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Messages - oren

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Arctic sea ice / Re: What the Buoys are telling
« on: Today at 12:00:38 PM »
Based on past performance 2017B will melt out in the Fram Strait before the year is out.
I'm wondering whether the floe and its surroundings survive to mid-Sep to participate in the minimum figures.

Arctic sea ice / Re: IJIS
« on: Today at 09:59:29 AM »
IJIS is laughing at PIOMAS...  ???

Arctic sea ice / Re: What the Buoys are telling
« on: Today at 01:00:01 AM »
Looking at 2017A and 2017B's melt rate graphically: 2017A, located in the Beaufort side of the CAB, IMHO should finish melting in 1-2 weeks. It is ~350km deep inside the pack but in a region of 75% concentration on the Bremen maps, a region which might disappear quickly if the buoy's floe is typical.
2017B between the pole and Fram seems like it could survive the season with its current melt rate. It is now ~300k deep inside the pack, at a region of 75-100% concentration. It is moving south at an average ~35km per week (highly variable), and its melt rate might increase sharply if it encounters Atlantic waters.

Arctic sea ice / Re: The 2017 melting season
« on: July 25, 2017, 08:53:32 PM »
Remember that PIOMAS graphics shows average ice thickness, though it models a distribution in each grid cell. Actual measurements a few months ago did indeed show 3 thick ice in the Lincoln Sea, so it was no mistake back then. In addition, some of the thick ice has been exported to Nares and Fram. So it is not impossible to have holes in the middle of this area. The rest of the ice could still be quite thick. I have no clue about current thickness, but the 2D evidence does not necessarily disprove PIOMAS.

Arctic sea ice / Re: Stupid Questions :o
« on: July 25, 2017, 06:53:09 PM »
Great map Ned. Reaching 1 million will not be easy. The actual melting season around the pole is just 3.5 months (~June 1st to Sep 15th). Ice mobility, waves, cyclones, season lengthening, all contribute to more melt. But it could take a decade to get there.
In terms of effects on climate, 1 million is much closer to ice free than to the previous ice/climate regime, so I think it's a good proxy.

Arctic sea ice / Re: IJIS
« on: July 25, 2017, 06:28:50 PM »
Volume loss is the definition and measure of melt. But volume is not measured, just modelled, and is not published daily unfortunately.
Area is a good physical proxy for melt. Area is measured, but suffers from inaccuracies and is not widely published.
Extent is a proxy for area. It is measured more accurately and is widely followed.
Easy to see why extent equals melt in everyday speak, though it's not technically correct. Even the freezing thread is switched to the melting thread according to the extent maximum (March), not the volume maximum (May). So I would suggest to skip the technicalities and just keep on with the very interesting melting season.

Arctic sea ice / Re: Latest PIOMAS update (mid July update)
« on: July 25, 2017, 05:57:18 PM »
   ... It seems 2017 leads in the thicker categories (>1.46, >2.61) but lags in the thinner ones (>0.26, >0.71) which could lead to a higher area/volume ratio at the minimum, making a record area very unlikely based on this data, but a record volume potentially more achievable.
Not sure I follow your reasoning.  My take on the graph is that (relative to recent years) 2017 has proportionately less area in the thicker places.  If so, wouldn't we expect the area/volume ratio to drop faster than usual between now and the minimum?
Note that curently 2017's area/volume ratio is much higher than 2012 was at this point. It should drop faster, but still remain higher than 2012 at minimum.
Let me lay down my reasoning, as it took me a while to figure it out again...:

Typically the >0.26 figure determines the minimum, and in low years it's somewhere between the >0.26 and >0.71. At most, it drops a little below the >0.71.
As 2017 has a higher >0.26 area, (and slightly higher >0.71 as well) compared to 2012, it is not a natural candidate for breaking the area record, as 2012 had a freak August.
2016 is a case in point. It had a GAC in August, and indeed managed to crash the area, but looking at Wipneus' chart might explain why no record was achieved - the July >0.26 and >0.71 figures were too high.
So 2017 will need a freakier August than 2012 and 2016 to achieve an area record. Mostly it needs a bigger GAC. (Not saying it can't happen, just that it has a lower likelihood - when judging by this PIOMAS data).

OTOH, 2017 has the lowest ever July figures for the >1.46 and >2.61 ice types. So its final distribution at minimum could be expected to have lower average thickness = lower volume/area = higher area/volume compared to 2012. Meaning a low volume record is still possible without an area record.

Arctic sea ice / Re: Latest PIOMAS update (mid July update)
« on: July 25, 2017, 09:35:43 AM »
Thank you Wipneus (for the 100th time) for the data and the very interesting analysis. It seems 2017 leads in the thicker categories (>1.46, >2.61) but lags in the thinner ones (>0.26, >0.71) which could lead to a higher area/volume ratio at the minimum, making a record area very unlikely based on this data, but a record volume potentially more achievable.

Looking at a close-up of the total volume, 2017 continues to lead using the same gradient as the other low years, but 2012 could take the lead in the first half of August thanks to a certain GAC.
Note: Extrapolation now takes the 2nd-lowest loss (out of the 4 low years) instead of the lowest loss.

Arctic sea ice / Re: What the Buoys are telling
« on: July 25, 2017, 07:48:39 AM »
At O-Buoy 14, top melt continues at a relaxed pace (snow lowering, ponds deepening and expanding) while the camera continues to lean. Click.

Arctic sea ice / Re: The 2017 melting season
« on: July 25, 2017, 12:26:05 AM »
Looking like we are already below all previous Sept volume minimums.
Respectfully disagree. I estimate we are at 7.5 (1000 km3) using extrapolation, while the 2012 minimum was 3.67.

Espen thank you for keeping us updated. The whole front is crumbling. This will probably speed up both glaciers, as they lose the buttressing of each other and the buttressing of the island.

Policy and solutions / Re: Oil and Gas Issues
« on: July 24, 2017, 06:01:09 PM »
only an economically-driven transition could work. It's not sufficient, but it's better  than nothing.

Why would an economically driven transition not  be sufficient?
In my view it will not happen globally fast enough and thoroughly enough to avoid most of the effects of AGW. Time will tell of course. I'm still happy that it's happening though. Humanity should and could have been doing much more, a "war effort" to avert the risk, but sadly that's not happening, so economically-driven transition is currently the only practicable way forward.

Policy and solutions / Re: Oil and Gas Issues
« on: July 24, 2017, 10:49:20 AM »
As a side note, in Israel there is a very high tax on gasoline, which sells at the pump for $1.5 per litre (is that 4xUS price?). Similar for diesel. Supposedly to pay for transport investments and for pollution.
Many grumble and use cars. Many others use e-bikes and scooters, but the main reasons are congestion and parking. The country's emissions are not particularly low.
Obviously, a "war effort" and a major shift of the government budgets could cut emissions by half. But nobody in goverment gives a hoot, and most voters don't seem to care either. At least here, only an economically-driven transition could work. It's not sufficient, but it's better  than nothing.

Greenland and Arctic Circle / Re: The Nares Strait thread
« on: July 24, 2017, 10:03:18 AM »
Oren , that is not fast ice it is ordinary sea ice.
I thought that sea ice which is static by way of being attached to something is fast ice?

Arctic sea ice / Re: The 2017 melting season
« on: July 24, 2017, 09:58:01 AM »
It's finally possible to compare Uni Bremen concentration maps from 2012 to 2017, as July 23rd is the first date for which a map is available.
This is very confusing, as the years are similar in both extent and volume, but the ice distribution and shape look nothing alike. There are vast differences almost everywhere (except for the inner CAB).
Eyeballing, it seems that 2012 ice was much more vulnerable and dispersed, but OTOH looking at the concentrations it doesn't seem like both years have the same volume (admittedly it's guessing 3D from 2D, but still it feels like something doesn't fit).
Does anyone know whether the maps are directly comparable from then til now? I recall reading here that the color code may have changed?
CLICK to animate.

Arctic sea ice / Re: IJIS
« on: July 24, 2017, 02:53:56 AM »
I've been wanting to crunch some numbers, having followed gerontocrat's informative calculations for a while now, to try and correlate between extent loss and low July volume. It is quite difficult as the ice regime has changed over the years (loss of MYI), volume distribution matters a lot, extent depends on dispersion, day of minimum matters a lot, PIOMAS has some error margins, and in addition, the correlations are not very strong.

So I made the attached table, sorry for the lack of annotation, but it takes the years 2010-2016, looking at losses of volume and extent from last known date to day 250 (Sep 7th) and comparing to the average of those years. I did not calculate correlations (though they exist), but instead here are some thoughts on why 2012 was a freak.
2012 on day 203 had a low extent - but 2011 was lower.
2012 to day 250 lost a good volume figure - but 2015 and 2016 lost much more.
2012 had a low volume on day 196 - but 2011 wasn't far behind.
On the other hand, 2012 had a low volume on day 250 - with no other year coming close. And by some miracle, it also produced a freak extent loss.
So maybe current extent isn't such a good predictor, and current volume can't make a strong case, but when absolute volume falls below a threshold, extent crashes?

Speculating: If 2011 had lost an above-average amount of volume in this period, it might have finished as 2012.
If 2016 had entered day 196 with a low volume figure, it might have finished as 2012 or below (as it was area did crash, but extent didn't).
More speculation: the last volume is in the highest latitudes, therefore harder to melt, so having a low volume in July could cause a low loss of volume later. (But a GAC can help bring the volume loss numbers back up.)

My unscientific conclusion - starting with lower volume than 2012, this year needs just an average loss of volume so it might crash in extent. Will an average volume loss happen? I give it 40%. Will this actually crash extent? I think it a serious possibility. So a 20% chance for an extent record seems reasonable.

** Why day 250 - to avoid the effect of early/late minimum, which adds the noise of weather and the distribution of open water latitudes.
Why from 2010 - looking at their volume numbers I believe 2007-2009 were much too different.

Greenland and Arctic Circle / Re: The Nares Strait thread
« on: July 24, 2017, 12:42:04 AM »
Here is an example of fast ice in Kane Basin, attached to the Humboldt Glacier front. It has been subjected to above-zero temps for a long while, and the effects are showing - breakage, melt ponds, draining of ponds, more breakage. The high temps couldn't melt it all yet, though it's quite certain it will disappear by the time the melting season ends.
The animation runs from May 16th to July 21st, skipping 3-5 days at a time except at crucial points or where clouds prevent it. Please forgive the very crude date labels.

Arctic sea ice / Re: The 2017 melting season
« on: July 23, 2017, 04:12:07 PM »
Not a lot of the season left. Extent reduction this year is currently some 4 percent below the average for the last ten years. Due to high positive SST anomalies and low volume (and therefore reduced average thickness), an increased late season melt is certainly on the cards. I do not expect that to result in a new record low extent, as this would require an extraordinary series of meteorological events. A 2nd lowest extent (and a record low volume) is still eminently possible.
Thanks gerontocrat. If I understand your table correctly, the required extent loss is almost the same as actually happened in 2012 from now til minimum. Extraordinary indeed, but still possible, especially as volume is tracking 2012 as well. I'd give extent a 20% chance of a record, but the next couple of weeks are critical.
As for volume, I'd give it a 50% and there's still much time to get there. A lot depends on a GAC or two, but even average volume loss could go far.

Policy and solutions / Re: Oil and Gas Issues
« on: July 23, 2017, 07:39:41 AM »
Is anyone here against a carbon tax, with or without dividend? I'm sure Bob supports it as well. I wish for it with all my heart. It's not a new idea either, but it hasn't happened yet. Until it happens, pushing renewables and EVs seems like a good approach.

Arctic sea ice / Re: Stupid Questions :o
« on: July 23, 2017, 07:22:28 AM »
Ktonine, I believe the question was about Top of Atmosphere outgoing "black body" radiation

Arctic sea ice / Re: IJIS
« on: July 23, 2017, 12:44:17 AM »
I was weeding me environment directory and found a little file dated 8th June on prospects for various outcomes as regards sea ice extent. Below is the table for 21st July. There is not a lot of difference. Mind you, I still think that 2nd lowest is most likely - low volume and warm seas. Also added a graph.
I finally realised what was bothering me with your cery reasonable predictions, and it's not even PIOMAS-related. As 2012 is more or less at the same extent currently, and has been so for a while, that means that 2012 gave almost the same surprise that is now forecast as having a very low probabilty. But one out of ten years is 10%, not really negligible. To counter this, I would suggest adding somewhere in the table the % of average melt actually achieved by 2012 (and 2016, 2007) from now until minimum. This will enable to gause a range of possible outcomes based on actual past events.

Greenland and Arctic Circle / Re: Greenland 2017 melt season
« on: July 22, 2017, 01:24:00 PM »
I don't see a contradiction. Isn't rain included in the SMB as well? As long as it doesn't run off the ice sheet, and I'm sure a lot of it doesn't,  it adds to surface mass, and registers as surface melt as well.

Policy and solutions / Re: Oil and Gas Issues
« on: July 21, 2017, 10:53:43 PM »
Let's get back to the real issue.  There are a number of people who need a car.  And a number of people who don't actually need a car but want one.  The number of people who don't actually need a car, only want one, and are willing to give up their car in order to combat climate change is insignificant. 

We will not get oil out of our transportation systems by asking people to make a sacrifice. 

We won't get coal and natural gas off our grids by asking people to not buy coal/gas generated electricity.

I've watched and been part of the "green" movement since the mid 1960s.  We haven't stopped the use of fossil fuels.  We weren't able to decrease the use of fossil fuels any appreciable amount.  Fifty years of trying should be enough to tell us that we will not be able to avoid extreme climate by getting people to give up stuff, be that stuff cars or buying new clothes.

The only hopeful route I see off fossil fuels is to give people acceptable, affordable alternatives. 
I fully agree.

Policy and solutions / Re: Oil and Gas Issues
« on: July 21, 2017, 05:14:54 PM »
Bob, there are shades of "need". Millions don't need a car but still have one. Convenience isn't a true "need", it depends on your tastes and definition. My sister doesn't buy her clothes in second-hand clothes stores because she can't afford new clothes, but because she despises consumerism. She dresses very fashionably btw, so there's no suffering involved. And some people give up their cars not because the alternatives are much cheaper or more covenient, but because it's a small enough sacrifice that they can withstand it for a greater good. My own sacrifices are few, but I admire others who can make more of them without getting to "hair-shirt" status.

Policy and solutions / Re: The Hyperloop
« on: July 21, 2017, 12:07:15 AM »
Color me highly doubtful. Not that I disbelieve Elon's intentions, but where is the business plan? Long-term financing? Where are the billions that will be invested upfront to pay for all this boring, infrastructure, stations etc., with very slow payback? I just hope he doesn't mean to do it through Tesla, as it might cause it to go bankrupt.

Greenland and Arctic Circle / Re: Greenland 2017 melt season
« on: July 20, 2017, 10:20:01 PM »
 Holy s**t!

Arctic sea ice / Re: The 2017 melting season
« on: July 20, 2017, 02:59:27 PM »
Animation of Uni Bremen's concentration on the pacific side, July 13-19.
Note how floes are winking out north of Barrow and the front is receding, while the Gyre is pushing ice south in the eastern Beaufort, and what seems like dispersion north of Wrangel.

Policy and solutions / Re: Oil and Gas Issues
« on: July 20, 2017, 09:56:47 AM »
Green BAU realist - knowing it won't "save the world" but that it's the only way forward given greedy/selfish human nature and current weak governance. And hoping it will accelerate enough to make a significant impact. And pushing it on all fronts. This is you Bob, and a job well done.
(Should be careful though to avoid hinting that it sufficiently solves the fundamental problem, as it might lull some people who might otherwise be willing to make some deeper changes.)

Policy and solutions / Re: Oil and Gas Issues
« on: July 20, 2017, 12:36:32 AM »
Bob, I'm far from being an expert on this, JimD for example used to write a lot about it on this forum, but I'll give it a try. Note this is heading OT fast, there were some threads for this if anyone can dig them up.
Define BAU as business as usual = we do not need to change our lifestyles. Economic growth, A/C, vacations in faraway places, big homes, cars, meat, having as many children as we want, no limit on personal wealth, etc.
Black BAU - what we have today, fossil fuels based BAU.
Green BAU - how to achieve BAU while avoiding climate change. Supposedly, through technological progress, renewables and EVs becoming so cheap and compelling that the entire globe is converted, we are saved without serious pain and sacrifice.
Some of the problems with Green BAU are its speed, too slow considering where we are already, and its lack of full coverage (agriculture, cement, flights, population beyond carrying capacity, and all the rest of the unsustainable bunch). It also lulls us to sleep believing all will be well. Its biggest advantage - not a lot of backlash, it's highly marketable. Plus it's progress in the right direction even if it doesn't save us, as you explained well a few posts back.
Real Green - how to actually avoid catastrophic climate change, and avoid an uncontrolled population collapse, but giving up a lot of privileges we are used to, "cutting out the fat", with a WWII-style (or worse) joint global effort. Biggest advantage - it could work. Biggest drawback - it will not be adopted unfortunately

Arctic sea ice / Re: The 2017 melting season
« on: July 19, 2017, 04:09:35 PM »
Gents, could I kindly ask to put some limit on discussing Antarctic/global sea ice in this high-profile thread? Not that it's not interesting, but I feel it's veering OT.

Arctic sea ice / Re: The 2017 melting season
« on: July 19, 2017, 12:48:35 AM »
Latest weekly MODIS 7-day composite image from Environment Canada:

I've converted this to an animation to enable easier comparison to 2012. What strikes me is how different the two years are. 2012 seems to have a lot more ice (though I know extent metrics say otherwise), but also has areas of much lower concentration inside the pack on the Pacific side.

Arctic sea ice / Re: Latest PIOMAS update (mid July update)
« on: July 18, 2017, 04:55:41 PM »
TB, I dislike DMI volume comparisons as I find the volume model unreliable.
In any case, my table shows 2017 having some more volume in the CAA. In absolute figures it's 579 km3 vs. 462 in 2012. It's not a huge difference though.

Arctic sea ice / Re: Stupid Questions :o
« on: July 18, 2017, 03:07:53 PM »
From the Melting Season thread:

Given that <15% SIE represents an Ice Free Arctic, can anyone tell me what the actual figure would relate to 15% and how much was year 2012 greater than this figure.
Jontenoy, The 15% criterion is used to determine whether a given grid cell has ice extent or not. It is not used on an arctic-wide basis. So for the NSIDC grid, take a 25x25km box, 625 km2 total, if ice area in that box is less than 93.75 km2 then that specific box is counted as "ice free".
The usual definition of "ice free arctic" is "less than 1 million km2 of ice extent". 2012 came in at 3.18 million km2 for the daily record low, still way above the criterion.

Arctic sea ice / Re: Latest PIOMAS update (mid July update)
« on: July 18, 2017, 02:40:40 PM »
Turns out the 2017-2012 gap closed by about ~150 on the pacific side, and by ~150 in the CAB, while in the periphery the 2012 advantage shrank by ~300 on the atlantic side, keeping the same total volume difference.
          2017 lead   2017 lead   2017 lead
Region   Day 181   Day 196    Fell by
Beauf         16        -27           43
Chukc        477       378          99
ESS           422       401          21
Laptv        -152      -162         10
KaraS       -230      -85          -145
Baren       -91        -44          -47
GrnLS      -217       -92          -125
CAB          210        28           182
CAA         -149      -117          -32
Baffn        -196      -126         -70
Hudsn        42         -4             46
Pacific        915       752          163
Atlantic     -538      -221         -317
Inner Basin   824      501         323
Periph. Seas -692   -351         -341
(all numbers in km3)
Graphically, 2017 seems to be losing steam in the CAB, while 2012 has the GAC visibly waiting. Time will tell if the remaining pacific advantage can be translated to an acceleration in the CAB.

Arctic sea ice / Re: Latest PIOMAS update (mid July update)
« on: July 18, 2017, 01:23:13 PM »
My estimated total volume on July 1-15:

array([ 11.953,  11.734,  11.52 ,  11.309,  11.102,  10.916,  10.686,
        10.437,  10.239,  10.068,   9.894,   9.709,   9.527,   9.28 ])

Updated egional daily data file is here:
As usual, thank you for all the updates. Note one day is missing at the end, ~9.05.

An update to the Inner Basin volume chart. The gap to 2012/2011 closed by ~300km3, which is ~200km3 more than expected by my "method" and a sign of lowering probabilities for records. My next extrapolations were shifted upwards accordingly. In my next post I will attempt to find out which region contributed the most to this.

Arctic sea ice / Re: Latest PIOMAS update (mid July update)
« on: July 18, 2017, 10:23:41 AM »
I think the high-concentration ice next to Nordauslandet is what PIOMAS "means" when showing that blob, with somewhat wrong location. By end-July this whole blob might be gone.

Science / Re: "climate porn" vs. "not alarmed enough"
« on: July 18, 2017, 01:26:29 AM »
oren said, "...continues contributing to the problem in his/her own tiny way"

Well, tiny compared to the whole entire effect perhaps. But  given that we are collectively unleashing the energy equivalent of about half a million Hiroshima-obliterating bombs onto the planet every day, and that the top 20% or so is responsible for some 80% of the problem...probably most of the people you talk to are responsible for something like one of those 'bombs' every decade or so (but others should check my maths, etc.).

Greenland and Arctic Circle / Re: The Nares Strait thread
« on: July 18, 2017, 01:21:45 AM »
Temps have been spiking recently, reaching 10oc. I find it surprising that any fast ice still remains in the fjords around the strait.

For now, I just want to point out that what Anderson emphasizes is using what we already have more efficiently, and spreading the tech we already have.

JimD has been hammering the futility of Green or Brown BAU around here for a while.

We need a grid powered by renewable, low carbon sources (mainly wind, solar, and hydro).

We need electricity powered transportation - EVs, battery buses, electrified rail.  Charged from a clean grid.

We need better insulated houses/buildings heated and cooled by efficient heat pumps.  Powered by a clean grid.

None of this requires we change our lifestyles in any appreciable, certainly negative way.  In fact, our lives should greatly improve.  We'll have cleaner air and water.  Our roads will be quieter.  We'll spend less for electricity and on transportation.

JimD and Bob provide two very different viewpoints, and I happen to agree with both (schizophrenic I know). I believe Green BAU, Bob's way, comes too late to save the world. It will be implemented globally too slowly, especially considering that population growth occurs only in the undeveloped countries, and that all aspire to live like the rich/America. However, I still believe green BAU is the only practical way to go. No one is going to implement a WWII-style global effort of decarbonising everything while sharply cutting away at unsustainable practices that cannot be decarbonised (flying). Given that, some progress is better than no progress, and green BAU is better than black BAU, even though it might lead to a similar collapse down the line.
Veering slightly into the thread's topic, I believe local planning should assume that the long-term civilization, if there is one, will be less complex, with partial collapse. So, a town should hopefully strive towards being more self-sustainable, getting its electricity/energy (rooftop solar, wind etc.) and its food (greenhouses, vertical farming) locally. Try to avoid relying on long-range interconnections and supply lines for basic necessities. Avoid floodplains and low-lying coastal areas, assume that maintenance and weather protection currently done by the government might be lacking. Avoid nuclear plants, as under collapse scenarios they become more of a danger than a benefit. And avoid high population density.

Antarctica / Re: Can ice mass change rotational axis of earth
« on: July 18, 2017, 12:36:49 AM »
Just a little note, the hydrosphere may be 0.001% of the mass, but is not 0.001% of the angular momentum (as it is all on the surface), which I would guess should the deciding factor regarding rotation.

Science / Re: "climate porn" vs. "not alarmed enough"
« on: July 17, 2017, 08:14:26 PM »
People I talk to move very fast from not knowing about the subject and ignoring it, to understanding/believing and still ignoring. Why? Not because of fear, but because evolution bred into us to ignore what we cannot change or do anything about. Each one personally accepts it and moves on. And continues contributing to the problem in his/her own tiny way. Disheartening.
As someone said here, if we discovered that a huge asteroid was headed to Earth and would hit on the year 2100, would we still ignore it ho hum? Of course not. And the real problem is quite similar in its risk.

Arctic sea ice / Re: IJIS
« on: July 17, 2017, 05:53:39 PM »
There is the issue of ice thickness, postulated by PIOMAS to be lower this year. If this is correct, an average melt could see above-average area/extent disappearance. Time will tell.

Science / Re: "climate porn" vs. "not alarmed enough"
« on: July 17, 2017, 11:03:21 AM »
jai, I think you are somewhat harsh towards Dr. Mann, but still you are basically right. His criticism as quoted here stinks.

Arctic sea ice / Re: The 2017 melting season
« on: July 17, 2017, 08:54:26 AM »
Chukchi / Beaufort 1 week.

Not difficult to imagine where this is likely headed in the next week or 2...
gd2, thanks for all of these animations. I believe the whole pacific side about to get cliffed, continuing the ESS crash of the previous week.
I note that the Gyre is moving, slowly pushing ice south into previously open water in the eastern Beaufort, where I'm quite sure it won't last very long.

Arctic sea ice / Re: What the Buoys are telling
« on: July 17, 2017, 08:42:09 AM »
Just a little gif comparing 7/11 to 7/16 at 2300 UTC. (I've been busy in the analog world, just getting back to this- looks like I missed a lot of fog in the interim, click to animate) At any rate, though we are excitedly looking forward to movement, the features before us are quite constant for now. The peculiarly persistent pond in the near right is still there! (why 2300 UTC? that's about when I start work in the evening LOL)
Vigilius thanks for this. Staring at the images daily I could swear no change was going on. From your animation it seems top melt is slowly continuing under the clouds and the snow dusting (the right pond is growing again). Also it seems the camera leaned backwards slightly during these 5 days, as the far features have move further away.

Arctic sea ice / Re: 2017 sea ice area and extent data
« on: July 17, 2017, 08:31:44 AM »

rebounds in ESS and Chukchi.

Yes - but that just seems to be the wrong word, somehow. It implies a strengthening or improvement in the state of the ice. Considering the direction it's headed and what's going to happen to it when it gets there, perhaps "diffusion" would be a better term?
A common behavior of extent (also area), especially in NSIDC, ice winking in and out of existence when it is marginal or covered with water (ponds, rain, storms). This only "matters" around the minimum.

Arctic sea ice / Re: The 2017 melting season
« on: July 17, 2017, 08:23:42 AM »
Many interesting posts this morning, I'm making a bulk response.

Looks like 3,000km or more of fast ice just broke free of NE Greenland by the polynya.
Nice spotting stackmaster.

For what it's worth, this animation more or less shows the difference in extent for 2016 and 17 for this day (from Polar Portal) A bit rough, but, ie. 2016 extent that 2017 does not have, and 2017 extent that 2016 did not have.
Thanks for this TB. Great animation. 2016 had all the advantage on the Atlantic side, which I believe is relatively easy ice that will go anyway this year. Therefore 2017 has much less chance of stalling like 2016 did.

One aspect of this part of the melting season I do not have a good grasp of is the 'practical' relation of sea ice area (SIA) and sea ice extent (SIE).  I know it is 'all about' grid size, but that's 'theory' to me.  In practical terms, can someone show a 'real live' grid with 15% SIA so I can see what it looks like?  For example, when we look at the North Pole to Greenland image, how many grids are along the 30W longitude line? (10s or 1000s?) Off the NE corner of Greenland, are there ice-free grids right now?  (If so, about how many?)
Tor, this depends on the grid. the distance from the North pole to Kap Moris Jesup (northernmost Greenland point) is 711 km. In NSIDC (25km grid) you get <30 grid points covering this distance. In AMSR2 (3.25km grid) you get >200 grid points. Wipneus' wonderful AMSR2 animations on the home brew thread give a grasp of the level of detail of this grid, almost better than sat images.
You can easily understand the meaning of the coarser grids by toggling sea ice concentration in worldview, one of the layers gives you the 25km grid concentration, there's another giving you a 12 km AMSR concentration, toggle it against the actual images. Check out Nares for example.

JAXA volume just dropped to about 6,000 km3, which is surprisingly low when you consider the JAXA average thickness of Arctic sea ice.
Compare to PIOMAS average thickness.
TT, JAXA volume is quite meaningless at this time of year, and certainly not comparable to PIOMAS. The satellite cannot measure ice thickness in summer, and only partially in winter IIRC.

Arctic sea ice / Re: IJIS
« on: July 16, 2017, 03:55:49 PM »
We've nearly seen two consecutive doubles in the last couple of days with 344 extent losses in 48hrs.
In NSIDC yes, but not so in IJIS/JAXA data. Much harder to achieve.

We own one family car that normally serves for many small city trips, therefore my wish for some kind of electric car. But every now and then we go on long trips, and there is no charging infrastructure anywhere here, so I need a gasoline backup. But if a gasoline generator can charge the battery, then there is really no need for a full hybrid with its cost, weight and maintenance.

Arctic sea ice / Re: The 2017 melting season
« on: July 16, 2017, 12:24:14 PM »
I find interesting that despite what seems like compaction on the Beaufort frontal features, the concentration behind the front is dropping.

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