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Messages - subgeometer

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1
Arctic sea ice / Re: The 2017/2018 freezing season
« on: January 15, 2018, 01:16:46 AM »
Andrew Slater used to make a FDD graph for the entire Arctic Ocean (vs only 80N). I've asked Nico Sun, aka commenter Tealight, if it would be easy to make a 66N FDD chart as well for the last 10 years. I can't believe I haven't asked this before.  :-[

In the meantime, snowfall still relatively low on the Northern Hemisphere, still mainly because there's no snow in Europe (we finally received like 1-2 cm of snow today, here in Southeast Austria), but in parts of the US as well:

GFS reanalysis maps from climate reanalyser - http://cci-reanalyzer.org/reanalysis/daily_maps/ -  give a value for daily temperature anomaly in the Arctic circle - that's a potential source for an FDD chart but one that maybe misleading because its really just the Arctic Ocean that is of interest. Extreme cold in northern Siberia and/or Canada can offset warm anomalies over the ice. If there was a way of masking out the surrounding landmasses and the north Atlantic that would be great

2
Arctic sea ice / Re: The 2017/2018 freezing season
« on: January 12, 2018, 05:16:48 AM »
The GFS is showing a storm passing just north of Svalbard which intensifies to 972hPa about 54hrs out and stays around that intensity for a day or so. It grows out of a pulse of moist warm air fired up by a low acting as a slingshot off the coast of Greenland

3
Arctic sea ice / Re: The 2017/2018 freezing season
« on: January 09, 2018, 11:05:49 AM »
According to NOAA's NCEP/NCAR data 65N-90N December air temps at 1000mb set a new record, although seemingly not as much of a record as the 925mb temps illuminated in Neven's PIOMAS update: http://neven1.typepad.com/blog/2018/01/piomas-january-2018.html

https://www.esrl.noaa.gov/psd/cgi-bin/data/timeseries/timeseries1.pl

This GFS reanalysis of december via climate reanalyser shows the ugly story of anomalies at surface level (click to animate)

4
Arctic sea ice / Re: The 2017/2018 freezing season
« on: January 07, 2018, 10:55:23 PM »
The jetstream blows above a temperature contour on the surface - between cold/not cold or icy/melted, so as the winter temperature difference between the Arctic Ocean and the surrounding continents becomes greater with late refreeze, thin ice or none etc I expect to see more loops off the jetstream sheperding warm air into the basin. For now that should be most pronounced in the first half of winter while open water remains in the basin. Ie now the Chukchi Sea is frozen and as the Bering hopefully freezes perhaps the Pacific incursions will be less likely/extreme.

Edit: topography and the various climatic modes like AO etc obviously play a role as well

This is just a layman's take

5
Arctic sea ice / Re: The 2017/2018 freezing season
« on: January 06, 2018, 10:17:11 AM »
The last few GFS runs on climate reanalyser are showing a succession of warm blasts coming in through Fram and over Greenland, the first in about 96 hours. Of course they can't be believed, but the one's  further out are successively more insane, with massive foehn winds bringing a huge area above freezing.

All the cold air is continually shunted into N America and Siberia

6
Arctic sea ice / Re: The 2017/2018 freezing season
« on: January 01, 2018, 03:13:01 AM »
The graphic below quantitates that by looking at the 'outer' two-thirds of the year via blue pixel counting that shows the mean temperature difference between 2017 and climate as 5.3ÂșC...
That is all well and good, but the range prior to this winter was indicative of a wildly unstable system, and suddenly we have a system which so far is looking very stable.

That's equivalent to the total FDD anomaly over those days, divided by their number. Nico Sun's FDD anomaly charts gives a way of comparing years. One interesting visualisation might be all the years of the DMI graphsoverlaid with the years in a colour gradient, say red for the most recent through yellow to green for the oldest


7
Arctic sea ice / Re: The 2017/2018 freezing season
« on: January 01, 2018, 02:37:52 AM »
The 8 or 9K average temperature 'step change' (eyeballed difference between current winter average and graph's average line) occurred at the end of December 2015 on the DMI 80N chart.  I don't recall anybody identifying a concurrent weather/climate change.  Did I miss the discussion or is this worthy of its own thread [maybe "DMI's 80N step change in winter temperatures" or "Step change in winter temperatures (e.g., DMI's 80N)"].  If so, someone with weather-cred should start such a thread, as they could better describe what appears to be happening ("climate" being '30-years' and we have 'two'.)

While the past 3 winters have made the change in conditions clear time will tell if dec 2015 is a stepchange or whether it constitutes our moment of recognition.If you look at the DMI charts there's a trend towards the new temperature band - you have to look before 2010 to find years where the temperature falls below the  average - I've included the chart for 2012

8
Arctic sea ice / Re: The 2017/2018 freezing season
« on: December 30, 2017, 05:26:41 AM »
The DMI SST anomaly map show shows a lot of warmth on the Atlantic side that will retard ice growth in that direction. What it doesn't show arethe temps of ice covered regions, but looking at the SST map reveals a large 'warm' area of the Alaskan/Canadian coast all the way to the Mackenzie delta left over from the huge area of open water that opened last summer. Much of the really cold ice is in the CAA. Continuing warm influxes from the Pacific will precondition the Chukchi etc for reall yrapid melt come spring.

Edit ; I fixed the transparency on the SST png.


9
Arctic sea ice / Re: The 2017/2018 freezing season
« on: December 30, 2017, 12:12:10 AM »
Closing in?

What are we looking at here?

Extent I believe, currently second lowest for the date and closing in on last year

10
Arctic sea ice / Re: The 2017 melting season
« on: August 22, 2017, 02:51:29 AM »
That's a really nice animation ATeam. Those DMI SSTs sure are noisy. Interestingly it shows the blob I circled also appearing for one day about 2 weeks ago with what appears to be exactly the same shape

11
Arctic sea ice / Re: The 2017 melting season
« on: August 21, 2017, 01:50:48 PM »
DMI are showing a fairly large area of recently ice free water in the Northern Beaufort with a 4C+ anomaly. If its not an artefact it looks like warm water has been coming to the surface there also

12
Arctic sea ice / Re: The 2017 melting season
« on: August 08, 2017, 01:03:15 PM »
The PAC has been pretty persistent so far and may yet deepen in into a GAC, as the sun lowers. It seems to have a production line of lows on a track to feed it

13
Arctic sea ice / Re: The 2017 melting season
« on: August 08, 2017, 05:21:48 AM »
The waves forecast for the next few days from windy tv on the Pacific and Siberian side. The rapid retreat of the ice should continue on that side. On the Atlantic bulwark breezes turn to push the ice inwards. Luckily no storms on that side, for now

Edit - click the the forecast gif to animate

The northern route is open now, only a bit of slush to delay a yacht around Vilkitsky strait

14
Arctic sea ice / Re: The 2017 melting season
« on: August 05, 2017, 01:58:58 PM »
140K drop on NIPR today

 This is when 2012 went through the floor so there's a long of ground to catch up but there's a lot of extent that's obviously going soon on the Pacific/Siberian side, and a lot more that looks like this stuff right by the pole around 86-88N towards FJL. Who knows, but I think in the next month the FDD anomaly last winter will show its effect.

We may have dodged a cannonball, for now, but lets not say it's just a flesh wound yet

15
Arctic sea ice / Re: The 2017 melting season
« on: August 04, 2017, 03:27:07 AM »
Here are my first gifs of the lagging minimum post-processed Bremen NIC maps. (Might need an acronym for that  :D ). For these I have used the minimum over 3 days, which seems to get rid of most but not all of the atmospheric artifacts. These are for the last week (7 days ending Aug 2nd).

I produced 2 gifs:
1.) A side-by-side next to the original unmodified image for the same end day. This is for those who prefer the originals, and to help evaluate the effect of the post-processing.
2.) One just showing just the post-processed image, which has better resolution (due to restrictions on what can be posted).

They do seem quite useful. For example, the rapid acceleration of melt in the last 2 days is much more obvious with the clouds removed.

I plan to make longer ones soon that go back to earlier dates, and also to play merges over longer than 3 days.

As an Acronym I propose LAMP-B (ie LAgging Minimum post-Processing-Bremen), as they're illuminating and you need a lamp at hand when in PYJAMAS

16
Arctic sea ice / Re: The 2017 melting season
« on: August 04, 2017, 03:15:40 AM »
There's a hole developing between FJL and the pole at around 85N. It's been showing as part of the border of the 2-3million km2 of remaining solid pack on the concentration maps for a while. Clouds continue to obscure everything north of 85N in this region, but the map has low concentration continuing to 87N,

 I've attached a closeup with a wider view showing FJL at right, the new hole at bottom left and the other hole north of the Laptev at top, as well as a Bremen map with the 'border' marked in crudely. Hopefully most of that extent will survive. Outside that I think we might see detached blobs , more than arms

17
Arctic sea ice / Re: The 2017 melting season
« on: August 04, 2017, 02:29:02 AM »
My bet is that all the open water there already will tend to suck the weather systems in and keep driving the loss, rather than 2017 taking a 2011 path and heading for minor loss and a #4/5 level finish.

I'm fairly sure that all that open water will pull in the fog next Winter.  I don't know enough about cold-core storms to really say about the rest of Summer.  I will note that we've had plenty of them the last couple of years.

Last autumn all that open water invited storms. I think were likely to see a repeat, at least in theme. What is maybe interesting and a bit different this year is that lows can enter from Siberia and track all the way to the ice north of the the CAA with warmish ocean on their southern flank. That seems to the the pattern at the moment and if it continues, the storms might intensify as the sun drops,

18
Arctic sea ice / Re: The 2017 melting season
« on: August 03, 2017, 12:53:27 AM »
Some of the remaining high concentration ice in the Beaufort Sea. It looks very fragile nevertheless

19
Arctic sea ice / Re: The 2017 melting season
« on: August 02, 2017, 01:06:33 PM »
It's not just this storm I think,  a lt has been hidden under cloud for weeks and now they open for a bit,  there's been a lot of warm air and moisture entering  and s,, the storm gave thin ice about to expire a little push

20
Arctic sea ice / Re: The 2017 melting season
« on: August 02, 2017, 12:50:56 PM »
Ice soup from the Western Beaufort through to to Severnaya Zemlya (not New Siberian I slands, oops), with scarsely a 5km floe in the mush, and open water

21
Arctic sea ice / Re: The 2017 melting season
« on: July 31, 2017, 01:27:32 PM »
20 days in the Beaufort Sea. The area shown is from about 73-77N, 137-157W.

To my eye concentration increases as melt sets in, before catastrophically collapsing

22
Arctic sea ice / Re: The 2017 melting season
« on: July 31, 2017, 11:49:48 AM »
The little storm is generating 60kmh winds over the pacific edge of central pack today, according to GFS anyway.

The Windy/ECMWF forecast show it drawing in warm moist air delivering 10-36mm to a broad swathe north of the CAA in a couple of days.  Rain at 2mm an hour for 12 hours on Wednesday at the location pinpointed. I don't think it's snow. I've attached a Precipation map for the next 3 days with the forecast embedded as well surface and 850mb temp as the rain sets in

 It would be great there were more observations to back them forecasts of course. Do vessels like the Healy that was the source for the images of the Beaufort ice publish weather logs?

There will also be intense southerly winds north of the CAA aand out of Nares strai to accompany the rain so I've adde an extra attachment


23
Arctic sea ice / Re: The 2017 melting season
« on: July 30, 2017, 04:21:19 AM »
It was clear on the Pacific front yesterday, and the ice in the Western Beaufort looks even worse than on the Hamburg concentration map. The image shows an area from 148-152W which is almost open water already. It's interesting that the areas of highest concentration are at the edge. I've been wondering if, at the periphery, in this era of mush, area is measuring something different from in the past, where bottom melt reaching far into the pack spreads the melting ice over all the area, and floes are too small to see te open water between them from the satellites

24
Arctic sea ice / Re: The 2017 melting season
« on: July 26, 2017, 09:49:04 AM »
Things have been kind of quite lately in the Arctic. Really not that bad of a year. Not much momentum, the melt season seeming to just fizzle out. Or is it just being a little sneakier this year.
21st-25th CLICK IMAGE


GFS predicts a dipole setting up in a day or so with highs returning to the Beaufort, and the PAC drawing in some deeper fast moving lows from about 100hrs. As Pavel noted the weather has been driving the periphery outward toward Russia etc, whereas I can't help think that compaction and consolidation would be better for ice preservation despite the big extent drops that would imply. And there is that monster cyclone developing east of Japan.

25
Arctic sea ice / Re: The 2017 melting season
« on: July 22, 2017, 12:35:16 AM »
NSIDC SIE  x 106 km2

2017,    07,  17,      7.765
2017,    07,  18,      7.640       Down 125k
2017,    07,  19,      7.518       Down 122k
2017,    07,  20,      7.395       Down 123k

 Some have commented that cooler air is on the way for many parts of the Arctic. Still, most surface air will remain above freezing, even if slightly, and insolation will continue either way.
Looks like a little wave activity starting to kick up here and there today and over the next few days. This may redistribute enough warm water to escalate the attack on the sea ice.

The coldest temps are on the Siberian/Pacific side where the ice is thin and SSTs will melt much or all of it out, whereas warm winds are blowing north of Greenland and Ellesmere Island most of the week according to ECMWF/Windy, as well as along the Atlantic fringe. For ice retention it would be better if the core of the cold were between the Pole and Greenland/CAA.

The NH tropical cyclone season is cranking up, so we'll likely soon see one tracking into the Polar region with attendant warmth and moisture.

[edit} And waves... The low tracking from the ESS through the Beaufort will generate large waves right at the ice edge, up to about 4m by the colour of the visual, unfortunately the conditions at location feature doesn't seem to work in the Windy TV 3D view

26
Arctic sea ice / Re: The 2017 melting season
« on: July 20, 2017, 11:04:24 AM »
@subgeometer

It looks like that is going to continue around the Svalbard area for several days, with some ups and downs in wave heights, of course. This should move some of the warm water around, and there is plenty in the area.

Thanks TT

It would also be interesting to see a few profile from the huge swathe of open water  around the coast from Canada to the Laptev.

The waves at Svalbard are being driven by persistent warm southerlies. This low could have a bad effect on the now peripheral Atlantic fringe, while the cold is blown to already melted areas on the Pacific side.


27
Arctic sea ice / Re: The 2017 melting season
« on: July 20, 2017, 06:07:40 AM »
Windy TV predict persistent waves around 2m north of Svalbard this week while warm air is drawn over the Atlantic sector. Also plenty of waves on the Pacific front at various times

I'm not sure how this is determined but it's scary how far into the pack the model sees waves propagating

28
Arctic sea ice / Re: The 2017 melting season
« on: July 17, 2017, 05:10:42 PM »
On the Atlantic side Winds have turned around to come from the south for the next few days, with a big influx of warm air and moisture, And the ice looks bad .

Here is a region from 85-87.6N north of FJL over the past 2 days as well as 850hPa from WindyTV temps showing twin assaults from Pacific and Atlantic. Windy TV has a 3D globe projection! That makes it much more useful,

29
Arctic sea ice / Re: The 2017 melting season
« on: July 16, 2017, 02:16:20 PM »
I think the heat is on now on the pacific side of the CAB. This doesn't look like a "mood" for me of the Bremen graph, there's too much green already.

No, this is real, Uni Hamburg AMSR2 shows it too. There's a lot of melting potential there, and given the 'piggy bank' ice in the Kara Sea, Laptev Sea and Baffin Bay, I'm expecting the series of JAXA century breaks to continue for a while longer.

Here's a comparison of DMI SST anomalies for 2012 (left), 2016 (middle) and 2017 (right) for July 15th. I would say that 2017 is well ahead of 2012 on the Pacific side, slightly behind on the Atlantic, and I'm somewhat surprised that no red still hasn't shown up in the Laptev Sea this year. The story for 2017 vs 2016 is the same, except that 2016's lead on the Atlantic side was much larger. But given the current forecast, with persistent high pressure on the Siberian side of the Arctic, 2017 might still catch up.

My impression that there is some sort of conservatism in how data is assimilated to the DMI model as compared to NOAA. There seemed to be an initial lag in temps earlier in the the other open areas, beaufort, ESS etc as compared to the NOAA chart before catching up. NOAA is now showing warmer than 0C in parts of the Laptev bite. Perhaps DMI will show a different reading soon. Kara on DMI showed a negatory anomaly not long ago, now bright red.  On the other hand NOAA's model just seems to make stuff up in places, like the 16C it shows near Svalbard

30
Arctic sea ice / Re: The 2017 melting season
« on: July 15, 2017, 02:30:44 AM »
Current DMI and NOAA SST anomaly charts. They are different in specifics but the general theme is the same - a lot of warmer water all around, especially on the Pacific side. NOAA's version has been getting particularly angry looking recently.

Still a few more weeks of serious insolation to crank those temps higher, and the remaining ice will be surrounded by a killing field,( as well as storm driver and source of anomalous snowfalls later on)

AS a note, at some point the link between NH snow extent and ice pack extent must be severed if a warmer Arctic continues driving anomalously high snowfalls in Siberia and Canada. At some point there will be icefree Ocean but still a lot of snow on land

31
Arctic sea ice / Re: The 2017 melting season
« on: July 11, 2017, 06:05:58 PM »
Once the pack in the Arctic itself starts splitting in chunks it can't be long to game over. Deep gulfs between arms went close last year.

Here is an area of low concentration ice stretching from the open water in Chukchi sea through to at least 81N on worldview  today.

32
Arctic sea ice / Re: The 2017 melting season
« on: July 10, 2017, 10:37:39 AM »
Thanks Darvince. Those are really helpful.

5 day GFS precipitable water for the Arctic
CLICK IMAGE


The air with the moisture that comes in over the New Siberian islands is very warm very high - here are rain forecast and 700mb temps for a couple days out on windy TV from ECMWF - 4C at 3000 m at this spot where 13mm forecast to fall in three hours - a lot of energy transfer

However unreliable and unverifiable the models are in the region, that has to be rain

33
Arctic sea ice / Re: The 2017 melting season
« on: July 07, 2017, 04:19:33 AM »
ECMWF/ Windy TV predict a lot of rain today off Northern Greenland, over 25mm in some locations. The forecast temp  there at ground level is 1C today (so surely its rain not snow?)rising to 4C on Sunday and 3C on monday. That can't do the ice there any good

The forecast for 4 or 5 days also shows another large gulp of atmospheric moisture entering the basin via the Laptev. with more substantial rainfall. It comes with a warm airmass at up to 10C at 925mb.

Large areas of the basin are going to see rain over the next 6 days, further conditioning it for destruction, and rendering the outlook from May meltponds irrelevant, in my opinion anyway

34
Arctic sea ice / Re: The 2017 melting season
« on: July 07, 2017, 02:13:35 AM »
Re GFS/climate reanalyser overcooking its arctic forecasts, the models rely on sparse and iffy data on the region. eg GFS sees SSTs up to 16.4C today at the Svalbard hotspot whereas ECWMF/Windy shows SSTs under 6C in the same place. That's a huge difference and makes me wonder what other dubious inputs GFS is fed

35
Arctic sea ice / Re: The 2017 melting season
« on: July 06, 2017, 10:09:09 AM »
The clouds have opened for a moment to reveal the last ice between Laptev and ESS bites, it won't last long.

Windy TV is showing a lot of rain in the next few days at various places - how much damage will 23mm of rain do?

36
Arctic sea ice / Re: The 2017 melting season
« on: July 05, 2017, 02:51:03 AM »
By popular request, the animation shows three more features tracked from the end of the 2016 melt season up to July 10th of this year. Some of them don't recognizably kick in until later in in the fall. The last frame shows initial and final positions (or the full track for point features).

Overall the fluidity is like 'someone' was swirling different colors of paint on a turntable in a freezer that got moved later to the greenhouse. It's very hard to discern the patterns of movement shown in older textbooks (pre-2010?) such as ice caught up for multiple years in a full Beaufort gyre, or transported linearly eurasia-ward by a Transpolar drift. (Note currents per se are not shown but rather currents + wind-induced motion.)

There'll be a lot of turnover before the season has finished. This is part of the reset mechanism that Oren mentioned up-forum by which piomas, hycom and others get a clean slate each fall to paint a known ice edge, large areas of open water and FYI with basic thermo, as otherwise persisting mistakes are melted and exported away.

[The animation should be animating but wasn't, even though it fell well within the 700x700 pixel and file size limits. The cure, as it often is, is to crop size down very slightly and save again.]

Thanks for these instructive anims.

Another interesting feature is the loop of thick ice that tracks from northwest of Ellesmore Is;and and out the Fram exit. The remaining thick ice has been squeezed in as primer for the garlic press once the NWP melts out

37
Arctic sea ice / Re: The 2017 melting season
« on: July 04, 2017, 03:28:36 PM »
SST anomaly on July 1st, 2012 vs 2017:

The Pacific side is worse this year which is maybe more important than the the big lead in anomalies in Kara sea in 2012.

38
Arctic sea ice / Re: The 2017 melting season
« on: June 26, 2017, 03:35:29 AM »
81 hour loop June 21-24, Chukchi Sea on the NW Alaskan coast.
Look at all that blue ponding on the right hand side. Small wonder the NASIDC area cratered in the Beaufort/Chukchi.

And the abrupt massaging of the ice edge into a smooth line

39
Arctic sea ice / Re: The 2017 melting season
« on: June 26, 2017, 03:05:57 AM »
Edit: err, having some trouble attaching images. Any tips? I took it straight from the hycom snapshot archive.
The image is probably too large. 700 x 700 pixels should work, width especially is a constraint, try to crop or resize.

There appears to be a certain amount of weirdness in how the site handles gifs. Oversize gifs usually will open in a separate window on clicking but some, like STA's demand to be downloaded for reason I don't understand. This can also happen with gifs under 700 pixels I think, one of 3 animations I posted of Chukchi, Laptev and ESS seas the other day but I haven;t had time or inclination to try to understand the bug or issue

40
Arctic sea ice / Re: The 2017 melting season
« on: June 26, 2017, 02:37:43 AM »
Bill, slightly OT but that means that the loss of sea ice in the Antarctic would have a greater warming effect per square metre, albedo wise, than the loss at the same latitude (north vs. south) in the Arctic?

There's no sea ice below 80S and very little below 75. Wouldn't this lessen the effect?

41
Arctic sea ice / Re: The 2017 melting season
« on: June 22, 2017, 05:06:04 AM »
A few gifs of the Chukchi, ESS and Laptev seas in recent days and there does seeem, as LMV says, to be rmelt ponds appearing across much of the Siberian side, and not just on  the fast ice

42
Arctic sea ice / Re: The 2017 melting season
« on: June 20, 2017, 05:53:56 AM »
In the ESS and Laptev seas meltponds have been appearing on the fast ice but not on adjacent mobile floes. The meltponds appear to be rapidly draining, sometimes they only appear to last a day or 2. So a bay in the eastern ESS where meltponds appeared on June 5 is now in a state of disintegration(first image). The region to its west was showing intensely blue meltponds a few days later, which also soon disappeared leaving a grey discoloured ice(?) within a few days, and is now beginning to crack up.

Now the Laptev seas has bright blue on the fast ice, but mobile ice beside it remains whitish(second image). Why, I don't know, but there is definitely something interfering with the appearance of meltponds.

As for cci-reanalyser rain forecasts, we are now in the season of above freezing temperatures in the arctic, DMI is showing above freezing avg temps above 80N, so if precipitation is coming down, surely it falls as rain except in those areas where it is freezing

43
Arctic sea ice / Re: The 2017 melting season
« on: June 17, 2017, 03:16:41 AM »
If that bomb cyclone eventuates - and its still a long way off - there will be widespread wind including in the Bering, accelerating the inflow of warm water,  and Chukchi seas creating waves, as well as around the cyclone itself . It also drags very warm air in from Siberia. According to GFS 12z run

It is a long way off so unlikely to play out this way, but I posted the image because it seems remarkable for its "oceanic" windiness - a sign of things to come?

44
Arctic sea ice / Re: The 2017 melting season
« on: June 16, 2017, 09:26:26 AM »
The circulation around low pressure systems entering around the Laptev is driving the cold from the residual snow into the Kara and Barents Seas where it can't do much good. Over the next week on climate reanalyser those seas are consistently below freezing whereas the rest of the Arctic will see above freezing temperatures

45
Arctic sea ice / Re: The 2017 melting season
« on: June 14, 2017, 04:42:08 PM »

I believe in the experiment the fissures sealed after the third melt, the first two times the melt water drained away, more slowly the second time.

Thanks. That makes sense and is believable. However, if whatever caused the cracks and fissures  from the beginning causes new ones, then the process resets. If it had been waves vs thin ice, the waves will probably win in long run, as they seem to be reaching deeper into the Arctic now.

Also there are no 100km floes in areas with any dispersal, maybe some 50km in the Beaufort sea, with the odd 10-20km solid floe  in sea of mush elsewhere

46
Arctic sea ice / Re: The 2017 melting season
« on: June 13, 2017, 04:28:18 AM »
I wonder how much of the sea ice anywhere in the Arctic has enough freeboard to allow for melt-ponding. Obviously, everything is whiter this year, but it may just be because there is not much more than snow above the water. If someone has some pics from here and there, they can easily shoot down that supposition.

P.S. A little tangent to this discussion; check this out.
www.bbc.com/news/av/world-europe-38562814/parts-of-greece-have-been-blanketed-in-snow



Photos a few days ago of ice in Fram Strait pushed below the waterline by thick snow don't fill me with confidence. Melt ponds aren't so important if the sea can wash over, especially with fragmentation and dispersal. And all that snow would have retarded thickening when the weather got cold at the end of winter.

SSTs will drive momentum. Anomalous warmth is appearing almost everywhere with the exception of southern Baffin Bay and the cold pool south of it in the Atlantic which . There are some pretty outrageous temperature gradients to fire up the cyclone cannon later on -

47
Arctic sea ice / Re: The 2017 melting season
« on: June 12, 2017, 05:08:50 AM »
This cloudless image from june 10 shows areas of "grey mush" between the large, and bright white icefloes in the Beaufort. What is that stuff?

48
Arctic sea ice / Re: The 2017 melting season
« on: June 12, 2017, 04:44:49 AM »
My apologies to the users, I uploaded the wrong gif. I deleted that post. Here is the one I wanted to share.

This is in the Chukchi Sea area. In 2016 the pack seems a blueish tinge while in 2017 it is completely white. I think the blue is either melt ponds or maybe just ice without snow cover. To me the whiteness of 2017 signals a good amount of snow. I think that is a good sign.

With the absense of meltponds so far t least there is one factor retarding melt. But the 2017 image is still much darker because of all the open water - There's also a lot of ice on the Siberian side that appears greyish, all along the margin of the fast ice and has for months, maybe because its very thin and fractured. I fear absence of meltponds is not going to be enough to save the situation

The 2 images are from june 11 - even if the coast remains ice bound open water has appeared beyond the fast ice already along much of the northern route

49
Arctic sea ice / Re: The 2017 melting season
« on: June 10, 2017, 08:59:30 AM »
Melt appeared immediately in the open water from FJL through the Barents Sea so bottom melt must be going on nearby as well, there's been a fair bit of wind in the region. The image is from June 9  -edit: this area is still showing as solid white on the NSIDC extent chart despite the totally open strip being over 50km wide!

There's also strong wind forecast in the Chukchi for the next day or 2 which will keep the ice retreating

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Arctic sea ice / Re: The 2017 melting season
« on: June 06, 2017, 03:45:56 AM »
It's windier over sea water than ice.

The climate reanalyser/GFS forecasts seem to have been showing  a correlation between the open areas and increased windiness recently. (despite those waters still being near freezing, so I'm not sure how seriously to take it) The latest 12z run it shows at least 30kmh wind all week in the open area in the Chukchi Sea, blowing at the ice, and peaking around 60kmh about 5 days out. The forecasts are garbage that far out of course

A low is also forecast to head into the basin over the  New Siberian Islands in about 60 hours, whose winds intensify, again to around 60kmh, as it heads over the open water nearby. I guess we'll see if this plays out.

Extra waves hammer the ice, but also mix warmer water from below feeding back into more wind (?)

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