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Messages - oren

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Arctic sea ice / Re: 2017 sea ice area and extent data
« on: November 19, 2017, 10:55:38 PM »
Jim,  I really like your graph.  However, the 2000's average is getting a little long in the tooth as a "current" baseline.  It would be nice to have a more recent aggregated average to compare against.

While you can't do a 2010's average yet, maybe you can add in a dashed line for the previous 10 years average.
I would simply add a 2010-2016 average, I think it could be informative despite the sub-decadal data set.

Arctic sea ice / Re: The 2017/2018 freezing season
« on: November 19, 2017, 08:02:22 AM »
I've been playing a bit with temperature data from the NCEP reanalysis dataset

I've divided the Arctic (65-90N) into four sections:

Here are graphs for October 2005-2017 and 1948-2017:
Thank you Neven, very interesting. It seems 2016 automn "craziness" was mostly in the Pacific sector, which also shows the strongest long-term warming trend.

Policy and solutions / Re: Cars, cars and more cars. And trucks, and....
« on: November 17, 2017, 10:04:13 AM »
Wow at these specs. And if a lot of Semi reservations come in, he gets another round of free financing, which might help explain why he's running ahead with it even at this crucial point of time.

Arctic sea ice / Re: The 2017/2018 freezing season
« on: November 13, 2017, 10:15:07 PM »
A-Team thank you for these wonderful animations. I had a "feeling" that 2017 was refreezing much better than 2016, but it seems on the Chukchi front that is not the case.

Arctic sea ice / Re: The 2017/2018 freezing season
« on: November 07, 2017, 09:43:27 PM »
2016 was unprecedented. 2017 now looks like it is trying to break away from the pack, not only with a slow refreeze but with FDD anomalies as well. The question in my mind, if this continues, is whether we are seeing a shift in winter climate. I have found winters to be as exciting as summers. I just wish there were more experts commenting during the freeze season to explain what I am seeing.
I don't post much on the freezing thread atm as I can't think of much to contribute. What you wrote represents my thinking as well, and I think the jury is still out on whether it's a step-changed winter climate or just random variations on a slow trend.
I just want to point out that the seasonal FDD chart is much more appropriate to this thread than the yearly one.

Policy and solutions / Re: But, but, but, China....
« on: November 07, 2017, 08:05:40 PM »
If China wants to dump solar panels and wind turbines on any nation, that nation should gladly accept with thanks. "Dumping" is a strange concept when someone hands out capital goods.

Antarctica / Re: EAIS Contributions to SLR by 2100
« on: November 05, 2017, 07:52:31 AM »
I think this is an ingenious paper, and I don't have major quibbles with linking ice shelf velocity to bottom melt, but i think that the calculation from surface wind stress to upwelling is not so well supported and must await longer time series measurements of ocean upwelling over a larger area. (They do have float data from a single float for 2015 and have shown some correlation but that is just for that year along that float track using the -0.4C isotherm depth as as proxy for upwelling.)  Projections for the future must likewise await models with finer temporal and spatial resolution and accuracy. That said, I dont see how the strengthened ACC in the deep ocean forcing more CDW upward wont find a way to the bottom of Totten and the rest, but that's just me.

Thank you sidd for the well-explained criticism of the paper.

Antarctica / Re: EAIS Contributions to SLR by 2100
« on: November 05, 2017, 12:32:32 AM »
Daniel B., I just have had enough with you. I've seen some posts from you that I disliked as they all seemed biased in one direction and sometimes derailing the discussions. But I did give you the benefit of the doubt until today. Quotingthe whole post by ASLR, one of the most respected posters on the site, just to stick an unexplained slur in the middle, and then when rebuked you resort to an ad hominem attack, there can be no other verdict but that you are an intentional troll. Best begone.

Antarctica / Re: PIG has calved
« on: November 01, 2017, 12:47:37 AM »
Nice time lapse video in this article.  Also includes Thwaites.
The animation above shows Pine Island glacier flowing into the Amundsen Sea from 2014 to 2017. Twice in that period, the glacier released an iceberg larger than 100 square miles.
Thanks. These NYT animations are superb, especially the Thwaites one. The Thwaites discharge area is very "messy", and the animation helps understand what is going on where in there.

Antarctica / Re: Rift in Larsen C
« on: November 01, 2017, 12:39:45 AM »
Thanks for the updates Tor.

The rest / Re: Empire - America and the future
« on: October 29, 2017, 12:14:45 PM »
Seems as though the conspirators are turning on each other.

The whole Syrian thing now appears to have been an outside job, rather than an uprising against Assad.

I read it differently. After the uprising started, outside countries intervened (for their own interests) to help the rebels. Massive and persistent uprisings don't start so easily by someone pressing a button.

Policy and solutions / Re: Pope Francis' Encyclical on Climate Change
« on: October 29, 2017, 11:13:48 AM »
When the Catholic Church can lecture the US government about recognizing the truths of science, we've turned some strange corner.

 ;D  So true!
Indeed. Mad world.

Consequences / Re: Population: Public Enemy No. 1
« on: October 29, 2017, 11:06:51 AM »
If we went back to subsistence living we could grow to a population of 20bn. And then what? We'd be up against the planetary limits again. It's not that population per se is the only problem, but there's no denying it's a very significant problem.

Policy and solutions / Re: Oil and Gas Issues
« on: October 27, 2017, 12:41:36 AM »
I think this forum is suffering from a recent abundance of political issues, including the Trump stuff, Democratic party issues, and the "russian" threads, which tend to polarize posters and lead to slinging matches, without anyone being convinced of anything. I skip all these threads as noise, but the resulting personal animosity has been migrating to the more scientific threads. A bad long-term trend.

Policy and solutions / Re: Cars, cars and more cars. And trucks, and....
« on: October 26, 2017, 11:35:20 AM »
The tide is turning towards more and more EVs, reading all these recent announcements by the major manufacturers, but should Tesla somehow fail and go belly up in the near term, before model 3 becomes ubiquitous, then I have a strong worry that the big guys will forget all their announcements and go back to their oligopoly. There is no real competition or strong leadership out there at the moment, besides Tesla. So I hope Elon is focusing on this goal with all hands.

Antarctica / Re: PIG has calved
« on: October 26, 2017, 08:41:15 AM »
Thank you. Highly interesting, a pity it's pay-walled.
A MICI model supported by actual evidence on the seafloor, a strong argument indeed.

Arctic sea ice / Re: The 2017/2018 freezing season
« on: October 24, 2017, 12:43:55 AM »
What I've marked from the current freezing:
  • The Garlic Press worked hard and there's a lot of thick ice in the CAA already
  • The Fram export resumes but still low. There could be more MYI in the CAB by the end of the freezing than last year.
I don't know what to say more. It's cold and the water freezes - the summary of the freezing season
Well said Pavel. Last winter the arctic kept moving towards the Atlantic side, which was what kept the Chukchi open for quite a while, the Beaufort mostly free of MYI, and the max volume at a low level (coupled with low FDDs of course). OTOH, this same phenomenon may have stalled this summer's Atlantic melt, as a lot of volume was stuck on this side of the arctic. I suspect the same happened in the CAA, where last year's garlic press brought a lot of ice this summer that insisted on not melting out, despite warm temps and a lot of melt ponds.
A-Team, thanks as usual for the deep-level animations and data.
And SH, thanks for reminding about the FDD anomaly chart, though I prefer the seasonal version (attached) that better tracks the effects of temps on refreeze.

The rest / Re: Is Degrowth necessary for Decarbonization ?
« on: October 23, 2017, 08:10:58 AM »
I should point out that GDP measures economic activity (usually a proxy for tax base) and not accymulated economic capital.
To the point, if you grow green technologies fast enough then theoretically you can continue growth in the near term and still begin to decarbonise. But as we lack the time and are way over our carbon budget, degrowth is necessary.
On the other hand, as each individual aspires to a better life, and as most individuals live in poor or developing countries,  while many individuals in developed countries are in a consumption frenzy, degrowth is sadly a pipe dream.

Permafrost / Re: Arctic Methane Release
« on: October 21, 2017, 10:39:34 AM »
Thanks A-Team.

Antarctica / Re: PIG has calved
« on: October 18, 2017, 12:41:55 AM »
The rapid crumbling of the PIIS calf is scary. As if it was barely holding itself together before the calving.
p.s. the animation also shows another (very minor) calving at the eastern tip.

Greenland and Arctic Circle / Re: What's new in Greenland?
« on: October 15, 2017, 12:04:49 AM »
@Tealight, thank you. Very interesting.

Consequences / Re: Places becoming less livable
« on: October 13, 2017, 12:12:50 PM »
BBC piece on the Death of ghe Nile:
Excellent article, thanks sidd. While the river is deteriorating, the population of the basin grows quickly. This will result in some major catastrophe for millions or even 10s of millions at some point, with the resulting death toll, human suffering and waves of refugees.

Consequences / Re: Hurricane season 2017
« on: October 12, 2017, 08:19:02 AM »
Hello Archimid. My heart goes to you and your people. At least it sounds like you fared better than most.

Policy and solutions / Re: Oil and Gas Issues
« on: October 11, 2017, 03:31:15 PM »
Could you also define PHEV ? Thanks.
I believe the term refers to Plug-in Hybrid Electric Vehicles, which have an internal combustion engine but should probably use electric energy for most of their mileage.

Permafrost / Re: Arctic Methane Release
« on: October 11, 2017, 12:28:01 AM »
At the risk of oversimplifying a complex issue
ASLR - thank you for your very good explanation. Simplification is what I was looking for, as sometimes understanding is lost among the details. And that you for all the other responses to my questions.
I too believe that the research in Svalbard is not necessarily applicable to the ESS, due to different conditions (rate of seepage and depth of seafloor), but hopefully the research will be extended to that area as well at some point.
TB - I was looking to see whether algae blooms have empirically appeared in greater numbers in areas of methane seeps, compared to areas with no seeps. If they appear over the whole arctic, then maybe they are not connected to methane.

Permafrost / Re: Arctic Methane Release
« on: October 10, 2017, 01:04:05 PM »
Two idiot questions pertaining to all of the above:
TB - if the research shows that methane release causes explosions of algae blooms, thus saving us. Consider that S&S have discovered numerous methane hot spots above the ESAS, so ARE there explosions of algae blooms in the ESS? I mean, here's a real life test case, from the little I understand of the research.
S&S or whoever knows - if the methane has been building over a million years, over quite a few glacials and interglacials, what has changed recently to cause the release? Is AGW in its current level enough to cause such a profound change? Or is it the loss of ESS summer ice cover? In short, why now?

Thanks for the explanations Juan. I like the drink analogy. Surely ice melting in Greenland and Antarctica significantly affects the heat balance in the whole ocean system.

Arctic sea ice / Re: 2017 sea ice area and extent data
« on: October 09, 2017, 10:49:00 PM »
The last few days have been very specific, separating 2017 from 2016 and the "low years" and sticking it squarely with (the low end of) the "pack".
Added with the DMI 80N chart dipping much below 2016 for the same date, my gut feeling is this winter refreeze will be stronger than the previous one.

The 2 pics above  , from Greenland. What are they telling us ? The central part, blue/white, is that below sea level ?

Yes. The legend on each of the pics shows this, enlarge to see clearly.

It turns out that Greenland and Antarctica have ice bottom melting, in contact with warm ocean water, that is greater than what it was believe before. This should be cooling the oceans and could be making a negative feedback on the summer ASI melting.
Juan, check the currents around Greenland, they are all flowing southward, so Greenland melt is surely affecting the Atlantic ocean but I doubt it has much to do with low ASI melt in the Arctic.

Arctic sea ice / Re: 2017 sea ice area and extent data
« on: October 07, 2017, 09:10:22 AM »
Jim - thank you for the change - and for the whole thing. (I think there's a bug in the sign though, the text should say up from previous, not down)
Binntho, the image should be saved and then uploaded, otherwise it's a cached copy. When it's uploaded you don't need to click it.

Edit: there's still the issue of size, as the uploaded image is beyond forum limits it is only partially shown (unless clicked), and the new text is half-hidden. If the text can be moved more to the left it will be a great help.

Edit 2: Neven, as the IJIS thread was bolded, I think this thread can be bolded as well.

Consequences / Re: Places becoming less livable
« on: October 06, 2017, 11:11:18 AM »
Some tweets from Miami's Republican mayor this morning:
- Today, Miami is flooding as if a hurricane went through it.
- In Downtown Miami. The ocean is rising above the sea walls.
- I *was* wearing rain boots. Didn't help.
- Firefighter boots are above the knee. #Kingtide water rises above them. #sealevelrise #drycleaning
- Spoiler alert. It's climate change
- The #MiamiForever bond will include pumping stations, higher sea walls, new parks and affordable housing.
The mayor is surprisingly sensible (perhaps not surprising actually, as in Miami it's hard to avoid noticing SLR), but the name of the bond is funny in a sad sort of way. Some decades from here, many won't laugh at the joke.

Consequences / Re: Hurricane season 2017
« on: October 05, 2017, 09:34:54 PM »
Current official NHC forecast calls for 80 mph (Cat 1) before landfall, however rapid intensification is possible and then it would be above that.
My personal gut feeling, based on this year's craziness, is that it could easily become a major hurricane. Hope not though.

Arctic sea ice / Re: 2017 sea ice area and extent data
« on: October 05, 2017, 01:38:54 PM »
Here's the chart from Jim's wonderful site.
Jim - would it be possible for you to add the daily extent number as a text label on the graph? Then it would be much easier to post the number and the calculable daily change as well as the chart from a single web source.

5,287,762 km2, up a whopping 91,097 km2, and 6th lowest for the date.

Arctic sea ice / Re: The 2017 melting season
« on: October 04, 2017, 03:27:44 PM »

Was Svalbard temperatures at near record highs throughout this melt season? If so, how do we explain the persistent ice on the Atlantic side of the CAB? Could it be that insolation is far more important to melt than air temperatures?
Or that wind and waves (or lack thereof) matter.

Arctic sea ice / Re: Arctic Image of the Day
« on: October 04, 2017, 03:26:46 PM »
It seemed like a whale to me as well, but I was too afraid to ask...

Arctic sea ice / Re: IJIS
« on: October 04, 2017, 12:52:41 PM »
I would prefer that there be a group effort. I don't mind checking in as a backup, but if any of you guys can get here first, have at it.

I think this is the best approach. Whoever gets first into the thread and see that the daily posting is still missing can post the daily numbers in text or chart form. I think this should work fine.

@Echougton, this belongs in the questions thread, but in short: as the melting season becomes stronger and longer, and the freezing season weaker and weaker, the arctic has less ice extent and volume each September compared to 30 years ago.  But then the ice, some ice, comes back in the winter, and the cycle begins anew.

Arctic sea ice / Re: What the Buoys are telling
« on: October 03, 2017, 06:23:05 PM »
It's starting to look decidedly wintry around O-Buoy 14:
A couple of days ago I noticed the area to the left has finally frozen solid but was rather thin. Now it's covered by snow. I wonder what this will do to winter thickening.

Arctic sea ice / Re: IJIS
« on: October 02, 2017, 11:18:50 PM »
Thanks again to Espen for honouring the best daily data source for the past 10 years.

I'm going to lock this thread tomorrow. I'm just not sure what to do next:

1. Start a new JAXA thread.
2. Or let folks discuss JAXA in the general sea ice extent and area thread.

What do you all think?
I for one really appreciate the existence of a separate IJIS/JAXA thread, to go to for the latest data with very little discussion. And to look for past comparisons when the need arises.

Consequences / Re: Population: Public Enemy No. 1
« on: October 02, 2017, 09:16:15 AM »
Sadly, I believe that for Africa this slow pace of improvement will not be enough, and that the population bomb will explode in large scale wars and famines well before the end of the century.

Arctic sea ice / Re: The 2017/2018 freezing season
« on: September 30, 2017, 03:21:43 PM »
After the initial refreeze of the.central CAB, the refreezing very much stalled, but in the last few days it picked up vigorously. Initially I would have bet on another lame freezing season, but now I am back on the fence.

Policy and solutions / Re: Cars, cars and more cars. And trucks, and....
« on: September 28, 2017, 07:04:05 PM »
In an EV world, the time spent at the "gas" station increases, which could increase profits for the convenience store/restaurant.
The fuel distribution network should thankfully die.

Arctic sea ice / Re: The 2017/2018 freezing season
« on: September 28, 2017, 03:32:58 PM »
peak rate of volume loss
That would be the slope (first derivative) of the Piomas volume graphs. Since that is determined primarily as a first-of-the-month monthly average, those graphs are curve-fit to a very sparse set of points, only 3-4, so the nuances are illusory. As the graph stands, the rate of volume loss is flat (2nd derivative indistinguishable from zero) for most of the summer.
I believe Wipneus plots his PIOMAS graph from the daily PIOMAS data, not from the monthly, and from my experience with the data there are differences in slopes during the month. Of course it doesn't change the fact that the smoothed 2nd derivative is near zero during most summers.

Antarctica / Re: PIG has calved
« on: September 24, 2017, 08:34:58 AM »
Twitter link provides a better animation as well as a reminder of previous calving front locations.
And an animation (posted Jan 17) showing rift progression since 2015.
Can anyone estimate the next breaking point on the main PIG? I can't see any new crack coming up.

Arctic sea ice / Re: Home brew AMSR2 extent & area calculation
« on: September 24, 2017, 12:32:59 AM »
Arctic Basin animation in 6.25km resolution.
Wipneus, thank you again for your wonderful animations (and relentless updates).

Antarctica / Re: PIG has calved
« on: September 24, 2017, 12:16:05 AM »
I believe PIG is in record retreat and the SW tributary has lost major buttressing (can't verify this atm though).
Turns out verification is important... the last major calving of the PIG happened around Aug 1st 2015 (If I am not mistaken). Turns out the new PIG calving front near the SW tributary is at the same location as the front in 2015, and in general the whole front is in record retreat but just barely. Apologies for the lousy resolution. And for unverified assumptions.
In addition, can the honored folks here confirm that the new calving is based on a crack that has been developing since 2015? This was my impression as I browsed up-forum.
If the past is any indication, one side of the new berg - on the left in the animation - could become grounded for a while. Will be interesting to watch.

Antarctica / Re: PIG has calved
« on: September 22, 2017, 11:53:55 PM »
I know it's been expected on this forum for months but it's still jaw-dropping.
I believe PIG is in record retreat and the SW tributary has lost major buttressing (can't verify this atm though).

Policy and solutions / Re: Carbon Capture and Storage (CCS)
« on: September 22, 2017, 01:56:49 PM »
I see again  an idea which has come up before, deeo ocean CO2 storage as liquid (which is stable  in the deepest parts of the ocean.) When i last thought about this i was worried about tectonic instability returning the deep CO2 pool to the atmosphere, but the author does not seem to address that issue.
Interesting idea.

Arctic sea ice / Re: 2017 sea ice area and extent data
« on: September 22, 2017, 10:04:54 AM »
NSIDC monthly "average" in a growth month is more or less the extent at the 75% mark of the month, ~Sep 23rd. The minimum figure has little to do with it. I doubt it will pass 5 M km2.

Walking the walk / Re: Managing PV + battery system
« on: September 21, 2017, 10:49:18 PM »
Nice project etienne. I envy you. Nothing like real life experience with these things.

Consequences / Re: Hurricane season 2017
« on: September 19, 2017, 09:44:38 PM »
Hurricane Hunters have just found flight level winds of 155kt, or ~180mph in the N-NE eyewall. Expecting an intensity bump up in NHC update.

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