift from one state to the another seems to always be catastrophic for life as it exists, but ultimately beneficial for life and evolution. Our existence as complex intelligent life may well be the direct result of these episodic catastrophes.

But that doesn't mean either that mankind will or would survive such a transition. Ignoring those risks and pumping immense stores of carbon into the atmosphere seems to be the major cause for transition to the hot Earth state, whether by asteroid impact, or supervolcanic flood basalt eruptions. 

12
Arctic sea ice / Re: When will the Arctic Go Ice Free?
« on: July 30, 2018, 04:56:39 PM »
Gerontocrat -

If we trigger the release of the ~1,600 gigatons of carbon in the methane and carbon stores of the Arctic planes and the tundra, it is game over. The earth will go to the hot earth stable state. The Arctic will melt rapidly. The Antarctic will take substantially longer, but will also completely melt before CO2 levels can reduce.

Once that happens, the Earth reenters a climate state that we do not understand how to model - the equable climate. That isn't a bad place once we get there. The pressure is higher along with O2 percentage (30%) and temperature. Wet forests burn in the rain. Giant insects become common as O2 transport becomes easy.

The problem is in getting there. In the interim, the oceans go anoxic. O2 levels plummet to 14%. Large animals die from insufficient O2 unless they have extreme high altitude adaptations. Iron falls out of the oceans. Shelled creatures all but vanish as the oceanic pH falls. All of the biomes are disrupted and most species die off leading to an evolutionary explosion as the survivors move to fill all of the vacant evolutionary niches.

In the end it becomes a massively good thing as new life flourishes on the graves of the last failed attempt. New adaptations take over and dominate.

The problem there is that we only have about 500 million years left to leave the Earth before we begin the terminal slide to a lifeless Earth as the goldilocjs zone moves outward with an ever hotter aging sun. By 750 million years, large life cannot exist. By a billion, life is done as the thermal runaway begins.

13
Arctic sea ice / Re: The 2018 melting season
« on: July 19, 2018, 09:39:52 PM »
For 2018 the thing that REALLY surprises me is the Bering sea.  The straight never fully froze over, and was open in February. The ice edge was so far back from what it normally is.  Many articles were written even outside of sea ice geek circles about how unusual it was.

But the ice edge has moved back so incredibly slowly in the melting season it's getting close to normal there. What the heck happened?  Where did all that extra insolation go?  Was that heat shuffled off somewhere else (like out?)  I was almost sure all those warm bering sea waters would cause all kinds of melt and it absolutely didn't materialize.

14
Arctic sea ice / Re: Latest PIOMAS update (July mid-monthly update)
« on: July 19, 2018, 11:47:05 AM »
Here are several regional charts based on the data from Wipneus. This time I am focusing on this year's laggards - Kara, Beaufort and the ESS, in addition to my usual chart summing up all the regions typically participating in the September volume minimum.
As can be seen, Kara has done some catching up, Beaufort and ESS are still lagging, and the "Inner+" is still keeping up with the leaders.

15
Arctic sea ice / Re: Latest PIOMAS update (July mid-monthly update)
« on: July 19, 2018, 10:42:54 AM »
The volume and volume-anomaly graphs show the melt in July is higher than most until now.

16
Arctic sea ice / Re: The 2018 melting season
« on: July 18, 2018, 04:58:28 PM »
Can anyone explain me how it is possibble that the past 3 winters were the warmest "ever" in the Arctic and yet summers are not much to talk about. Where does the extra heat from winter go? Why does it not show up in big extent losses later on?
Where the extra heat in winter goes is out of the atmosphere, replacing heat that would have come out of the Arctic Ocean.

The result is, less ice being formed.

Less ice forms in peripheral seas that normally contribute to early extent loss.  Ice doesn't thicken as much in central regions.

QED, the heat isn't melting more ice.  That energy budget annually is actually pretty much fixed by insolation.  It's gone up slightly, but that has more to do with increases in heat imported via currents, which doesn't vary as dramatically over the year as does insolation and weather.  However, you can see looking at Jim Pettit's excellent graph that average annual ice loss has only increased by about 15% or so, and any given year can vary as much as 10-15% above or below that average.

The annual maximum is where the story really rests - that's decreased by around 40%...

http://iwantsomeproof.com/extimg/siv_annual_max_loss_and_ice_remaining.png

So in that context, even with our recent very warm winters, what's happening this melt season with an apparently "anemic" melt is entirely within the kind of deviation range I'd expect.

17
Arctic sea ice / Re: The 2018 melting season
« on: June 29, 2018, 10:51:40 PM »
Here's how the CMOS microwave maps look for the past 40 days.

Downloaded from: https://seaice.uni-bremen.de/data/smos/png/
...
There is a definite trend from beige to other colours: dry -> wet

I played around a bit with those SMOS images.  I wrote a script to download the daily SMOS images for June 2010-2018 and to count the number of beige pixels in each image:




Average for the first 28 days of June:

(For what it's worth...)

18
Why bother discussing the merits of incrementalism when it has already failed?

How long ago has it been since climate change has been understood? And in the mainstream discourse? The 80s, 90s? How far has incrementalism gotten us in the last three decades? We’ve almost doubled the amount of emissions in the atmosphere. Littered our oceans. And destroyed much of our soil.

It’s simply too late for incrementalism. Because a significant part of the world will feel the devastation of climate change. Incrementalism is only a concept that serves wealthy nations.  An idea that justifies the costly lifestyle of westerners, while simultaneously ignoring the grim reality for the rest of the world.

Try doing this.

Go to Bangladesh and talk to the people that are about to get their communities swallowed by the sea and tell them this:
“Hey, sorry that your entire life is about to be washed away. Don’t worry, once Elon builds me an electric car everything will be fine.  Thanks for the shirt by-the-way, it fits perfect. Barely cost me anything”

Or go talk to an inuit person whose community is sinking into the permafrost:
“hey, sorry your way of life is being evaporated into the atmosphere. Don’t worry though, natural gas plants are replacing coal plants. Thanks for all the land by-the-way. Didn’t cost us anything”

This is incrementalism: I will not make any substantial sacrifices to combat climate change. The economic system that supports my lifestyle is sacred and must not be changed.  And the suffering of exploited persons is an acceptable sacrifice to the problem.

----------------

Incrementalism has more challenges than just technological fixes. It is the political and social implications of maintaining the status quo.

Incrementalism is liberalism. The idea that our society can make progressive change while maintaining existing class structure. Liberalism worked great in the post-war era when we had essentially unlimited resources and labour to exploit. Liberalism requires stability. Something that is no longer being afforded to us. Our economy and environment are quickly deteriorating. And liberalism does not have the proper tools to deal with our current challenges.

Do you think that the rise of right wing extremism is simply a passing phase? Do you believe trump became president by accident?

Will the climate change induced refugees make the world a better or worse place? Do you think the nationalist will have a change of heart when they have millions of coloured people knocking on their door?

Dealing with millions of refugees is not something that is done ‘incrementally’. You either open your arms or you don’t.

The world is convulsing. And liberalism and ‘incrementalism’ is not equipped to handle this type of crisis.  It is the extremes that will prevail. Reactionary vs. equality. Fascism vs. Socialism.   It is the arrogance of western exceptionalism that our societies are impervious to hate. The faster you realize that the redistribution of wealth is the only option solving the crisis, the less likely we are to degenerate into fascism.  And I can give you countless examples in history where the ‘incrementalists’ (Liberals) either cowardly kept their mouths shut or joined the fascists.


Today is the day you decide to be on the right side of history. Hindsight will buy you nothing.

19
Arctic sea ice / Re: The 2018 melting season
« on: June 21, 2018, 08:35:17 PM »
So I've been thinking about the apparent "slowness" of this year's extent behavior, and have come to the conclusion that a lot of it has to do with the Kara Sea. This is something that has been predicted in advance - a high volume calculated by PIOMAS during the max volume season made the ice less susceptible to early melting.
I've compiled a few charts to help drive that point home. Almost regardless of the current conditions, Kara volume and extent are expected to mostly disappear by September, potentially putting 2018 back in the race among the low extent years.
The first chart shows how 2018 maxed out very high on volume. But June started with impressive melting, and I expect this year to join all other recent years at the bottom later in the summer. Data courtesy of Wipneus.
The second chart shows how on day 135 (mid-May) 2018 had the highest Kara volume since 2005, even though on day 45 it was among the 5 lowest years. But on day 166 (mid-June) it's already correcting, though still very far from the leaders such as 2012 and 2016. And on day 260  (~minimum), all years since 2004 had virtually zero volume.
The third chart shows how extent in June has started to be highly variable in the Kara since 2010, but regardless of this variability has been highly consistent and very low at minimum.
Bottom line - 2018 has a "bank" of 300-400k km2 of extent that it could use to get back in the leading pack.

20
Arctic sea ice / Re: How soon could we go ice free?
« on: June 16, 2018, 06:07:27 AM »
How soon could we...? Within a week or so, if we really wanted to.

21
Arctic sea ice / Re: The 2018 melting season
« on: June 16, 2018, 12:17:10 AM »
Quote
What  a "blue-ocean" event would look like?  some possibility this 2018 melting season. Does it look like  any of these?
No. The key items to consider are the 2007 and 2012 ice age youtubes. They have been posted here dozens of times. Many people here are overly focused strictly on thermodynamics and single-point summaries of the entire Arctic Ocean, such as a number for area without regards to how that area is distributed. However that distribution is critical to end-of-season.

In those record years (and most others), while thermodynamics plays a decisive role in setting the stage, when extent gets low, winds become the decisive agent via both dispersion of ice to scattered more vulnerable floes, rapid advection to places where the ocean surface water is too warm, and out-of-basin export.

This results in a September picture resembling a comma ","rotated 180º CWwith its tail in the Chukchi and ESS. As with 2018, the lower CAA is the source of this residual ice which was initially about the oldest and thickest left.

Given enough weeks of a quasi-stationary high centered off the Beaufort with an associated westward wind along the Alaskan coast but not a return gyre (a frequent pattern this spring), another 2007 will develop, in conjunction with strong FJL-SV and Fram export.

However pack strength and ice thickness are drastically reduced today relative to 2007 whereas surface water is warmer and freeze-up much later. There's no requirement for another GAC black gray swan event though one would certainly contribute.

/*/*/*/*

The whole question of 'first blue ocean' is ill-posed to begin with. It just kicks the climate change can  down the road. We should be talking about the knock-on effects of the partially blue ocean  already the current reality. No significant effects at 25% ... 50% ... 75% blue ocean?

For example, the Chukchi Sea has open water 11.5 months of the year now. Surely that is way past 'seasonally ice-free'. Who here can remember a meaningful winter ice cover of the Barents Sea? It is actually part of the officially defined Arctic Ocean but now gets thrown in with the Greenland Sea or even North Atlantic. 

The discussion on some forums reminds me of one soccer team moving their goal post into the grandstands and even out to the street but the other team somehow not noticing and still playing up to the newly contrived set-up. They'll never score a blue ocean goal because the goal post will then be moved to "twelve months for five consecutive years". After that, thirty years of stats needed to rule out "natural variation". Then more decades to rule out cycles.

Meanwhile we're already in big trouble now from Arctic amplification, with more of it baked in. Whatever the full effects of an altogether missing 'planetary refrigerator' might be, the partial effects of a diminished planetary refrigerator are already upon us. And that's just the albedo part ... there are many other adverse considerations in the literature.

22
Arctic background / Re: Arctic Maps
« on: May 14, 2018, 07:40:23 PM »
Slightly OT but interesting:
Greenland’s Hand-Sized Wooden Maps Were Used for Storytelling, Not Navigation
<snip>
Quote
On February 8, 1885, a hunter named Kunit approached Holm (Danish explorer) with a driftwood carving he had made—a representation of unbroken coastline that could be flipped around as one followed the contours of the coast. “[Kunit] had carved the chart himself and declared that it was not unusual to make such charts when one wanted to tell others about regions they did not know,” Holm wrote. The hunter produced three maps in total, now collectively referred to as the “Ammassalik maps.”

One carving, 5.5 inches in length, is highly detailed, embedded with all sorts of information and place names for the fjords above and beyond the 65th parallel. It even indicates locations where a traveler would need to carry his kayak overland to get to the next fjord. Another carving measures a little over 8.5 inches long and depicts a specific chain of islands along the coast, connected by narrow stems. These two maps could be placed next to one another to demonstrate the relative positions of the islands along the coast. A third, smaller map was also commissioned by Holm and shows the fjords stretching from Sermiligaaq to Kangerlussuatsiaq and includes valleys, shores, and inlets farther inland. Holm never actually traveled through the regions represented by the maps, but they helped him get a larger understanding of the local geography.

Much more, including pictures and video, at the link.
Atlas Obscura

23
Policy and solutions / Re: Batteries: Today's Energy Solution
« on: May 14, 2018, 04:37:51 PM »
Tesla Powerpacks Balancing the Grid in Terhills, Belgium


24
Arctic sea ice / Re: Stupid Questions :o
« on: July 25, 2017, 02:53:16 PM »
Mind you, by an ironic conincidence, "less than 1 million km2 of ice extent"  is almost exactly 15% of the average 1990s summer minimum...

Ha, I was wondering about that. Thanks, Peter. [...]

I like to say 'ice-free for all practical purposes', after hearing Walt Meier putting it like that once.

Someone has almost certainly already done this, but I don't know where, so I re-invented this wheel...

Here's a map showing what 1.0 million, 0.5 million, and 0.1 million km2 of ice extent could look like.  It's based on the grid cells with the maximum concentration in NSIDC September maps for the years 2008-2016.  My assumption is that ice will last longest in grid cells where Sept concentration is consistently the highest over the past decade.



If someone knows of a better version of this analysis here or elsewhere, please let me know!

Looking at the map, I'd say that 1 million km2 is actually a bit high for an "ice-free" threshold, personally.   

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