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Hyperion

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Re: SMOS
« Reply #50 on: July 20, 2018, 10:42:33 AM »
You really should expect the majority of the ice surface in the estuary to be dry in the current regime Tor. Ice conducts heat better than water. And with the consistent high atmospheric energy input over the whole estuary surface. The salinity differential bottom to top. Its a bottom melt surface freeze paradigm we are in. Remember the Arctic Estuary is only 2.7% of the earths surface. Insolation directly on the estuary is not significant in a thin, young ice regime.

Wikipedia:
The Arctic Ocean is the smallest and shallowest of the world's five major oceans.[1] The International Hydrographic Organization (IHO) recognizes it as an ocean, although some oceanographers call it the Arctic Mediterranean Sea or simply the Arctic Sea, classifying it a mediterranean sea or an estuary of the Atlantic Ocean.[2][
Policy: The diversion of NZ aluminum production to build giant space-mirrors to melt the icecaps and destroy the foolish greed-worshiping cities of man. Thereby returning man to the sea, which he should never have left in the first place.
https://en.wikipedia.org/wiki/McGillicuddy_Serious_Party

Peter Ellis

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Re: SMOS
« Reply #51 on: July 20, 2018, 12:09:05 PM »
So massive thickening in the CAB, so I presume melt season somehow ended already?
It's not thickening.  SMOS doesn't measure thickness accurately during the melt season.
(This could be posted as a followup to every other post in this thread, so let's just assume it was)

oren

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Re: SMOS
« Reply #52 on: July 20, 2018, 12:11:54 PM »
I get the feeling RikW's comment was missing a  ;)

binntho

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Re: SMOS
« Reply #53 on: July 20, 2018, 12:12:23 PM »
You really should expect the majority of the ice surface in the estuary to be dry in the current regime Tor.

What estuary are we talking about here?  The areas that seem to be dry in the SMOS image are not over any known estuaries.

And with the consistent high atmospheric energy input over the whole estuary surface.

What estuary?

The salinity differential bottom to top. Its a bottom melt surface freeze paradigm we are in.

Again, where? On the "dry" part of SMOS? And by "bottom melt surface freeze paradigm" do you mean that the surface is freezing as a consequence of bottom melt, or that some third factor is causing both? Any evidence?

Remember the Arctic Estuary is only 2.7% of the earths surface.

Oh! The "Arctic Estuary" is not on any known maps. An estuary is defined as the tidal mouth of a large river and is obviously not a useful label for the Arctic Ocean which does in deed cover 2.7% of the earth's surface.

Insolation directly on the estuary is not significant in a thin, young ice regime.

But no entrainment? Baseless claim without evidence and flouting the laws of physics.
because a thing is eloquently expressed it should not be taken to be as necessarily true
St. Augustine, Confessions V, 6

Ned W

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Re: SMOS
« Reply #54 on: July 20, 2018, 04:04:11 PM »
Oh! The "Arctic Estuary" is not on any known maps. An estuary is defined as the tidal mouth of a large river and is obviously not a useful label for the Arctic Ocean which does in deed cover 2.7% of the earth's surface.

Well, this 2012 paper does analogize the Arctic Ocean to an estuary:

https://link.springer.com/article/10.1007/s12237-010-9357-3

But it also calls the Arctic a "beta ocean," in contrast to other "alpha oceans".  Which seems ... not so nice.

Hyperion

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Re: SMOS
« Reply #55 on: July 20, 2018, 04:11:52 PM »
<snip, no endless quoting, please; N.>

Binntho, this is the third time you have appeared to be deliberately wasting forum space and my time by claiming that I am making baseless claims, and demanding evidence belligerently while quoting me providing that evidence in the same post. Please read Wikipedia's article on the Arctic ocean for yourself. And the references provided there as to why oceanographers describe it as an estuary. Which is a body of lower and often  stratified salinity water where one or more riverine freshwater entries mix with ocean water before entering the ocean through a constricted exit.

<snip, stop playing the victim, please; N.>
« Last Edit: July 20, 2018, 04:49:35 PM by Neven »
Policy: The diversion of NZ aluminum production to build giant space-mirrors to melt the icecaps and destroy the foolish greed-worshiping cities of man. Thereby returning man to the sea, which he should never have left in the first place.
https://en.wikipedia.org/wiki/McGillicuddy_Serious_Party

binntho

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Re: SMOS
« Reply #56 on: July 20, 2018, 04:18:51 PM »
Oh! The "Arctic Estuary" is not on any known maps. An estuary is defined as the tidal mouth of a large river and is obviously not a useful label for the Arctic Ocean which does in deed cover 2.7% of the earth's surface.

Well, this 2012 paper does analogize the Arctic Ocean to an estuary:

https://link.springer.com/article/10.1007/s12237-010-9357-3

But it also calls the Arctic a "beta ocean," in contrast to other "alpha oceans".  Which seems ... not so nice.

I think the "estuary" metaphor is not meant to be taken seriously. The Arctic Ocean is more than 14 times bigger then the largest sea (the Mediterranean) but 10 times smaller then the largest ocean (the Pacific).

The Arctic Ocean is 64% of the size of the Southern Ocean, and 5 times smaller than the Atlantic. So based on size alone, the Arctic Ocean seems to be properly named.

On the other hand, it is mostly enclosed by land while the other Oceans communicate more or less freely with each other with large "ocean-border" areas.
because a thing is eloquently expressed it should not be taken to be as necessarily true
St. Augustine, Confessions V, 6

RikW

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Re: SMOS
« Reply #57 on: July 20, 2018, 04:34:53 PM »
does the atlantic ocean communicate freely with the other oceans?

gerontocrat

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Re: SMOS
« Reply #58 on: July 20, 2018, 04:56:49 PM »
does the atlantic ocean communicate freely with the other oceans?

The Arctic for one, the Southern Ocean for two, the Indian Ocean for three (saw it 35 years ago at the tip of Africa - amazing how you could see the difference and the boundary between the two).
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"And that's all I'm going to say about that". Forrest Gump
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binntho

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Re: SMOS
« Reply #59 on: July 20, 2018, 05:02:58 PM »
does the atlantic ocean communicate freely with the other oceans?

--- edit: Misread the question, thought you were asking about the Atlantic Arctic (doh!)... ---

I guess it depends on what you mean by "freely" ... much more so than the Mediterranean, less than e.g. the Southern Ocean.

The Arctic body of water is either an ocean or a sea. Most of the worlds seas (as named) are actually subdivisions of oceans or other, larger seas,, such as e.g. the Norwegian Sea and the Ionic Sea, but the Black, Mediterranean, and the Caribbean seas are more or less cut off from other seas/oceans (and the Caspian totally ...).

Based on size, the Arctic Ocean is properly named as such, being much closer to the next-smallest ocean than the biggest sea. If, on the other hand, a sea was to be defined as having little or restricted communication with other seas or oceans, then the Arctic Sea might be better. But then again, if such a definition was to be adopted, what would happen to the Sargasso sea which lies more or less in the middle of the Atlantic without touching land!
because a thing is eloquently expressed it should not be taken to be as necessarily true
St. Augustine, Confessions V, 6

Pmt111500

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Re: SMOS
« Reply #60 on: July 20, 2018, 05:07:10 PM »
does the atlantic ocean communicate freely with the other oceans?
I think Indian ocean provides most of the surface waters, intermediate waters and northern Atlantic bottom waters come mostly from interaction with Arctic ocean and some northern bottom water and all of southern bottom water come from interaction through acc and southern ocean. Mediterranean is mostly a water sink and would dry up if Gibraltar and Suez were blocked. Simplified.

gerontocrat

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Re: SMOS
« Reply #61 on: July 20, 2018, 05:18:00 PM »
If the Arctic was demoted to a sea - what becomes of the seas of the Arctic Ocean? Chukchi, Beaufort, ESS etc - ponds?

Pluto it is not - no demotion on the horizon. It has been, is, and will be an ocean, until it is ice-free for at least most of the year. Then perhaps someone will say - it is now totally Atlantified (horrible word) - so is part of the Atlantic Ocean.
"Para a Causa do Povo a Luta Continua!"
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Dharma Rupa

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Re: SMOS
« Reply #62 on: July 20, 2018, 06:08:21 PM »
Pluto it is not - no demotion on the horizon. It has been, is, and will be an ocean, until it is ice-free for at least most of the year. Then perhaps someone will say - it is now totally Atlantified (horrible word) - so is part of the Atlantic Ocean.

Atlantisized?

binntho

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Re: SMOS
« Reply #63 on: July 20, 2018, 06:19:11 PM »
Pluto it is not - no demotion on the horizon. It has been, is, and will be an ocean, until it is ice-free for at least most of the year. Then perhaps someone will say - it is now totally Atlantified (horrible word) - so is part of the Atlantic Ocean.

Atlantisized?

The Atlantic is of course named after the giant Atlas who holds the world on his shoulders (cf. the mythical "Atlantis" in ancient Greek is Ἀτλαντὶς νῆσος (Atlantic nisos, literally the Island of Atlas).

So to follow tradition (cf. Sargasso Sea), once blue ocean is reached, we could rename the Arctic Ocean the Atlasso Sea, being a part (or sea) of the Atlantic after beging Atlassoed (presumably with one hand) by Atlas.
because a thing is eloquently expressed it should not be taken to be as necessarily true
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Hyperion

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Re: SMOS
« Reply #64 on: July 21, 2018, 07:59:06 AM »
Really there is one world ocean. With Antarctica in the middle of it. Since for most of the last few million years, the Arctic has been an icelocked pond with almost no communication with the world ocean, its probably quite fair to call it a deep brackish tidal lagoon or estuary. My point in pointing this out is that at only 2.7% of the earths surface and less than half of that in annual insolation. Insolation is no where near as important as the energy coming in and out from surrounding landmasses.
I wrote an extensive post about this on the melting thread.
Policy: The diversion of NZ aluminum production to build giant space-mirrors to melt the icecaps and destroy the foolish greed-worshiping cities of man. Thereby returning man to the sea, which he should never have left in the first place.
https://en.wikipedia.org/wiki/McGillicuddy_Serious_Party

binntho

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Re: SMOS
« Reply #65 on: July 21, 2018, 10:28:56 AM »
I don't think the Arctic Ocean can be called a "deep brackish tidal lagoon or estuary" at 14 million square kilometers, an average depth in excess of 1 km, maximum depth 4.5 kilometers.

My point in pointing this out is that at only 2.7% of the earths surface and less than half of that in annual insolation. Insolation is no where near as important as the energy coming in and out from surrounding landmasses.

What you did say was "Insolation directly on the estuary is not significant in a thin, young ice regime" which is a baseless claim, i.e. without evidence. It also goes against the laws of physics,  since a "thin young ice regime" would be more affected by direct sunlight than thicker ice.

Now you make another claim, based on percentages, i.e. that insolation over the Arctic Ocean is nowhere near as important as the energy coming in and out from surrounding landmasses. Again this is without evidence, and seems to go against the consensus. But it depends on circumstances - if the Arctic Ocean is covered with clouds and strong low-pressure areas, sunlight will not reach the ice but warm air will be sucked in from surrounding landmasses.

But that has nothing to do with 2.7% or any other figure you might want to put forward.

As for me criticizing your post, the "estuary" remarks were what we adults call "sarcasm" and the factual claims you keep making are large, strange and without evidence, and I see it as my duty to point this out before this forum becomes a fantasy free-for-all.
because a thing is eloquently expressed it should not be taken to be as necessarily true
St. Augustine, Confessions V, 6

Peter Ellis

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Re: SMOS
« Reply #66 on: July 21, 2018, 10:38:50 AM »
...the factual claims you keep making are large, strange and without evidence, and I see it as my duty to point this out before this forum becomes a fantasy free-for-all.
Quite. As far as I can tell from Hyperion's ramblings, warm air currents are supposed to magically cause bottom melt without top melt, so the ice surface stays dry.  A contention that's trivially disproved with a large dry martini and a hairdryer.

This magical bottom-only melt arises because "Ice conducts heat better than water", and so it will conduct the atmospheric energy through to the water under the ice, allowing the ice to melt from the bottom, but not the top.  This is drivel.  Heat cannot of itself pass from one body to a hotter body. i.e. if the ice is conducting heat downwards, then the top of the ice is hotter than the bottom, so the top will melt first.

Hyperion

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Re: SMOS
« Reply #67 on: July 21, 2018, 10:45:55 AM »
...the factual claims you keep making are large, strange and without evidence, and I see it as my duty to point this out before this forum becomes a fantasy free-for-all.
Quite. As far as I can tell from Hyperion's ramblings, warm air currents are supposed to magically cause bottom melt without top melt, so the ice surface stays dry.  A contention that's trivially disproved with a large dry martini and a hairdryer.
Actually proven with a handful of salt, some ice cubes and some water to float them, while you use your hairdryer Peter. Its how everyone did freezers before electric ones.
« Last Edit: July 21, 2018, 10:52:27 AM by Hyperion »
Policy: The diversion of NZ aluminum production to build giant space-mirrors to melt the icecaps and destroy the foolish greed-worshiping cities of man. Thereby returning man to the sea, which he should never have left in the first place.
https://en.wikipedia.org/wiki/McGillicuddy_Serious_Party

oren

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Re: SMOS
« Reply #68 on: July 21, 2018, 11:02:10 AM »
They are just that, ramblings, which is why I mostly don't bother to respond.

Tor Bejnar

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Re: SMOS
« Reply #69 on: July 21, 2018, 02:39:48 PM »
The second sentence in the Wikipedia article on Arctic Ocean:
Quote
The International Hydrographic Organization (IHO) recognizes it as an ocean, although some oceanographers call it the Arctic Mediterranean Sea or simply the Arctic Sea, classifying it a mediterranean sea or an estuary of the Atlantic Ocean.[2][3]


Quote
...
2."'Arctic Ocean' - Encyclopædia Britannica". Retrieved 2012-07-02. "As an approximation, the Arctic Ocean may be regarded as an estuary of the Atlantic Ocean."

I was surprised too...
Arctic ice is healthy for children and other living things because "we cannot negotiate with the melting point of ice"

slow wing

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Re: SMOS
« Reply #70 on: July 21, 2018, 02:49:20 PM »
This magical bottom-only melt arises because "Ice conducts heat better than water", and so it will conduct the atmospheric energy through to the water under the ice, allowing the ice to melt from the bottom, but not the top.  This is drivel.  Heat cannot of itself pass from one body to a hotter body. i.e. if the ice is conducting heat downwards, then the top of the ice is hotter than the bottom, so the top will melt first.

Commenting in this discussion, this is my understanding of the situation.

Hyperion is technically correct - this situation is possible under some circumstances.

The quote above is correct that the top will be 'hotter' than the bottom, because that is where the heat is coming from.

However, it is incorrect in claiming that means the top will always melt first. The reason is the presence of salt at the bottom, but not at the top, which lowers the melting point at the bottom.

E.g the top will melt at 0 degrees C if there's no salt, but the bottom may melt at -1.8 degrees C at a reasonable salinity for sea water.

So the situation of bottom melt in Arctic sea ice with heat carried from a dry top is theoretically possible.

In practice, on the other hand, I suspect that such a scenario is presumably unlikely to make a big contribution to the overall melt.

The reason is that the thermal conductivity of ice is not all that good: it's around 2.2 W/(mK). So there is going to be a non-negligible temperature gradient in order to carry a non-negligible flow of heat down through the ice.

Consider this scenario, chosen to be a type of threshold case:
1 meter thick ice
0 degrees at the top
-1.8 degrees at the bottom
With both top and bottom at the threshold temperature for melting.

Linearizing for simplicity, the thermal gradient is 1.8 degrees/meter.

This implies a heat flow of ~2.2 W/(m.K) x 1.8 K/m = 4 W/m^2

The heat of melting of ice is 334 kJ/kg (same reference as above).

So rate of melting is ~4 J/(s.m^2) x / (334,000 J/kg x 900 kg/m^3) ~ 1.3e-8 m/s
(presuming a density of 900 J/kg)

A month is ~pi x 10^7s / 12 (using a useful mnemonic for approximate number of seconds in a year)

So that rate of melting would be 1.3e-8 m/s x pi x 10^7 / 12 ~ 3.5e-2 m/month = 3.5 cm/month.

So this threshold situation would be a bottom melt rate of only 3 or 4 cm per month.

If the bottom melt rate is:
a) Above this, then the top will be wet;
b) Below this, then the top can be dry even when the bottom is melting from heat carried downwards.

This is obviously a simplified situation - it is not rigorous - and is for ice that is 1 meter thick.
(If the ice is thinner\thicker then the melt rate can be more\less, in approximately inverse proportion to the thickness.)


But it illustrates the general point that ice dry at the top cannot be carrying much heat down to be melting the bottom.

SUMMARY:

Consider a situation for the Arctic sea ice where the heat to melt ice is coming from above. Then:

1) Bottom melt can only be fast, or even moderately fast, if the top is wet; and

2) The maximum bottom melt rate where a dry top is even possible (where the heat comes from above, & holding to some sort of long term equilibrium) is only of order a few cm/month.

So bottom melt with a dry top but still using heat arriving through the ice and from the top, while physically possible, is likely not the dominant scenario for Arctic sea ice.
« Last Edit: July 21, 2018, 03:08:59 PM by slow wing »

FishOutofWater

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Re: SMOS
« Reply #71 on: July 21, 2018, 05:05:23 PM »
After the snow on top melts, light passes through the ice warming the water below the ice. That's physically possible when the sun is at a high enough angle. There's also advection of Atlantic water into the Arctic ocean. There's also the transport of ice over Beaufort & Chukchi sea summer water. We don't need to invent non-physical processes to get bottom melting. Sometimes that will happen when the top surface isn't melting, but generally not in July.

slow wing

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Re: SMOS
« Reply #72 on: July 21, 2018, 11:13:18 PM »
Agree, Fish, that there are other processes - that you have given - that can cause a lot of bottom melt even when the top of the ice is dry.

The above discussion relates specifically to heat conduction down through the ice when the top is heated by warm winds.

Parenthetically, there are also a couple of other issues that work against lots of heat transfer by that mechanism: air can carry only very little heat per unit volume - orders of magnitude less than water, and the thermal coupling to the ice will usually be poor. (Water vapour in the air helps though.)

johnm33

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Re: SMOS
« Reply #73 on: July 22, 2018, 01:06:37 AM »
OT but 'Atlas' carried the sky on his shoulders, actually inside his head he was a navigator in the days before maps and atlas's curiously. Without complete star knowledge sailors got lost.

RoxTheGeologist

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Re: SMOS
« Reply #74 on: July 22, 2018, 01:32:53 AM »

I would think there is a gradient, the base of the ice is fixed at >-1.8°C and the top of the ice at <0°C which would match a salinity gradient through the ice. If you heat the basal water (insolation, pushing the ice over warm sea) then the ice melts from the bottom.

If you heat the ice from the top, insolation, warm air, warm rain, then you might be in a thermodynamic environment to cause bottom melt. I could easily see water on top of the ice causing bottom melt, as it freezes and releases heat of fusion and then ice conducting that energy to the base. Perhaps that is one mechanism by which ice becomes fresher as it ages. In reality, at equlibrium, the ice surface should be 'dry', it refreezes at 0°C causing bottom melt.

Peter Ellis

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Re: SMOS
« Reply #75 on: July 22, 2018, 02:44:12 AM »
Bottom melt happens primarily near the edges of floes, and the heat source is from radiation absorbed by the open water between the floes.  The onset is generally quite late in the season, but because of the huge thermal mass of the ocean, it can continue even after atmospheric temperatures have dropped below freezing at the transition from summer to autumn.

Anything other than the above is a mere detail in the small decimal places. This forum used to know stuff like this!

Hyperion

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Re: SMOS
« Reply #76 on: July 22, 2018, 04:06:52 AM »
When the ice is a fractured and mobile pack of porous honeycombed ice, as per today's arctic, there's a lot more complexity than a one dimensional conduction calculation can give good approximations from s-wing.
Like the thermo karst effect. The densest fresh water is 4-6 degC. So it is quite normal for the top of waterlogged cavities to be at zero degrees, or even frozen over,  whilst deeper down there is warmer water burrowing deeper. You might call this subsurface micro-meltponding

Under the floe a similar but salinity driven process works as warmer saltier water below is exchanged and turned over as it gives energy to the ice and is freshened by melt in a non uniform process. One can even envisage outward flow of freshened melt from the edges of floes drawing up warmer more saline stuff from below in the middle. Exactly like the process tunneling under the ice shelves of Antarctica and Greenland.
Algal growth into the porous bottom of the ice absorbs solar energy, metabolic heat and antifreeze secretionsthat lower the melting point still further, increases porosity, and of course warm salty water rises.
These convection processes should vastly increase the   thermal transfer through the average 1m ice.

And then there is radiative energy transfered in microwave and ultraviolet spectra that ice is near transparent to.
Policy: The diversion of NZ aluminum production to build giant space-mirrors to melt the icecaps and destroy the foolish greed-worshiping cities of man. Thereby returning man to the sea, which he should never have left in the first place.
https://en.wikipedia.org/wiki/McGillicuddy_Serious_Party

Hyperion

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Re: SMOS
« Reply #77 on: July 22, 2018, 11:38:36 AM »
16 to 21 July. Apart from the major disintegration of the pac-ruski quadrant, major changes appear to be compaction into the CAA garlic press and Svalbard region killing grounds.
Policy: The diversion of NZ aluminum production to build giant space-mirrors to melt the icecaps and destroy the foolish greed-worshiping cities of man. Thereby returning man to the sea, which he should never have left in the first place.
https://en.wikipedia.org/wiki/McGillicuddy_Serious_Party

FishOutofWater

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Re: SMOS
« Reply #78 on: July 22, 2018, 06:30:29 PM »
Generally, in the Arctic the density gradient is controlled by salinity not temperature. The light fresh water floats above the saline layers. Thus the process you propose generally does not happen in the Arctic.

"Under the floe a similar but salinity driven process works as warmer saltier water below is exchanged and turned over as it gives energy to the ice and is freshened by melt in a non uniform process."

Neven

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Re: SMOS
« Reply #79 on: July 22, 2018, 07:11:11 PM »
Hyperion can't answer, because he's banned from the ASIF.
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Re: SMOS
« Reply #80 on: July 22, 2018, 08:14:05 PM »
Neven, that will improve the signal to noise ratio around here.

Hefaistos

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Re: SMOS
« Reply #81 on: July 22, 2018, 09:54:50 PM »
It near as dammit is a blue ocean event already Neven. I bet my left nut that anything near the periphery, extending now to a Chukchi to Barents strip right across the pole where meltponding is being reported is actually open water, and satellites being fooled by wave action.
And what I cannot stand is bullying. Which is what you supported.

As said, if there's a BOE event this year (it's already practically there according to you), I will apologize. Conversely, if there's no BOE, you'll get banned from this forum.
So already now we know for sure there will be no BOE this year :)

Neven

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Re: SMOS
« Reply #82 on: July 22, 2018, 10:34:46 PM »
No, it was simply taking up too much time and energy, reading the posts from beginning to end, deciding whether to approve, editing out the bad parts, replying to angry mails.

If there's a BOE, I will reinstate Hyperion and apologise. In fact, I will do so if I ever think there could be a BOE (and I hope I will be able to see it coming).
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Steven

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Re: SMOS
« Reply #83 on: July 22, 2018, 10:40:14 PM »
I updated my pixel-counting calculations with SMOS images that were quoted in the topmost post of this thread.  First, I counted the number of beige pixels for each daily SMOS image for July 2010-2018:




Clearly 2013 and 2014 stand out.  But in general the number of beige pixels in July is quite small. 

As an alternative, I included more pixel colors from the color legend of the SMOS images.  More specifically, I lumped together all the beige, purple, red and yellow pixels of the SMOS images in the pixel counting algorithm:





Average number of pixels for the first 21 days of July:

« Last Edit: July 22, 2018, 10:50:50 PM by Steven »

AvantGuardian

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Re: SMOS
« Reply #84 on: August 13, 2018, 03:10:57 AM »
Looks like this is the place where usnavy and German data is not unwelcome. So someone needs to post the SMOs and us navy stuff here huh.
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Re: SMOS
« Reply #85 on: August 13, 2018, 11:07:11 AM »
Looks like this is the place where usnavy and German data is not unwelcome. So someone needs to post the SMOs and us navy stuff here huh.

That's right, and it would be even better if you could compare it to previous years.
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Re: SMOS
« Reply #86 on: August 14, 2018, 12:58:58 AM »
11, 12 Aug smas


Re: SMOS
« Reply #88 on: Today at 01:35:38 PM »
Note: This message is awaiting approval by a moderator.
I've asked my professors and C/O about your questions sir. Thank you for asking sir.
They believe this seems to show the results of the hot and humid winds that blew from the Atlantic front, for most of the preceding week right across the pole to the  Chukchi and Siberian theatre. This pushed a lot of the floes in the central pack 20-40 degrees to the right of the wind direction, and caused a lot of surface melting in the active corridor also. A lot of meltwater was pushed out of the pack onto the ESAS, and into the CAA, because winds move the surface waters faster than ice floes. And large gaps within the pack allowed the high winds to create a large storm surge. Now that the winds have reversed direction, the cooling effect of them blowing over heavily fractured ice distributed in  highly saline surface waters, is causing surface crusting on the floes, and meltwater flooded surface channels and ponds of the central pack causing this area to read as thicker than it actually is.
Regarding how this compares with SMOS datasets from previous years. My superiors suggest that the high surface salinity and fragmented pack is causing SMOS to overstate thickness relative to previous years.
« Last Edit: August 15, 2018, 05:34:22 PM by AvantGuardian »
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Re: SMOS
« Reply #87 on: August 14, 2018, 08:39:51 AM »
What does this show and how does it compare to previous years?
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Re: SMOS
« Reply #88 on: August 15, 2018, 01:35:38 PM »
I've asked my professors and C/O about your questions sir. Thank you for asking sir.
They believe this seems to show the results of the hot and humid winds that blew from the Atlantic front, for most of the preceding week right across the pole to the  Chukchi and Siberian theatre. This pushed a lot of the floes in the central pack 20-40 degrees to the right of the wind direction, and caused a lot of surface melting in the active corridor also. A lot of meltwater was pushed out of the pack onto the ESAS, and into the CAA, because winds move the surface waters faster than ice floes. And large gaps within the pack allowed the high winds to create a large storm surge. Now that the winds have reversed direction, the cooling effect of them blowing over heavily fractured ice distributed in  highly saline surface waters, is causing surface crusting on the floes, and meltwater flooded surface channels and ponds of the central pack causing this area to read as thicker than it actually is.
Regarding how this compares with SMOS datasets from previous years. My superiors suggest that the high surface salinity and fragmented pack is causing SMOS to overstate thickness relative to previous years.

Can you ask your professors/superiors for the images of previous years (2012 to now, preferably) and put them side by side, so we can all compare them, instead of having to rely on their word and convoluted theories where 2-3 days of wind cause massive shifts at ultra-high speed?

Note: This message is awaiting approval by a moderator.
No Sir, there seems to be no longer a website at https://seaice.uni-bremen.de/
Perhaps they have decided there is no more sea ice.

And with respect sir. If sir had ever tried to paddle a small boat in a wind, on even a harbour or lagoon, sir would understand that the surface of the water can blow very fast in a wind. This in fact is how waves are generated.
« Last Edit: August 16, 2018, 02:51:46 PM by AvantGuardian »
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Re: SMOS
« Reply #89 on: August 16, 2018, 10:39:59 AM »
Can you ask your professors/superiors for the images of previous years (2012 to now, preferably) and put them side by side, so we can all compare them, instead of having to rely on their word and convoluted theories where 2-3 days of wind cause massive shifts at ultra-high speed?
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Re: SMOS
« Reply #90 on: August 16, 2018, 01:28:36 PM »
No Sir, there seems to be no longer a website at https://seaice.uni-bremen.de/
Perhaps they have decided there is no more sea ice.

And with respect. If you had ever tried to paddle a small boat in a wind, on even a harbour or lagoon, you would understand that the surface of the water can blow very fast in a wind. This in fact is how waves are generated.
Navy brat, student at Hawaiki state, majoring in oceanography, climate and parapsychology.

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Re: SMOS
« Reply #91 on: August 17, 2018, 06:32:26 AM »
"For my part, whatever anguish of spirit it may cost, I am willing to know the whole truth; to know the worst and provide for it." - Patrick Henry

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Re: SMOS
« Reply #92 on: August 19, 2018, 09:56:45 AM »
Let's just wait until Bremen SMOS comes back on-line.
Then we can do the proper year-by-year comparisons.
https://seaice.uni-bremen.de/data/smos/png/
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Re: SMOS
« Reply #93 on: August 20, 2018, 09:07:05 PM »
The SMOS images are back online.  Here are some updated graphs obtained using a pixel-counting script.

First, here's a look at the beige pixels, which are at the far right end of the SMOS color legend:






The graph below counts more pixel colors, lumping together all the pixel colors from beige to green in the SMOS color legend (including the intermediate yellow, red and purple colors).  At this time of year, this graph has a good correlation with the September minimum extent.







Finally, here is a weighted average of all pixels in the SMOS image, with each pixel weighted according to its numerical value in the color legend:



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Re: SMOS
« Reply #94 on: August 21, 2018, 09:20:00 AM »
That's great work, Steven. Thank you.

It appears that 2018 ranks rather high on your various SMOS graphs, suggesting less "water" on the ice than in previous years (some even suggesting a resemblance to 2013/2014).

Also, just eye-balling the results, it seems to me that the SMOS data bears clear resemblance to the "ice concentration" data, as visualized by Wipneus (the "compactness" graph) here :
https://sites.google.com/site/arcticseaicegraphs/regional
which is also been high for much of the summer.

With the side-note that some of your SMOS data graphs appears to have less "noise" than the concentration data.

Do you know (did you calculate?) which metric (SMOS or ice "concentration") has better predictive skill for determining the minimum in September, especially this late into the melting season ?
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Re: SMOS
« Reply #95 on: August 21, 2018, 11:03:11 PM »
It appears that 2018 ranks rather high on your various SMOS graphs, suggesting less "water" on the ice than in previous years (some even suggesting a resemblance to 2013/2014).

Also, just eye-balling the results, it seems to me that the SMOS data bears clear resemblance to the "ice concentration" data, as visualized by Wipneus (the "compactness" graph) here :
https://sites.google.com/site/arcticseaicegraphs/regional
which is also been high for much of the summer.

It also agrees with the JAXA AMSR2 melt graphs on Wipneus' website, which suggest that surface melting has been relatively weak this melt season.

Regarding compactness, there were also some anecdotes from the Swedish icebreaker Oden, which traveled from Svalbard to the North Pole earlier this month.  The captain of the ship reported that the sea ice is very compact and that he had not seen such high compactness in more than a decade.  That seems to be due to the prevalent weather conditions during this melt season: a reverse dipole anomaly with ensuing northward sea ice drift (and compaction) on the Atlantic side of the CAB.


Do you know (did you calculate?) which metric (SMOS or ice "concentration") has better predictive skill for determining the minimum in September, especially this late into the melting season ?

This late in the melt season, I would just use the extent trajectories for previous years.  That suggests about 4.7 million km2 for the September 2018 NSIDC extent.  As for the SMOS data, the second graph I posted yesterday suggests a slightly higher value, about 4.9.  That is also similar to what Slater's method predicts.  The skill of those 3 different methods seems to be rather similar in mid-August.

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Re: SMOS
« Reply #96 on: June 05, 2019, 05:06:07 PM »
The 2019 melt season is now well underway.  Like last year, I run a pixel counting algorithm on the SMOS images. 

In summer SMOS is sensitive to surface melting.  The beige pixels in the SMOS images would correspond to sea ice with a dry surface (without melt ponds).  During June, the number of beige pixels in the images tends to decrease fast as surface melting becomes more widespread in the Arctic Ocean.

Based on this metric, surface melting in 2019 has been mediocre in the last few weeks (slightly weaker than the 2010s average).  But it's still early in the season and a lot can happen.



https://www.dropbox.com/s/fl2xs6aeop3ioen/SMOS_beige_pixels.png

To keep this graph up-to-date, I uploaded it on dropbox.com and it will be updated every day with the latest data.

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Re: SMOS
« Reply #97 on: June 05, 2019, 05:28:35 PM »
The 2019 melt season is now well underway.  Like last year, I run a pixel counting algorithm on the SMOS images. 

In summer SMOS is sensitive to surface melting.  The beige pixels in the SMOS images would correspond to sea ice with a dry surface (without melt ponds).  During June, the number of beige pixels in the images tends to decrease fast as surface melting becomes more widespread in the Arctic Ocean.

Based on this metric, surface melting in 2019 has been mediocre in the last few weeks (slightly weaker than the 2010s average).  But it's still early in the season and a lot can happen.



https://www.dropbox.com/s/fl2xs6aeop3ioen/SMOS_beige_pixels.png

To keep this graph up-to-date, I uploaded it on dropbox.com and it will be updated every day with the latest data.
Great stuff! By mid June 2012 had only 1/5 of the surface “dry”. Let’s see how this year will go, my feeling is that it will get there but with some days of lag. Obviously if the lag is too long, we get into July and the possibility of keeping pace with 2012 will be nil.

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Re: SMOS
« Reply #98 on: June 06, 2019, 11:51:14 AM »
That graph is exactly what I needed!

But... is the map from this date 2012 accessible somewhere too?

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Re: SMOS
« Reply #99 on: June 06, 2019, 12:15:31 PM »
Yes, here.

Thanks for reminding me of Steven's great graph. I see it is still updated, and will try to insert it in the ASIG daily graphs page.
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