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Messages - seaicesailor

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1
Arctic sea ice / Re: The 2017 melting season
« on: Today at 12:26:13 PM »
I promise my last OT comment on this. I can imagine a thought scenario, unrealistic but not by much, where the Arctic melts out with negative TDD (say, a massive and unprecedented inflow of Bering water, for instance, combined with a high anticyclone with relatively cold temperatures but sun radiation helping the ocean current in bottom melting the ice).
However I cannot imagine a weak winter without low FDD

Add storm effects to enhance ice melting. All that is elusive to the Thawing DD. Just saying.

2
Arctic sea ice / Re: The 2017 melting season
« on: Today at 09:45:55 AM »
Latest thawing degree days: [from http://sites.uci.edu/zlabe/arctic-temperatures/]



With all due respect, I am not sure what kind of information one can extract from the thawing dd. It is influenced by things other than an indication of thawing, like:
- Proportion of first year ice vs. multi-year ice
- In summer, change in circulation pattern affect temps often in ways that, although it may seem the main pack is around freezing temps, the periphery area and extent are plummeting.

And it misses a few:
- Heat absorption from direct insolation (insolation, as AndreasT pointed us several times, is not that well correlated with temperature and onset of surface melting; conversely, as Andreas pointed out too, can be causing direct melting beneath the ice by heating algae, bottom water, the ice itself)
- Heat transfer by rain, or humidity effects,
- Heat transfer by whatever other means, ocean currents
- Mechanical effects of storms that may even induce a dip in the atmospheric temperatures but that in August are devastating in the marginal ice, churning down ice to smaller and smaller pieces until the last bits melt out at temperatures that may be even lower in average than in the 80's

And there is a certain, although very small, downwards trend in the DMI 80N 2m temp. especially in August for the recent years, possibly because of much less MYI in the Arctic, the equillibrium temperature of the melting ice is overall slightly lower. We would end up with lower valyes of thawing degree days or with diminished in the last stretch of the melting season in the 2010's ?

3
The storm has dispersed the ice pack all these days but extent stayed put or kept going down depending on the region. This Laptev hole is an example.

4
Arctic sea ice / Re: The 2017 melting season
« on: June 27, 2017, 06:42:18 PM »
Now that it has been a week since my last Worldview Sea Ice Outlook for Summer 2017, I've done a Part 2 using the latest Worldview imagery and my subjective take on it:
https://youtu.be/beVkmkMPySA

In summary:  things have accelerated more than I expected, such that I now think 2017 will end up somewhere between 2012 and 2016.

Nice explanations, thank you
There is an awful lot of ice so vulnerable, like the ice you point out that has "crumbled down" in almost a single blow

5
Arctic sea ice / Re: The 2017 melting season
« on: June 26, 2017, 09:46:33 PM »
The fact is, 2017 has the lowest volume as of this date. All else that might be said about the volume metric entails a bias or an emphasis that departs from objectivity.
I don't agree. All Rubikscube says is there is another metric, the rate of volume decline, and this one has been in the low side since May. Objectively, this is correct, and not wanting to see it is biased thinking. There was a lot of snow in the NH, a lot of coldness associated and it really showed.
Said so, the melting has really gained momentum with the heat dragged by the storm, didn't it? Prospects are not good.
EDIT. Actually I would say that the rate of volume decline has not been smaller, but has been delayed by weeks, as delayed as the snow cover melt in the NH has been, as was clearly shown in the Rutgers maps. The thing is: the solstice comes at the same date always, give or take one day, so that delay means for sure more ice in September

Your edit suggests that you do not agree with Ribikscube, though you don't actually say that. I would add that I do not consider Rubikscube as having introduced a metric of rate of volume decline because Rubikscube has chosen to limit the field of data comparison to only a handful of years, precisely in a manner that might be seen as a bias in favor of predicting a high, non-record, minimum.
A delayed sinusoidal function is slower in its decline from its maximum than the original sine function without delay, for the same moment of time. Take the volume as a sinusoidal function. I really agree with Rubikscube

6
Arctic sea ice / Re: What the Buoys are telling
« on: June 26, 2017, 08:12:45 PM »
It's less than 1.5 metres thick, it's got to be FYI.

Moreover, it was only 80cm thick when they placed the buoy, so at least the bottom ~1/3rd of it is FYI.  But looking at the growth curve it's obvious that if there's any multi-year part of it, it's at most the top few cm.

Look at this and project the curve back to when the freeze-up started...
http://imb-crrel-dartmouth.org/imb.crrel/irid_data/2017A_thick.png

Thanks Peter, makes sense.

7
Arctic sea ice / Re: What the Buoys are telling
« on: June 26, 2017, 07:50:13 PM »
Is the top 40 cm of ice directly in contact with the thermisters gradually becoming less salty? I could imagine the melt water on the surface draining into the tube or area around the tube. Then diurnal temperature cycling resulting in brine rejection and a gradual raising of the freezing point.
I would say it makes sense. Don't know about brine draining, etc.,  although I have read about it, I still don't understand well how it works. So I don't talk about it :-|
The question I personally have is: is this MYI as I suspect or did they plant it over FYI?

8
Arctic sea ice / Re: The 2017 melting season
« on: June 26, 2017, 07:31:18 PM »
The fact is, 2017 has the lowest volume as of this date. All else that might be said about the volume metric entails a bias or an emphasis that departs from objectivity.
I don't agree. All Rubikscube says is there is another metric, the rate of volume decline, and this one has been in the low side since May. Objectively, this is correct, and not wanting to see it is biased thinking. There was a lot of snow in the NH, a lot of coldness associated and it really showed.
Said so, the melting has really gained momentum with the heat dragged by the storm, didn't it? Prospects are not good.
EDIT. Actually I would say that the rate of volume decline has not been smaller, but has been delayed by weeks, as delayed as the snow cover melt in the NH has been, as was clearly shown in the Rutgers maps. The thing is: the solstice comes at the same date always, give or take one day, so that delay means for sure more ice in September

9
Arctic sea ice / Re: What the Buoys are telling
« on: June 26, 2017, 05:26:22 PM »
Talking about fast transitions. The 2017A file was updated, showing the last 7-8 days.
If I do a too naive interpretation of these data that in reality have to be viewed with caution, I would say the ice has thinned about 20 cm in one week, but I doubt it is so much. For the temperature of the top thermistors, there is surface melt (or associated abundant drainage, plus direct sun radiation) and probably some centimeters of bottom melt.

10
Arctic sea ice / Re: 2017 sea ice area and extent data
« on: June 26, 2017, 12:16:31 PM »
NSIDC compactness dropping muy rapido:
Late Dr. Slater forecast takes a similar plunge

11
Arctic sea ice / Re: The 2017 melting season
« on: June 26, 2017, 09:52:43 AM »
Dipole or not, the OP shows some scary 850 hPa temps. Assuming warm air inflow from America, and insolation on top of it.
But let's wait and see, it is pretty far out

12
Arctic sea ice / Re: Latest PIOMAS update (June - mid month update)
« on: June 26, 2017, 08:22:52 AM »
They are different models after so many updates. This has been discussed at the forum tens of times. The current one is more realistic. A-Team comparison is not apples to apples (sorry...)
Rob, ACNFS was fairly aligned to PIOMAS a month ago

https://forum.arctic-sea-ice.net/index.php/topic,8.msg115948.html#msg115948

\A significant difference is the area around and directly north of Svalbard, which is also where PIOMAS shows a large anomalous chunk of volume. Suddenly PIOMAS and Hycom seem to be in better agreement on this.
Oren, the 2017 Hycom image from A-team does not show ANY large anomalous chunk of volume north of Svalbard.
It DOES show a massive anomalous chunk of volume in the Beaufort, and north of that, in 2012.
Am I missing something ?

13
Arctic sea ice / Re: The 2017 melting season
« on: June 26, 2017, 08:00:34 AM »
The thing is that the melt ponds have come with the storm, so it may have been a very bad solstice week for the Arctic, clouds and all

14
Arctic sea ice / Re: What the Buoys are telling
« on: June 26, 2017, 07:29:10 AM »
Whoa! just 17 hours later there is water everywhere!
Added another 5 hours, animated.
A serene and nice snow cover reaches the breaking point. CLICK.
Note the melt lake emerging in the distance (right side).
Blame the bear!
No seriously, the footprints did indeed do some preconditioning

15
Arctic sea ice / Re: What the Buoys are telling
« on: June 25, 2017, 10:51:03 AM »
@SIS concerning 2017A
I agree that water flowing down along the thermistor string could be an explanation. But heat is not only transgered by conduction and convection.
As snow becomes more translucent warming is also caused by sunlight. That can warm the temperature sensors directly or warm the ice. Since clear ice doesn't absorb much light this absorption gets stronger when there are any algae etc present, this is more likely near the bottom of the floe. The sea below the ice absorbs any light passing through, this heat is available for bottom melt although it is warming a lot of water and therefore does not show a noticeable rise in water temperature.
Those are my conclusions from what I have picked up over the years, no one here has direct experience of this
Right, I forgot that from last year that direct sunlight is another factor. I think we just catched the snow melting in the last frame, and after this week I am sure there will be big changes at the surface of this buoy.
Andreas and Jim thank you

16
Arctic sea ice / Re: The 2017 melting season
« on: June 25, 2017, 10:26:54 AM »
Once past the storm the ECMWF ensemble is pretty assertive in bringing back the Beaufort high with lows all along the Asian coast. 850 hPa temps high over Beaufort sea and Central Arctic meaning inflow of warm air. Will be really interesting.
Below the mean day 6 to day 10 MSLP and 850 hPa temp. Noteworthy that the Beaufort high does not seem very diluted by the averages across members and days, but  just my opinion. ECMWF.int has uncertainty data as well, might have a look later.

17
Arctic sea ice / Re: What the Buoys are telling
« on: June 24, 2017, 06:56:02 PM »
I would guess that this (your animated graphs) shed light to us "ASIF Lurkers" ond others on how gigantic areas of the Arctic ice just suddenly vanish when the heat eventually gets through from top or bottom.

I don't think that you'll find that the floe on which 2017A is sitting is going to "suddenly vanish" any time soon. Once the blue line has risen completely above the dotted red line is when bottom melt can begin in earnest. Melting away to nothing takes a lot longer.

Not quite sure why this is called 'bottom' melt?  According to the plot for 17A the ice above 25cm is above the melting point and so should be melting now, the deeper ice is still below the melting point.  The ice is getting warmer from above, soon we'd expect to get a profile without a minimum and ice at all depths will be melting but fastest at the surface.
Phil I suspect this is a MYI block despite the location and will be melting at closer to 0°C (at least at the top). Otherwise that raise of ice temperature does not make sense to me... might there be another explanation?

The truth is that there is only one thermistor (marked with a question mark below), which temperature was slowly rising reaching somewhere about -1.6C, that started to show faster rising temperature on June 18 and following days. I think this is the ice being heated by conduction, but if it is another thing (melt snow/ice draining from above transferring heat directly to the thermistor?) other people with more experience here may know. That could work with First Year ice. If we wait three days to next update, we probably will have a clearer idea.

18
Arctic sea ice / Re: The 2017 melting season
« on: June 24, 2017, 02:38:01 PM »
If this proves true anything could happen from July onwards

That's a really big "if". GLB has been showing this sort of scenario for years. I refuse to even look at it anymore. I do still look at ARC https://www7320.nrlssc.navy.mil/hycomARC/arctic.html, which seems be be a little better grounded in reality.
Agree. The glb goes nuts in summer, the ARC (or ACNFS) is behaving pretty well imho, and it showed fair agreement with PIOMAS this year.

ACNFS still seems to still over-predict effect of storms on thickness (A-Team showed a nice example of it recently). Anyway even in that case, one can expect dispersed broken ice in the areas where ACNFS predicts sudden drops of thickness. Taken with common sense it does not hurt.

19
Arctic sea ice / Re: The 2017 melting season
« on: June 24, 2017, 01:53:56 PM »
The cumulative albedo potential of Nico Sun (Tealight) is in second place virtually tied with 2011. I attach a cropped view of his map for 6/22 that can be seen here
https://sites.google.com/site/cryospherecomputing/warming-potential/graphs
Despite all the excess in the Atlantic side and the relatively late of surface melt onset, which give the Arctic pack a slightly negative potential, the big openings in Beaufort, Chukchi and ESS (plus the early retreat in Okhotsk and Bering seas) make for that.

The human eye could evaluate, to some extent, how this potential translated to real absorbed heat by these open water areas. Looking at worldview since May 15 the Beaufort has seen a lot of clear skies thanks to the persistent highs, but with a fair share of fog or clouds. Chukchi and ESS seas have seen a more mixed weather. 

Note the change of tonality of the ice in both animations in the last few days, these animations end in Jun 22

20
Arctic sea ice / Re: Latest PIOMAS update (June - mid month update)
« on: June 24, 2017, 01:05:17 PM »
Here is an update of the area-by-thickness graph (for a description see this post)

Area of all ice thicker than 1.46m at 21st June seems to be a proxy for the September minimum for years since 2007. The value for 2017 is still record low.

Nice plot.
That should be especially true this year where all Pacific-half ice, with exception of traces, is not only thinner overall but first year ice. The Pacific side has recieved a lot of heat so far, despite the delay of surface melt. FYI bottom melt will eventually be fast: for same heat input required to elevate MYI temperature to near zero, we have direct 60 or 70 cm FYI melt.
But well, Arctic weather will surprise us in any way.

21
Arctic sea ice / Re: The 2017 melting season
« on: June 24, 2017, 09:17:59 AM »
At 4 days out, both the GFS and Euro have been trending toward splitting the low into two discrete and localized cyclones. This creates more focused and intense winds north of CAA/Greenland and Russia while seemingly diminishing the overall effect of the winds on Pacific side (Beaufort, etc).
Yes but with a reappearance of the Beaufort high, with Gyre and insolation included, this time over a "sea" of melt ponds rather than just snow. Let's see how long that situation lasts,

22
Arctic sea ice / Re: The 2017 melting season
« on: June 24, 2017, 01:17:08 AM »
The latest EC forecast is warmer for the Arctic than the previous ones, including the warm spell in Beaufort sea these days but also a deep low entering from Siberia will bring very warm airmasses (but very briefly) into Laptev and ESS in day 3-4. In previous runs the Arctic seemed shielded from Siberian heat wave. All within 5 days ;)
I assume the Laptev/ESS warm temperatures will come with rain.

23
Arctic sea ice / Re: The 2017 melting season
« on: June 23, 2017, 07:54:27 PM »
Wow thx Crocodile23 for reminding us about the tool and all the uses...
So didnt wait to check on the Beaufort winds and temps next 5 days, and yes, major melt along Alaska, if this tool is showing temps right, it looks pretty in accord with what can be inferred from the tripicaltidbits. The Beaufort sea is well in its way to ice-free again.

24
Arctic sea ice / Re: The 2017 melting season
« on: June 23, 2017, 02:41:37 PM »
I was wondering if the Jaxa sea ice thickness images over the last few days have been showing the effect of winds in the CAB, especially the almost circular striations. If so, does that also indicate the poor state of the ice in both thickness and compaction?
Well, the melt over the Beaufort sea is monumental, that map confirms. Almost not visible by clouds. Really warm along  Alaska

25
Arctic sea ice / Re: The 2017 melting season
« on: June 22, 2017, 10:37:46 PM »
The circulation around the low is going to shield the Arctic against the heat wave in Siberia.
The ECMWF ensemble forecast shows a colder Arctic indeed but with a much warmer Beaufort sea and CAA from day 5. Strong pull of airmass from the Pacific and North America.
Edit. Forgot to add the plot of 850 hPa temp anomalies in five days.

26
Arctic sea ice / Re: What the Buoys are telling
« on: June 22, 2017, 06:16:59 PM »
Same for 2017B.
The last couple of days have a rapid change in the profile, something similar to what we saw last year with 2015F (for whatever reasons).
The webpage reports start of minute bottom melt also these last few days (before 20th). Fairly warm days with mean temps near zero.


27
Arctic sea ice / Re: What the Buoys are telling
« on: June 22, 2017, 05:21:15 PM »
I downloaded the update from the 2017A webpage. The last frame from the 20th is very interesting. For a few data lines, on the 19th and 20th, one of the thermistors next above what I have assumed ice surface (depth=0 in the plots), seems getting anchored to 0C. Melting water from the snow? Last days seem pretty warm.
The temperature of the ice is getting close to melt temperature for what would be FYI, even well above it for the first 25cm of ice, which might mean I assumed ice surface in the wrong place. But I would not be surprised that this buoy was instead anchored to a residual of MYI of last year. Somebody I think mentioned that possibility.
The page has stopped giving bottom melt and snow depth, the database just shows 11 cm snow  (???) and constant thickness of around 1.15 meters. I would expect more melt, top and bottom but who knows.
The bottom water is now clearly warmer, if only by 0.1C or so.

28
Arctic sea ice / Re: The 2017 melting season
« on: June 21, 2017, 07:36:55 PM »
Is it just my eyesight or have the current cyclone dragged so much heat and rain from south that melt ponds are now visible over a big swath of the Russian Arctic as well as the Pacific side? Judge for yourself! I have encircled the approximate areas for this with red as the color there seems to be somewhat bluish.
Nice handwriting LMV :)
I agree with you, also some areas of the Beaufort (close to Alaska) have worsened subtly and not because of the cyclone
Jplotinus the Laptev is done! Unlike last year

29
Arctic sea ice / Re: The 2017 melting season
« on: June 19, 2017, 06:08:02 PM »
I've seen a lot of snow melt, some deep and some shallow.  I recall thin snow (sometimes on lake ice) develop something like melt ponds.  I also recall walking in the spring through foot-deep snow and coming to 'bogs' where the surface was grey and 'melt pondy' or even a temporary pond, and places where the surface was pristine white but my feet got soaked by the hidden water below.

I want to guess there is a lot of this hidden water below the surface sort of melt pond in the Arctic right now.  The white surface is certainly causing a great deal of reflectance, but real damage is happening below, none-the-less.
F. Tnioli, here is the comment. I got snapped at earlier for referring back to it myself, but it makes sense to me. A percentage of energy gets past the snow surface, and some ponding could have formed between snows.
But that happens over soil frequently. However to find lhat pool of water sandwiched between snow and -1.8C or so of ice, which is under freezing temp for hypothetically melting snow or fresh-water, and without the direct source of heat ( siince insulated both at the top and bottom). I don't see it...

30
Arctic sea ice / Re: Stupid Questions :o
« on: June 19, 2017, 10:43:26 AM »
Isn't this the so-called Quasi Biennial Oscillation?
https://en.m.wikipedia.org/wiki/Quasi-biennial_oscillation

31
Arctic sea ice / Re: The 2017 melting season
« on: June 18, 2017, 01:08:27 PM »
In related news, the snow in Tiksi (Laptev shore) has finally given up and melted, the latest in at least 15 years.
Out of sheer boredom while waiting for cliffs and the hopeful mid-month PIOMAS update, I decided to graphically quantify this snowy lateness. Horizontal axis is date from present backwards.
BTW, took ages to produce. If anyone has a link to historical station data that can be downloaded, it would be very welcome.
Great plot Oren.
I think it is reasonable to expect as well a significant excess snow cover over the ice, due to the anomalous winter, spanning from the Barents and then along Eurasia, but that we cannot prove.Perhaps explainimg delay on melt ponds

32
Arctic sea ice / Re: The 2017 melting season
« on: June 16, 2017, 10:10:49 PM »
The ACNFS drift forecast at slow motion for today and following 6 days.
Interesting that the dispersion that the storm brings will not really push ice back toward the coasts in the open water areas, except for Kara. Laptev and ESS open areas gonna get bigger, even Beaufort and Chukchi it seems. Surprising given the storm but it must be that the coupling with the  Beaufort high keeps the circulation in this way

33
Arctic sea ice / Re: 2017 sea ice area and extent data
« on: June 16, 2017, 08:49:18 PM »
Magnamentis there is no reason to distrust the motives behind what simply is a piece of information with no distortion of any kind in a nice plot (thank you Steven).
Now I am surprised that you have mentioned the bad shape of extent. Yes it is.
I partly agree, 2012 dwarves the other cliffs but I guess it is important as well where area ends in second mid of June, ☀️

34
Arctic sea ice / Re: The 2017 melting season
« on: June 16, 2017, 03:53:10 PM »
The loss of snow in the last days has been swift and major, as others anticipated, and Laptev sea fast ice shows some areas in a really bad state. The cyclone is going to further destroy the drift ice in Laptev, but no doubt it is going to put a brake on this belated June momentum... interesting. Because the 850 hPa anomalies of 10 to 15 of June were pretty high.
OTOH the last run does not show such centered final GAC (which I think it would have really halted the melting season) but a weaker, persisting cyclone that stays close to the coasts of Asia, allowing (or even strengthening) for the general circulation Pacific-> Atlantic that has been displacing the ice pack gradually since March.
Now will the Arctic get the "2013 syndrome"?

35
Arctic sea ice / Re: Home brew AMSR2 extent & area calculation
« on: June 15, 2017, 09:36:12 PM »
Seaicesailor, by what metric or observation do you find the ice pack compact?

Shared Humanity, I share your sentiment. The lack of FDDs drained the pack of the life blood it needed to recover from the sorry state it was in toward the end of 2016, while the consistent storms/winds continue to deliver body blows.  Most people here emphasis the need for minimal insolation and heat, but the incessant body blows, even the moderate ones, need to stop IMO. The cumulative effect of all this has Arctic sea ice hanging on by a thread.
Not compact, but relatively it is not as disperse as one could expect or as implied by other posters in the forum (with all due respect).

Coincidentally I just saw the compactness graph by Wipneus from the ASIG and guess which year is "the most compact" as of today (see plot using NSIDC area/extent data) from the 2012 to 2017 group plus 2007
Edit. This metric being from NSIDC reflects low level of surface melting as Nico Sun's map also does, not only how loose or tight the ice pack is overall (which still, in large areas of the Arctic, the ice pack seems pretty tight to me, , if so momentarily).

36
Arctic sea ice / Re: Home brew AMSR2 extent & area calculation
« on: June 15, 2017, 07:47:42 PM »
You do mean June rather than May, don't you?

not sure but i think he meant what he wrote but the dates were for june not for may, why should he post 1 months old data today, as i said, just assuming from logic but facts may tell another story, let's see what wip has to say.

howerver, these anims show very well how much of the 100% extent is really 100% hence what
those number at this time of the year and nowadays are (not) worth LOL

i love this gif, tells a big tale.
To take into account that Wipneus increases the contrast to the extreme to show warming events etc.
The albedo anomaly plot of Nico Sun tells us quite a different story.
As a matter of fact I find the ice pack quite compact and that extent is not misleading much from what is going on, as much as it can tell

37
Arctic sea ice / Re: The 2017 melting season
« on: June 15, 2017, 12:53:36 PM »
Thanks for the graph John, but I think the drop in SSS has more to do with Hycom predicting start of bottom melt in those areas than anything else. Usually comes accompanied by a drop in salinity.
It is striking though, that circular area.
Btw Hycom does not show any other dramatic change there, no thickness or SST or concentration.

38
Arctic sea ice / Re: Home brew AMSR2 extent & area calculation
« on: June 13, 2017, 10:17:19 PM »
Who knows. Let's watch how it unfolds  :)

39
Arctic sea ice / Re: What the Buoys are telling
« on: June 13, 2017, 06:36:09 PM »
Latest 12 days of the 2017A buoy. The discontinuities that can be seen in the unfiltered signal are separated by two thermistors, that's 20 cm, really respond to the 15 cm of snow reported in the web page.
So the snow lasts even when there were several hours of over zero ambient temperature (as shown in the 2m DMI, in the buoy data itself, etc). Perhaps temps were just barely over zero and dropped almost daily. So snow resistance might be an example of the apparent lack of "Spring power"... anybody said "2014 syndrome"? "2014 High"? For how long? Top thermistor average temp is now well over zero.
There is a moment when the temperature of the water beneath starts to raise, then drop. Difficult to explain.

40
Arctic sea ice / Re: The 2017 melting season
« on: June 12, 2017, 11:22:08 PM »
Nice post Neven (now that I can't tell you in the blog :-) and FOOW, your arguments are really strong and well explained.
Just I am curious how fast the open water is developing, with the persistent circulation toward the Atlantic since March or April! There seems to be a lot of compaction too ---which can help our thin ice to pack together on the short run, but that can be disastrous come August ---.  Also, let's not say there is no June momentum; ice is darkening subtly as we speak Arctic wide; let us say it lacks a lot of punch, the air being pulled from Asia... we'll see what happens in the second mid and in July.
Fascinating how season after season things do not repeat at all.

41
Arctic sea ice / Re: The 2017 melting season
« on: June 11, 2017, 09:38:29 PM »
Really. 73 cm is just over 2 ft.  Not out of the ordinary for that location this time of year, especially since Northern Europe has been seeing more snow over the last few years due to climate change.  That can happen over a few hours and be gone in a couple days.

 
The question is not how fast can it go but how long it has been persisting. Like three or four weeks closer to the solstice. That is not ordinary.

42
Alright, thanks for the correction, I was one of the deluded then.

43
Arctic sea ice / Re: Stupid Questions :o
« on: June 10, 2017, 12:27:07 PM »
So I noticed a bunch of areas, like the Hudson, Greenland North Coast, etc, that have cycles where the wind blows the ice away from the coast, creating open water, and then later back towards the coast.

My question... does this have any particular impact on the ice? Does the water it's being blown into warm in a few days in the sun? Does the ice coming back push that water out of the way? Or does a few days of sun not really matter?
I don't think it is easy to answer this question. It has an effect, but my feeling is that for it to be relevant and substantial the opening has to be huge and receive insolation for weeks. Then it happens like Beaufort sea in 2015 or 2016. No matter the MYI it kept importing, the ice would melt before the end of the melting season (well, by the end of the melting season in 2015).
I am sure the effect has to be substantial in the Hudson sea (well, now that it is toasted it does not matter anymore).
For these other smaller openings, probably there is a small effect.
In Greenland North Coast there is an underlying current that is cold. If the current is vigorous enough, the warming on the water may be small or have been transported away, to really have an effect on the ice once it comes back.

44
Arctic sea ice / Re: The 2017 melting season
« on: June 10, 2017, 11:41:53 AM »
The anticyclone may be bringing some sizeable MYI blocks closer to the Beaufort Sea. If I recall correctly last year there were a couple of compaction events at the end of the Melting season, some of this ice is really thick.


46
I voted 3.5-4.0 M km2.
This is the first June in years that goes so clearly anticyclonic, and while the HP has been pulling air from the continent with the cold anomaly and not many melt ponds are really visible, it still has brought over zero temps to a significant portion of the Arctic (snow melting, ice warming up, bottom melting soon to kick up). This situation will be sustained for days.

Also, significant portion of the Pacific side is open water, and there is plenty of insolation.

The land snow cover has so clearly delayed melt in ESS and Laptev, and I guess all the warmth coming from Eurasia will lack some punch during the summer. That is a very important factor.

Still let's see what happens with all that ice thinner in average as never before, with the thicker MYI sitting too close to the Atlantic Ocean.

By the way, the NSIDC now computes the monthly average as the average of daily extents. This would have yielded around 4.3 M km2 in 2016.

47
Arctic sea ice / Re: The 2017 melting season
« on: June 09, 2017, 07:56:42 PM »
5-day averaged MSLP forecast, and on the ensemble of the ECMWF
I mean, this is June 9, if this is not bad enough...

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Arctic sea ice / Re: The 2017 melting season
« on: June 09, 2017, 06:38:30 PM »
The 2m temps today

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49
Arctic sea ice / Re: 2017 sea ice area and extent data
« on: June 09, 2017, 05:27:38 PM »
In other words

50
Arctic sea ice / Re: What the Buoys are telling
« on: June 08, 2017, 10:44:11 PM »
Thanks DuraSpec (and Oren) but doing this plots is pretty simple stuff, for the really scientific-level awesome things theres Wip and A-Team among others
I had no time to think much on the profiles to be honest, but one thing is that both buoys have relatively little insulation by snow on top (the one in the N. pole has almost none and the other a layer of 10 cm or so I think, recently increased a bit). That means the first 50 cm of ice react pretty quickly to change of outside average temperature... I have not noticed something particularly anomalous but as I said I have not looked at it with detail...

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