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A-Team

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Re: MOSAiC news
« Reply #1100 on: September 06, 2020, 10:55:54 PM »
Quite a spectacular photo today of two Mosaic scientists measuring upward heat flux from 60m to the surface. The device isn't identified but is probably a Rockland vertical microstructure profiler (VMP-250 turbulence profiler) of the type used by I Fer in previously published field work, “On Thin Ice: Role of Ocean Heat Flux in Sea Ice Melt”.

It has a buoyancy collar and weight release mechanism that allows it to be operated in depth-to-surface mode. Various probes on the top measure shear, CTD and other properties need to determine upward heat flux towards the cap of relatively fresh water from melt pond run-off and bottom melt. Heat rising from depth is very important to the onset and extent of the freezing season.

The Arctic Ocean has more than enough heat (from incoming Gulf Stream water) to melt the entire icepack several times over. That water would not be significantly present  at the current location of the PS at the depth mentioned. However Atlantic Water has reached a depth of 80m inthe eastern European Basin according to an important recent mooring study by Polyakov et al.

https://journals.ametsoc.org/jcli/article/33/18/8107/353233/Weakening-of-Cold-Halocline-Layer-Exposes-Sea-Ice

gandul

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Re: MOSAiC news
« Reply #1101 on: September 06, 2020, 11:49:32 PM »
The Arctic Ocean has more than enough heat (from incoming Gulf Stream water) to melt the entire icepack several times over.
Let’s mention that the statement above, originating from magazine-style articles like
https://www.sciencemag.org/news/2020/08/growing-underwater-heat-blob-speeds-demise-arctic-sea-ice
forgets to add that this has been the case for thousands of years.

The problem with facts like this thrown out of context here (the stratified nature of the Arctic Ocean permits the ice pack to survive yearlong even when warm Atlantic waters sink beneath) is that many posters keep repeating it as an impending doom, but as I said, it has been the case probably since the last deglaciation.

uniquorn

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Re: MOSAiC news
« Reply #1102 on: September 07, 2020, 12:13:40 AM »
The Arctic Ocean has more than enough heat (from incoming Gulf Stream water) to melt the entire icepack several times over. That water would not be significantly present  at the current location of the PS at the depth mentioned. However Atlantic Water has reached a depth of 80m inthe eastern European Basin according to an important recent mooring study by Polyakov et al.
https://journals.ametsoc.org/jcli/article/33/18/8107/353233/Weakening-of-Cold-Halocline-Layer-Exposes-Sea-Ice
gandul, were you trying to remove context?
edit: be careful, binntho will be checking on you 
« Last Edit: September 07, 2020, 12:42:29 AM by uniquorn »

uniquorn

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Re: MOSAiC news
« Reply #1103 on: September 07, 2020, 12:26:45 AM »
The main tidal component is pretty close to zero at the pole.
Of course, there are other components, but they are amplified by being near land masses and submarine topography.
Probably topical. https://www.nature.com/articles/s41597-020-00578-z.pdf

https://forum.arctic-sea-ice.net/index.php/topic,2417.msg283489.html#msg283489

uniquorn

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Re: MOSAiC news
« Reply #1104 on: September 07, 2020, 12:33:16 AM »
tbuoy update for those interested in data

oren

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Re: MOSAiC news
« Reply #1105 on: September 07, 2020, 02:53:21 AM »
tbuoy update for those interested in data
Very much so, thank you uniquorn.
I note that the negative air temps have managed to visibly reduce the temps inside the ice, which should slow bottom melt rates significantly.

FishOutofWater

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Re: MOSAiC news
« Reply #1106 on: September 07, 2020, 05:16:51 AM »
It's about time for the temperatures to drop and the melt to slow down. The sun is close to the horizon at the pole. Temperatures have been in extra time for too long. Yes, excellent graphic.

The paper cited by A-Team is important. The Laptev sea is undergoing "Atlantification". Note that paper discusses conditions from about 3 years or more back before this summer's surge of Atlantic water. I would expect the Atlantification to get worse this fall and winter in response to the surge of Atlantic water.

Location number 10 on the figure of tides and tidal currents shows very weak tides and currents at the pole. That figure is relevant.

Also note that the GAC tapped into a small fraction of the heat in the Atlantic layer which used to be found at depths below 150m, before Atlantification set in. It takes a persistent very strong storm to mix up heat from that depth. This summer's cyclone didn't cause the extent of mixing caused by the GAC. I have not seen evidence that it mixed up water from the Atlantic water layer.

uniquorn

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Re: MOSAiC news
« Reply #1107 on: September 07, 2020, 01:20:44 PM »
Location number 10 on the figure of tides and tidal currents shows very weak tides and currents at the pole. That figure is relevant.

Agreed, but does the drift speed chart imply a tidal component of the same order of magnitude as that caused by wind?
edit: changed the buoy example to P234 as it is nearer the pole at 89.5083N 142.9698 (latest loc)

« Last Edit: September 07, 2020, 03:21:00 PM by uniquorn »

UCMiami

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Re: MOSAiC news
« Reply #1108 on: September 07, 2020, 03:59:18 PM »
Uniquorn - I am new at trying to understand these buoy charts, but with the T81 chart does the significant shift of the temperature on the right side of the peak in thermistors #35-50 and the shift of constant tail at 1.5 from #75 to #60  suggest the bottom is melting?

uniquorn

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Re: MOSAiC news
« Reply #1109 on: September 07, 2020, 05:36:09 PM »
I think we need someone who's been under ice to answer that definitively. It's part of the melting process but it could be 'slushy ice' saturated with sea water. Have a look at the heat30 and heat120 data. They sometimes provide a clearer picture.

A-Team

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Re: MOSAiC news
« Reply #1110 on: September 07, 2020, 09:17:04 PM »
Quote
FooW:that paper discusses conditions from about 3 yearsback before this summer's surge of Atlantic water. I would expect the Atlantification to get worse.
Right. It's not just Mosaic pushing scientific revelations about the current melting season out to 2023, most 'current' journal articles are 2-3 years  back. There's a terrible mismatch between the rapid rate of Arctic change, the needs of policy planners, and mechanisms for keeping scientific research up to date.

To take just two examples, the biggest news this melt season was shoaling of Atlantic Waters and erosion of stratification described in the two Polyakov papers. Those had 2020 submission dates, spent 8 months in peer review but actually analyzed mooring data from 2004-2018 with the main focus 2016-18.

So what happened in 2019 and 2020? We have near real time satellite coverage and weather reanalysis, so surface ice comings and goings, wind, sea surface temperatures and sea surface salinities along with their statistical anomalies.

What's missing is what we're mostly interested in: worsening conditions below the sea surface. Polyakov has given excellent interviews that clarify tipping point consequences but their impact is diminished by lack of current information. If it was an emergency back then, what is it now?

The main nrt update option seems to be the Mercator Ocean model. It's not at all clear what modern mooring tie points if any have been assimilated there. MO has salinities and temperatures at -30m and -100m but now farther back than 2019. Temperature anomalies are only available for the surface.

It's not correct to attribute the record position of the ice front on the Atlantic side to melt or specifically to atlantification induced melt. A lot of the 'melt' has just been displacement by the wind.

Quote
The Arctic will freeze over every year long after the first BOE
Substitute 'Barents' for 'Arctic' above? The Barents, some 1500 km farther north than the southern Chukchi, has been in near-total BOE year-round for decades.The northern third has ice cover in winter but it apparently none of it forms locally: it is all blown in from the Kara and Arctic Ocean.

The Barents Sea counterpart to the Polyakov papers is S Lind's 2018 review of Barents oceanography which finds an equally dire ongoing atlantification there but for data ending in 2016. It's been cited 131 times since but has not brought up to date.

The story there is fresh water from ice melt is needed to sustain stratification but it's not there any more in the necessary volume. The Barents is approaching terminal atlantification.

Arctic warming hotspot in the northern Barents Sea linked to declining sea-ice import
S Lind  R Ingvaldsen T Furevik
https://www.nature.com/articles/s41558-018-0205-y
https://www.carbonbrief.org/atlantification-arctic-sea-tipping-towards-new-climate-regime

The Arctic has warmed dramatically in recent decades, with greatest temperature increases observed in the northern Barents Sea. The warming signatures are not constrained to the atmosphere, but extend throughout the water column. Here, using a compilation of hydrographic observations from 1970 to 2016, we investigate the link between changing sea-ice import and this Arctic warming hotspot.

A sharp increase in ocean temperature and salinity is apparent from the mid-2000s, which we show can be linked to a recent decline in sea-ice import and a corresponding loss in freshwater, leading to weakened ocean stratification, enhanced vertical mixing and increased upward fluxes of heat and salt that prevent sea-ice formation and increase ocean heat content. Thus, the northern Barents Sea may soon complete the transition from a cold and stratified Arctic to a warm and well-mixed Atlantic-dominated climate regime.
« Last Edit: September 07, 2020, 09:32:38 PM by A-Team »

Glen Koehler

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Re: MOSAiC news
« Reply #1111 on: September 08, 2020, 06:47:21 AM »
     The year dates on the salinity graphic seem to be reversed.  It looks like reverse Atlantification from the first image (2019) to the second (2020).  For example, north of FJF goes from mostly red in 2019 to mostly yellow in 2020.

Sepp

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Re: MOSAiC news
« Reply #1112 on: September 08, 2020, 09:30:19 AM »
Could a higher loss in ice volume result in lower salinity due to more fresh water or is this irrelevant in such depths? (Please delete, if this question is too obviously stupid ;) )

jdallen

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Re: MOSAiC news
« Reply #1113 on: September 08, 2020, 09:55:07 AM »
Could a higher loss in ice volume result in lower salinity due to more fresh water or is this irrelevant in such depths? (Please delete, if this question is too obviously stupid ;) )
Reasonable and not Stupid.

In previous melt seasons possibly, but one challenge the Arctic faces is increasing intrusion of more saline Atlantic and Pacific water, at steadily decreasing depths.  This makes the additional melt less relevant.

What also makes it less relevant is the general decrease in the "lens" of somewhat fresher water that used to persist year over year in the central Arctic and to some degree the Beaufort.  If it contributed to that, additional melt would help slow down the year over year decline in ice.  However under the rapidly evolving conditions we've seen over the last 10-15 years, it is not as helpful a factor as it might have been.  Far better would be for it to have remained ice instead.
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SimonF92

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Re: MOSAiC news
« Reply #1114 on: September 08, 2020, 12:20:48 PM »
     The year dates on the salinity graphic seem to be reversed.  It looks like reverse Atlantification from the first image (2019) to the second (2020).  For example, north of FJF goes from mostly red in 2019 to mostly yellow in 2020.

I think it makes sense, there was a resurgence in ice along the Atlantic side throughout spring 2020
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uniquorn

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Re: MOSAiC news
« Reply #1115 on: September 08, 2020, 07:24:38 PM »
A squadron of new Pbuoys in tight formation
click for movement and lat/lon

added tbuoys
« Last Edit: September 08, 2020, 09:26:03 PM by uniquorn »

A-Team

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Re: MOSAiC news
« Reply #1116 on: September 08, 2020, 09:41:44 PM »
Quote
year dates on the salinity graphic seem to be reversed
Good spotting! The dates are correct though. (It is easy to get them wrong in processing.) So it doesn't quite fit our presuppositions. SimonF92 offers a plausible explanation. It is instructive to see Mercator Ocean putting in observation instead of just modeling away on a trend narrative.

The two slides below show the surface salinity relative to the current AMSR2_AWI ice pack boundary, most of which is cut away in the first slide. Somehow MO has values for not directly observable salinity -- areas that have been under the ice pack for years and years, most notably the band between the NP and SV-FJL.

If their data can be believed, atlantification is much farther along than what one would guess from Atlantic Waters qua western boundary current + some tidal turbulence around the Yermak Plateau (eg Whaler's Bay). If so, there are issues to consider in slightly lower surface and bottom water freezing temperatures.
Quote
For every 5 psu increase in salinity, the freezing point decreases by 0.28 degrees C; thus, in polar regions with an ocean salinity of about 32 psu, the water begins to freeze at -1.8 degrees C -- NSIDC
The key Lind paper discussed in #1110 doesn't foresee total atlantification of the Barents until 2040; however the residual front between Arctic Ocean and North Atlantic waters is quite indistinct in the Mercator Ocean view of surface salinity. While it is somewhat more apparent in the 30m and 100m views, it seems a stretch to call this an effective halocline. With the ice pack edge so far away this year, it's unclear whether ice blown in will provide the necessary volume of fresh water melt to renew stratification.

http://bulletin.mercator-ocean.fr/en/PSY4#4/50.40/-70.80
« Last Edit: September 08, 2020, 10:17:45 PM by A-Team »

A-Team

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Re: MOSAiC news
« Reply #1117 on: September 08, 2020, 10:37:26 PM »
Quote
A squadron of new Pbuoys in tight formation added tbuoys
What do you suppose the scientific objective is, releasing them so close together? The buoys could lie on a regular grid across their base floe and so sample a large area avoiding the potential bias from placing just one buoy at an convenient location by the ship. These buoys are likely to stay together over winter and well into next melt season since the floe will be getting thicker and more stable.

We can do the kriging from the buoy data if they don't get to it but it will need lots of dp or an accurate description from 'Follow' of grid dimensions and buoy numbering (don't hold breath). The output gives continuous values (raster image) interpolated from the initial number of input buoys.

https://www.gislounge.com/danie-krige-kriging/
http://resources.arcgis.com/en/help/main/10.1/index.html#//009z0000006n000000
https://en.wikipedia.org/wiki/Kriging
« Last Edit: September 08, 2020, 10:46:53 PM by A-Team »

glennbuck

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Re: MOSAiC news
« Reply #1118 on: September 08, 2020, 11:15:45 PM »
The ship's mission: to assist the MOSAiC expedition's flagship vessel, the German icebreaker Polarstern, in setting up a network of drifting research stations on the Arctic sea ice.

Drifting on a ship in the middle of the Arctic Ocean, four women listened in quiet disbelief to the rules of a new dress code.

No leggings. No crop tops. No "hot pants." Nothing too tight or too revealing.

In the following weeks, the new rules would breed an undercurrent of resentment.

Expedition leaders denied the rules were meant to single out women. But many MOSAiC participants felt they perpetuated an insidious form of sexism: the idea that women's bodies are a distraction in the workplace and that women are responsible for managing the behavior of men.

The dress code was just one of several factors that participants say contributed to an unwelcoming atmosphere for the women on board Akademik Fedorov.

Problems with harassment were happening before the dress code was announced, raising concerns that the two events might be related. Later in the expedition, participants pointed out inequalities in the division of work assignments between men and women.

All the while, the mission was suffering from gender disparity. Women made up less than a third of the MOSAiC participants on the ship, and only a handful of the mission's senior scientists and engineers.

The breakdown was similar on Akademik Fedorov. The vessel exchanged personnel with the Polarstern several times, but at any given point there were about 25 women on board, compared with about 60 men.

There's hope that the field is becoming more balanced over time. Women now represent more than half the membership in the Association of Polar Early Career Scientists, a global organization of students and early-career academics.

But even as their numbers grow, women still face unique challenges in the field.

On Akademik Fedorov, the dress code was the first issue to raise widespread discussions about gender inequalities.

Before departing, participants were told they should dress warmly when venturing outdoors. They should wear sturdy, closed-toe shoes on the decks and don hard hats in certain work areas. And they must remove dirty boots and jackets before entering the mess hall, for sanitary reasons.

Otherwise, for the first two weeks, participants dressed for comfort when they weren't working outdoors. Athletic clothing, leggings, yoga pants and even shorts were common attire inside the warm corridors of the ship.

That changed with the new dress code.

https://www.eenews.net/stories/1063713099

SimonF92

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Re: MOSAiC news
« Reply #1119 on: September 08, 2020, 11:53:29 PM »
Tight clothing being a "safety issue", due to men onboard being at sea for a long time.

I literally dont even know what to make of that statement. Very sad any of this was allowed to happen.
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uniquorn

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Re: MOSAiC news
« Reply #1120 on: September 09, 2020, 12:11:50 AM »
What do you suppose the scientific objective is, releasing them so close together?
It's possible they are waiting for clear weather to distribute them but why not take some closer data while it's foggy etc.
If they don't redeploy it might be possible to create a more static presentation that shows very small lateral differences. Say, take the middle buoy and subtract its latlon from all the buoys. That would make it possible to maintain a very small focussed area at the loss of drift data. super zoomed delaunay.

Hopefully all genders feel equal on this thread.

FishOutofWater

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Re: MOSAiC news
« Reply #1121 on: September 09, 2020, 04:39:55 AM »
If you ran the Mercator animation at 100m depth for the whole year you would see that the stormy winter with strong cyclonic conditions in the Arctic ocean favored the influx of Atlantic water into the Barents sea and into the Laptev sea along the continental shelf margin. The relatively fresh water on the moved in the direction of the Fram strait. This is what happens when the polar vortex is strong through the winter. Some fresh water stored in the Beaufort gyre is released when the Beaufort high is replaced by frequent cyclones.

The Fram strait has salty Atlantic water flowing in on the European side and fresh Arctic water flowing out on the Greenland side so the picture gets very complicated near the Fram strait. It's three dimensional and a substantial fraction of Atlantic water gets retroflected back down along the coast of Greenland. Perhaps eddies involving retroflected Atlantic water  formed this summer when high pressure caused consistent anticyclonic winds north of Greenland. Perhaps not. It would be interesting to see sounding profiles at locations from Greenland to the pole.

What ever, much has happened over the past 12 months and that Mercator comparison gif shows a general cyclonic rotation of the salty and fresh water masses, not the details of how it evolved.

And about that dress code. Men need to evolve. The situation on board sounds very paternalistic and hostile to women scientists.

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Re: MOSAiC news
« Reply #1122 on: September 09, 2020, 07:30:04 AM »
Any man who spent any time on that ship and harassed women is an insecure little P***y Azz Biiiiiittttccccc ....


Hopefully any man caught being inapropriete is BANNED for life from ever Workin on another scientific expedition.




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FishOutofWater

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Re: MOSAiC news
« Reply #1123 on: September 09, 2020, 01:40:53 PM »
From the story by the EE News reporter it's hinted that harassment may have come from the crew. This may not be a problem of male scientists misbehaving - although they certainly are capable. It doesn't take much extrapolation to conclude that there was a serious leadership problem. The proper response to sexual harassment is not to tell the women how to dress after an episode of harassment. That's blaming the women for bad behavior by the men.

 If the leaders of this mission wanted to have a dress code they needed to suggest it before the mission began so it could be discussed and so women could plan their wardrobes for the trip. Let's be clear - this was a failure of leadership on top of bad behavior by individuals.

Back to the buoys. Those buoys needed to be deployed between Greenland and the pole, not in some tight group near the pole. They may learn something about dispersion or they may be awaiting an opportunity to deploy them on a larger grid but they blew the chance to study the region that is behaving in the most unusual way this year. I'm a geochemist, not an oceanographer, so I'm not an expert on this, but I don't have confidence that Mercator is getting the details right on what's happening between Greenland and the pole. Every model needs data or it's just garbage in, garbage out. This year's low area, extent and thickness north of Greenland was unprecedented, yet MOSAiC powered right through it, apparently without studying what's going on. I guess that they had already made their plans and they weren't going to disrupt them to do new science.

By the way, the EE article implies that A-Team's observations about the PR lady are on point.

I'm hoping that we will see some great research results from this mission in a few years, but I can't help but feel that they missed unique research opportunities. What is obvious is that the management did not empower women scientists. They did a very poor job of planning on how to deal with harassment before the mission began then dealt with it poorly when it happened.
« Last Edit: September 09, 2020, 06:09:14 PM by FishOutofWater »

uniquorn

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Re: MOSAiC news
« Reply #1124 on: September 09, 2020, 03:14:35 PM »
drift update using T78.
Tbuoy temperature data. Not long to wait till core temp drops to allow us to get a clearer idea of where the ice/ocean interface is. updated below
P234 drift speed update

Thinking overnight about the Pbuoy deployment, we know that there were many more local buoys on the first floe. Perhaps they are sharing even more buoy data this time. I haven't had time to calculate any distances yet, but a close array of buoys might be useful for documenting reduction of motion during the early stages of the freeze cycle in relation to other measurements being taken.

Agreed, possibly a missed opportunity with the north greenland gap. Maybe they thought they had to get through it before it closed up.
« Last Edit: September 10, 2020, 10:39:14 PM by uniquorn »

SimonF92

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Re: MOSAiC news
« Reply #1125 on: September 09, 2020, 05:10:29 PM »
drift update using T78.
Tbuoy temperature data. Not long to wait till core temp drops to allow us to get a clearer idea of where the ice/ocean interface is.
P234 drift speed update

Thinking overnight about the Pbuoy deployment, we know that there were many more local buoys on the first floe. Perhaps they are sharing even more buoy data this time. I haven't had time to calculate any distances yet, but a close array of buoys might be useful for documenting reduction of motion during the early stages of the freeze cycle in relation to other measurements being taken.

Agreed, possibly a missed opportunity with the north greenland gap. Maybe they thought they had to get through it before it closed up.

I have been thinking about it too, I know that covid19 has disrupted some of their operations. Is it possible that there was some sort of disruption to crew operation that forced them to deploy the Pbuoys in such a way? Doesnt say much on their twitter.
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A-Team

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Re: MOSAiC news
« Reply #1126 on: September 09, 2020, 07:25:12 PM »
It's turned significantly colder on the 38m mast at the current PS location. The only winds of consequence are westerlies off the AK coast that could still affect remnant ice in the Beaufort.

88.7  110.1 20-09-09 15:00  8 m/s  -7.6ºC

The polar night does not officially set in for another two weeks but daylight is winding down now. "Follow" is showing a snowy scene (depth not reported) but as usual we have no idea what we are looking at or when. There's no news at sea ice ticker and no announcement about the new buoy swarm at meereis.

It's too soon to say if significant science will emerge from all their efforts. While the original vision could not be executed, some of the ad hoc improvisation could have value.  However the inability to fly Polar 5&6 as scheduled was a huge loss in terms of broadening their observational swath..

They could not get timely permission from Canada, US, Denmark or Norway to fly ship-synchronized routes out of Alert, Thule, Nord or Longyearbyen as in past years. Those facilities have to maintain zero tolerance for covid19 introduction given everyone is confined in small places indoors with minimal medical support and difficult options for evacuation and site decontamination.

I wonder if Mosaic with be the last expedition of its type. While it's great to have a ship out there, the cost-effectiveness of new satellites, air-dropped buoys and undersea glider is increasing. A ship can carry large containers full of massive high tech gear but deploying it away from the diesel pollution envelope doesn't work out any more due to extreme ice mobility.

Societally, Nansen and Sverdrup were fully out of touch for three years; Dranitsyn lived in a floe tent for a year on canned food. Nowadays it's hard to find people willing to be offline for even a day despite sauna, pool, fresh cooked meals, two bars and dancing; this got them into 6 legs, attendant resupply complexity, and eventually third-round draft choices for technicians.
« Last Edit: September 09, 2020, 07:34:31 PM by A-Team »

uniquorn

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Re: MOSAiC news
« Reply #1127 on: September 09, 2020, 09:37:02 PM »
First attempt at delaunay triangulation on the close Pbuoys. This only uses the hourly locations. lat/lon scale is in metres.
Lateral movement at this scale is too fast to view the small changes in position so one buoy's lat/lon (in metres) has been subtracted from all buoys. That buoy is at 0,0.

We should be able to tell when freeze sets in.
The 3d version might be interesting on this close set

Adding a fine grid adds another 5MB to the file size. Either there is quite a lot of movement within this 1.44km2 area or we are at the limits of gps tracking this far north. I forgot that the presentation is not square, will look into that (squashed it horizontally).
Data is from iabp The conversion from lat/lon to utm is from plot-svalbard, saved as csv. Delaunay is run in octave. data is attached below as text.

oops, now it's less than 500px (unsquashed)
« Last Edit: September 09, 2020, 11:32:25 PM by uniquorn »

A-Team

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Re: MOSAiC news
« Reply #1128 on: September 09, 2020, 11:19:21 PM »
Taking pixel measurements on the above 11-buoy grid (final frame) and converting them to meters (at 3.26 m/pxl), the grid dimensions came out as shown below. (The x axis should have been rescaled to make it match the y.)

The animation above shows them to be stable in the short term, suggesting they are all embedded in the same floe (likely the same one as the Polarstern). They are not laid out in accordance to any strict geometrical pattern, probably because melt ponds and other irregularities precluded that.

The area came out to 282327 m^2 or about a fifth of a sq km. The situation mimics exactly what Krige had for boreholes in South African gold mining country so his method can be applied directly to whatever the buoys are measuring, ie the yellow below will get more nuanced coloring.
« Last Edit: September 09, 2020, 11:58:51 PM by A-Team »

uniquorn

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Re: MOSAiC news
« Reply #1129 on: September 10, 2020, 10:43:50 PM »
It's probably going to take a while so moving delaunay development to the dev thread

thickness update. t81 may be showing some snow.

p234 drift speed

Niall Dollard

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Re: MOSAiC news
« Reply #1130 on: September 11, 2020, 01:20:04 AM »
It's turned significantly colder on the 38m mast at the current PS location. The only winds of consequence are westerlies off the AK coast that could still affect remnant ice in the Beaufort.



Sub -12 C now:

  88.7  105.8 20-09-10 22:00      -12.4 
  88.7  106.0 20-09-10 21:00      -12.1 
  88.7  106.1 20-09-10 20:00      -12.6 
 
Quote

Societally, Nansen and Sverdrup were fully out of touch for three years; Dranitsyn lived in a floe tent for a year on canned food. Nowadays it's hard to find people willing to be offline for even a day despite sauna, pool, fresh cooked meals, two bars and dancing; this got them into 6 legs, attendant resupply complexity, and eventually third-round draft choices for technicians.



Unless you're Mike Horn - but it nearly killed him. But I did enjoy the images he sent us last autumn.

https://forum.arctic-sea-ice.net/index.php/topic,2886.msg229100.html#msg229100

Unfortunately visual imagery from MOSAiC to the public has been scanty.



A-Team

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Re: MOSAiC news
« Reply #1131 on: September 11, 2020, 10:58:25 AM »
Cold at the Polarstern, balmy in the Beaufort, Chukchi, ESS, Laptev, Kara and Barents.

The two adventurers had internet/sat phone the whole time and expert tech team support for it. Enough to send those pictures, receive weather forecasts and ice maps, have GPS lat lon and communicate with the rescue team on the rented icebreaker about the hopeless ice on the Svalbard side.

The Polarstern also has excellent internet according to the company that provided it with a new type of satellite. However they did not allow scientific staff to use it, only whatsapp on an outside stairwell and iridium if they bought a time card at the ship store.

There were apparently three reasons for this policy: AWI HQ wanted total control of PR messaging, a need for streaming home large data files, and enforcement of team interaction (rather than have everyone hunched over their laptop once back on ship).

Some participants brought their phones and recorded blogs, videos and stills for release on twitter once back home. Only 3-4 people have done that though, Lars K, M Shupe, S Hendricks and C Katlein being the best.

https://twitter.com/ckatlein?lang=en
« Last Edit: September 11, 2020, 11:40:21 AM by A-Team »

jdallen

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Re: MOSAiC news
« Reply #1132 on: September 11, 2020, 07:46:46 PM »
Cold at the Polarstern, balmy in the Beaufort, Chukchi, ESS, Laptev, Kara and Barents.

The two adventurers had internet/sat phone the whole time and expert tech team support for it. Enough to send those pictures, receive weather forecasts and ice maps, have GPS lat lon and communicate with the rescue team on the rented icebreaker about the hopeless ice on the Svalbard side.
<snip>
Suggests to me the ice is in worse shape even than what the expedition team leadership has already shown us.

It will be interesting to see what some of those researchers say and publish when they return.
This space for Rent.

A-Team

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Re: MOSAiC news
« Reply #1133 on: September 12, 2020, 12:36:46 AM »
Mosaic posted a beautiful photo of the new mooring site taken by a small drone on Sunday 06 Sept 2020. Since the Polarstern is 180m in length bow to stern, a grid of those specs can be put over the image to establish a distance scale of 2 pixels per meter.

However the drone was not directly overhead at the time of the photo because the more of the port than starboard side is shown (assuming the smokestack is centered amidship). As usual, all the Exif data has been stripped off the photo: we do not know time of day (sun angle), direction of north, nor height of the drone, nor nadir inclination of the camera.

The location of the Polarstern varied quite a bit that day, ranging from 88.7-8º  113.5-119.0º, so the lat lon at the time of the photo can only be estimated.

Consequently it is not possibly to orthorectify the photo for purposes of measure percent of melt pond area, leads and so forth. They've used Sentinel-2 in past months but that requires fog- and cloud-free conditions and decent sunlight at the time of overpass.

The new road system is visible but just barely. It heads out to 3-4 unlabelled gear depots where oceanographic and meteorological measurements are made. Some sites can be related to earlier ground-level scenes of sampling.

A curious feature of the photo: a swath 600 x 100 m just 'north' of the ship appears to show recent snow covering recently frozen melt ponds. The latter are visible after contrast enhancement. After that correction, the melt pond size and distribution appear fairly homogenous. They are in all stages of drainage and connectivity, well indicated by shades of blue. Black leads of open water and shattered ice cannot be interpreted without knowing how the ship approached the mooring site.

Mosaic's science communication through the ages:
Quote
Goethe 1774: Misunderstandings and lethargy perhaps produce more wrong in the world than deceit and malice do. At least the latter two are certainly rarer.

Heinlein 1941 "You have attributed conditions to villainy that simply result from stupidity."

FishOutofWater

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Re: MOSAiC news
« Reply #1134 on: September 12, 2020, 04:54:12 AM »
But these MOSAiC people in charge aren't stupid. They are control freaks right down to their misogynistic dress code. They did have bad luck concerning the virus, and they deserve to be cut some slack about that, but cutting off normal internet communications while the pandemic was ongoing was a brutal and insensitive thing to do to people concerned about aging parents and children at home.

oren

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Re: MOSAiC news
« Reply #1135 on: September 12, 2020, 09:57:14 AM »
IIRC correctly they posted some image showing people covering melt ponds (or was it a text saying the same?) That ponds are only covered near the ship tells me this is artificial.
In any case I would have thought at this very northern latitude and very late date that ponds should have been top-frozen by now, so these widespread blue ponds are IMHO another attestation to the strength of this melting season.

uniquorn

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Re: MOSAiC news
« Reply #1136 on: September 12, 2020, 04:13:16 PM »
I think we may be too harsh on mosaic. We have had loads of buoy data but it seems few are interested in it (or are willing to share their analysis). 1.4% of viewers can be bothered to look at recent ice temperature data to estimate thickness when it is practically spoon fed to them.
We need to up our own game and get some planks out of our eyes.

A-Team

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Re: MOSAiC news
« Reply #1137 on: September 12, 2020, 06:46:05 PM »
Quote
may be too harsh on mosaic. 98.8% of site visitors can't be bothered to look at ice thickness when spoon fed to them.
Yes but 99.8% won't provide feedback on an improved ice concentration product even when it is solicited. They would rather copy/paste obsolete extent data Provided by Authorities on an untended pipeline whose errors go unnoticed for years.

My sense is that buoy data needs a lot more edu: arrows drawn on stills, longer prose accounts of basics, fewer assumptions that such and such is obvious, tutorials even, sharing of explanations provided by buoy owners. Buoys have a history of bizarre malfunctions; people not specializing in them lack confidence in interpretation. No one ever errs on a forum by providing too much explanation:

https://quoteinvestigator.com/2020/03/01/underestimate/ HL Mencken 1926

The buoys reporting over iridium, international blowback if they had sequestered or encrypted that data. Buoys just reporting over LAN, we don't know how many are not shared at the meereis gallery.

That bow radar was good sharing while it lasted. I don't have a problem with it being done so stupidly but rather with their refusal to fix it.

In terms of dumbing down lat lon to 1 dp, now that took active malice. but it was also stupid because the ship was visible to 4dp on daily high resolution satellite imagery.

After Oct 2019, they never systematically disclosed what sensors were working at what locations at what times, presumably to avoid embarrassment.

A lot of what they did was driven by institutional prestige considerations that trumped any thought of sharing, especially after that truth-telling BBC reporter.

The Polarstern had a 30 year history of publishing a weekly captan's blog. Like everything else not under direct control of PR officers, it had to go. Mosaic was too big; the tail began to wag the dog.

Negotiations before the trip: they got everyone to agree on a central data repository but the price for that was keeping it shut down until 2023 when all interest would be gone. The culture of leisurely publication is deeply entrenched; it's a good fit with scientific escapism and controversy avoidance.

In fairness, a lot of coupled observational time series like the one below do not lend themselves to sharing. The data needs calibration and review first. However there is a middle road not taken -- a full year in to the expedition, this is really the first we have heard about these fancy drones and their mission.

AWI is research foundation of about a thousand staff founded in 1980; it is not a university or educational facility but rather part of the broader Helmholtz Association. The present expedition fits into their organizational chart as shown below.
« Last Edit: September 12, 2020, 09:23:05 PM by A-Team »

SimonF92

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Re: MOSAiC news
« Reply #1138 on: September 12, 2020, 07:34:26 PM »
I think we may be too harsh on mosaic. We have had loads of buoy data but it seems few are interested in it (or are willing to share their analysis). 1.4% of viewers can be bothered to look at recent ice temperature data to estimate thickness when it is practically spoon fed to them.
We need to up our own game and get some planks out of our eyes.

Im working on the stuff from last season but the data is pretty poor to be honest. There are 4 'active' thermistor buoys, but only T78 is providing reliable data at this point. The thickness for that one seems to be 90cm-1m.
Bunch of small python Arctic Apps:
https://github.com/SimonF92/Arctic

FishOutofWater

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Re: MOSAiC news
« Reply #1139 on: September 12, 2020, 07:36:15 PM »
The drone photo is both beautiful and shocking because of the blue water in the ponds apparently on 6 September. Because the basic info identifying the photo has been stripped, I'm left wondering if it was actually taken in the month of September at the pole.

With regard to the new ice concentration product, it takes time to become familiar with new tools, graphics and data sets. I'm not ready yet to comment on it and I'm pretty sure that how it is for other people here.

I have actually been restraining my anger at the Mosiac management.  We live in a period where politicians and "authorities" are gaslighting us. Science is under attack, especially in the U.S., right down to forecasts by the National Hurricane Center and reports by the CDC. Scientists need to respond by interacting with the public in a forthright and honest way - with data and figures that have appropriate identification, quality control and quality assurance. I'm not talking about crazy levels of QA/QC like I dealt with in the nuclear waste research business, but reasonable stuff like keeping the basic identifiers on photos.

I'm retired now but I once managed research projects and grants for the feds. If some group did the bullshit that Mosaic management has done, I would be inclined to never give them another dime if it was may say. What they are doing is undermining the public confidence in science. I don't expect them to share all of their data. Much information may need critical review before it is released to the public. I get that. But don't feed me bullshit and deception like we have given from the leaders of Mosaic.

Yes, the research drones are fantastic. I got excited about drones for research when they were used studying volcanic eruptions in Iceland and Hawaii. Great stuff. Great potential.

A-Team

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Re: MOSAiC news
« Reply #1140 on: September 12, 2020, 08:51:06 PM »
I couldn't find any specs on either drone (such as flight range, flight duration, maximal altitude and kg of payload). The big one has an utterly unsearchable name (Spectra) but appears to be made in India; I can only direct you to their marketing team for further information. However there are no prospects for autonomous flights over any sizable part of the Arctic.

The two working aircraft AWI is currently operating could do a whole lot more more. They don't need the Polarstern down below, being capable of stop-and-go landings for spot ice measurements as was done out of Alert (but not exactly disclosed).

This is very different situation from Greenland where the radar instrument builder required prompt and full public disclosure online of every track. Or NASA satellites -- imagine the uproar if they delayed fire weather release until every possible 2023 publications had been bagged.

Polar 5 is a DC-3 built in 1942 but refurbished as a Basler BT-67 after the AWI acquired the plane in 2007. Without payload, the flying range is around 3900 km, enough for instrumented  transects. Polar 6, another DC-3, was acquired by AWI in 2011. It is doing the thickness transects but not sharing anything about them.

In January 2005, Polar 4 was severely damaged during a rough landing at the British over-wintering station Rothera on the Antarctic Peninsula. It was impossible to repair the plane and now parts are in a museum. Since then, scientific and logistical tasks of polar flights have been performed by Polar 2. In February 1985, the Polar 3 was shot down by guerrillas of the Polisario Front over West Sahara. All three crew members died. It was on its way back from Antarctica and had taken off in Dakar, Senegal, to reach the  Canary Islands.
« Last Edit: September 12, 2020, 09:29:07 PM by A-Team »

uniquorn

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Re: MOSAiC news
« Reply #1141 on: September 12, 2020, 09:31:43 PM »
I think we may be too harsh on mosaic. We have had loads of buoy data but it seems few are interested in it (or are willing to share their analysis). 1.4% of viewers can be bothered to look at recent ice temperature data to estimate thickness when it is practically spoon fed to them.
We need to up our own game and get some planks out of our eyes.

Im working on the stuff from last season but the data is pretty poor to be honest. There are 4 'active' thermistor buoys, but only T78 is providing reliable data at this point. The thickness for that one seems to be 90cm-1m.
Had a look at T81 and the data is challenging. The colder weather is helping at the surface but not really at the ice/ocean interface yet. Dropped to -1.69C on sep10.

uniquorn

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Re: MOSAiC news
« Reply #1142 on: September 12, 2020, 09:38:10 PM »
The drone photo is both beautiful and shocking because of the blue water in the ponds apparently on 6 September. Because the basic info identifying the photo has been stripped, I'm left wondering if it was actually taken in the month of September at the pole.
Air temperature was mostly below 0C at PS location for a week before sep6. The pond water would have to be quite fresh saline.

aug25 was first full day on the floe according to fomo. Pics of fog. A lot of days with fog in awimet weather report
88.7  117.6 20-09-06 12:00    8  100     -2.8  8  2  99  0372
03 -- clouds developing 72 -- intermittent moderate snow
The camps and tracks look quite well developed.
« Last Edit: September 12, 2020, 10:22:47 PM by uniquorn »

uniquorn

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Re: MOSAiC news
« Reply #1143 on: September 12, 2020, 10:01:12 PM »
Quote
My sense is that buoy data needs a lot more edu: arrows drawn on stills, longer prose accounts of basics, fewer assumptions that such and such is obvious, tutorials even
You're probably right. Arrows on things no one looks at. Post some buoy data once a month.

oren

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Re: MOSAiC news
« Reply #1144 on: September 13, 2020, 12:54:42 AM »
Re this thread's stats, bear in mind many people read and are interested but do not have much to contribute and do not wish to clutter the thread.
Often thumbnails are enough so view counts may mislead.

dmarcus

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Re: MOSAiC news
« Reply #1145 on: September 13, 2020, 04:57:57 AM »
Oren points out that people may read but not post, and may look at the thumbnails of the graphics but not open them up and thus not get counted as having viewed the graphic. I can confirm anecdotally that Oren is correct. I am exactly such a person.

HapHazard

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Re: MOSAiC news
« Reply #1146 on: September 13, 2020, 07:18:00 AM »
Same here. I rarely open graphics, as the thumbnails are pretty much always good enough.

sja45uk

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Re: MOSAiC news
« Reply #1147 on: September 13, 2020, 09:29:19 AM »
[quote
Air temperature was mostly below 0C at PS location for a week before sep6. The pond water would have to be quite fresh saline.
I don't think meltwater ponds can be saline due to brine rejection, so either it must be fresh water or actually saline ocean water?

Tor Bejnar

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Re: MOSAiC news
« Reply #1148 on: September 13, 2020, 05:31:48 PM »
A 'true' doughnut-shaped 'melt pond' would be 'pure' sea water.  A shallow melt pond on a thick cold (at its core) floe will be mostly fresh (but maybe too saline for drinking).  In between these extremes there will be degrees of salinity., depending on how much mixing occurred.  Even honeycomb ice (which I know about from lake ice) will inhibit mixing some.
Arctic ice is healthy for children and other living things.

A-Team

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Re: MOSAiC news
« Reply #1149 on: September 13, 2020, 05:54:43 PM »
Quote
salinity/freshness of melt ponds varies
Right. It is not an either/or situation. Measured PSU (practical salinity units) can vary from near zero to 35 from pond to pond (ie fresh to brackish to salty) depending on drainage and connectivity to other ponds and open leads, possibly stratified by depth if dense brine channels become exposed. Brine is partially extruded upward onto newly formed ice -- it does not all sink out the bottom. Arctic FYI is generally too salty to supply drinkable melt water to humans. The city limit is 1000 ppm or about 1/35 of sea water.

https://www.engineeringtoolbox.com/water-salinity-d_1251.html

Since only 10's of cm of very low snow-water-equivalent snow fell this year along the Polarstern's route and that rapidly redeposited in the lee of pressure ridges, it's clear that an observed landscape of meter-deep melt pond was not filled with snow melt but rather with in situ ice melt.

A whole lot more is written about summer melt ponds than about what happens to them over the winter and spring. In a scene like the north pole, half the August landscape was melt ponds -- and not superficial ones at that. It follows the SYI will be very pocketed with them in the spring. None of this shows up in 'volume' models.

Yes it all freezes but depending on how fresh, brackish or saline it was, it never really "becomes one" with the ambient ice that matured but never melted. The ice retains aspects of its history; it never becomes one big crystal. Melt ponds have been around since forever but the issue today is the extent of ice heterogeneity -- it's gotten much greater. None of this shows up in satellite altimetry. It's often assumed for convenience that the ice pack is in local buoyancy equilibrium but it isn't really.

Since the freezing/melting point changes with salinity from 0ºC to -1.8ºC, floes wilt melt unevenly given their embedded melt ponds and false bottoms. If a melt pond began as brackish or salty, it will develop its own brine; if it never established a drain, that brine may become trapped. Brine reaches its eutectic point at −21.2 °C at which point it is 23.3% salt by mass.

https://www.britannica.com/science/seawater/Density-of-seawater-and-pressure
https://antoine.frostburg.edu/chem/senese/101/solutions/faq/saltwater-ice-volume.shtml

And don't be fooled by oceanography jargon. They'll talk about a giant pool of 'fresh water' in the Beaufort Gyre when in point of fact, there isn't any at all. The somewhat lower salinity equates to a certain volume of hypothetical pure fresh water needed to be added to the Beaufort Sea to lower the psu. But observed could equally well have been attained with brackish.

"Dimethyl sulfide (DMS) production in the northern Arctic Ocean has been considered to be minimal because of high sea ice concentration and extremely low productivity. However, we found DMS concentration (1–33 nM) in melt ponds on sea ice at a very high latitude (78°N) in the central Arctic Ocean to be up to ten times that in the adjacent open ocean (<3 nM). We divided melt ponds into three categories: freshwater melt ponds, brackish melt ponds, and open saline melt ponds. Melt ponds from each category had different formation mechanisms and associated DMS contents. Closed brackish ponds (salinity of >20) had particularly high DMS concentration. Water in brackish ponds was mixed with open ocean water in the past via a hole at the bottom of the floe that kept the pond open to the ocean; therefore, unlike freshwater melt ponds, brackish ponds became sites of DMS accumulation.

https://pubs.rsc.org/en/content/articlelanding/2019/em/c9em00195f#!divAbstract high DMS

In sea ice, interconnected pockets and channels of brine are surrounded by fresh ice. Over time, brine is lost by gravity drainage and flushing. The timing of salt release and its interaction with the underlying water can impact subsequent sea ice melt. Turbulence measurements 1 m below melting sea ice north of Svalbard reveal anticorrelated heat and salt fluxes. From the observations, 131 salty plumes descending from the warm sea ice are identified, confirming previous observations from a Svalbard fjord. The plumes are likely triggered by oceanic heat through bottom melt. Calculated over a composite plume, oceanic heat and salt fluxes during the plumes account for 6 and 9 % of the total fluxes, respectively, while only lasting in total 0.5 % of the time. The observed salt flux accumulates to 7.6 kg m−2, indicating nearly full desalination of the ice. Bulk salinity reduction between two nearby ice cores agrees with accumulated salt fluxes to within a factor of 2. The increasing fraction of younger, more saline ice in the Arctic suggests an increase in desalination processes with the transition to the “new Arctic”.

https://os.copernicus.org/articles/14/127/2018/os-14-127-2018.html brine plumes by Svalbard

In the summer months, melt water from the surface of the Arctic sea ice can percolate down through the ice and flow out of its base. This water is relatively warm and fresh compared to the ocean water beneath it, and so it floats between the ice and the oceanic mixed layer, forming pools of melt water called under-ice melt ponds. Sheets of ice, known as false bottoms, can subsequently form via double diffusion processes at the under-ice melt pond interface with the ocean, trapping the pond against the ice and completely isolating it from the ocean below. This has an insulating effect on the parent sea ice above the trapped pond, altering its rate of basal ablation.

https://ui.adsabs.harvard.edu/abs/2016AGUFM.C43B0741F/abstract under-ice melt ponds"
« Last Edit: September 14, 2020, 01:40:39 AM by A-Team »