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Messages - johnm33

Pages: [1] 2 3 ... 23
1
Developers Corner / Re: Test space
« on: May 18, 2019, 03:41:48 PM »
test gif


2
Developers Corner / Re: Creating Animated GIFs
« on: May 18, 2019, 11:00:51 AM »
That's an interesting combination, shows up the power of the surge in from the Pacific really well. Great stuff.

3
 You need to zoom in on this gif from hycom to see the impressive outburst of freshwater from Jakobshavn around the 11th
Looks like the granular ice in the channel is being finely ground, from sentinel


4
The rest / Re: Brexit...
« on: May 16, 2019, 12:51:17 AM »
I'm a bit disturbed by how well the Brexit party is polling. How many of them are aware that Nigel Farage is thoroughly alt right in his political views, do you suppose? (Not to mention a climate change denialist to boot).
Since this is an election without consequences, the EU parliament is little more than an expensive rubber stamp for the idealogically 'neoliberal' bureaucracy, it is a perfect opportunity to give the idealogical 'neoliberal' professional politicians of both major parties the finger/Vsign/insult of choice, and whilst one may not agree with his politics, whatever they are[?] , his speeches in the EU parliament are quite funny. I'm not sure about the tory side but expect the 'left' to return to 'tribal' voting come the Westminster elections.
Prescience has great value the slog was informed by sources in Brussels and Washington that we [uk] would not be allowed to leave, he recently posted Blast from the past

5
More recent and far better image from polarview I think the distinctive berg is by the bay on the north side, so 12+km and still enough melange being shed to fill the fjord.

I've been reviewing what I think, and realised the more important cill is the 700+m one which lies roughly between the two icebergs in the previous posts image, the 800m contour runs back from here both sides of the channel way upstream.

6
Arctic sea ice / Re: Arctic Ocean salinity, temperature and waves
« on: May 15, 2019, 10:44:25 PM »
Looking again at the break-up north of Greenland, I noticed on hycom th. an almost simultaneous series of internal waves[?] breaking though in Beaufort near Amundsen, then looked at nullschool   and as well as the low in the north Atlantic helping water pass north of Iceland-Faroes there was a distinct drop in pressure just off the coast in Beaufort [10-11]which probably assisted the Atlantic waters inflow and led to the breakaway of the thick ice along the CAA coastline. I can't think of any occasion short of the last few days of the melt-season when that area has looked so vulnerable.

7
The rest / Re: Is Man the "Unnatural Animal?"
« on: May 15, 2019, 05:37:32 PM »
"Really, I don't think there is one human behavior that is unique to humans, not even language or mathematics ( which are learned)."
I can't think of another animal that lives in groups of a size it is not adapted to, iirc humans are wired for about 160 contacts, so groups of maybe 600, it's very unnatural to be surrounded by 'strangers' and yet to have any kind of civilization inevitable.

8
In this post on the Greenland melt season thread one of the links has ice-bridge saying the calving front is now 100m high as the cill hereabouts is 8900m below sea level that suggests to me that the front is bouyant, just.
The front continues to calve and release meltwater[?] in the most recent Polarview the large iceberg just past the northern branch has moved out 2-3km. as a consequence, that leaves the calving front exposed, only slightly upstream of the cill apex, if with the full moon tides seawater penetrates beyond that point then both the bouyancy and melt rate of the submerged ice will increase.

9
Arctic sea ice / Re: Arctic Ocean salinity, temperature and waves
« on: May 13, 2019, 11:51:59 AM »
backwash If a powerful current is flowing and it gets stalled by a tidal surge, for instance rushing up from Kane then I suspect the flow of the current stalls and pressure waves build up and are expressed by upward and sideways movement from the current generating various eddies in the process, then the current resumes, rinse repeat, - - I think?

10
Arctic sea ice / Re: The 2019 melting season
« on: May 13, 2019, 11:32:52 AM »
"What stops the whole thing from continuing to rotate around to Fram Strait and exiting?"
The sheer mass of ice gathered around the pole used to be the answer. To move that south it has to be accelerated by about 22kph per deg. There's much less there and for the whole winter/freeze there's been a steady rotation pushing the densest ice across from the NSI towards anywhere between Fram and Axel Heiberg is., beneath it there's been a freshwater current which has sealed the cracks as it moved and reduced compaction,thus it hasn't had the integrity to close the Nares exit without which there can be no build up of mass around the pole. With enough integrity the 'polar mass' would rotate carrying the dense ice past the exits of Fram/Nares to either crush against the CAA or cruise around the arctic for another year or so, very little evidence of that this year.
New answer, not much. Welcome, did you bring your own popcorn?

11
Greenland and Arctic Circle / Re: The Nares Strait thread
« on: May 12, 2019, 08:02:35 PM »
"any suggestions"? there seems to be a strong current coming in from the Atlantic, I suspect that water has a self similar energetic potential, so as it's forced south, on the eastern side, it spins itself into vortices which reach up to the surface and accelerate the surface water flow on the western side... maybe
Sometimes when there's a powerful throughput standing waves appear south of Kane, never been sure whether these are actually in the water or cloud effects from turbulence.
added
 I guess a decent test would be if the fast ice on the eastern side breaks out from the north.

12
'then What' This looks like a pretty fair template to me, http://charleshughsmith.blogspot.com/2014/04/want-to-fix-incomewealth-inequality.html?m=1
Except instead of 'free' money just change the system to one where everyone gets access to a specific amount of credit at the same %rate as the Fed now charges the banks and corporations $30,000 annually sounds about right, recoup it with a transaction tax at 2.5% for every years worth of debt anyone carries. Have an asset tax of 2.5% on every layer of ownership*. Drop all other taxes[and welfare benefits] and introduce a simple broad based transaction tax, like http://www.apttax.com/index.htm
This would rapidly reduce the 40% of upstream interest charges on all current transactions as old debts at high% were paid off.
*with everyone entitled to the same tax free allowance say $300,000

13
Arctic sea ice / Re: Arctic Ocean salinity, temperature and waves
« on: May 12, 2019, 12:00:21 AM »
Wondering if the more powerful flow through Nares leads to a more powerful backwash as it temporarily stalls/reverses? again and again?

14
Greenland and Arctic Circle / Re: The 'Very Big Chunk' poll
« on: May 11, 2019, 11:14:04 PM »
I saw a documentry years ago where when there was thick ice the locals would cut a hole and go foraging along the coast, beneath the fast ice, I imagine the tides flow in and out of the fjords here leaving the surface ice intact. That'd be my guess for what's going on and driving the eddies in these stunning animations.
 Votings still open! as a not I might want some discount.

15
The output of the glacier continues, a detail from the latest Polarview


 It may be that sufficient ice is flowing down the main channel/falling down from the heights of the ice sheet that we are witnessing the squeezing out of the deep waters present, it seems a lttle early for melt water to be flooding out, or it could be that saline water has kept last seaons meltwater liquid and possibly eased the flow properties of the granular ice in the channel. If the latter is true then as the ice flow above is eased by melt we could witness a very abrupt advance of the calving front which could only be sustained by a widespread local slump of the ice sheet. On the other hand if we are witnessing the consolidation of the ice in the main channel then we may see little change over the next few years, just small advances, calvings and retreats.

16
Greenland and Arctic Circle / Re: Greenland 2019 Melt Season
« on: May 07, 2019, 04:56:24 PM »
The meltwater showing up in Baffin

or zoom in on the hycom animation, https://www7320.nrlssc.navy.mil/GLBhycomcice1-12/navo/arcticsss_nowcast_anim30d.gif

17
"North branch" this image is from 28:03 shows the extent of the winters advance, before the recent calvings. The western side is a different ice stream to the eastern side, which seems to have a variety of contributions to it's flow. It appears to me that the western side is also discharging considerable amounts of meltwater.

 

18
The calving and discharge of water continue


Sentinel with ac 0.4gain 1.7gamma

19
my take is that it then took three years for sufficient seawater ingress to float the basal ice in the first trough and have that break through the overburden of glacial discharge.
The glacier is too thick to float and both GPR & seismic indicate it's solid ice until water-permeated glacial till at the bottom. The meltwater is fresh and it's being dumped into the fjord continuously. Can you find a scientific publication where the authors argue that the saltwater gets to penetrate upstream?
"The glacier is too thick to float" agreed, but here I was only referring to the solid basal ice being lifted/floated from the base of the chasm,  which was very different in character to the granular ice above it.
"publication" no but then in 2014 A-Team was lamenting the fact that none of the data post 2008 had been processed and I assume that's still the case, until it's "established" that there's any space for salt water penetration to occur in why would anyone look for it, this notwithstanding the fact that the calving front remained several km. beyond the cill for more than 7 years, personally I'd regard seawater not making some ingress in that amount of time a near miracle.
I came across the following image which shows a shift in the flow path of the glacier post 2011, which ties in with what I would expect from a 'softening' of the ice in the deepest parts of the channel, and 2011 is apposite since that is the year the ice retreated 4km[?] beyond the cill for the first time. From https://www.nature.com/articles/s41561-019-0329-3

huge changes in the last month or so. Polarview


20
Greenland and Arctic Circle / Re: The Nares Strait thread
« on: May 02, 2019, 09:58:21 PM »
It would be interesting to know the timings of when warmer or more turbulent waters arrive below that 'fishing hole'.

21
Greenland and Arctic Circle / Re: Greenland 2019 Melt Season
« on: May 02, 2019, 09:47:44 PM »
The air is falling about 7000ft./2km and is probably bone dry, one of the few things I know about atmospherics is that as gas pressure increases it rises in temp. or have I got that wrong? Suggests some serious melt.

22
Yesterdays cloudless image from Sentinel shows 2+km movement of the previous calving group, with minimal retreat of the glacier. Looking further down the fjord the next cluster of bergs has moved about 10km putting some distance between the two, and the whole of the winters fast ice is on it's way out the fjord. 
effects:- atmospheric correction, .4 gain, 1.7gamma

23
Arctic sea ice / Re: Arctic Ocean salinity, temperature and waves
« on: April 30, 2019, 11:00:51 AM »
Looking at the above animation and, https://www7320.nrlssc.navy.mil/GLBhycomcice1-12/navo/arcticsss_nowcast_anim30d.gif zoomed fully in on the CAA. It seems that Pac. waters are penetrating along the coast even into Amundsen, and beyond where they are stirring up the fresher deep water, and I assume slowly replacing it. The current flowing through to Lancaster sound via Franklin strait suggests it still has the signature of Pac. energy and has been remarkably persistent, coincident with the Beaufort high. From the north it appears Atl. waters have penetrated the garlic press and are 'colonising' Mclure-Lancaster NWP and mixing there with the Pac. waters.
 If this persists the CAA will melt out and there's going to be nothing to inhibit the freshwater lens of Beaufort passing through to Baffin/Labrador, which in turn suggests much greater penetration of Atl.+Pac. waters into the Arctic.

24
Arctic sea ice / Re: The Rammb Slider Thread
« on: April 19, 2019, 11:19:16 PM »
"Amundsen" that's timely I've been thinking the tides there are about to kick off opening up the coastal ice off Banks driving ice across to Alaska and firing up the gyre. Plus that format gives me the opportunity to loop and adjust speed.

25
The forum / Re: Suggestions
« on: April 19, 2019, 10:58:32 PM »
There's a case to made for allowing high worth contributors to control/edit the threads they create and which they inform/maintain for the general good.

26
Cased closed? no the data is from 2014 outside the fjord they've no way of knowing where the mixing they acknowledge took place.
this image shows that whilst it's possible there may have been some seawater past the cill as early as 2006, the calving front retreated beyond the current 'grounding' line in 2009, my take is that it then took three years for sufficient seawater ingress to float the basal ice in the first trough and have that break through the overburden of glacial discharge. Then there was a major breakthrough and a period of rapid retreat followed, once the second trough was clear, by an ongoing steady avalanche of ice into the fjord, pushing the calving front back to the cill.
This shows the retreat +/- 4k beyond the current 'grounding' line/cill the ice is floating in?



27
lifeblack read this I'd be interested in your opinion it's mostly about tidal effects on the glacier it's movement and calving, bear in mind that due to it's geographical position the tides in Jacobshvn fjord are about 3-4hrs behind the 'natural' tide time so in some sense out of synch with any effects on the glacier. I found nothing in it that confirmed or challenged my view, apart from the step change of melange height above the cill [fig2] which, to me, suggests a deep logjam of melange, and if so then voids enough for tidal seawater/meltwater exchange.

28
I took a walk along the beach today at low tide, the tide was as far out as I would expect for a full or new moon low, and the nights high had swept the whole beach clean, so the above post is more than likely wrong. It's more probable that polarview caught the full flood of the receding tide, but why such extreme tides?

29
An interesting image from polarview today, it looks like there's been a serious flood of basal water break out from beneath the southern branch, which has advanced and calved and this before a big seasonal tide at the weekend. The second collapse feature on the northeast face of the southern branch, just before the bend, is not evident in the image so I await a clear day on sentinel.
  Coincident with this the northern glacier, not branch, which had a 'fan' calving this winter has begun to move too.

30
The rest / Re: Arctic Café
« on: April 14, 2019, 11:59:59 PM »
Solace for those who have visited the political threads.

31
Policy and solutions / Re: Concentrated Wealth and Carbon Emissions
« on: April 14, 2019, 11:36:37 PM »
"What is the goal of corporate power?"
To increase corporate power! Corporations are immortal entities which have no interest in human concerns, who attract the worst amongst us to serve them.

32
Arctic sea ice / Re: "Stupid" Questions :o
« on: April 14, 2019, 11:15:58 PM »
I pretty much agree with that, how many images and over what period crossed my mind, but yes if the water begins to fall/drop into a trough it will organise itself according to it's rotational potential and once established, i imagine, like a tornado it will twist turn and move according to the medium it's passing through. Atlantic waters reaching this far north will have acquired quite a lot of torque since passing 600N, or if you will may not yet have lost the intrinsic torque of being about 1/2 the planets radius away from the axis of rotation [in much the same plane], which will be expressed as it's forced into a coherent stream.

33
Arctic sea ice / Re: The 2019 melting season
« on: April 14, 2019, 10:45:24 PM »
"That net loss in the center of the ice sheet is a little troubling."
 I've mostly been focussed on the losses through Jakobshvn and since there's no extra loss, as ice, above the surface it has to be lost as liquid below?

34
Greenland and Arctic Circle / Re: Bedrock overlay poll
« on: April 14, 2019, 12:34:20 PM »
I think both are quite stunning.

35
The rest / Re: Brexit...
« on: April 13, 2019, 03:56:01 PM »
"So Corbyn" he's f---ed his sjw ideological metropolitan base are all remain[ish] whilst his 'tribal' traditional labour voters in the north are leavers, to get his program of privatisation through, should labour be elected, he needs to be out enough to not be constrained by EU rules, the mans not a natural two faced liar poor sod. It looks like moves are afoot to shift the blame for brexit failure onto him.
Given the long wait before 'article 50'[?] was invoked I suspect there was some serious collaberation between EU and UK bureaucracies on how to thwart the whole process and it seems to be following the sort of course any committee designed strategy does.
 The Slog and some of his regulars, and others, are trying to put together a number of independent Lab./Con. candidates to stand against sitting remainers in those constituences of either party which voted leave.

36
The rest / Re: Brexit...
« on: April 13, 2019, 09:19:51 AM »
I didn't vote, but the actual vote pretty fairly represented my position, more leave than remain.

I voted for joining the common market, no one mentioned surrendering our democracy/sovereignty to a pro German/French bureaucracy in thrall to it's own central bank and that it would eventually build it's own army to crush internal dissent. When I voted to join there was never any actual infromation in any newspaper just endless opinion peices about how their interpretation of the agreements they read were unequivocally positive for us, so no change as far as information lite argument goes for the recent referendum.
 Watching the government surrender every bargaining chip in the first hour of 'negotiations' was quite instructive and the together with the anti-democratic behaviour of the 'remain' camp has put me firmly on the side of no deal brexit and damn the consequences. Hence much to my surprise I find myself in agreement with SteveMDFP as far as the way forward goes.
 The Slog more or less represents my wider view. 

37
Arctic sea ice / Re: "Stupid" Questions :o
« on: April 12, 2019, 10:47:11 AM »
It's very close to the head of Santa Anna basin trough so maybe the waters from Kara are dropping into the basin trough hereabouts?

38
Looking back this is why I formed the view that seawater penetration once past the first cill, at 5K, was more or less unstoppable, the more saline water will always pass over the inner cills and move upstream before it becomes dilute enough to move back towards Disko. The recorded calvings of giant icebergs I suspect are the result of the ice in the deepest part of the trough being floated and breaking through the weight of ice above freeing that space for seawater penetration. There have been enough of these giant icebergs to convince me that some of them have come from inland of sills#1 and #2 from the first link. These blocks of coherent ice have been replace by ice moving downstream, so now in place of a smooth ice surface to grind over there is a melange of broken ice pressed to the depths of the chasms by the weight of the ice above it suffused with saline water.
 Were any cryopegs present beneath these giants? are there more upstream? as would seem probable if they froze from the top down.
 Tidal forces act on landmasses as well as oceans so they will act on ice bodies too the more fluid the ice the greater the potential effect, so it's not just a matter of the tidal waters penetrating and lifting the ice, and all I'm suggesting here is that the calvings and advances occur close to the extreme tidal range at new/full moons. The ice height of 200m ft. above the waters surface means there can't be any actual lifting from tidal penetration but increased melt is another matter.
See this comment too, https://forum.arctic-sea-ice.net/index.php/topic,154.msg56298.html#msg56298
So I'm still of the opinion that the cool saline water in Disko is discharge from the glacier mixed with tidal and possibly cryopeg waters. Is it correct to call it a grounding line if the ice is a composite of melange and seawater? if so ok.

39
Arctic sea ice / Re: Ice edge at minimum poll
« on: April 09, 2019, 03:09:00 PM »
"merge them for you?" thanks but I'll stick with the sparrowhawk.

40
Greenland and Arctic Circle / Re: The Nares Strait thread
« on: April 09, 2019, 02:59:36 PM »
A tidal wave has another meaning altogether, usually nothing to do with tides, I use the term surge because the tides high-high or low-low are about 12.5 hours apart so low-high 6+ so more like a really slow swell. The tides at the Lincoln end of Nares have some peculiar resonances too iirc, and I've yet to understand them. This links to Alert and there's a tide station map for others https://www.tide-forecast.com/locations/Alert-Nunavut/tides/latest
and more here

41
Greenland and Arctic Circle / Re: The Nares Strait thread
« on: April 09, 2019, 10:26:33 AM »

I believe that's the man himself.
"Is this a tidal wave reversing the flow briefly?"
 more surge than wave, the northward movement of the tidal forcing in Baffin gives high tides in Kane and that surge does reach Lincoln sometimes.

42
Arctic sea ice / Re: Ice edge at minimum poll
« on: April 09, 2019, 10:17:39 AM »
I was thinking somewhere between these two but I'll go with green.


43
Arctic sea ice / Re: The 2019 melting season
« on: April 08, 2019, 11:12:26 AM »
"speeding up the whole darned thing" There's constant pressure on the Atl. side trying to force water in to the Arctic, if Nares, and the CAA generally, blocks the surface flow then the fractions below the surface have to force their way out which calls for far more energy. If Nares is flowing freely then the speed of surface waters towards Greenland increases and more flows through Fram too dragging the ice with it. Then more Atl. water flows in and the most energetic fraction moves towards Kara the nursery for thick ice.

44
Arctic sea ice / Re: The 2019 melting season
« on: April 05, 2019, 11:31:21 AM »
"melt ponds" Looks more like weak 2 dimensional ice being pushed around by winds/currents as much opening as there is compaction followed by rapid surface freezing.
"I think this pre-conditioning is setting the stage for an epic collapse of the Beaufort, ESS, and Chukchi come May->June. Kara also looks to be in staunch retreat already although I guess regrowth is still possible there. " I agree.

45
The image below is no.9 from the paper above. My interpretation of it is that the 'zebra' layers are the mobile ice, below that is ice/boulder yedoma, and the interfaces below that already show signs of water penetration. At that depth I believe that even when these images were generated were indications of salt/sea-water penetration. Given that the glacier sheds about 17km of ice every year and that we've had 14 years of tidal penetration since the grounding line moved east of the cill below the current calving front, the eastern penetration of saline water [to the round feature] doesn't seem unreasonable. That all of the yedoma ice has been lifted into the outflow I'm much less confident about, but still consider it possible.
 So I'm guessing the build up of ice at the calving front is just a logjam of bergs waiting to be melted/lifted above the cill hence the pulsed release of bergs associated with tidal extremes.


46
Greenland and Arctic Circle / Re: The Nares Strait thread
« on: April 02, 2019, 04:36:06 PM »
"From the north and northwest", the Beaufort gyre has met the incoming Atl. water in Chukchi/ESS the two counter rotations are forming a thicker band of ice that heads for Ellesmere, some shifts towards Fram some exits Nares some recycles around the B. gyre. Look back at one of unicorns ascat animations.
Right now there's a powerful high in the west of Beaufort and a deep low in Labrador, we've also had persistent 4? days of wind blowing ice towards Banks Is. That implies some Pacific waters will surge in through the strait, so all three exits are busy exporting the freshwater lens and Nares may not settle til' after the new moon.

47
The rest / Re: How Educated are we as a Forum
« on: March 31, 2019, 11:24:38 AM »
Ivory tower? je pons pas. nota nada zilch.

48
Greenland and Arctic Circle / Re: The Nares Strait thread
« on: March 29, 2019, 03:46:42 PM »
"I struggle" me too, one way I think of it is that southern waters have to shed 22kph per deg. to move north, or they will move east, northern waters have to be accelerated by 22kph per deg. to move south or they will move west. Thus Atlantic waters have no business passing through Fram and yet there's a persistent deep Atl. current beneath Petermann.
There's an image of the tides and their hourly rotation through the various amphidromic points in the introduction to this paper. I'm guessing that first the Atl. waters that climb to Barents displace other waters through Fram then when the tidal imperative is at work in Nares water is drawn through Fram to meet it. The meridian shows that the south of Greenland is going to have that imperative arrive at a similar time and there's not time for that surge to pass through Baffin. So I'm sure some variable harmonic exists between the Atl. tides and those in Nares but no real clue what it is. I keep meaning to see what the Fram array says about inflows but haven't got round to it.

49
Thanks for the link, I've speed read it and will try to digest it later.
I'm not sure either, but once the calving front began to retreat into the southern branch we began to see huge bergs with keels being calved which, for me, the simplest source would be deep ice freed from the chasms, and the simplest mechanism would be sea-water penetration beyond the cill in this vicinity. Once that started it's density would would keep the saline water in the deeps filling any voids, and moving upstream into the deeper cuts. These are so far below sea level it's hard to think of a mechanism which would clear them of salt-water so there may be deposits of salt in them, just as below ice yedoma elsewhere. There have been enough keel shaped bergs to account for most of the length of these deep cuts, so my guess is that the fjord is now lubricated by saline waters and there's so much ice falling into the troughs it almost fills them causing a build-up of ice at the 'southern front' cill, liberated now in pulses by tidal action.
This process probably began arond 2004, but once the first basin was cleared of ice the retreat moved swiftly to the next cill around 2012 from there, there are no barriers to the saline water penetrating deep in to the interior [page18 of the pdf]. Also it took a while but the ice on the NE side of the fjord began to speed up it's fall which continues apace, when that slows the flow lines visible on polarwiew images will shift direction to a more southern direction.
 IF my guess is good then the flow of ice will continue to 'flood' the fjord preventing sustained retreat from the first cill of the southern front and on the other hand the ice will be so smashed up when it breaks out over that cill that there will be no sustained advance either apart from winter 'logjams'.

I entertain the possibility that the cold waters in Disko are the basal waters flowing out beneath the glacier.

50
Greenland and Arctic Circle / Re: The Nares Strait thread
« on: March 28, 2019, 04:08:31 PM »
'Variables' going back to the 22nd the mslp set up in the north Atlantic was ideal for moving Atl. water north of Iceland/Faroes and on into Barents with the tidal surges. That water would move at it's own pace but the tidal surge would precede it into the Arctic so I suspect it delivers a double blow first softening up the pack by forcing changes on the waters present then delivering more heat as it follows through [days later?]. All this happening about twice a day, hard to capture with one image. https://earth.nullschool.net/#2019/03/22/2100Z/wind/surface/level/overlay=mean_sea_level_pressure/orthographic=-42.86,82.60,512/loc=-8.568,67.584

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