Support the Arctic Sea Ice Forum and Blog

Show Posts

This section allows you to view all posts made by this member. Note that you can only see posts made in areas you currently have access to.


Messages - ajouis

Pages: [1]
1
Arctic background / Re: Russian Arctic Exploration
« on: August 23, 2020, 05:19:17 AM »
A video on the first nuclear icebreaker

2
Arctic sea ice / Re: The 2020 melting season
« on: August 21, 2020, 10:46:34 PM »
A very important observation!
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
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

3
The rest / forums
« on: August 20, 2020, 03:47:49 PM »
What are other forums you know, especially those similar to asif on their scientific focus?

4
Arctic sea ice / Re: The 2020 melting season
« on: August 19, 2020, 09:37:16 PM »
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.

Quite a bit of that ice isn't there anymore, it also accounts for a lot of the weaker thinner ice glennbuck mentioned, so will we be able to trust piomas at minimum? Further if melts happen beyond normal parameters I think we can see how piomas model is like when stretched beyond its capabilities

5
Arctic sea ice / Re: The 2020 melting season
« on: August 19, 2020, 09:33:22 PM »
Yes 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.

2014    0.1 C 
2016    0.9 C
2018    2.1 C
2020    6.0 C
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.
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 it
https://sites.google.com/site/arcticseaicegraphs/forecasts

6
The forum / Re: Forum Decorum
« on: August 18, 2020, 07:40:56 PM »
Looks like it.

Lovely community vibe here.

We lost a valuable member today

7
The forum / Re: Forum Decorum
« on: August 18, 2020, 07:39:30 PM »
anyways this is the last pm I tried to send him, unfortunately too late, hopefully he will read it, his part redacted for privacy, for context I approached him a couple of hours ago to suggest just blocking pms.

Quote
Quote from: blumenkraft
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]
I 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)

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.



8
The forum / Re: Forum Decorum
« on: August 18, 2020, 07:25:30 PM »
did Blumenkraft just quit?

9
The forum / Re: Forum Decorum
« on: August 18, 2020, 05:44:13 PM »
Freegrass, I didn't say that

10
The forum / Re: Forum Decorum
« on: August 18, 2020, 04:54:56 PM »
when I said self restraint by EVERYONE, I wasn’t kidding, that includes you Neven, as the admin, sure you’re fallible, like all of us, however remember this is a public forum and how you are portraying yourself, would you be proud if a family member saw what you just said? or prominent members of your community for that matter? To reflect poorly on yourself and diminish your office is something beyond a thing you can just not care about, this is shallow and deep down you know you care, we all care, like when other things happened in this forum. Please consider using a tone and content appropriate for your position, it is not just because of trust from the asif members but because you will regret your newfound public persona because of private beef, should I remind this is how future generations will remember you? They may even take cyber museum tours of the forum, given the topic, so rise to the moment and self moderate, everything you say is here forever, it’s the internet after all.

To Freegrass, I don’t think anyone is gaslighting you, if they are, sure that would be bad and shouldn’t be allowed on the forum, otherwise please seek help like talking to closed ones about how you feel or professionals, I have family who has similar thoughts, unsubstantiated, and it gets sour for everyone and alienates you.

To Kessy, hope this was an I am sorry you feel this way comment, I am optimistic so I will say it is, not an arrogant/sarcastic one

11
Policy and solutions / Re: Lessons from COVID-19
« on: August 18, 2020, 11:24:20 AM »
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.

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.
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

12
The forum / Re: Forum Decorum
« on: August 18, 2020, 11:12:37 AM »
(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>

To me this is clear overreach, being a mod doesn’t allow to hijack good faith level headed comments because they disagree with another mod edit, Oren, which I would consider the gold standard in snipping and editing, only use this to correct behaviour that is moddable and to explain the etiquette for modding not to happen again, whereas this doesn’t qualify to a reasonable criteria and advance the mod interest rather than the community, albeit most likely not on purpose.

I think it is a shame Blumenkraft quit modding, and given the circumstances it happened in, may I suggest for EVERYONE to exercise self restraint, even admins, and also keep in mind more generally that your info might be false or supplied by people who can be intoxicated, mentally unwell or otherwise partial sources, which should be welcomed with open arms on the forum but engaged in a constructive way that doesn’t lend too much credence to hearsay and try to stave off any episode and not play into it.


I am now for guidelines because the complexification of social relationships, especially on non cryoshpere threads, necessitates them for the mods to do a clean job, though I might be biased coming from a civil law nation. This should include safeguarding guidelines on mental health and inclusivity. the mods are not at fault, it is just the natural course of a mini human society.

13
Arctic sea ice / Re: The 2020 melting season
« on: August 08, 2020, 04:23:03 PM »
a Bremen graph that I do not see often and that they don’t seem to publish often

14
Arctic sea ice / Re: The 2020 melting season
« on: July 30, 2020, 05:48:17 PM »
I think given that the boundaries still have high pressure (chuchki and eastern cab), that there will be some rain in the low pressures, that the temperatures at the surface are globally still positive and therefore conducing to top melt, especially with the waa north of Greenland and Fram, with continued pronounced positive temperature anomalies in the Siberia to Greenland front, all for the next five days at least, it is not unreasonable to predict that the cab area nosedive will probably continue at the present pace (50 k) for at least a week, putting us in a very good position to beat the record low and affecting both concentration and ice pack integrity (compaction is already back to very low levels), and probably the piomas numbers too as they take the area numbers into account. The run to the pole before refreeze is on

15
Arctic sea ice / Re: The 2020 melting season
« on: July 30, 2020, 05:38:59 PM »
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.

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.

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.
Edit added high res amsr2 on the Beaufort you can see the preliminary results of the storm and I think even the clouds that blocked concentration in the real colour image

16
Arctic sea ice / Re: The 2020 melting season
« on: July 29, 2020, 10:14:11 PM »
:o

JAXA arctic sea ice volume

isn't that near boe values for volume (1000 km*km*km)?
does anyone explain the discrepancy with piomas, is it just regular model differences or is there something I am missing?
Anyways I hope this quiets the choirs expecting a relatively muted end of season, when we're first everywhere with incredible preconditioning and almost the worst possible scenario in weather, I really don't see any evidence pointing in the other direction. Hopefully we'll still miss the mark of my prediction down below.

17
Arctic sea ice / Re: The science of ice ridging and rafting
« on: July 23, 2020, 11:25:57 PM »
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.

18
Arctic sea ice / Re: The 2020 melting season
« on: July 23, 2020, 06:20:26 AM »
I do not agree with the above statements that we are most likely on track for second place. We have had unprecedented continued extent losses that give us almost a million on 2012, the amount it lost during the second cliff btw, and we are not third in area, in high res we are still first. Piomas is only a model, and as I have shown on the artifact thread the conditions we are in were not even anticipated by the best predicting model, slater’s, with a very big gap now between it and reality, so I din’t think we can expect it to show what is right until thinning to zero has occurred in a big enough way for lower res nsidc to pick it up.
My own prediction is outlandish (below 3000 cubic kilometers) but ending up first in area and extent is the most reasonable, especially taking into account melt momentum and accumulated insolation

19
The forum / Re: Suggestions
« on: July 22, 2020, 08:16:55 PM »
I don’t know what will happen either Oren, but they keep contesting the mods authority, so I think letting them see what happens without any could be a learning experience, I mean Neven could straight up ban them but I am quite against the idea to be honest, on the other hand they are starting to question everything blumenkraft does which is not acceptable either

20
Slater’s model show ice where there isn’t currently any, in the Laptev, as well as between Svalbard and fjl, further those are separated from the main pack. This means that Slater predicts an early refreeze starting vy the island. Further an unusual long term inversion on the simpler model and slater’s prediction means that if anything close to what we are currently seeing carries on over to the minimum, slater’s model would be very poorly performing. Already we can see the forecasted pause isn’t comingto fruition at all, leaving a large gap between both models and reality, is it the time where actual conditions render modelisation obsolete? Would that extend to other models like Piomas?

21
Arctic background / Re: Aerosol reduction effects
« on: July 22, 2020, 01:55:09 AM »
For the comment synthesizing various papers the link on aerosol reduction and jetstream is broken, here is the good one https://www.nature.com/articles/s41558-020-0693-4?draft=journal&proof=true#change-history

22
Guygee, the correlation between melt and surface temperature is very weak, insolation through high pressure, lower cloud cover and less storms, in the central seas, is responsible for the bulk of it https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2014JD022608#jgrd52033-fig-0006

23
My post from another thread on aerosols in Arctic background

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)

24
Arctic sea ice / Re: The 2020 melting season
« on: July 18, 2020, 05:30:20 PM »
As suggested by b. c. my post from what’s new in the arctic

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.

25
Arctic sea ice / Re: What's new in the Arctic ?
« on: July 18, 2020, 04:24:13 PM »
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.

26
Arctic sea ice / Re: DHACSOO - A Durable Arctic Hypothesis
« on: July 18, 2020, 04:16:19 PM »
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 enjoin everyone to read it, it’s very informative. Obviously correlation isn’t causation, but that punches a hole in the waa necessity, trending instead to more general high pressure. It also talks about a pacific ocean waa, so it doesn’t have to be connected to continents.

27
Arctic sea ice / Re: The 2020 melting season
« on: July 17, 2020, 04:46:33 AM »
It 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.
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 here

28
Arctic sea ice / Re: The 2020 melting season
« on: July 15, 2020, 11:59:26 PM »
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.
Edit: Euro has 3.5 m further out. Windy clipping further nth.
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

29
Arctic sea ice / Re: The 2020 melting season
« on: July 15, 2020, 05:02:58 PM »
Admitting 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.
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 year

30
Arctic sea ice / Re: The 2020 melting season
« on: July 11, 2020, 11:19:19 AM »
You’re welcome Blumenkraft  :) it’s easier to know when you’re from an ice climbing background since most ice that is formed in a non glacier environment is from freeze and thaw, on the other hand I didn’t know that glaciers were created by compression until a couple years ago, so you win some, you lose some

31
Arctic sea ice / Re: The 2020 melting season
« on: July 11, 2020, 10:55:54 AM »
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.
My guess would be the freshening of old ice by salt extrusion, and the layers built in successive winters.
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 bluer

32
Arctic sea ice / Re: 2020 Sea ice area and extent data
« on: July 09, 2020, 11:32:12 PM »
Bremen university data

33
Arctic sea ice / Re: The 2020 melting season
« on: July 08, 2020, 01:31:10 PM »
A picture is worth a thousand words, preconditioning of the ice is getting bad, the lack of beige picture is to be expected at this time of year but the amount of wetness detected in many areas close to the pole is very high, on par with 2012 everywhere apart from Beaufort and slightly better than 2016. We are not lacking momentum for the later season, let's if the train stops before the terminus this time or goes into uncharted territory.

34
I have seen some people here say there is no real academic evidence for an amoc slowdown, while I have seen studies backing it up, am I missing something?

35
Arctic sea ice / Re: HYCOM
« on: July 05, 2020, 01:12:59 AM »
Interstitial, that last hycom run gives you the perfect opportunity to test it against reality, one, in a general manner, given that widespread white “almost gone” areas, that should mean a peak of losses july 15-22, second, some of those very thin areas should be visible from satellite photos, especially for the north of Svalbard, compared to now (provided it is not too cloudy), similarly we could compare with piomas on ice distribution at the mid july release. The quasi arm in Beaufort has shown to be very similar in piomas and hycom, so we can see if they are really parallel or divergent on some important features.

36
Arctic sea ice / Re: The 2020 melting season
« on: June 23, 2020, 10:27:15 AM »
It is obviously a bit outlandish and might be due to artifacts from melt-ponds, but it is nonetheless important to point out that Slater’s model is now predicting the entire caa will likely melt out before the Hudson bay

37
Thank you Oren for grounding the model in reality, I thought that as it was showing actual open water, as opposed to black, the southern spot on the bend would be partly ice free, but apparently not, still not good for the long term though

38
Arctic background / Re: Aerosol reduction effects
« on: June 05, 2020, 04:10:32 PM »
this map does seem to indicate some warming due to reduction in aerosol (see all of south east Asia and eastern china plus Spain and Italy) if we correlate with industrial output and severity of lockdown, this reduction would have been doubly important because aerosol tend to concentrate in a few places, reduction would have also spread what it still produced out of those spots and into the rest of the atmosphere. However, it is too early to try to spot a global effect or do it systematically because it is too early and some countries have phased out their production later than others, or not at all. I suspect we will see the biggest impact with the economic recession if it sticks. For your hypothesis, articmelt, I think this is inconclusive, one way or another, as this does show in fact an effect opposite to what would be expected for an aerosol producing region in your targeted area but it is still a relatively short time since the oil shock and pandemic, the us didn't have a full lockdown and it loosened environmental emission standards.
I don't know what the anomaly is but I think it would be much more revealing if the spots had the anomaly compared to their local or regional baseline, because that would help understanding local systems in a global context, like aerosols act.

39
Arctic sea ice / Re: The 2020 melting season
« on: May 27, 2020, 12:43:29 AM »
When you look back at modis367.....

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.
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)?
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 weather

40
Arctic background / Re: Aerosol reduction effects
« on: May 17, 2020, 10:12:36 PM »
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.

https://twitter.com/Climatologist49/status/1260400682089082880

Quote
Here 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.
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

41
Arctic background / Re: Aerosol reduction effects
« on: April 27, 2020, 06:52:31 PM »
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)




42
Arctic sea ice / Re: The 2020 melting season
« on: April 27, 2020, 02:36:57 PM »
From what I understand, the slowing of the gulf stream had an impact on the sea ice, with atlantic ice retreating less than pacific or landfast ice. How does the increased insolation in this melt season, with the diminution of economic activity linked aerosols, affect that?

43
Arctic sea ice / Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« on: October 02, 2019, 02:57:07 AM »
When i worked on a glacier, the black ash that was on it actually insulated the ice, do you know if it still hold up at macro level or if the type of matter (volcanic ash) is important? Would be interested to hear of other phenomenas in the arctic where something doesn t work out as usual.

44
Arctic sea ice / Re: The 2019 melting season
« on: July 30, 2019, 02:14:25 PM »
The image of bremen for yesterday can tell us quite a bit on where the melting season is headed.
We are having strands of weakness ( low concentration) that are now reaching 80 north in the beaufort chuchki junction. Similarly, whilst a huge chunk of the ess is now very thinned out, its dispersion starts affecting the pack above 80 north too in places.
The laptev bite has steadily progressed, both in depth and towards the atlantic, avoiding the compaction point of the siberian islands. This could mean an arc of free water from the laptev to the kara, with a blip of ice near those islands.
The atlantic side is resisting suprisingly well, with little movement, probably an indication of weaker warm currents than usual, but there are still weaknesses north of the fjl. If we see a colder end of season here, we won t see a retreat far off from svalbard.
On the other hand, the spectacular greenland retreat, probably pushed by a mix of recurring currents and exceptional weather, might deepen the blow inside the pack, and enlarge the already growing crack. This is coupled with some lower concentration between the nares and the pole, hopefully just meltponding, although days old smos data indicates it might not be.  If it is real we could see the melt of the cone leading from the north pole to nares and, subsequently, a full lift off of the pack from the caa greenland garlic press.
The caa is steadily melting, but the wider channels in the north west seems to remain solid. This extra area might be enough to avoid a new record or to only better the record by a short amount, the latter being what i am leaning towards.
The strongest areas are the arm “south” of beaufort, just next to the caa, but the crack forbids it from replenishing the northern caa fully, and it stable only till the 76-78 north, the cone of compression towards svalbard, some of the north pole, and the siberian islands point of compaction. Three of them are or will be for certain subject to side melt (exception is north pole) while both beaufort and north pole are getting thinned by dispersion. Those are the areas (minus the siberian islands compaction point) to monitor to see whether we will get a new record or even a near boe (still low probability). If a gac destroys one or more of those areas, it is sealed.
Meanwhile the hudson artifacts continue.

45
Arctic sea ice / Re: The 2019 melting season
« on: July 26, 2019, 10:49:23 PM »
I am seeing some people here speculating that this season might not be a record breaker, and indeed cab area, the one most important to determine the minimum is lagging very far behind other record years. However, volume and extent are at record low and area is close behind. In addition to all the general indicators that are in the red, pious shows that the cab volume is at an all time low, meaning there has been extreme thinning throughout that region. This is the worst preconditioning possible if any notable event arise or melting momentum continues. Either we get lucky with an extremely cold august and we dodge the bullet and end up with a relatively high minimum, or, more likely, insolation remains high with severe storms, and we end up with an extremely diminished cab and a new record low by quite a mile. I d be betting on the second option

46
Arctic sea ice / Re: The 2019 melting season
« on: July 21, 2019, 04:36:36 PM »
It looks like the difference between 2012 and 2019 grows on smos.
Pending the piomas update, it seems that the 2019 melting momentum is continuing everywhere, whilst 2012 starts to have a growing area where top melt has ended (beige pixel), meaning that there would be no safe zones in 2019 with very high thickness loss, even in the pole. 2012 has passed from a stronger melt where it was melting (maybe due to differences in ice that allowed for a wetter upper layer to be sustained), to only visibly stronger melt in the atlantic side, which means that 2019 is likely to remain lacking on that side but that it is overall better suited than 2012 to finish first in that data set,  given that the atlantic side is mostly determined by side melt, and 2019 is better keeping the melt momentum everywhere else.
The data also shows continued melt on the greenland north coast, while bremen has shown that concentration is low there, so, unless the weather pattern that allows fram export is restored, the crack will continue to grow, which is unusual so early in the season and could be the symptom of a changed paradigm.

47
Arctic sea ice / Re: The 2019 melting season
« on: July 14, 2019, 11:32:33 AM »
Looking at the most current bremen amsr2 map, a few things stand out.
The ess is steadily “darkening” (losing concentration) and retreating, which will continue to provide sustained area losses for a while. The laptev bite is still widening towards the ess (helping its deeper collapse within less than 10 days?) and is crucially starting to also get bigger in the 80 north, possibly starting the race to the north pole that some here have predicted.
There is another torching of the greenland sea ice which might also contribute to losses if either the export stop or the cab can t sustain it anymore without showing visible signs of dispersion. Although expected, it is necessary to poin it out given the imminent loss of a few hundreds square kilometers there.
The more siberian side for the chuchki is headed for collapse with large patches of water visible, after a few days of preconditionning and lower retreat, it will soon fully eat onto the ess, precipitating collapse there in a domino effect.
The beaufort is looking rather poorly, not only because of the extending holes inside it, but also because the instabilities (read open water areas) that its dispersion created deep inside the pack are spreading towards the chuchki whose alaskan bite has now breached the 75 north parallel.
All in all, the pacific side looks pretty bad and worsening with each new amsr2. On the other hand, it looks like I was wrong about the cab/ kara blob, it will still remain for a while longer, but atlantification has started between svalbard and fjl islands, directly affecting the cab.
In other news, the Hudson is finally giving out, with very low concentration almost throughout, and despite some attack on the channels from the baffin, the caa looks to be little affected by melt, especially on the western side, maybe somewhat replenished by drifting floes from the beaufort?
So to conclude, pacification is getting worse and i think we will have the same result there as with the 2012 gac, but with no gac. Atlantification is also starting proper, but we have yet to see if it will be a decisive force this melting season. The cab is starting to get attacked in multiple sides, so the only real respite we have now is really only the western caa, but for how long

48
Arctic sea ice / Re: The 2019 melting season
« on: July 13, 2019, 01:19:30 PM »
I see a lot of predictions reassuring us that 2019 will not hit first place, but the melting momentum is built in june and early july, as remarked earlier most of July 2012 was average and had cloudy bouts. All the indicators are in the red, and we can now see edge melting picking up speed, with a three fronts assault, widening and deepening of the laptev bite, quick retreat of the ess, continuous slow retreat and worsening of concentration in the chuchki. It also looks like the atlantic will activate in a couple of weeks with lower export, and the channels that possibly won t see sustained loss of extent ie beaufort and greenland are participating in the thinning of the pack with the export. When comparing with other years, that edge melting was the trademark of the later season but didn t use to be as widespread as early, because this season as seen early melting of several landfast seas, so we will probably have a new record of melting through that method. Concerning the other mechanism of melt in the later season, which is destruction by storm, i share the concern of many that fiven the ssts and awp, we might mechanically have a very stormy august, so even if it doesn t rival the gac, it will get close. This is enough to run a course parallel to 2012 and maybe (like 50/50) be first. My own prediction is that either we will see extreme compaction towards the atlantic islands, and a pack broken in two through the pole with an atlantic side and pacific side, or that we will see half the pack disappear, from the caa cab crack to the laptev bite, leaving only a very small pack close to a boe. The first scenario depends on a halting of the fram export and continuous meltponding (through rain) on the cab, whilst the other one require a gac like storm, but we will see what happens

49
Is there any map that combines concentration and thickness to get something like volume of ice per square meter?

Pages: [1]