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Author Topic: Arctic Ocean salinity, temperature and waves  (Read 101952 times)

b_lumenkraft

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Re: Arctic Ocean salinity, temperature and waves
« Reply #300 on: June 22, 2019, 11:40:52 AM »
30m 100m Mercator model, 01.06 to 21.06.

Atlantic waters are close to penetrating the Beauford Gyre.

(Thank you Uniquorn for the correction)
« Last Edit: June 22, 2019, 03:12:33 PM by b_lumenkraft »

uniquorn

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Re: Arctic Ocean salinity, temperature and waves
« Reply #301 on: June 22, 2019, 03:07:54 PM »
That looks like 92m salinity. jun16 shown here with noaa bathymetry.
edit: chukchi plateau keeping most of the atlantic water away for now,
 unless you mean along the CAA
« Last Edit: June 22, 2019, 05:07:55 PM by uniquorn »

TeaPotty

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Re: Arctic Ocean salinity, temperature and waves
« Reply #302 on: June 22, 2019, 06:05:20 PM »
30m 100m Mercator model, 01.06 to 21.06.

Atlantic waters are close to penetrating the Beauford Gyre.

(Thank you Uniquorn for the correction)

Hey b_lumenkraft, do you have a link to that animated arctic SST map you posted?

b_lumenkraft

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Re: Arctic Ocean salinity, temperature and waves
« Reply #303 on: June 22, 2019, 06:36:54 PM »
Hey b_lumenkraft, do you have a link to that animated arctic SST map you posted?

That's salinity though, but sure! :)

http://bulletin.mercator-ocean.fr/en/PSY4/animation

FishOutofWater

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Re: Arctic Ocean salinity, temperature and waves
« Reply #304 on: June 22, 2019, 09:17:25 PM »
That salty Atlantic water cools and sinks at the 300m level. The water doesn't penetrate the Beaufort gyre, but it does mix at depth with the cold fresher water that exits the gyre  and slowly moves towards the Fram strait at depths below 300m.

http://bulletin.mercator-ocean.fr/en/permalink/PSY4/animation/3/20190101/20190621/2/4

The sea bottom topography of the Arctic ocean and seas plays a key part in controlling the transport of salinity and heat in Arctic waters.

b_lumenkraft

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Re: Arctic Ocean salinity, temperature and waves
« Reply #305 on: June 22, 2019, 09:44:26 PM »
Thanks, FOOW.

I guess i need to look more at these things. Never noticed it spins counterclockwise in this depth.

Here is the linked data as a GIF, speed up.

uniquorn

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Re: Arctic Ocean salinity, temperature and waves
« Reply #306 on: June 22, 2019, 10:13:10 PM »
thankfully it doesn't (yet). Mercator salinity 318m, jan1-jun21, 32days/sec. (not optimised)
Maybe an ezgif optimisation problem or an accidental reverse?
Still looking forward to more dates on your animations ;)
« Last Edit: June 22, 2019, 10:19:08 PM by uniquorn »

b_lumenkraft

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Re: Arctic Ocean salinity, temperature and waves
« Reply #307 on: June 22, 2019, 10:19:12 PM »
I'm very confused right now.  ???

Kinda late here, will check tomorrow what's the problem with ezgif.

FishOutofWater

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Re: Arctic Ocean salinity, temperature and waves
« Reply #308 on: June 23, 2019, 04:31:39 AM »
That part of the ocean is confusing. There are 2 major factors to consider. One is the Coriolis effect. Pacific water entering the Arctic from the Bering strait tends to turn right, thanks to the Coriolis effect which is related to the conservation of angular momentum and the vorticity of water masses. Fresh water from Siberian rivers tends to hug the Siberian shores if it is moving counterclockwise. Likewise, incoming salty Atlantic water tends to hug the Siberian continental shelf.

It all turns into a spinning mess when the waters meet in the Chukchi sea. Note that the Alaska coastal current carrying Pacific water is moving in the opposite direction from the water and ice in the Beaufort gyre. When the Beaufort high is intense there is no ACC. Warm salty water from the Atlantic layer upwells along the shelf margin when the easterly winds are strong and persistent, often in the month of May. The ACC returns, typically this time of year, when the easterly winds die down near the coast.

And that's not all. This is also a part of the Arctic where water "densifies" and sinks to considerable depths. So it's no wonder the animations are confusing you.

b_lumenkraft

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Re: Arctic Ocean salinity, temperature and waves
« Reply #309 on: June 23, 2019, 08:33:30 AM »
Thanks so much, FOOW! I bet this post is not only useful for me. :)

uniquorn

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Re: Arctic Ocean salinity, temperature and waves
« Reply #310 on: June 26, 2019, 04:02:37 PM »
update on whoi itp110. Only 3 or 4 floes away from open water now. No surprises in the charts yet. Perhaps the temperatures above 80m depth are starting to rise a little. The profiler is struggling to move from depth today probably due to high drift speed. https://www.whoi.edu/page.do?pid=163197
animation of temp/salinity, day158-177.(jun7-26)
whoi itp110 profile, jun26
worldview terra modis approximate location, jun19-26
« Last Edit: June 26, 2019, 04:15:31 PM by uniquorn »

uniquorn

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Re: Arctic Ocean salinity, temperature and waves
« Reply #311 on: June 27, 2019, 01:48:03 PM »
Prompted by Brigantine's post in the buoys thread I finally got around to running the numbers on whoi itp103. A lot of data as the profiler does 2 or 3 0-250m runs in between the 0-800m. Only showing 0-250, both up and down, in the animation below and no attempt to match the data with location. Some interesting turbulence here and there.
Interesting too that itp103 drift track roughly replicates the ice lift off from the caa.
whoi itp103 location, internal temperature, drift speed and profile for comparison. https://www.whoi.edu/page.do?pid=163356

uniquorn

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Re: Arctic Ocean salinity, temperature and waves
« Reply #312 on: June 27, 2019, 03:32:59 PM »
mercator sea temperature 0m jun1-26, laptev-kara

uniquorn

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Re: Arctic Ocean salinity, temperature and waves
« Reply #313 on: June 27, 2019, 10:04:12 PM »
whoi itp104 temperature and salinity, 0-250m, up to jun27.
whoi itp104 location/profile, jun27 for comparison   https://www.whoi.edu/page.do?pid=163376
Tends to confirm mercator model increase in salinity 0-50m as the buoy heads further north
Why not cane the computer while it's super hot?

uniquorn

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Re: Arctic Ocean salinity, temperature and waves
« Reply #314 on: June 27, 2019, 10:54:45 PM »
caa-cab crack, jun24-27 https://go.nasa.gov/31XrAmH
unihamburg amsr2-uhh apr29-jun26
« Last Edit: June 27, 2019, 11:15:03 PM by uniquorn »

johnm33

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Re: Arctic Ocean salinity, temperature and waves
« Reply #315 on: June 28, 2019, 09:51:53 AM »
Maybe something maybe nothing, I was looking at hycom beaufort ice strength gif, towards the end the ice appears to change state and is no longer able to sustain cracks, that is evidence of internal waves.

and looking at A.H.s most recent gifs on the Nares thread suggests the same

uniquorn

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Re: Arctic Ocean salinity, temperature and waves
« Reply #316 on: June 28, 2019, 01:05:50 PM »
https://en.wikipedia.org/wiki/Internal_wave
Thanks. Mostly floes up to 80N. Fine fractures further north. Ice with, apparently, little compressive strength. Last year looks similar though
https://www7320.nrlssc.navy.mil/GLBhycomcice1-12/navo/beaufortstrength_nowcast_anim365d.gif
Quote
Internal waves are gravity waves that oscillate within a fluid medium, rather than on its surface.[1] To exist, the fluid must be stratified: the density must change (continuously or discontinuously) with depth/height due to changes, for example, in temperature and/or salinity. If the density changes over a small vertical distance (as in the case of the thermocline in lakes and oceans or an atmospheric inversion), the waves propagate horizontally like surface waves, but do so at slower speeds as determined by the density difference of the fluid below and above the interface. If the density changes continuously, the waves can propagate vertically as well as horizontally through the fluid.
worldview aqua modis jun27, heavy contrast (click for default)

uniquorn

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Re: Arctic Ocean salinity, temperature and waves
« Reply #317 on: June 28, 2019, 01:18:44 PM »
While it's all set up here is whoi itp105 temp/salinity 0-250m  https://www.whoi.edu/page.do?pid=163456
edit:wasn't expecting that temperature spike, though I see it on the profile now.. ;)
« Last Edit: June 28, 2019, 01:28:22 PM by uniquorn »

uniquorn

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Re: Arctic Ocean salinity, temperature and waves
« Reply #318 on: June 28, 2019, 03:15:22 PM »
update on whoi itp110. https://www.whoi.edu/page.do?pid=163197
worldview image of local area https://go.nasa.gov/31VURyl
« Last Edit: June 28, 2019, 03:37:28 PM by uniquorn »

uniquorn

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Re: Arctic Ocean salinity, temperature and waves
« Reply #319 on: June 28, 2019, 03:31:22 PM »
whoi itp109 starting to show some temperature change. https://www.whoi.edu/page.do?pid=163196

Bruce Steele

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Re: Arctic Ocean salinity, temperature and waves
« Reply #320 on: June 29, 2019, 01:04:37 AM »
Uniquorn, I was looking at itp110 data for their SAMI which measures pCO2 and it appears several things have happened over the last couple weeks as the itp bouy switched direction . There was some warm pacific summer water that is the red colors on the temp/salinity contours,  the pCO2 increased as would be expected with an inflow of pacific water, the salinity jumped at the depth of the SAMI and there is a huge shift in PAR. Photo Active Radiation
https://www.researchgate.net/post/Can_I_convert_PAR_photo_active_radiation_value_of_micro_mole_M2_S_to_Solar_radiation_in_Watt_m22

So even though the bouy hasn't hit open water a very large jump in solar radiation has already occurred.
https://www.whoi.edu/page.do?pid=163197
Here is the SAMI info for itp 110


uniquorn

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Re: Arctic Ocean salinity, temperature and waves
« Reply #321 on: June 29, 2019, 10:38:06 AM »
Thanks Bruce Steele. The SAMI is mounted at 6m depth.

Bruce Steele

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Re: Arctic Ocean salinity, temperature and waves
« Reply #322 on: June 29, 2019, 05:04:35 PM »
I looked around for more info on PAR ,interested in what to expect at various depths. I found this graph of PAR values in the Arabian Sea.

https://www.hindawi.com/journals/ijocean/2014/279412/fig3/

I made a mistake about changes in salinity , sorry. I am interested in these PAR measurements because they can be converted to watts per meter and so reflect a value for insolation. I am suprised  that the PAR values at 6 meters under broken ice is as high as it is and seems comparable to values in the Arabian Sea.

uniquorn

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Re: Arctic Ocean salinity, temperature and waves
« Reply #323 on: June 29, 2019, 09:22:25 PM »
no prob. I'd be grateful for anything 'plain english' you can find. The constant 6m temperature chart is already a big step forward :)

uniquorn

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Re: Arctic Ocean salinity, temperature and waves
« Reply #324 on: June 30, 2019, 01:39:15 PM »
update on the shear fractures north of fjl extending beyond 86N. Worldview aqua modis, jun29-30, heavy contrast. click to run. Default here https://go.nasa.gov/2XaAR7d
Looks different in polarview sentinel1 but the polynyas are clearly visible.
Detected also on unihamburg amsr2-uhh, jun29, default and heavy contrast.
added piomas jun15 for good measure
« Last Edit: June 30, 2019, 04:54:03 PM by uniquorn »

Shared Humanity

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Re: Arctic Ocean salinity, temperature and waves
« Reply #325 on: June 30, 2019, 02:46:00 PM »
Due to ice drift from the CAB, the ice north of FJI and Svalbard is in remarkably better shape then years past. It will be interesting to see where the ice edge is at the end of the melt season. I believe this region of the Arctic is key to how close we end up to the 2012 minimum.

uniquorn

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Re: Arctic Ocean salinity, temperature and waves
« Reply #326 on: June 30, 2019, 02:56:09 PM »
I think the ice north of fjl is thinner than most previous years largely due to the rapid southerly drift and fram export causing fracture and refreeze over the last freezing season and this melting season.

Here is a look at mercator sea surface height, sea temperature and salinity, pacific side, 0m, mar19-jun29
missing 0430 ssh and 0630 ssh is a forecast, oh well...
« Last Edit: June 30, 2019, 03:16:35 PM by uniquorn »

johnm33

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Re: Arctic Ocean salinity, temperature and waves
« Reply #327 on: June 30, 2019, 08:26:59 PM »
I was thinking about Chukchi/Ess, theres a new moon building up the tides coming through the strait, and developing lows just in/out of the Arctic, given that any water making the journey is probably energetically tuned to 10deg further south, so 1/6 further from the polar axis, when it arrives it will, if my guess is good, add turbulence wherever waves form, so could do a lot of damage on the shelf. Once it drops into the deep eddies will form and damage the ice further in, if  there were no poweful lows on the Atlantic side my guess would be it flows west but since it looks like increased flow in from the Atlantic is all I expect is an acceleration of flow out through Fram/Nares/Caa, if it's mainly the latter that will draw the Pacific water towards it and do a lot of damage there in a couple of weeks time. As it stands it looks like ESS gets hammered.
most recent amsr2, 02:07 nullschool

Bruce Steele

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Re: Arctic Ocean salinity, temperature and waves
« Reply #328 on: June 30, 2019, 10:15:01 PM »
I found this SAMI from completed ITP missions. Itp 69 included a SAMI and a temperature chart.
The SAMI didn't work for long but the temperatures never rose to the -.8 that itp 110 is currently reading.

https://www.whoi.edu/page.do?pid=163476

uniquorn

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Re: Arctic Ocean salinity, temperature and waves
« Reply #329 on: June 30, 2019, 11:13:40 PM »
@Bruce, looking at the drift track itp69 followed the 80N line so it probably wouldn't have been close to open water during time the sami was working. That 50m warm layer is quite thick on the profile in 2013/14 though.

@John, itp107 is on the edge of the chukchi plateau. The profiler is hardly moving but I grabbed what I could from it, between 180-300m, over the last 86 days. If the data means anything it's having a rough time of it. The microcat and sami, mounted at 6m depth, are still working and both show a ~0.2C rise over the last 20 days. Also a big spike on day 490.
Worldview terra modis view of approximate location jun30 https://go.nasa.gov/2X8dkny
whoi itp107 drift track, microcat and sami, jun30ish
whoi itp107 location, temperature and salinity, day96-181(jun30) click to run

edit: Could the sami readings be used as a proxy for ice thickness? I suppose not with a spike like that. Thinking about it, the profiler is probably being dragged along the ocean floor. In a few more days it might reach deeper water.
edit2: Temperature spike was roughly when it hit the chukchi plateau on day125 (490-365)
2019  125.00054  -154.4100  76.4394
« Last Edit: July 01, 2019, 12:04:38 AM by uniquorn »

johnm33

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Re: Arctic Ocean salinity, temperature and waves
« Reply #330 on: July 01, 2019, 02:01:17 AM »
107, the bathymetry thereabouts is extremely complex, it's clear we have increased flows coming in from the Pacific, it's likely that a significant fraction of that water is falling into the deep east of the plateau, I guess that general shifts in the whole body of water creates complex tornado like vortices with shear zones at salinity thresholds, akin to refraction, whilst the vortices seek out the deepest 'holes' ... expend their energy and die/to achieve equilibrium. That in contrast to the relative calm on the surface which anchors the bouy somewhat like a reverse sea anchor.

microcat and sami I'm gonna run with Bruces take until i think I  have any insight that might help.
ice thickness, Until the ice begins to react in some logically transparent way I have to believe it's a complex mix of plates with no keel and lets say bottles which are mostly keel, the big plates transition to bottles and the shrinking bottles transition to small plates, and they're all constrained by their surroundings until they're not. We may see them sorted by the passing waves. So I'd guess there's something to be learned about what near surface/surface waters are running through the area  from the bouys, something else to think about.

FishOutofWater

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Re: Arctic Ocean salinity, temperature and waves
« Reply #331 on: July 01, 2019, 03:27:56 AM »
That summer water layer is a key to understanding why the Beaufort sea has turned into a killing zone for thick ice rotated in from the CAA. Over the past several decades the amount of heat stored over the winter in the summer layer has increased substantially. There's a positive feedback now with more open water in late spring and more solar heat taken up by open water.

All that shattered and dispersed ice that we see now in the Beaufort sea is going to melt out quickly under the combined effects of sunshine, open water that took up early heat and heat stored over winter in the summer water layer.

Pragma

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Re: Arctic Ocean salinity, temperature and waves
« Reply #332 on: July 01, 2019, 07:11:06 AM »
1.3 m ~ 4.4 feet. I took a lot of grief last night for suggesting the "surge" through the Strait would be maintained to the ice front.

I confess to being uncertain as to what happens dynamically at the water / ice interface but I'm not confident that anyone here thus far has the answer to that.

I'm sticking with my gut here and suggesting that there is a real possibility that a LOT of (warm) water goes over the top.of the ice edge.
Rich:

For the sake of everyone on the forum, would you please look up the definition of the word "swell" in the context of "ocean swell"?

When a chart or met forecast talks about "5 foot seas", they mean 5 foot waves.
When someone refers to 5 foot swells, they also mean 5 foot waves.

Swells are not surges. Swells are waves. They are up and down motions of a body of water, so a 5 foot swell has a peak to trough height of 5 feet, or plus and minus 2.5 feet from the average water height. The term "swell" typically applies to long slow waves. In other words, a long wavelength, or the distance between successive peaks. They are associated with large bodies of water, usually oceans. Shorter wavelength waves are referred to as chop or choppy waves.

You did not get grief last night as much as you had a bunch of knowledgeable people trying to explain that you were misinterpreting charts and confusing terms, among other things.

It appears that those sincere efforts have been in vain.

Rich

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Re: Arctic Ocean salinity, temperature and waves
« Reply #333 on: July 01, 2019, 08:14:46 AM »
Pragma...I'm happy to continue the discussion here.

I understand the distinction between a swell (wave) and a surge. Nevertheless, I persist. Why is that?

In the event of a surge, how would the software which is informing of us a "swell" differentiate a surge from a swell? To assume that there is sufficient intelligence to make that differentiation would be a bad assumption on my part.

At this point in time, I'm going to assume that characterization of swell is accurate. My gut understanding is that the volume of water coming through the Strait SO FAR is insufficient to sustain a surge all the way to the ice front.

But this is not a one day phenomena and there are many factors to consider in making a judgement as to the potential for a genuine surge.

1) The long "fetch" of the tail winds in the Pacific.

2) The duration , consistency and strength of the wind field.

3) The wind field within the Arctic which is concentrating any buildup of water on the Asian side of the Arctic. It's blowing from the Beaufort toward the ESS.

4) The uncertainty of what happens at the ocean / ice interface.

The conventional wisdom of the forum is that a surge is impossible. I'm trying to explore the constraints of that assumption.

If you want to debunk the possibility of a surge, there should be some math which suggests the volume of water required to produce one in a given location and demonstrating that the current environment doesn't have the possibility of producing it

5 people on ASIF saying that they don't consider it possible is hardly scientific, no?

binntho

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Re: Arctic Ocean salinity, temperature and waves
« Reply #334 on: July 01, 2019, 08:35:26 AM »
Pragma...I'm happy to continue the discussion here.

I understand the distinction between a swell (wave) and a surge. Nevertheless, I persist. Why is that?

In the event of a surge, how would the software which is informing of us a "swell" differentiate a surge from a swell? To assume that there is sufficient intelligence to make that differentiation would be a bad assumption on my part.

Why would it make any difference if it is a surge and not a swell? Surges are very common and do not in any way imply lateral movement of water. Surges are created by pressure differences, when pressure goes down, the ocean surface goes up, but there is no lateral movement of water!


At this point in time, I'm going to assume that characterization of swell is accurate. My gut understanding is that the volume of water coming through the Strait SO FAR is insufficient to sustain a surge all the way to the ice front.


There is no volume of water coming through the Bering Strait connected to any surge. Surges are not lateral movements of water, but pressure-induced vertical movements of water.


But this is not a one day phenomena and there are many factors to consider in making a judgement as to the potential for a genuine surge.

1) The long "fetch" of the tail winds in the Pacific.

2) The duration , consistency and strength of the wind field.

3) The wind field within the Arctic which is concentrating any buildup of water on the Asian side of the Arctic. It's blowing from the Beaufort toward the ESS.

4) The uncertainty of what happens at the ocean / ice interface.


There is no uncertainty here. Surges and waves are an everyday occurrence at the ice edge, and never does the water flow over the ice. Never. The ice stays on top and moves with the waves and surges and what have you.


The conventional wisdom of the forum is that a surge is impossible. I'm trying to explore the constraints of that assumption.


The conventional wisdom is that surges are common and mostly harmless.

"Trying to explore the constraints of that assumption"  ... please!

If you want to debunk the possibility of a surge, there should be some math which suggests the volume of water required to produce one in a given location and demonstrating that the current environment doesn't have the possibility of producing it

5 people on ASIF saying that they don't consider it possible is hardly scientific, no?

What volume of water? Who is denying the possibility of surges? Your claims are:

1) A possible storm surge coming in from the Pacific would be 1 m high entering the Bering strait and somehow come out on the other side twice as tall.

2) That his surge will maintain the 2 meters for the next 400 kilometers until it meets the ice.

3) That this surge will then inundate the ice for a considerable distance.

4) Underlying is an unstated assumption that a surge involves the lateral movement of water. It does not.

All of this is wrong - point 1 because this is not a lateral movement of water, point 2 because even if it did gain an extra 1 m it would lose that very quickly, 3 is wrong because that is not what happens when waves meet ice, and 4 is wrong because that is simply not how things work!
because a thing is eloquently expressed it should not be taken to be as necessarily true
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oren

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Re: Arctic Ocean salinity, temperature and waves
« Reply #335 on: July 01, 2019, 08:36:10 AM »
Rich, I know you mean well and you have a good point regarding the importance of the long fetch south wind from the Bering Strait to the ice front. However, that cannot justify a scientific error that you seem to be making (or I am misinterpreting). A mass of water, be it a surge or a swell, cannot overtop and drown sea ice. Ice floats, it acts like a buoy, it bobs up and down the swell or climbs on top of the surge. I am aware of several effects that are possible with surges/swell/waves (warning - layman's terms):
* Tall frequent waves spraying or hitting the ice edge - the first few meters of a floe. Remember that most floes are hundreds of meters or kilometers across. Small marginal floes can be obliterated by this wave action.
* Deep swells making the ice bob so hard that it breaks, this mainly affects large floes as the swell lifts just part of the floe. The flip side is that the ice attenuates such swells, and they can't go very deep into the pack.
* Surge/wind pushing the ice so that it compacts. This shows up as drops in extent, but in the longer term may be better for the ice as it becomes more protected.

I am not aware of a phenomenon whereby a surge overtops a field of ice. Your experience from Miami gives you a false intuition, as the surge in the Arctic is a slow moving thing rather than a hurricane-driven monstrosity, and the ice is a floating and mobile object rather than a stationary coastal installation.

Rich

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Re: Arctic Ocean salinity, temperature and waves
« Reply #336 on: July 01, 2019, 08:40:01 AM »
This conversation reminds of an exchange in the Princess Bride, a movie full of memorable exchanges....

(as they are entering the Fire Swamp)

Buttercup: "We'll never survive"

Wesley: "Nonsense. You're just saying that because no one ever has (survived the Fire Swamp)".

Rich

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Re: Arctic Ocean salinity, temperature and waves
« Reply #337 on: July 01, 2019, 09:12:16 AM »
Rich, I know you mean well and you have a good point regarding the importance of the long fetch south wind from the Bering Strait to the ice front. However, that cannot justify a scientific error that you seem to be making (or I am misinterpreting). A mass of water, be it a surge or a swell, cannot overtop and drown sea ice. Ice floats, it acts like a buoy, it bobs up and down the swell or climbs on top of the surge. I am aware of several effects that are possible with surges/swell/waves (warning - layman's terms):
* Tall frequent waves spraying or hitting the ice edge - the first few meters of a floe. Remember that most floes are hundreds of meters or kilometers across. Small marginal floes can be obliterated by this wave action.
* Deep swells making the ice bob so hard that it breaks, this mainly affects large floes as the swell lifts just part of the floe. The flip side is that the ice attenuates such swells, and they can't go very deep into the pack.
* Surge/wind pushing the ice so that it compacts. This shows up as drops in extent, but in the longer term may be better for the ice as it becomes more protected.

I am not aware of a phenomenon whereby a surge overtops a field of ice. Your experience from Miami gives you a false intuition, as the surge in the Arctic is a slow moving thing rather than a hurricane-driven monstrosity, and the ice is a floating and mobile object rather than a stationary coastal installation.

Hi Oren,

I'm not so dense as to miss the point you are making. Yes, of course ice floats on water and I see the conventional wisdom that is being pushed in my direction.

But we need to consider the properties of the incoming water and ask ourselves whether it will sink when it comes into contact with it's new surroundings.

The incoming water will be much warmer than the Arctic water it encounters and less dense on that factor. It will be saltier making, a factor making it more dense. Net relative density...uncertain.


So let's say the initial waves hitting the coastal ice have some splashes going over the ice edge. Easy to imagine.

The incoming water travels a few meters over the ice surface until it finds a gap and goes down to meet the existing water below. Also easy to imagine.

What happens next is key. Is the incoming water dense enough to displace existing water and force water underneath the ice? Or is the incoming water light enough to float on top of the existing water?

In the scenario where the incoming water is either going under the itself or forcing the existing freshwater under the ice, then of course the ice pack will float higher with the influx of new water.

In the scenario where the incoming is not dense enough to force itself or the existing water under the ice, then the assumption of the ice rising with the influx of water can be questioned.

The salt content of the Pacific is generally much less than the Atlantic. I'm not sure how obvious it is that the water will sink upon arrival. This looks like the thread where one is most likely to get an educated guess.

oren

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Re: Arctic Ocean salinity, temperature and waves
« Reply #338 on: July 01, 2019, 09:36:11 AM »
What happens next is key. Is the incoming water dense enough to displace existing water and force water underneath the ice? Or is the incoming water light enough to float on top of the existing water?

In the scenario where the incoming water is either going under the itself or forcing the existing freshwater under the ice, then of course the ice pack will float higher with the influx of new water.

In the scenario where the incoming is not dense enough to force itself or the existing water under the ice, then the assumption of the ice rising with the influx of water can be questioned.
Whether the incoming water floats over the existing water makes no matter. In both cases the ice will float on top of both. You don't need to force the water under the ice - the ice will rise above any water you stick in its way.

binntho

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Re: Arctic Ocean salinity, temperature and waves
« Reply #339 on: July 01, 2019, 09:50:16 AM »

But we need to consider the properties of the incoming water and ask ourselves whether it will sink when it comes into contact with it's new surroundings.


THERE IS NO INCOMING WATER!

How often does this have to be repeated: A wave, a surge or a swell does not move water sideways! If a surge enters the Bering and continues into the Arctic, this does not imply ANY sideways movement of water.

A storm swell or surge through the Bering and continuing into the Arctic ocean does not bring any warm water with it. It's only the surface going up and down because of pressure differentials.
because a thing is eloquently expressed it should not be taken to be as necessarily true
St. Augustine, Confessions V, 6

Rich

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Re: Arctic Ocean salinity, temperature and waves
« Reply #340 on: July 01, 2019, 10:08:38 AM »

But we need to consider the properties of the incoming water and ask ourselves whether it will sink when it comes into contact with it's new surroundings.


THERE IS NO INCOMING WATER!

How often does this have to be repeated: A wave, a surge or a swell does not move water sideways! If a surge enters the Bering and continues into the Arctic, this does not imply ANY sideways movement of water.

A storm swell or surge through the Bering and continuing into the Arctic ocean does not bring any warm water with it. It's only the surface going up and down because of pressure differentials.

Keep shouting. That's the key.

First of all, if you are right.... there is already warm water at the ocean ice interface in the Chuchki.

Second, the sensors as reported by Windy.com and reported in the melting season thread are showing a 0.5 knot current speed heading into the Arctic. Surely, wind can influence current and move water laterally.

Hopen Times

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Re: Arctic Ocean salinity, temperature and waves
« Reply #341 on: July 01, 2019, 10:17:21 AM »
I am going a bit out of my comfort sone, but I will try to add a piece to the surge/swell/wave-hitting-the-ice discussion. I would like to say that a tidal wave is a kind of a surge, please correct me if am wrong here. If Rich is correct about his thoughts about surges flooding ice, then I think tidal waves should have the capacity to flood ice, at least in some spots. Tidal waves, needles to say, occur regularly, so it should be easy to find examples of tidal waves/surges flooding the ice.

Rich, you have a hypothesis that surges can flood ice, can you back it with observations?

I think you will have a hard time finding examples of flooded sea ice. My self, I have never seen, or never heard of, the ice be flooded by waves or surges and I have spent six winters on a smal island in the Barent Sea, surrounded by drift ice, spending a lot of time on the ice and watching the ice. 

I have a video that shows what happens to the ice when the tidal waves passes. 


binntho

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Re: Arctic Ocean salinity, temperature and waves
« Reply #342 on: July 01, 2019, 10:37:19 AM »

But we need to consider the properties of the incoming water and ask ourselves whether it will sink when it comes into contact with it's new surroundings.


THERE IS NO INCOMING WATER!

How often does this have to be repeated: A wave, a surge or a swell does not move water sideways! If a surge enters the Bering and continues into the Arctic, this does not imply ANY sideways movement of water.

A storm swell or surge through the Bering and continuing into the Arctic ocean does not bring any warm water with it. It's only the surface going up and down because of pressure differentials.

Keep shouting. That's the key.

Well it seems such a fundamental thing to get wrong. Any literature about waves will tell you this, and I honestly thought that this was something that all adults knew.


First of all, if you are right.... there is already warm water at the ocean ice interface in the Chuchki.

Second, the sensors as reported by Windy.com and reported in the melting season thread are showing a 0.5 knot current speed heading into the Arctic. Surely, wind can influence current and move water laterally.

Wind does indeed influence current and does indeed move water laterally. Wind push is generally considered to constitute 1/3 of the driving force behind the Gulf Current. But this does not mean that waves move water laterally. They do not.

Waves are essentially pressure ridges - high pressure lifts the water up, and the pressure ridges propagate like ... like waves. (Edit: High pressure here indicates pressure within the wave-propagating medium, i.e. water. Not to be confused by the following discussion about the effects of air pressure on sea surface height).

Storm surges are caused by pressure differentials, each 10 hPa in pressure differential can lift/depress the ocean surface by roughly 10cm. So the water that rises inside the surge is being pushed up by water elsewhere, where pressure is higher. This of course implies some minor lateral movement, but each water molecule is perhaps shifted a few meters to one side or the other.

(A common analogy is the movement of electrons in a wire when alternating current is applied. The current flows at close to the speed of light, but the electrons are moving down the wire at a speed of a few cm per hour. It's the waves in the electric current that move very fast, but the electrons mostly just shuffle back and forth).

Of course, once a wave or a surge hits land, things start behaving very differently. A shelfing shore will push the wave upwards until it starts falling over (i.e. breakers) and the height increase may cause inundation (i.e. flooding). But even the huge tsunamis that drench whole coastlines are only waves that move water up and down, and it is the very large increase in sea surface that causes the eventual flooding and dissipation of the wave energy at the same time.

But we are not talking about anything like that here.
because a thing is eloquently expressed it should not be taken to be as necessarily true
St. Augustine, Confessions V, 6

Rich

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Re: Arctic Ocean salinity, temperature and waves
« Reply #343 on: July 01, 2019, 11:05:07 AM »
So, at this point I'm not pushing the idea the warm salty water molecule is heading for the ice front.

I'm on to the idea that wave is pushing the fresh warm water molecule currently at the Chuchki ice interface over the ice wall in front of it.

In the meantime, a 0.5 knot current is roughly 0.9 km / hr. traveling through an 82 km wide opening in the Strait.

I don't know the depth of the current. Does it extend to the floor of the strait or is it just a few meters deep. That would tell us how much 5-10C water is being added to the Arctic.

For each meter of depth, the current is adding ~ 82 * 0.9 / 1000 or ~ 0.075 km3 of water to the Arctic each hour. If we assume a 10m depth (just a guess), then that works out to 18.0 km3 per day of water moving laterally through the Strait into the Arctic.

Is that material or significant ? Perhaps not. It's just my response to your shouting that "THERE IS NO INCOMING WATER".


uniquorn

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Re: Arctic Ocean salinity, temperature and waves
« Reply #344 on: July 01, 2019, 11:16:49 AM »
That reminds me. We haven't had a wave forecast for a long time.
windy ecmwf wam (wave) forecast, chukchi sea, junjul1-10 and today for the greenland sea
For big wave action on ice I'd recommend looking at the greenland sea at the moment.
https://www.windy.com/-Waves-waves?waves,75.453,33.750,3
@Hopen Times. Thanks for that lovely video.
« Last Edit: July 01, 2019, 12:19:33 PM by uniquorn »

binntho

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Re: Arctic Ocean salinity, temperature and waves
« Reply #345 on: July 01, 2019, 11:26:21 AM »
I'm on to the idea that wave is pushing the fresh warm water molecule currently at the Chuchki ice interface over the ice wall in front of it.

You really don't give up do you. But the lack of grammar and the spuriously introduced "ice wall" tells me that the batteries are running out.
because a thing is eloquently expressed it should not be taken to be as necessarily true
St. Augustine, Confessions V, 6

Sterks

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Re: Arctic Ocean salinity, temperature and waves
« Reply #346 on: July 01, 2019, 11:38:07 AM »

But we need to consider the properties of the incoming water and ask ourselves whether it will sink when it comes into contact with it's new surroundings.


THERE IS NO INCOMING WATER!

How often does this have to be repeated: A wave, a surge or a swell does not move water sideways! If a surge enters the Bering and continues into the Arctic, this does not imply ANY sideways movement of water.

A storm swell or surge through the Bering and continuing into the Arctic ocean does not bring any warm water with it. It's only the surface going up and down because of pressure differentials.
A wave, swell, surge or  will transform the vertical movement energy into lateral movement as the incoming wave or surge reaches a shallower waters and ultimately the coast.

But that wont work with ice: no shallowing of the ocean, and no rigid boundary, just ice that floats like a buoy. That’s what’s confusing Rich, there are no breaking wave in this scenario

BenB

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Re: Arctic Ocean salinity, temperature and waves
« Reply #347 on: July 01, 2019, 12:32:00 PM »
Re storm surge:

https://scied.ucar.edu/what-causes-storm-surge

Quote:

Wind piles up the water.

As winds swirl around a hurricane or tropical storm, seawater is pushed into a mound at the storm’s center. Faster wind is able to pile up more water. Because wind speed determines a hurricane’s category according to the Saffir-Simpson Scale, Category 4 and 5 storms are able to produce a larger mound of water than Category 1 and 2 storms. The mound of water isn’t noticeable out at sea, but as it approaches a coast, the impact is seen as storm surge flooding.

Low air pressure also plays a role.

At the center of a hurricane, air pressure is low. Low air pressure causes a slight bulge in the ocean, which adds to the mound of water that causes storm surge. Most of the water is piled up by wind, but about 5% of the mound is due to low air pressure.


I know this refers specifically to hurricanes, because that's when storm surge is the biggest problem, but I think the basic principles are the same for less powerful cyclones. Either way, like others I don't see how this is relevant to what is happening in the Bering Strait/Chukchi. For the water to pile up significantly, it really needs something to pile up against, which generally means land, or at least shallower water. The bathymetry of the Chukchi doesn't support that.

More relevantly, I've read that as a rule of thumb wind-generated surface ocean currents travel at about 3% of the wind speed. That would, in very round numbers, tie in with 20 knot winds generating a 0.5 knot current. A current of that magnitude brings quite a lot of relatively warm water into contact with the ice edge, but the impact will be incremental, and not a game-changer on its own.

Rich

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Re: Arctic Ocean salinity, temperature and waves
« Reply #348 on: July 01, 2019, 12:42:52 PM »
I'm on to the idea that wave is pushing the fresh warm water molecule currently at the Chuchki ice interface over the ice wall in front of it.

You really don't give up do you. But the lack of grammar and the spuriously introduced "ice wall" tells me that the batteries are running out.

No, I don't, give up easily. Your resorting to ad hominem attacks suggests you're the one who is wearing out.

I like your initiative of breaking it down to a molecule by molecule basis.

What happens when the water on the edge of the ice / ocean interface rises? If there is a solid ice barrier (wall), the water level will rise until an open space and gravity force the water to move laterally into the ice pack.

Gravitational force and ice boundaries will dictate the lateral movement of the incoming water. It will move to the lowest point possible, but not through solid ice.

If gravity takes the incoming water to a location where there is already water present, then the density of the incoming water becomes relevant. If the incoming water is less dense (or equallly dense) than the water layer it comes into contact with, it will not mix. It will just sit stop the existing layer until enough water is added to let gravity do it's thing again.

If the water is not heavy enough to cause mixing, then the argument that the ice will rise is based upon what?

My argument can easily be killed by claiming that the incoming water is dense enough that it will definitely cause mixing. But no one is yet making that argument and so I persist until someone can stick a fork in my argument to my satisfaction.

You don't want people to give up w/o understanding, do you?

binntho

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Re: Arctic Ocean salinity, temperature and waves
« Reply #349 on: July 01, 2019, 12:49:21 PM »
What happens when the water on the edge of the ice / ocean interface rises? If there is a solid ice barrier (wall), the water level will rise until an open space and gravity force the water to move laterally into the ice pack.

The water rises and falls all the time, with waves and tides etc. There is no solid ice barrier or wall, just a bunch of floating floes.


Gravitational force and ice boundaries will dictate the lateral movement of the incoming water. It will move to the lowest point possible, but not through solid ice.
No it just floats under the ice.

If gravity takes the incoming water to a location where there is already water present, then the density of the incoming water becomes relevant. If the incoming water is less dense (or equallly dense) than the water layer it comes into contact with, it will not mix. It will just sit stop the existing layer until enough water is added to let gravity do it's thing again.

If the water is not heavy enough to cause mixing, then the argument that the ice will rise is based upon what?

My argument can easily be killed by claiming that the incoming water is dense enough that it will definitely cause mixing. But no one is yet making that argument and so I persist until someone can stick a fork in my argument to my satisfaction.

You don't want people to give up w/o understanding, do you?
because a thing is eloquently expressed it should not be taken to be as necessarily true
St. Augustine, Confessions V, 6