What the Buoys are telling

[vigilius]

How about this one,  from September 10th?

My goodness, aren't you the packrat?
Sure saves me some combing through the thread...

[Jim Hunt]

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.

2017A is apparently colocated with a WArming and irRadiance Measurement (WARM) buoy:

https://www.mbari.org/wp-content/uploads/2016/01/WARM-outline.docx

The timing or phenology of primary production in the Arctic is driven by light availability.  A thinner ice cover, with less snow and more ponded area increases the transmission of light to the upper water column, deepening the euphotic layer, and increasing the light available for photosynthesis and net primary production (NPP).

Some areas of the Arctic are now experiencing a second fall bloom initiated by storm mixing, which is more indicative of temperate ecosystems.

[Andreas T]

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

There was still movement after that date which is why I picked an image of early Octuber further up thread. This poorer quality image from the 1st of Oct show conditions when the ice froze in place.

[woodstea]

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    )

The big yellow bucket is still out there, just a bit farther west, on the other side of Stefansson Island:

http://www.whoi.edu/page.do?pid=148096

[seaicesailor]

2017B had updated on the 20th too, I add the plots here.
Even though this buoy is closer to the North Pole, it had no snow on top, and so seems to have (one centimeter of) surface melt. Also 8 cm of bottom melt (185 cm of thickness). This is reported in the web page of the buoy.
http://imb-crrel-dartmouth.org/imb.crrel/2017B.htm

[magnamentis]

melt lakes would be the term i suppose :-)

BTW i doubt those slightly <2m thickness, we shall see but in places it looks very dark like black ocean shining through, let's see :-)

in such places insolaton must have a significant impact, warming surface waters and accellerating the melt process a lot. if this is not local as it seems not to be, we could see very early openings over large areas in the NW-Passage. sat images underline that somehow.

[Tor Bejnar]

I can sort of match (in image that magnamentis just posted) the whiter sections that are under water with the thicker ice from last fall (see Andreas' June 28 post just above).  Am I making this up?

[Yuha]

I can sort of match (in image that magnamentis just posted) the whiter sections that are under water with the thicker ice from last fall (see Andreas' June 28 post just above).  Am I making this up?

I'm seeing it too, and it's even clearer when you compare to the image vigilius posted yesterday:

http://forum.arctic-sea-ice.net/index.php/topic,327.msg118567.html#msg118567

[magnamentis]

I can sort of match (in image that magnamentis just posted) the whiter sections that are under water with the thicker ice from last fall (see Andreas' June 28 post just above).  Am I making this up?

that's about it while the already "deeper" waters hide some of that what yesterday was even more obvious

EDIT: as mentioned above

[oren]

Anyone care to guesstimate the depth of the melt lake? Could it be 30-50 cm? (Probably belongs in stupid question thread...)
It's been developing at a crazy pace.

[Lord M Vader]

Wasn't there someone here at the forum who is living at/near Resolute? Maybe he/she has some good info about the melt water sea

[magnamentis]

Anyone care to guesstimate the depth of the melt lake? Could it be 30-50 cm? (Probably belongs in stupid question thread...)
It's been developing at a crazy pace.

30-50 sound reasonable while i think some small spots could be a bit deeper. and then as we know from our private pools the breaking light plays often games with our visual receptors LOL

[magnamentis]

Wasn't there someone here at the forum who is living at/near Resolute? Maybe he/she has some good info about the melt water sea

i don't think those are very local and even in case they are widely spread, a connection between the shape and depth of one lake to another cannot be made and certainly not when that far apart.
too many factors like the state of a spot on freezing day, the day when things got mostly immobile, play a role here.

[seaicesailor]

Wasn't there someone here at the forum who is living at/near Resolute? Maybe he/she has some good info about the melt water sea

Wayne Davidson over the blog if Im not mistaken

[ghoti]

On May 2, 2017 Wayne posted his predictions. He nailed the sudden melt event we've witnessed at Obuoy 14:

  I would expect record number of melt Ponds -late- from all that thick snow cover.  This will accelerate the melt rapidly,   numerous melt ponds will signal the start of very rapid melting, after seemingly sluggish melt daily rates interspersed with at times great variations caused by the lack of sea ice consolidation.

He also wrote:

...since too much snow halted accretion for more than a month,  the melt season also was delayed but from a thinner point,  when this snow disappears in June,  there will be huge water ponds, the ice will vanish extremely quickly then after.  So the later first melt date would have significance if the sea ice thickness was more average in thickness.  Otherwise,  on a larger Arctic Ocean scale,  if thick snow is laced all over the Arctic as it appears to be so,  the illusion of a normal sea ice melt rate will last until severe sudden disintegration.

 

He lives only a few hundred km from Obouy 14.

[oren]

Newsflash - I could swear the lake is draining or something. The white features are much higher in the water than they were earlier today. Also the water's coloring gives the hint of less depth.

[woodstea]

Newsflash - I could swear the lake is draining or something. The white features are much higher in the water than they were earlier today. Also the water's coloring gives the hint of less depth.

Perhaps -- it's so hard to tell though with such a different sun angle. The first picture is more of a dawn type lighting from behind the camera.

[magnamentis]

Newsflash - I could swear the lake is draining or something. The white features are much higher in the water than they were earlier today. Also the water's coloring gives the hint of less depth.

interesting, i just thought that those are not 30-50cm anymore but then who knows how much is due to light playing games with our eyes. however i as well would say that there is less depth.

let's see, if it really drains it will clearly show quite soon.

[vigilius]

Just two hours later, basically the same shot but with the reflection of the sun the pool seems more robust.

[vigilius]

And just for perspective the clearer skies today afford a nice Worldview shot of dramatic breakup between #14 and Resolute. The buoy is somewhere in the neighborhood of the upper left corner of this image, I think. All this abrupt change is sort of exciting as I continue to anthropomorphize the heroic buoy.

[Watching_from_Canberra]

Just looking at the OB14 pitch and roll graphs:
http://obuoy.datatransport.org/monitor#buoy14/gps

Pitch fluctuates by up to 10 degrees, generally returning to zero.  Roll is only fluctuating by fractions of a degree around an average that is changing slightly.  Seems odd for one to vary by significantly more than the other.  Thoughts?  Malfunctioning sensors?

[woodstea]

Pitch fluctuates by up to 10 degrees, generally returning to zero.  Roll is only fluctuating by fractions of a degree around an average that is changing slightly.  Seems odd for one to vary by significantly more than the other.  Thoughts?  Malfunctioning sensors?

I wouldn't doubt that after all this time that the sensors aren't operating at 100%. But I can also imagine that, depending on the configuration of the ice that the buoy is frozen into, as well as typical wind/current/wave patterns at that location, that there could be more motion in one direction than another. If you're in a boat facing into a series of waves, for instance, there's going to be more pitch than roll. Turn the boat 90 degrees and you'll have the opposite.

I sure with the camera would update. We've had lapses before, but it worries me.

[magnamentis]

Pitch fluctuates by up to 10 degrees, generally returning to zero.  Roll is only fluctuating by fractions of a degree around an average that is changing slightly.  Seems odd for one to vary by significantly more than the other.  Thoughts?  Malfunctioning sensors?

I wouldn't doubt that after all this time that the sensors aren't operating at 100%. But I can also imagine that, depending on the configuration of the ice that the buoy is frozen into, as well as typical wind/current/wave patterns at that location, that there could be more motion in one direction than another. If you're in a boat facing into a series of waves, for instance, there's going to be more pitch than roll. Turn the boat 90 degrees and you'll have the opposite.

I sure with the camera would update. We've had lapses before, but it worries me.

damn, you're right, sure don't want to loose the only remaining little key-hole that allows us to get a tiny giimps at what happens up there. worried as well. the rest i gonna safe because i'm not a priest LOL

[oren]

I have a bad feeling all that water got to it, as someone upthread suggested might happen.

[magnamentis]

I have a bad feeling all that water got to it, as someone upthread suggested might happen.

batteries and weather station still online, right now it's the cam, power also looks fine,
perhaps the ice-bear came back and didn't want to be filmed/photographed [JK]

[stonedwaldo]

Agreed, the camera going offline yesterday is not a good sign.... Given that we see no strange voltage spikes, load spikes, and other equipment is working, I'm holding out hope that we begin to receive fresh images when the computer restarts after the next power shortage. (My theory is that the batteries failed earlier this spring and are only providing a little buffering for the solar panels. As such, when you combine the lower intensity sunlight during arctic summer nights with some heavy cloud cover, the buoy powers down)

I too have absolutely loved looking at this camera over the last year+ and REALLY hope that this is not the first sign of #14 filling with water as the melt progresses. Being a pessimist, i still don't think she will handle open ocean nearly as well as she did last fall..... even if everything comes back online after the next computer reboot.

[Pmt111500]

Just looking at the OB14 pitch and roll graphs:
http://obuoy.datatransport.org/monitor#buoy14/gps

Pitch fluctuates by up to 10 degrees, generally returning to zero.  Roll is only fluctuating by fractions of a degree around an average that is changing slightly.  Seems odd for one to vary by significantly more than the other.  Thoughts?  Malfunctioning sensors?

I don't see sensors malfunctioning, there's of course the m/s mark on speed graph on which the 's' should be something else than 'second'. Maybe 'meters per signal'? Then we would just have to know what's the data sending/receiving frequency on this metric and the true speed of the floe would be 'easy' to calculate...

The data looks like the the floe the Obuoy14 is on has cracked itself free of the neigboring floes on June 26th. Disintegration of the pack on the area would thus have begun. It's still a pack though and the continued returning to 0 would say the floe is one of the thickest up there. The tilt could soon change to show constant small tilt as the floe should capture loose ice to its nooks and crannies underneath surface. The wobbles in the tilt could just be the floes reaction to ice that's been pushed umder the ice by opposing forces of current and constant pushback by the lands nearby. 10 degrees isn't that much.

That the roll is near zero would (to me) say the neighboring floes are keeping the pack tight, so there could be several cycles of meltponds/draining ahead before final melt.

On the currents in the area, on the buoy location afaik they have still been towards east and Greenland and then turning south through the archipelago. Thus the buoy might end up near the shore of continental Canada.

[Andreas T]

as discussed several times before, the m/s has to be read together with the 100m on the axis making it 100mm/s i.e. 0.1m  still a fair speed but not in a single direction.
There are no changes in Azimuth which usually happens when floes move, this shows up before the low resolution of the lat/lon display in the graph shows movement.
The small change in roll is most likely a sign of a gap starting to form around the buoy. The clear satellite images of the area near the buoy still show no signs of breakup and movement in the last two days.
What I expect to happen before breakup starts is a draining of meltponds, which will show up as a whitening in the satellite images.

[Darvince]

The camera still hasn't updated...

Might the bear have chewed some wires when it was visiting? 

[Andreas T]

....without leaving footprints now that the snow is gone.
I am surprised nobody has commented on it yet, but on the 28th there was another high CO2 reading. If it is genuine and not a bear breathing close to the sensor, what else could that be. Not intending this as a rhetorical question. Could CO2 be released from the ice, below the ice?

[vigilius]

Yippee! And I guess it has drained a bit.

[Darvince]

....without leaving footprints now that the snow is gone.
I am surprised nobody has commented on it yet, but on the 28th there was another high CO2 reading. If it is genuine and not a bear breathing close to the sensor, what else could that be. Not intending this as a rhetorical question. Could CO2 be released from the ice, below the ice?

I was thinking that the bear that visited on the 23rd,

just like that, an ice-bear sniffing at the co2 sensor LOL (not sayin' just for fun )

may have tried to open it to find something inside, but wound up chewing wires and making them much more unreliable instead.

[oren]

Very glad it's back. A little animation to prove to myself that there actually was a lowering of the water level. On a curious note, it seems the tilt is different between the images. CLICK.

[RoxTheGeologist]

The surface has gone from white (snow) to blue (melt ponds) to gray (ice?). This color sequence is not uncommon on worldview.

A loosely compacted layer of snow would melt with relatively little energy input compared to the old ice, so a wide range of conditions with melt pond drainage could create the visible effect.

[A-Team]

On a curious note, it seems the tilt is different between the images

The horizons match but are off from level by 0.96º (left is too low). Beyond that, it seems the camera mast has tilted off-vertical in the later image, compressing the perspective. Do we know how the camera is gimbaled? (https://en.wikipedia.org/wiki/Gimbal)

[Yuha]

On a curious note, it seems the tilt is different between the images.

My theory is that the buoy was held down by the ice and has popped upwards when the grip of the ice was released. In fact, the melt pond may well have been drained through the buoy hole.

[Andreas T]

I agree with Yuha, the change is consistent with raising the camera without changing its tilt. The closer any features are to the camera the further they have moved down in the image, I would call that expanding the perspective.
The "roll" angle has become a little less (back to where it was after the 24th). If the camera elevation above the ice had changed by tilting the buoy and keeping the camera horizontally alligned (I guess that is what A-team suggests) the tilt of the buoy would have to be significantly larger. Back in september there were large changes in the position of the horizon in the images togther with a roll angle of 10 degrees, which speaks against thre camera being gimballed to remain horizontal.
I am struggling to think of a process which would lock the buoy in the ice in autumn when it was floating on the ocean but float it higher when it refloats in the summer, but it is the most logical explanation.

The other feature that orens animation (thank you) brings out is that the features I recognized from Octuber in the flooded images but not in the drained later images are recognizable again. They are not so much differences in surface elevation but differences in transparency of the ice, probably thickness too.

[Jim Hunt]

Do we know how the camera is gimbaled?

I don't think it is. Watch the video from ~7:50, when it melted out of its floe last summer. It looks to me as if the camera is firmly tied to the mast.

[Andreas T]

taking the buoy location from the data shown in the "movie" frames as
 74^o11'42"N / 103^o03'24"W  (the minute and second symbols are misplaced in the frame display)
and locating that in worldview where pointer locations are diplayed in the bottom right corner. Ithen 3located the same floe pattern in sentinel playground where I don't know what the lat/lon reference in the URL refers to
http://apps.sentinel-hub.com/sentinel-playground/?lat=74.19198024243777&lng=-102.94498443603516&zoom=11&preset=CUSTOM&layers=B8A,B03,B02&maxcc=100&gain=0.4&gamma=0.7&time=2015-01-01|2017-07-01&cloudCorrection=none&atmFilter=&showDates=false&evalscript=
This way I arrive at a close up view of the approximate location of Obuoy14 shon below. Not hugely informative but lets see if it becomes more interesting as the melt progresses. It nice to have such  higher resolution images at our fingertips

[Jim Hunt]

locating that in worldview where pointer locations are diplayed in the bottom right corner. I then located the same floe pattern in sentinel playground where I don't know what the lat/lon reference in the URL refers to.

Why not cut out the middle man and simply add the decimal version of the lat/long to the URL?

http://apps.sentinel-hub.com/sentinel-playground/?lat=74.195&lng=-103.0567&zoom=13&maxcc=100&gain=0.5&time=2017-07-01

[magnamentis]

Do we know how the camera is gimbaled?

I don't think it is. Watch the video from ~7:50, when it melted out of its floe last summer. It looks to me as if the camera is firmly tied to the mast.

don't forget about the bear LOL [Just Kidding]

[woodstea]

What a relief! I remember losing the camera image for a day or two before. I wonder whether perhaps some drive filled up back at Wood's Hole or Bigelow, wherever they process and archive the imagery.

I don't think the buoy has come free from the ice. If it has, it's not free enough yet to rotate so that the azimuth changes as it did when the buoy was free last year.

My guess is that the different floes around the buoy are moving somewhat relative to each other, heaving a little bit, tilting a bit, as winds and currents cause compression and decompression. The floes may not be completely independent yet -- but there are enough fractures and thinner areas that some movement is possible.

[A-Team]

heaving a little bit, tilting a bit, as winds and currents cause compression and decompression.

See what it does next, I guess.

The animation shows the zoom sequence at Sentinel playground. The stages are 2x at the low end but depart from that later. I looked at the 2016 for a comparable date but the clouds made it difficult to pin down a melt-date.

While this is a fabulous front end, the related site Land Viewer adds Landsat-7, Landsat-8 and Modis to the options as well as different contrast controls, pin placement, and Area of Interest storage (in the form of .geojson text files in which the lat,lon for the buoy can be entered.

{"type":"Feature","properties":{},"geometry":{"type":"Point","coordinates":[-103.056,74.195}}

[Andreas T]

am I doing something wrong? I can seen much fewer sentinel and even MODIS images on that Land Viewer site than I see on sentinel playground or worldview. It offered me nothing more recent than 13. June on MODIS at  poorer quality than on worldview.
Do I need different settings?

[A-Team]

see far fewer sentinel and MODIS images on Land Viewer site than on sentinel playground or worldview

What Worldview does, it does very well, so for Modis stick with that. A possible advantage with these other portals could be co-registration. Over at Petermann, where 3-4 Sentinels per day can be taken because of the orbit, LandViewer shows 29 June as the latest. I don't know their update policy nor how rapidly the interface is diverging from Playground nor whether they respond to user feature requests.

There can be advantages to Playground, for example single-click to step back a year. I have not been to the usgs Landsat-8 interface for a while; they had been intending to add Sentinel-2AB.

For an easy time series, take whole-window screenshots (command - control - shift - 4 - space on Macs), then crop or resize to 700x700 pixels for animation layers. This may lose something relative to downloading original jp2 channels (which are cut to size) but it is a lot faster.

The CAA buoy area has far fewer visits and the June weather was so cloudy that it was difficult to resuscitate the 25 June scene (foggy 2nd frame, global contrast/brightness 3rd frame, CLAHE local contrast enhancement 4th frame. (The tools provided are not sufficient for this at either portal.) Bulk motion of ice over the course of a week is not apparent at the resolution shown.

The buoy gps may be much better for this. Note the WHOI 'movie" shows slightly varying azimuth (yaw), pitch and roll relative to the mast and camera axes. Those provide three elemental rotation matrices whose product could fix the horizon and tilt if entered in the perspective tool of gimp. WHOI could have done this on the fly but did not.

[vigilius]

Comparing 7/1 to 7/3, there's a nice block in the center foreground that has popped up nicely after lurking under the water for the last week. So have all the little lumps in front of it. Looks like a tub full of ice cubes. With increasing points of communication between the top and bottom we may not see many more draining events where the water level drops, instead, just ice blocks bobbing up and down. (click to animate)

[Andreas T]

not a spectacular development but I think these openings which are developing along the islands surrounding this part of the Parry channel are going to allow the ice there room for movement which will start the breakup. Together with the sunshine on lowered albedo ice which is melting old cracks and weak points the now snow free islands are a major driver. Now clear skies do have a warming effect they didn't have earlier in the season.

[oren]

The buoy images change a lot every few hours, mostly I guess having to do with sun angle, but also some actual changes going on when looking carefully, such as some disappearing ice pieces in the right-hand foreground. CLICK to animate.

[Rob Dekker]

Those images from Obuoy 14 are quite dramatic.

It is clear that the melting ponds already drained, which means there are openings in the ice to the ocean. What is not clear is how much longer this ice can withstand the relentless insolation that came with the high pressure zone over the area.

At some point, this ice should disintegrate in-situ and start breaking up.
Even Slater's forecast is that Parry Channel will likely open up this year :

[magnamentis]

Those images from Obuoy 14 are quite dramatic.

It is clear that the melting ponds already drained, which means there are openings in the ice to the ocean. What is not clear is how much longer this ice can withstand the relentless insolation that came with the high pressure zone over the area.

At some point, this ice should disintegrate in-situ and start breaking up.
Even Slater's forecast is that Parry Channel will likely open up this year :

this is a very optimistic ( ice friendly ) prediction IMO, almost looks like what we see today extent wise. i expect much less extent that in that image by the end of august ( i consider 22nd of august end of august )