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oren

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Re: What the Buoys are telling
« Reply #1400 on: June 20, 2017, 11:24:03 PM »
Newsflash, I could swear that there are refrozen melt areas (not quite ponds yet, but beginning) in the current image (posted below).
It also seems that the snow level maybe dropped a bit in the last 4 days, rather than covered by new drifts (click animation).
« Last Edit: June 20, 2017, 11:48:12 PM by oren »

ghoti

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Re: What the Buoys are telling
« Reply #1401 on: June 21, 2017, 01:05:53 AM »
Yeah your animated comparison does seem to show a drop in snow level. I clearly misinterpreted the smoothing.

seaicesailor

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Re: What the Buoys are telling
« Reply #1402 on: June 22, 2017, 05:21:15 PM »
I downloaded the update from the 2017A webpage. The last frame from the 20th is very interesting. For a few data lines, on the 19th and 20th, one of the thermistors next above what I have assumed ice surface (depth=0 in the plots), seems getting anchored to 0C. Melting water from the snow? Last days seem pretty warm.
The temperature of the ice is getting close to melt temperature for what would be FYI, even well above it for the first 25cm of ice, which might mean I assumed ice surface in the wrong place. But I would not be surprised that this buoy was instead anchored to a residual of MYI of last year. Somebody I think mentioned that possibility.
The page has stopped giving bottom melt and snow depth, the database just shows 11 cm snow  (???) and constant thickness of around 1.15 meters. I would expect more melt, top and bottom but who knows.
The bottom water is now clearly warmer, if only by 0.1C or so.

magnamentis

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Re: What the Buoys are telling
« Reply #1403 on: June 22, 2017, 06:04:13 PM »
Newsflash, I could swear that there are refrozen melt areas (not quite ponds yet, but beginning) in the current image (posted below).
It also seems that the snow level maybe dropped a bit in the last 4 days, rather than covered by new drifts (click animation).

generally i'd agree, could also be darker blank ice showing through the snow, ( or where the snow has melted, snow depth is significantly lower taking the peaks of those little bumps in the background as a reference. not saying it's not re-frozen, just adding to the yes, could be, a second, perhaps a bit more far fetched possibility.
« Last Edit: June 22, 2017, 06:54:45 PM by magnamentis »

seaicesailor

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Re: What the Buoys are telling
« Reply #1404 on: June 22, 2017, 06:16:59 PM »
Same for 2017B.
The last couple of days have a rapid change in the profile, something similar to what we saw last year with 2015F (for whatever reasons).
The webpage reports start of minute bottom melt also these last few days (before 20th). Fairly warm days with mean temps near zero.


DuraSpec

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Re: What the Buoys are telling
« Reply #1405 on: June 22, 2017, 10:07:52 PM »
SeaIceSailor, Thanks for these! It astonishes me that the ice responds so rapidly throughout its depth. I'm trying to grasp that response effect across the entire Arctic.... it seems much more fragile/responsive to external input than I had expected.

I would guess that this (your animated graphs) shed light to us "ASIF Lurkers" ond others on how gigantic areas of the Arctic ice just suddenly vanish when the heat eventually gets through from top or bottom.

I'm really curious to see the time lag effect of latent heat represented in the animations. And possibly the fresh water ice and sea water interactions as the ice thins.

And thanks for posting the buoy locations along with the graphs. I'm going to try flipping through Worldview while looking at these to sort of see what is happening.

...see attachments of message « Reply #1402 » above.

...see attachments of message « Reply #1404 » above.

magnamentis

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Re: What the Buoys are telling
« Reply #1406 on: June 24, 2017, 01:42:03 AM »
just like that, an ice-bear sniffing at the co2 sensor LOL (not sayin' just for fun )

oren

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Re: What the Buoys are telling
« Reply #1407 on: June 24, 2017, 05:59:17 AM »
Wow. A rare event indeed.
So it came back after realizing it wasn't photographed.
But seriously, I'm mostly concerned it will knock over the dear buoy, or break something. On the other hand its footsteps are useful for gauging snow status.

Jim Hunt

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Re: What the Buoys are telling
« Reply #1408 on: June 24, 2017, 10:00:53 AM »
I would guess that this (your animated graphs) shed light to us "ASIF Lurkers" ond others on how gigantic areas of the Arctic ice just suddenly vanish when the heat eventually gets through from top or bottom.

I don't think that you'll find that the floe on which 2017A is sitting is going to "suddenly vanish" any time soon. Once the blue line has risen completely above the dotted red line is when bottom melt can begin in earnest. Melting away to nothing takes a lot longer.
"The most revolutionary thing one can do always is to proclaim loudly what is happening" - Rosa Luxemburg

Phil.

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Re: What the Buoys are telling
« Reply #1409 on: June 24, 2017, 06:44:54 PM »
I would guess that this (your animated graphs) shed light to us "ASIF Lurkers" ond others on how gigantic areas of the Arctic ice just suddenly vanish when the heat eventually gets through from top or bottom.

I don't think that you'll find that the floe on which 2017A is sitting is going to "suddenly vanish" any time soon. Once the blue line has risen completely above the dotted red line is when bottom melt can begin in earnest. Melting away to nothing takes a lot longer.

Not quite sure why this is called 'bottom' melt?  According to the plot for 17A the ice above 25cm is above the melting point and so should be melting now, the deeper ice is still below the melting point.  The ice is getting warmer from above, soon we'd expect to get a profile without a minimum and ice at all depths will be melting but fastest at the surface.

seaicesailor

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Re: What the Buoys are telling
« Reply #1410 on: June 24, 2017, 06:56:02 PM »
I would guess that this (your animated graphs) shed light to us "ASIF Lurkers" ond others on how gigantic areas of the Arctic ice just suddenly vanish when the heat eventually gets through from top or bottom.

I don't think that you'll find that the floe on which 2017A is sitting is going to "suddenly vanish" any time soon. Once the blue line has risen completely above the dotted red line is when bottom melt can begin in earnest. Melting away to nothing takes a lot longer.

Not quite sure why this is called 'bottom' melt?  According to the plot for 17A the ice above 25cm is above the melting point and so should be melting now, the deeper ice is still below the melting point.  The ice is getting warmer from above, soon we'd expect to get a profile without a minimum and ice at all depths will be melting but fastest at the surface.
Phil I suspect this is a MYI block despite the location and will be melting at closer to 0°C (at least at the top). Otherwise that raise of ice temperature does not make sense to me... might there be another explanation?

The truth is that there is only one thermistor (marked with a question mark below), which temperature was slowly rising reaching somewhere about -1.6C, that started to show faster rising temperature on June 18 and following days. I think this is the ice being heated by conduction, but if it is another thing (melt snow/ice draining from above transferring heat directly to the thermistor?) other people with more experience here may know. That could work with First Year ice. If we wait three days to next update, we probably will have a clearer idea.
« Last Edit: June 24, 2017, 07:52:55 PM by seaicesailor »

Jim Hunt

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Re: What the Buoys are telling
« Reply #1411 on: June 24, 2017, 08:00:22 PM »
Not quite sure why this is called 'bottom' melt?

On June 20th the other sensors on the buoy were reporting snow depth of 11 cm and bottom melt to date of 4 cm. QED?

As SIS suggests, brine rejection means the bulk of the floe still isn't "above freezing" yet. Once we "get a profile without a minimum" the bottom melt rate will increase. Let's see what the next update reveals!
"The most revolutionary thing one can do always is to proclaim loudly what is happening" - Rosa Luxemburg

Andreas T

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Re: What the Buoys are telling
« Reply #1412 on: June 25, 2017, 09:50:13 AM »
I am waiting fora clearer view of what we are seeing there, but I have noticed a darker area to the right and another further away to the left which are not shadows and have become more pronounced over the last 12h. Now a bear footprint has become darker as well, I think this is water accumulating on the ice surface which makes the water logged snow transparent and therefore appear dark as the underlying sea.

The "movie" has updated recently by the way

Andreas T

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Re: What the Buoys are telling
« Reply #1413 on: June 25, 2017, 10:35:02 AM »
@SIS concerning 2017A
I agree that water flowing down along the thermistor string could be an explanation. But heat is not only transgered by conduction and convection.
As snow becomes more translucent warming is also caused by sunlight. That can warm the temperature sensors directly or warm the ice. Since clear ice doesn't absorb much light this absorption gets stronger when there are any algae etc present, this is more likely near the bottom of the floe. The sea below the ice absorbs any light passing through, this heat is available for bottom melt although it is warming a lot of water and therefore does not show a noticeable rise in water temperature.
Those are my conclusions from what I have picked up over the years, no one here has direct experience of this

seaicesailor

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Re: What the Buoys are telling
« Reply #1414 on: June 25, 2017, 10:51:03 AM »
@SIS concerning 2017A
I agree that water flowing down along the thermistor string could be an explanation. But heat is not only transgered by conduction and convection.
As snow becomes more translucent warming is also caused by sunlight. That can warm the temperature sensors directly or warm the ice. Since clear ice doesn't absorb much light this absorption gets stronger when there are any algae etc present, this is more likely near the bottom of the floe. The sea below the ice absorbs any light passing through, this heat is available for bottom melt although it is warming a lot of water and therefore does not show a noticeable rise in water temperature.
Those are my conclusions from what I have picked up over the years, no one here has direct experience of this
Right, I forgot that from last year that direct sunlight is another factor. I think we just catched the snow melting in the last frame, and after this week I am sure there will be big changes at the surface of this buoy.
Andreas and Jim thank you

Watching_from_Canberra

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Re: What the Buoys are telling
« Reply #1415 on: June 25, 2017, 10:58:52 AM »
I am waiting fora clearer view of what we are seeing there, but I have noticed a darker area to the right and another further away to the left which are not shadows and have become more pronounced over the last 12h. Now a bear footprint has become darker as well, I think this is water accumulating on the ice surface which makes the water logged snow transparent and therefore appear dark as the underlying sea.

The ice in that area last year looks fairly broken up on Worldview.  OB14 might be on the move again soon...

Andreas T

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Re: What the Buoys are telling
« Reply #1416 on: June 26, 2017, 12:03:00 AM »
the snow at Obuoy14 looks definitely soggy now, I think the area on the right can be called a meltpond now, the reflection on the surface indicates water.
I combined the 21:00 with the 07:00 from this morning to show how quickly the area of the footsteps has developed.
The shot from last year (oct 16th) shows that this was new ice , the lowest, thinnest ice one would expect.
...this area was newly formed back in October whereas there was some piled up older ice on the right. This is just so we can see how this affects further development (I hope this edit makes it clearer, but I have no idea what you mean Hyperion)

click to play animation
« Last Edit: June 26, 2017, 12:37:30 AM by Andreas T »

Hyperion

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Re: What the Buoys are telling
« Reply #1417 on: June 26, 2017, 12:21:52 AM »
 :o
Oh good golly gosh! So is what you may be saying that it is a thicker bit of ice at a metre that it is being than many that is being its neighbours to in what it is penetrates?
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

ghoti

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Re: What the Buoys are telling
« Reply #1418 on: June 26, 2017, 01:48:13 AM »
Whoa! just 17 hours later there is water everywhere!


oren

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Re: What the Buoys are telling
« Reply #1419 on: June 26, 2017, 07:22:08 AM »
Whoa! just 17 hours later there is water everywhere!
Added another 5 hours, animated.
A serene and nice snow cover reaches the breaking point. CLICK.
Note the melt lake emerging in the distance (right side).

seaicesailor

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Re: What the Buoys are telling
« Reply #1420 on: June 26, 2017, 07:29:10 AM »
Whoa! just 17 hours later there is water everywhere!
Added another 5 hours, animated.
A serene and nice snow cover reaches the breaking point. CLICK.
Note the melt lake emerging in the distance (right side).
Blame the bear!
No seriously, the footprints did indeed do some preconditioning

Andreas T

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Re: What the Buoys are telling
« Reply #1421 on: June 26, 2017, 08:37:27 AM »
seriously? yes it must have reduced albedo for a few hours but I don't think this would have made a significant contribution.
I showed the still from last October because the surface contours of the ice determines where the pools form.  Snow melt  is occurring probably mostly from warm air, or even rain with a contribution of some diffuse insolation through the clouds, that is I think it melts fairly evenly over the whole surface. That water pools on the ice surface below the snow, and the areas of lowest surface elevation fill to the top of the snow surface. Of course drifts with greater depth of snow also keep their tops above water.
Clearly the albedo has now changed and we have seen deepening of pools before which indicates that melting of ice is stronger there. But this is usually not very quick, which also indicates I think that much of the incoming shortwave radiation which isn't reflected is not absorbed near the surface but over the depth of ice and ocean.
Apologies if I am stating the obvious, but writing this down helps me to be clearer about it in my own head. Feel free to point out where I might go wrong.

The line of water across the picture in the (mid?)distance (beyond the piled ice on the right) is not obvious as a low area in October maybe there was some movement in the dark months?

DuraSpec

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Re: What the Buoys are telling
« Reply #1422 on: June 26, 2017, 09:21:53 AM »
This is a great discussion - thank you everyone!

Peter Ellis

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Re: What the Buoys are telling
« Reply #1423 on: June 26, 2017, 12:27:45 PM »
:o
Oh good golly gosh! So is what you may be saying that it is a thicker bit of ice at a metre that it is being than many that is being its neighbours to in what it is penetrates?
... come again?

Adam Ash

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Re: What the Buoys are telling
« Reply #1424 on: June 26, 2017, 03:23:53 PM »
@SIS concerning 2017A
I agree that water flowing down along the thermistor string could be an explanation...

As snow becomes more translucent warming is also caused by sunlight. That can warm the temperature sensors directly or warm the ice. Since clear ice doesn't absorb much light this absorption gets stronger when there are any algae etc present, this is more likely near the bottom of the floe. ...

Good point Andreas.  And of course its a nice positive feedback loop... transparent ice of thickness x allows sunlight to penetrate.  Algae forms under the ice.  Darker algae captures more sunlight, raising temperature of water at the base of the floe, thinning the floe.  Thinner floe allows more sunlight to penetrate which enhances algae growth which... and around it goes.  Hence possibility for strong bottom melt even if air temp well below zero.  Nice.

epiphyte

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Re: What the Buoys are telling
« Reply #1425 on: June 26, 2017, 04:31:02 PM »
:o
Oh good golly gosh! So is what you may be saying that it is a thicker bit of ice at a metre that it is being than many that is being its neighbours to in what it is penetrates?
... come again?

Recalling that this buoy is sited in an area of partially melted-out MYI from last year, perhaps Hyperion is suggesting that the meltwater may be visibly pooling only over the thicker chunks, but draining immediately (i.e. without visibly affecting the snow cover) over thiner and more permeable FYI?

...BTW I think this may be true - but probably not directly observable over the small area visible to the camera.

woodstea

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Re: What the Buoys are telling
« Reply #1426 on: June 26, 2017, 05:03:05 PM »
It's amazing to me how fast the transition happened, but I suppose it shouldn't be.

If it's like last year, the buoy will break free first in a melt hole immediately around it, so you'll see the azimuth (and view) start to change as it rotates before the real break up happens.

seaicesailor

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Re: What the Buoys are telling
« Reply #1427 on: June 26, 2017, 05:26:22 PM »
Talking about fast transitions. The 2017A file was updated, showing the last 7-8 days.
If I do a too naive interpretation of these data that in reality have to be viewed with caution, I would say the ice has thinned about 20 cm in one week, but I doubt it is so much. For the temperature of the top thermistors, there is surface melt (or associated abundant drainage, plus direct sun radiation) and probably some centimeters of bottom melt.
« Last Edit: June 26, 2017, 05:39:29 PM by seaicesailor »

ghoti

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Re: What the Buoys are telling
« Reply #1428 on: June 26, 2017, 05:34:54 PM »
Is the top 40 cm of ice directly in contact with the thermisters gradually becoming less salty? I could imagine the melt water on the surface draining into the tube or area around the tube. Then diurnal temperature cycling resulting in brine rejection and a gradual raising of the freezing point.

seaicesailor

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Re: What the Buoys are telling
« Reply #1429 on: June 26, 2017, 07:50:13 PM »
Is the top 40 cm of ice directly in contact with the thermisters gradually becoming less salty? I could imagine the melt water on the surface draining into the tube or area around the tube. Then diurnal temperature cycling resulting in brine rejection and a gradual raising of the freezing point.
I would say it makes sense. Don't know about brine draining, etc.,  although I have read about it, I still don't understand well how it works. So I don't talk about it :-|
The question I personally have is: is this MYI as I suspect or did they plant it over FYI?

Peter Ellis

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Re: What the Buoys are telling
« Reply #1430 on: June 26, 2017, 07:58:21 PM »
It's less than 1.5 metres thick, it's got to be FYI.

Moreover, it was only 80cm thick when they placed the buoy, so at least the bottom ~1/3rd of it is FYI.  But looking at the growth curve it's obvious that if there's any multi-year part of it, it's at most the top few cm.

Look at this and project the curve back to when the freeze-up started...
http://imb-crrel-dartmouth.org/imb.crrel/irid_data/2017A_thick.png

seaicesailor

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Re: What the Buoys are telling
« Reply #1431 on: June 26, 2017, 08:12:45 PM »
It's less than 1.5 metres thick, it's got to be FYI.

Moreover, it was only 80cm thick when they placed the buoy, so at least the bottom ~1/3rd of it is FYI.  But looking at the growth curve it's obvious that if there's any multi-year part of it, it's at most the top few cm.

Look at this and project the curve back to when the freeze-up started...
http://imb-crrel-dartmouth.org/imb.crrel/irid_data/2017A_thick.png
Thanks Peter, makes sense.

Jim Hunt

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Re: What the Buoys are telling
« Reply #1432 on: June 26, 2017, 08:24:20 PM »
I would say the ice has thinned about 20 cm in one week, but I doubt it is so much.

Bear in mind that the top & bottom sounders report:

Snow depth : 5 cm
Ice thickness : 111 cm

i.e. no surface melt yet, and 4 cm bottom melt over the last week.  Trying to estimate floe thickness from the thermistor readings is fraught with difficulty at this stage of proceedings.
"The most revolutionary thing one can do always is to proclaim loudly what is happening" - Rosa Luxemburg

magnamentis

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Re: What the Buoys are telling
« Reply #1433 on: June 26, 2017, 08:53:15 PM »
I would say the ice has thinned about 20 cm in one week, but I doubt it is so much.

Bear in mind that the top & bottom sounders report:

Snow depth : 5 cm
Ice thickness : 111 cm

i.e. no surface melt yet, and 4 cm bottom melt over the last week.  Trying to estimate floe thickness from the thermistor readings is fraught with difficulty at this stage of proceedings.

did you see the latest image? mean about "no surface melt" i call this surface melt, if it is not teach me about what IS surface melt. would be happy to get rid of an eventual mis-interpretation of a term that is key in this forum.

Greenbelt

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Re: What the Buoys are telling
« Reply #1434 on: June 26, 2017, 09:05:48 PM »
Movie has updated, including polar bear selfie at 18:16
http://obuoy.datatransport.org/monitor#buoy14/movie

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Re: What the Buoys are telling
« Reply #1435 on: June 27, 2017, 12:08:24 AM »
did you see the latest image? mean about "no surface melt" i call this surface melt, if it is not teach me about what IS surface melt. would be happy to get rid of an eventual mis-interpretation of a term that is key in this forum.

There are two different buoys being discussed here. When they say "no surface melt", they're talking about IMB 2017A, which doesn't have a camera:

http://imb-crrel-dartmouth.org/imb.crrel/2017A.htm

Jim Hunt

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Re: What the Buoys are telling
« Reply #1436 on: June 27, 2017, 12:44:58 AM »
Teach me about what IS surface melt

This looks like surface melt to me:
"The most revolutionary thing one can do always is to proclaim loudly what is happening" - Rosa Luxemburg

RoxTheGeologist

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Re: What the Buoys are telling
« Reply #1437 on: June 27, 2017, 01:08:18 AM »
I was about to post the same image!

That happened fast.

sedziobs

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Re: What the Buoys are telling
« Reply #1438 on: June 27, 2017, 01:09:20 AM »
Just a friendly reminder that there are 3 different buoys being discussed in this thread: 2017A on the Pacific side of the main basin, 2017B on the Atlantic side, and OBuoy14 in the Canadian Arctic Archipelago. 

magnamentis

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Re: What the Buoys are telling
« Reply #1439 on: June 27, 2017, 02:42:53 AM »
did you see the latest image? mean about "no surface melt" i call this surface melt, if it is not teach me about what IS surface melt. would be happy to get rid of an eventual mis-interpretation of a term that is key in this forum.

There are two different buoys being discussed here. When they say "no surface melt", they're talking about IMB 2017A, which doesn't have a camera:

http://imb-crrel-dartmouth.org/imb.crrel/2017A.htm

thanks a lot woodstea, you obviously saw the reason for the little misunderstanding:-)

magnamentis

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Re: What the Buoys are telling
« Reply #1440 on: June 27, 2017, 02:44:01 AM »
Teach me about what IS surface melt

This looks like surface melt to me:

yep, full agreement obviously, was a misunderstanding as i was referring to B14 and you to another. that's the image i meant, hence all clear and good ;)

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Re: What the Buoys are telling
« Reply #1441 on: June 27, 2017, 04:45:17 AM »
There appears to be an abrupt shift in the "Roll" reading for #14 between the 23rd and 24th. Given the incredible age of this hardware, I often take small changes with a grain of salt (abrupt and unlikely temp spikes for example).

However, the change in Roll appears to be more consistent and I'm wondering if it could indicate an early sign of ice starting to melt out around #14. Back in the early days when #14 had a family, I recall seeing this happen to nearby instruments. (RIP big yellow bucket  :'(  )

Another question came to mind: How deep does #14 sit? In other words, how deep would a melt pond have to be for #14 to float freely?

stonedwaldo

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Re: What the Buoys are telling
« Reply #1442 on: June 27, 2017, 05:01:41 AM »
Something else to mention:
After the consistently warm temps of the last 2+ weeks, mix of sun and overcast/possibly misty wet days, and now all the surface water, #14 is still online! This indicates to me that the seals aren't completely destroyed and the electronics retain some ability to stay dry.

The next big test: Will she float? Then is she seaworthy for her journey to the Nares? (I think)

I'd be curious to take a poll of who thinks #14 will stay online when completely freed from ice.

Jim Hunt

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Re: What the Buoys are telling
« Reply #1443 on: June 27, 2017, 10:32:44 AM »
However, the change in Roll appears to be more consistent and I'm wondering if it could indicate an early sign of ice starting to melt out around #14.

Perhaps it's a sign of being the recipient of a bear hug?

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Back in the early days when #14 had a family, I recall seeing this happen to nearby instruments. (RIP big yellow bucket  :'(  )

2017B has a family that includes a "big yellow bucket". AKA ITP 95

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Another question came to mind: How deep does #14 sit? In other words, how deep would a melt pond have to be for #14 to float freely?

A "melt hole" would be required:

"The most revolutionary thing one can do always is to proclaim loudly what is happening" - Rosa Luxemburg

Jim Hunt

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Re: What the Buoys are telling
« Reply #1444 on: June 27, 2017, 10:45:27 AM »
All clear and good

For additional clarity, it is not beyond the bounds of possibility that the surface around 2017A currently resembles that image. In which case 2017A's top sounder could conceivably be measuring the surface of a melt pond instead of snow. A bit like this perhaps?

http://GreatWhiteCon.info/resources/arctic-sea-ice-images/summer-2015-images/#IMB2015A
"The most revolutionary thing one can do always is to proclaim loudly what is happening" - Rosa Luxemburg

Andreas T

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Re: What the Buoys are telling
« Reply #1445 on: June 27, 2017, 09:22:14 PM »
While we have to guess what we see in front of a remote camera, some people get to poke around in the real thing and see developments close up. Polarstern has spent to weeks tied up along side a floe north of Fram strait taking a wide range of measurements including light levels below the ice as meltponds grow. Sadly we have to wait a long time to see any of the results.
https://www.awi.de/nc/en/expedition/ships/polarstern/weekly-reports/single-view/presse/woche-2-an-der-eisstation.html

A-Team

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Re: What the Buoys are telling
« Reply #1446 on: June 27, 2017, 11:35:18 PM »
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we have to wait a long time to see any of the results.
Thanks for the pointer to 2nd Polarstern blog. These are quite interesting reads and give a good sense of instrument complexity and breadth of scientific angles. They arrived in perfect timing to capture the current melt season.

I don't think it would be helpful to hear scientists cussing fogged-up online goPro cameras as their instruments dump terabytes of mis-calibrated real-time data onto the cloud. Still, we could hope for more rapid dissemination of data that the 28 month wait on N-ICE2015 papers.

In the first post, they go on about the algae Melosira arctica, which [google search] contributes about 45% of photosynthetic carbon fixation in the central Arctic basin. The attached pictures illuminate the limitations (futility?) of just overhead satellites for understanding the modern melt season.

Indeed, none of our algorithmic products (eg ice thickness or extent) incorporate any awareness of algal or planktonic effects on insolation re-distribution; indeed that is completely infeasible since so little is known about them or how rapidly they will change in composition and distribution over time with thinner ice.

https://www.awi.de/nc/en/expedition/ships/polarstern/weekly-reports/single-view/presse/woche-1-an-der-eisstation.html 14 June 2017
https://www.awi.de/nc/en/expedition/ships/polarstern/weekly-reports/single-view/presse/woche-2-an-der-eisstation.html 21 June 2017
https://www.awi.de/nc/en/expedition/ships/polarstern/weekly-reports/single-view/presse/woche-2-an-der-eisstation.html [28 June 2017]
https://www.awi.de/nc/en/expedition/ships/polarstern/weekly-reports/single-view/presse/woche-3-an-der-eisstation.html [05 July 2017]
« Last Edit: June 27, 2017, 11:47:30 PM by A-Team »

vigilius

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Re: What the Buoys are telling
« Reply #1447 on: June 28, 2017, 05:36:26 AM »
Help me understand one thing- didn't #14 totally "go for a swim" in the Beaufort last year before passing McClure Strait? So wouldn't the ice around it be pretty much mostly first year ice? (Attached picture from Jim Hunt's post of September 3, 2016.) I guess I gotta go back and review more pix to see what it met up with when it drifted down the channel...   ...but in any event any MYI it's next to now doesn't seem to me to be the same MYI it was planted in.
« Last Edit: June 28, 2017, 05:51:55 AM by vigilius »

vigilius

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Re: What the Buoys are telling
« Reply #1448 on: June 28, 2017, 05:49:42 AM »
Anyway back to real time updates. That foreground sure is a dark color....

Jim Hunt

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Re: What the Buoys are telling
« Reply #1449 on: June 28, 2017, 08:06:30 AM »
I guess I gotta go back and review more pix to see what it met up with when it drifted down the channel.

How about this one,  from September 10th?

http://GreatWhiteCon.info/resources/arctic-sea-ice-images/winter-201617-images/#OBuoy14
"The most revolutionary thing one can do always is to proclaim loudly what is happening" - Rosa Luxemburg