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Arctic background / Re: Russian Arctic Exploration
« on: August 23, 2020, 05:19:17 AM »
A video on the first nuclear icebreaker
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A very important observation!I would challenge this notion in the current arctic, given that darkness sets in above 80N and the smallness of the area of the arctic sea ice, especially outside 80N, in late September, it seems very unlikely that even strong SSTs could delay area gains more than a week at most, let alone continue the thaw. It would be interesting with column mixing, but given the low winter temperatures it would still not amount to much, especially if we are talking about continued thaw, although it could have effects on reduced thickness increase and delayed freezing. Now the Laptev and the ESS are where it’s at, heated at depth, mostly below 80N, but they don’t play a role in a boe or the cutoff between the freezing and thawing season anymore
IMHO
The major metrics that are currently referenced during this stage of the 2020 melt season VOLUME. AREA and EXTENT may serve little useful purpose; the exceptions are compaction, weather and observations.
In particular, wrt the posting by Bremer, the presumption that the BOE will be a September minima must be challenged. Indeed, October or even November must now be given serious consideration and should this prove to be the actuality the implications for both summer and winter sea ice will be very significant.
+1 for thinking outside of the box
PIOMAS gridded thickness data was updated to day 228 (15/16 August). Calculated volume on that day is 5.14 [1000km3], which means a third lowest place before 2012 and 2019.
Here is the animation for August thus far.
Not according to the gfs 2m temperature forecast where half the arctic basin is consistently above 0 an there are not many areas wit temperatures below sea water freezing point, note that the areas above 0 change wildly too, leaving the whole basin to at least still get a taste of itYes very warm surface air temps for this time of year in the Arctic Ocean. 2016 surface air temp today vs 2020, 2018 and 2014. Surface Air Temp in green circle. That area is 4C - 6C for the next 5 days.Warmer than earlier years, sure, but there's no ice where your circle is. In general even in 2020 there are no areas with ice above freezing except a few areas off the Canadian Arctic Coast. This might slow refreezing in the fall, but record heat notwithstanding, top melt is still basically done.
2014 0.1 C
2016 0.9 C
2018 2.1 C
2020 6.0 C
Looks like it.
Lovely community vibe here.
Quote from: blumenkraftI didn't mean take screenshots of him, rather screenshots of your pms showing the absence of conspiracy, but whatever I get why you're uneasy but if you want (if you don't that's fine too) Neven to recognize he was wrong, private messages are a lot better than a public forum where he has acumen and open backing, which never go well with revising your positions. (I don't know what NT means btw)I don't think Oren is doing this on a personal basis, more because of the general amount of bottom notifications this drama created, maybe you should take it up to Neven directly on the matter of your mod retirement with, for example, screenshot proof of your innocence. He is stubborn though so he may not even acknowledge he was wrong. In which case start a different forum thread, so at least it's not pinned to the top and can subside once everything is settled.[redacted blumenkraft pm for privacy]
The harassment was noticeable, even in public, and I don't get why the other mods didn't stick by you more, hopefully it at least gets better now. I am sorry you experienced this, and please remain an Asif member
Not everyone thinks you're an asshole, most people will not even read the thread (thank god), and distanciation should do the trick of him not going after you. However it is not the first time something happened with [redacted for drama avoidance], and that kind of pattern needs to be regulated, which is what I alluded to both in my comments and here. I know you're not a mod anymore, but if it repeats itself again (happened on the cryosphere before) we really need to talk to Neven, because it's not going to get better.
Hoping you're doing better,
regards
PS: I relent any privacy privilege from this conversation so feel free to quote whatever you want, with no incidence on the privacy of your messages of course.
It's not just the masks, but also this idea that the enemy is everywhere around you (which to me is Al Qaeda on steroids) and that the only way to fight this enemy is through mandatory vaccinations, vaccination passports, tracking apps etc. And that anyone who doesn't support this, is an insensitive, dumb person.The problem is the hoarding of power by governments, it is sensible to have temporary measures in the face of unexpected catastrophe but there needs to be institutional resilience to revert back to normal once it’s over. New Zealand is probably the best example of that, while China is almost the opposite, using routine powers (to them) to impose strict measures
One of these days I will try to convey how I would like the presentation to shift (by media and politicians), and make an effort to evade polarizing pitfalls.
(When I recreated my account 2 days ago, I did it with the intention of explaining more thoroughly my reason for leaving this site. The comment did not pass moderation and I am fine with that. Below is a condensed version.)
1. I was attracted to this site in 2013 by its grounding in science.
2. I am dismayed by persons on this thread for whom I had developed a great deal of respect who have abandoned all science in arguing how inconsequential this disease is.
3. This has caused me to question in a very personal way why I come here.
I hope this comment passes muster.
<I think you are wrong on count 2. Neven chose a category in his description. The actual detail was not really important because it was more about the media in general. One problem is that we make a division when someone foregrounds an issue and then people focus on the less important part as intended by the poster.
If we would all be on voice comms you can ask quick questions to clarify. Here we can´t but we can ask slow questions before jumping to conclusions.
This is a general point not for SH per se.
kassy>
Thank you Kassy for allowing this comment to post.
As for point 2, I am dismayed.
I did not single out Neven and, if I had the time or inclination, (I don't) I could go back into this thread and find numerous persons who have dismissed the data and argued for a ridiculously low IFR and dismissed the science that points to serious health problems for many who recover from the virus, the kinds of health problems you never find from persons who have recovered from the flu.
At any rate, the three numbered points above stand. They accurately and succinctly summarize exactly where I am. While I suspect this is my last comment on this site, I will not hastily delete the account this time. This will allow me to reconsider this decision in the future.
Everyone - Take care and stay safe.
<Another general comment: The main interest for this site is the Arctic ice. You can ignore huge parts of this site and still do things. Or even read AGWiG/C and just ignore covid. kassy>
Comparing the last 2 days of AMSR2 sea ice concentrations, we can already see the start of a correction in the Central Arctic and southwestern Beaufort.It is not faux reduction, it is a known effect subsequent to meltponding, similarly the concentration is artificially inflated where the low is compared to reality due to clouds, sensor error makes it seem like a one time thing, which is being adjusted back, it is only the long acknowledged response to certain phenomenons.
I suspect we will continue to see corrections from sensor errors, that are currently showing faux reductions of sea ice concentrations. This will be obvious in the Central Arctic and Beaufort over the next several days.
JAXA arctic sea ice volume
the formation of the sea ice ridges, they require freezing (-1.8 ) air temperatures to form.
https://www.eolss.net/Sample-Chapters/C05/E6-178-66.pdf
The initial phase starts during ridge formation and is characterized by the formation of
freeze-bonds. Three different heat fluxes are important: a) the surface flux ( qsur ), into the cold surrounding air, b) the oceanic flux ( qocean ), from the ocean beneath and c) the
internal fluxes ( qre ), in between the cold pieces of ice and the warm water pockets
inside the keel (Figure 3). The surface flux freezes the water pockets from the top and downwards and creates a cold front that defines the consolidated layer. The initial cold content of the ice is partly spent in making freeze bonds and partly consumed by the oceanic flux. The fraction that goes into making freeze bonds depends on the initial ice temperatures, the block thicknesses, the ridge size and the oceanic conditions. When all the ice and water below the cold front is isothermal that is at the freezing point of the surrounding water the initial phase ends.
The rubble beneath the consolidated layer is thermally insulated by the freezing front on top of it, and feels only the water below. Since the conditions are isothermal there is no longer any cold reserve available and the rubble decays continuously. The rubble transforms from individual ice blocks with freeze bonds to an ice skeleton with a hierarchy of pores, from a few centimeters and up to meter(s).
In the decay phase the ridge is heated both from the top and from the bottom. The ridge now either melts completely, or it transforms into a second-year ridge during the summer. Several processes take place. On the surface the warm air and the sun radiation melts the snow and the surface ice and creates relatively fresh melt-water. Its freezing point is above the temperature in the rubble so it will freeze as it drizzles down in the keel. This freezing process release heat and increases the temperatures in the rubble. In this way the decay phase includes both melting and freezing. Freezing can take place as long as there is cold capacity (ice temperature less than the freezing point of the melt water) in the keel. However, another mechanism can contribute to further consolidation. If the pore water salinity is changed cyclically, either by periodic surface melting or by tidally driven river runoff the ridge could actually expel heat into the surrounding water
and contribute to further freezing (consolidation). This mechanism is only shown in laboratory investigations and in simulations. Finally the ridge keel could collapse and in this way decrease the porosity and increase the degree of consolidation. By the end of the melt season the ridge has become a second-year ridge.
What we know about aerosol reduction
It will probably worsen heatwaves, especially in the northern hemisphere which is bad news if it penetrates into the arctic circle, like with last year’s Siberian and Canadian heatwave, or for arctic centred heatwaves like we had in northern Greenland
https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2019GL082269
It can strengthen the jet stream in winter, when localized in eurasia, because of warming, lessening extreme weathers outside the arctic, so probably good news for the refreeze given that most aerosol is concentrated away from the arctic.
https://www.nature.com/articles/s41558-020-0693-4t
There is further evidence that aerosols could inhibit thermal contrast between land and sea, in east Asia, as well as further evidence that they reduce insolation
https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2015RG000500
In contrast of the decreased surface insolation, aerosols increase air Temperatures, which seems less important on melting ice, but they also are the cause of more stormy events as opposed to light rain, which will have a definite differentiated impact on the melting season, though I cannot guess which, and on the freezing season with probably earlier refreeze due to less storm events but lesser refreeze due to more ubiquitous snow cover. As the study concentrates on a blackspot for aerosols, it will probably be a much lesser impact in the arctic.
https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2019JD030758
Finally there is a feedback loop that increases aerosol concentration, stabilizing it in place, along with the atmosphere, with the creation of a heat gradient. It being broken could paradoxically mean more aerosols in the arctic for a little while (so opposite effects to those discussed above) and more chaos in an already volatile weather and climate system.
https://academic.oup.com/nsr/article/4/6/810/4191281
Additionally another feedback loop between reduced precipitation and higher aerosol concentration, also tributary to the same atmospheric stabilization, strengthens the case for increased precipitations and chaos in the system with reduction in aerosol, although locally
https://opensky.ucar.edu/islandora/object/articles%3A7038/datastream/PDF/download/citation.pdf
Overall, simulations tend to agree that its macro effect is additional melt within the arctic
https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2015GL065504?campaign=wlytk-41855.6211458333
And, warming in various world regions
https://iopscience.iop.org/article/10.1088/1748-9326/ab6b34
Additional links
https://eos.org/editors-vox/intensified-investigations-of-east-asian-aerosols-and-climate
https://ftp.cpc.ncep.noaa.gov/hwang/Papers_pdf/Publication_2007-present/2008_Zhang_JGR.pdf (Could mean a change in moisture repartition in a reduction event if taken along with the feedback article)
Not that new but very informative on both the high pressure/low pressure and anticyclonic/waa debates on what is more conducive to melt (hint probably the formers is what the study says)
https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2014JD022608#jgrd52033-fig-0006
High melt months are linked to higher pressure, increased sea of Okhotsk cloud cover in the later part of the melt season, very weakly with increased surface temperatures who trend towards 0, less clouds overall but an increase at the ice edge in august, reduced precipitations overall but higher in the sea of Okhotsk, less arctic cyclones except northern Alaska and northeastern Siberia, also a southward jet shift in the N. Atlantic and increased sea ice export.
I really urge you to read it, it’s very informative. Obviously correlation isn’t causation. It also has various other snippets of information, notably on the relationships that exist with the weather patterns of the rest of the northern hemisphere.
When worldview, bremen concentration maps, hycom and the july piomas agree on the impact of the gaac on melt it cannot be argued, the fact that ess concentration is dropping while in a compaction pattern says it all. Furthermore, denying it would be like denying thermodynamics, temperatures have been reliably above the ice melting point, both air and sst, the insolation is high unabated by the usual clouds and albedo is low. Denying physical phenomenons is also the m. o. of climate change deniers, but beyond that it is just plain wrong, especially with the relative wealth of information provided hereIt can not be argued that we have (not) seen some extreme surface melting over the last few days.
I added the word "not" that I think you meant to put in there.
I don't think it's very scientific to try and draw boundaries around what can and can not be argued. Clearly there is visible and undeniable evidence supporting the massive extent declines being reported by JAXA. The 2D shrinkage is undeniable.
But there is room for reasonable people to question how much of that shrinkage is due to melting and how much is due to relocation.
There is a lot of evidence which will be forthcoming in the next two months which will shed more light on what has transpired during the GAAC. There isn't any reason to label less common perspectives such as those implied by Nico Sun (and his depiction of a negative current melting energy anomaly) as being invalid at this moment. The likelihood of proof is just around the corner.
I certainly think its fair to criticize and dissect the logic of unpopular arguments, but we should not make declarations that characterize arguments which have yet to be made before the proof. At this point, I don't see proof which enables us to reasonably quantify how much of the extent reduction is due to ice relocation.
Hycoms concentration plummeting from ESS, through centre of Chukchi and Beaufort to mckenzie delta. Right now decent fetch winds hitting the laptev ice front with warm ssta and over 2.6m waves. Pity nullschool cuts off waves nth of 77deg, probably bigger at the ice edge. click to animate Hycom.I would suggest that the wave height would probably drop once its reached the deeper parts of the basin, although the layering could create a form of homeostasis
Edit: Euro has 3.5 m further out. Windy clipping further nth.
Not quite, there is much more atlantification and greater melt in the caa, really no recent season resemble each other, they all vary for at least one front in this time of yearAdmitting my ignorance, I don't get the comparisons to 2019. By this time last year melt momentum had clearly fizzled out, as many posters were saying at the time. This year it's been building and building without pause. If 2020 doesn't finish well below 2019, then I think this forum will collectively have to spend the freeze season reconsidering almost all of our assumptions about ice melt.
This year is not at all like 2019. Then the ice melted strongly from Alaska - the earliest melting in the Barrow area. Now it is melting more from Siberia. 2020 is more like 2011 or 2014 but with some more power.
Pressure is not what’s needed for obtaining blue ice but several freeze thaw cycles, which is why it is usually the upper layer just after the melt crust that is blue. My guess is that the conditions are even more thaw freeze cycles for ice from salted water, which is why you need that much more time, plus the conditions might be more uniform, being conducive to either solely melt or freeze, because of the constant sun that doesn’t allow a great day gradient. You can however see that refrozen meltponds are slightly bluerMy guess would be the freshening of old ice by salt extrusion, and the layers built in successive winters.way back when there was 10 year-old.
That was before my time, Pmt!
Do you know, what's causing 10yo ice to appear blue? I mean, sea ice is not constantly under pressure, which causes the glacier ice to develop its bluish tint.
It is bad because it melts ice, creates melt ponds which precondition ice, increase ssts, increase air moisture (necessary for a gac), means no replenished snow cover (although that’s a lot less important as we go into summer, and, as you said, it lowers albedo. On the other hand high pressure means no immediate storms, more heat dissipation and less of other modes of melting (bottom melt, export) that can benefit from stormy weatherWhen you look back at modis367.....This might be a dumb question, but is anomalous insolation bad for the ice independent of its effects or because of the effects caused? For example, was the recent high pressure over the high arctic bad for some reason other than the observable impacts (e.g. the temporary reduction in albedo in the ESS)?
2020 looks worse than every year.
2011 is similar.
All years are cloudy with high albedo still. Except 2015 was low in the Beaufort region.
2014 was lowish in the laptev region.
2013 was way behind every year even 2009.
2018 and 2020 we're the most clear with 2011 right behind.
The Arctic will only become more clear the next few days.
All can say is regardless of the extent and area which will run near record lows because of the quasidipole flow and Kara being f$#_ed.
But the most important thing is the ice is being hammered with INSOLATION
The 00z gem is straight deadly for the ice. But that model sucks.
Strong evidence of the effects of aerosols is how the winters fell on the border of Canada and the United States, in places where hard-to-recover oil and gas are developed.I would challenge your assertion because neither Texas in its permian basin, nor China, is affected the way this spot is, same for more northern Canadian tar sand. I would think that this might be a siberization of the canadian and upper US core, maybe the jet stream or the effect of more seasonal ice on the northern shores but I don’t know
https://twitter.com/Climatologist49/status/1260400682089082880QuoteHere is the combined change for the January-April period. One part of the globe is different than the rest.
In fact, this is now the only place on the planet where winters have sharply cooled in recent years. This is in full accordance with the fact that Canada and the United States are the only large countries where in recent years oil and gas production has grown by about 2 times.