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Rubikscube

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Re: What the Buoys are telling
« Reply #550 on: May 22, 2015, 07:54:23 PM »


Buoy 2015B, somewhere deep in the Beaufort/Chukchi region
Everything seems to be falling apart around this buoy at the moment, suddenly the crack was transformed into an ocean of slush. It can't be too many weeks before the camera starts bouncing around.
« Last Edit: May 22, 2015, 07:59:58 PM by Rubikscube »

helorime

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Re: What the Buoys are telling
« Reply #551 on: May 23, 2015, 07:43:28 AM »
Wow, that's impressive!

O-Buoy #9   #9   #9  is starting to develop a serieas of new cracks right around it.  Even though it is still quite cold there immediately North of Greenland, it may not have functionality long either.
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Jim Hunt

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Re: What the Buoys are telling
« Reply #552 on: May 23, 2015, 11:50:16 AM »
O-Buoy #9 may not have functionality long either.

O-Buoys are sturdy creatures! Watch the end of this video from October 2013 for evidence of that:

http://youtu.be/mxWIiX-jEQo?t=3m25s
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plinius

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Re: What the Buoys are telling
« Reply #553 on: May 23, 2015, 03:58:31 PM »
I'd like to modify the "despite the clouds". Massive WLA and warm clouds on top give you downwelling long-wave that is more efficient in killing snow than sunshine. That place has seen basically the worst possible melt conditions for May.

ghoti

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Re: What the Buoys are telling
« Reply #554 on: May 23, 2015, 04:53:29 PM »
The 2015A webcam is suddenly back to horizontal showing great watery views. No doubt about the melt ponds there.


plinius

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Re: What the Buoys are telling
« Reply #555 on: May 23, 2015, 06:23:21 PM »
;-) we have kind of a habit to post exactly the same images at quite exactly the same time.

Rubikscube

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Re: What the Buoys are telling
« Reply #556 on: May 27, 2015, 01:04:07 PM »
20 cm of fresh (and wet?) snow just fell on 2015b

Jim Hunt

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Re: What the Buoys are telling
« Reply #557 on: May 27, 2015, 01:25:23 PM »
Whilst 2015A looks distinctly damp in the misty morning light:
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Andreas T

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Re: What the Buoys are telling
« Reply #558 on: May 27, 2015, 04:45:53 PM »
comparing the image in Jims comment #557 with the images of 2015A archived on http://GreatWhiteCon.info/resources/arctic-sea-ice-images/winter-201415-images/#IMB2015A shows recent melt in the increased exposure of the ablation stakes. The ones on the left of the picture were shortened presumed broken off  by the visiting polar bear, but now approx 100mm are visible as the surface level goes down.
http://psc.apl.washington.edu/northpole/NPEO2014/NPEO2014_webcams.html
Quote
Web Camera #1 was a system built and deployed by the Polar Science Center in April 2014 at the Barneo ice camp approximately 25 miles from the North Pole as part of the NSF-funded North Pole Environmental Observatory (NPEO). It was meant to give a visual record of ice changes over the spring-summer-fall season. Ablation stakes made of plywood strips 10-cm wide and marked with alternating black and white 10-cm squares are planted in the ice near the buoy to indicate visually the amount of surface melting as the summer proceeds. The camera was about 1.5 m above the April ice surface.
Interesting description of prototype IMB here http://www.chrispolashenski.com/docs/a57a149.pdf

plinius

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Re: What the Buoys are telling
« Reply #559 on: May 27, 2015, 06:31:07 PM »
From the texture I would hint to semifrozen snow-slush, by the way. Visible from the blurry reflection on the surface, so not real ice so far.

Andreas T

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Re: What the Buoys are telling
« Reply #560 on: May 27, 2015, 06:45:28 PM »

air temperatures are -5deg C according to IMB2015B the snow in the image looks cold to me

The ablation stakes confirm the 20cm Rubikscube showed from the top sounder graph
« Last Edit: May 27, 2015, 09:46:14 PM by Andreas T »

jai mitchell

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Re: What the Buoys are telling
« Reply #561 on: May 27, 2015, 07:05:11 PM »
20 cm of fresh (and wet?) snow just fell on 2015b

That is going to really help!
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JayW

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Re: What the Buoys are telling
« Reply #562 on: May 28, 2015, 10:43:01 AM »
20 cm of fresh (and wet?) snow just fell on 2015b

Compared to this morning's picture.  I don't know how thick the bands are, but looks like the snow went down almost a whole red band.  Temp is 2.7°C currently
http://imb.erdc.dren.mil/2015B.htm
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Siffy

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Re: What the Buoys are telling
« Reply #563 on: May 28, 2015, 10:45:53 AM »
20 cm of fresh (and wet?) snow just fell on 2015b

Compared to this morning's picture.  I don't know how thick the bands are, but looks like the snow went down almost a whole red band.  Temp is 2.7°C currently
http://imb.erdc.dren.mil/2015B.htm

I believe each band is 10cm.

Andreas T

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Re: What the Buoys are telling
« Reply #564 on: May 28, 2015, 01:45:40 PM »
from a description of barneo ice camp
Quote
Ablation stakes made of plywood strips 10-cm wide and marked with alternating black and white 10-cm squares are planted in the ice near the buoy to indicate visually the amount of surface melting as the summer proceeds.
I think this applies to the white / red strips here too
interesting is how, as I noticed last year, clear skies go often with lower air temperatures than low clouds. The input from sun being shortwave and reflected from snow does little to warm surface and air, but is absorbed over greater depth where it penetrates into water and ice. So the heat input shows little or no temp increase when melting point is reached (at bottom salinity) because it goes into latent heat of meltwater
Advected air especially when carrying condensing moisture brings higher air temperature but not as much input into depth. 

epiphyte

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Re: What the Buoys are telling
« Reply #565 on: May 28, 2015, 07:19:40 PM »
That's real heart-attack snow. The kind you don't bother to clear from your driveway because a) you'd probably kill yourself trying to shift more than a few square feet of it, and b) it's so wet that it's almost certain to have disappeared by the time you get home from work.Unless the sky clears above it, that's probably what will happen. Also if there's more precipitation in the area I'd guess it's quite likely to fall as rain and wash it away...

Nightvid Cole

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Re: What the Buoys are telling
« Reply #566 on: May 28, 2015, 07:55:30 PM »
20 cm of fresh (and wet?) snow just fell on 2015b

That is going to really help!

If you look at the JAXA/VISHOP map RGB for 5/27, you can see the white blob of snow cover some distance NNW of Barrow. Compare to the map for 5/24 if you aren't convinced. It's actually fairly localized - the vast majority of the Beaufort/Chuckchi Seas, it appears, got no accumulation at all from the system.

This "blob" could turn out to be an area that is melted into an "ice island" sometime around August 1 and doesn't melt until a week or two afterward.

Rubikscube

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Re: What the Buoys are telling
« Reply #567 on: May 28, 2015, 08:00:10 PM »
That's real heart-attack snow. The kind you don't bother to clear from your driveway because a) you'd probably kill yourself trying to shift more than a few square feet of it, and b) it's so wet that it's almost certain to have disappeared by the time you get home from work.

I agree, but it didn't look that way yesterday, certainly not on the pic posted by Andreas. Really interesting situation.

Meanwhile on O-buoy 12, slightly further north in the same area, there is sun and some visible surface melt.

Nightvid Cole

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Re: What the Buoys are telling
« Reply #568 on: May 29, 2015, 03:13:30 PM »
Surface melt is now discernible at 2013 F:

http://obuoy.datatransport.org/monitor#buoy10/camera

plinius

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Re: What the Buoys are telling
« Reply #569 on: May 29, 2015, 08:19:58 PM »
Also Camera 12 - look at the golden cut on the middle left - getting rapidly bigger

Nightvid Cole

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Re: What the Buoys are telling
« Reply #570 on: May 30, 2015, 03:18:11 AM »
Also Camera 12 - look at the golden cut on the middle left - getting rapidly bigger

It's a melt pond now.

JayW

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Re: What the Buoys are telling
« Reply #571 on: May 30, 2015, 11:02:32 PM »
Looks like bumper cars around buoy 2015B

Attached is a gif of the last 4 images. Edit: apologies, first image is from the other day, messed up when making the gif  :) but the motion is still evident.
« Last Edit: May 30, 2015, 11:10:28 PM by JayW »
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Andreas T

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Re: What the Buoys are telling
« Reply #572 on: May 30, 2015, 11:54:13 PM »
definitely a wet patch near obuoy 12

Andreas T

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Re: What the Buoys are telling
« Reply #573 on: May 31, 2015, 03:11:14 PM »
temperature sensor data from IMB2015A this month: notice the quick rise in water temperature  it went up from -1.7 deg C on the 26th to -0.5 on the 29th and is -0.3 today It'll be interesting to see how long this floe can last with top melt and bottom melt.
x axis is sensor numbers from top starting above ice surface at 100mm spacing
first data point is air temperature, sensors in air are warmed by sunlight and often read too high

ghoti

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Re: What the Buoys are telling
« Reply #574 on: May 31, 2015, 04:13:30 PM »
It really is amazing how this shows the effect of massive flows coming out of the rivers flowing into the Arctic. As Jim Hunt has pointed out the Colville river flow rose rapidly to well above 100,000 cubic feet per second at the time the buoy started measuring -0.5C temperatures below the ice that normally melts at -1.8C

How far out is the nearest ITP buoy and does the fresh water flow that far?

Andreas T

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Re: What the Buoys are telling
« Reply #575 on: June 01, 2015, 10:56:05 PM »
ITP buoy locations are seen here http://www.whoi.edu/page.do?pid=20781, they are a lot further out into the ocean than 2015A which is not far from the coast as seen in the map on Jim's site. The nearest profilers show little change of salinity during the year so rivermeltwater must get diffused a lot under the ice.
One thing that occurred to me is that of course lower salinity of the river water means that higher temperatures are necessary to melt the ice, i.e. low salinity water of -0.5 deg C possibly does less damage that higher salinity water of -1.0 but we will soon see what actually happens.

sedziobs

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Re: What the Buoys are telling
« Reply #576 on: June 02, 2015, 04:21:05 PM »
Air temp at ITP 2015E in the vicinity of Fram Strait reached 0 deg C today.  It will be interesting to track its progress as the low develops over there.

Also, another few cm of snow fell at 2015B.

Andreas T

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Re: What the Buoys are telling
« Reply #577 on: June 03, 2015, 05:53:33 PM »
not so sure about additional snow at 2013B have a look at the image archive at http://ipab.apl.washington.edu/WEB_CAM/USIABP_WEB_CAMERAS.php
The images don't always update so a snowfall would not necessarily be caught on camera but I don't see a change on the red and white ablation stakes.

2015A puzzles me, again I see no change of level on the ablation stakes but there is more white and less water than on 1.6. with snow covering the lens on the 2.6.  Has the water level fallen? Air temp at -3 is that enough for refreezing?  Ice temp is up to -1.5 through the whole floe, not much bottom melt despite water temp at -0.3
In this state I expect sunshine to make a big difference with heat input going in at low albedo.

Peter Ellis

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Re: What the Buoys are telling
« Reply #578 on: June 03, 2015, 06:15:30 PM »
I see a clear change on the ablation stakes.

Compare the left stake in these three (in order)
1)http://ipab.apl.washington.edu/WEB_CAM/camera1/usiabp_camera1_20150531071807.jpg
2) http://ipab.apl.washington.edu/WEB_CAM/camera1/usiabp_camera1_20150601071024.jpg
3)http://ipab.apl.washington.edu/WEB_CAM/camera1/usiabp_camera1_20150603071300.jpg

The water level is just below the first yellow square in picture 1, but almost the whole of the second red square is exposed in picture 3. More of the central white pole is exposed, too. Picture 2 is in between, and the old shoreline of the melt pond is clearly visible.

There has been some new snowfall in between each of these pictures, but the melt pond is also draining.

Yuha

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Re: What the Buoys are telling
« Reply #579 on: June 03, 2015, 06:50:19 PM »
Peter, you are right. The recent big drop in the ice surface level is the melt pond draining. The actual melt happened already earlier during the May heat wave but wasn't observed by the sensor because of the melt pond.

Jim Hunt

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Re: What the Buoys are telling
« Reply #580 on: June 03, 2015, 06:53:47 PM »
A parallel conversation along similar lines is also going on over at:

http://forum.arctic-sea-ice.net/index.php/topic,578.msg53198.html#msg53198

where you can also read the shock news about all the horrid things "Steve Goddard" and his merry minions are saying about yours truly  :o
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Andreas T

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Re: What the Buoys are telling
« Reply #581 on: June 04, 2015, 02:17:47 AM »
Obuoy12 shows some slump in the snow and growing meltponds.
IMB 2014G which is colocated I think doesn't have a working top sounder.

On closer inspection I agree with you, Peter, water level is down. 
Yuha I remember you posted last year on landfast ice becoming lighter in the MODIS images before breaking up.
The draining of the meltponds could be related to the rising ice temperature opening up brine channels making ice more porous.

Yuha

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Re: What the Buoys are telling
« Reply #582 on: June 04, 2015, 02:22:30 PM »
Yuha I remember you posted last year on landfast ice becoming lighter in the MODIS images before breaking up.

Yes, I've observed that when (landfast) ice turns from blue to grey it usually breaks up soon. I don't know if that is caused by melt ponds draining or by the internal structure of the ice disintegrating changing the optical properties of the ice.

Andreas T

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Re: What the Buoys are telling
« Reply #583 on: June 06, 2015, 09:22:29 PM »
Obuoy9 shows  Greenland coast again behind the recently pushed up ridge s
temp at about -4
this will be an interesting picture to come back to as the season develops

Jim Hunt

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Re: What the Buoys are telling
« Reply #584 on: June 06, 2015, 10:33:51 PM »
ITP 59 made its last transmission on June 4th. I reckon I can just about make out what's left of it in the pressure ridge on the extreme left of the picture. Here's how far it got before that fateful day:
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plinius

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Re: What the Buoys are telling
« Reply #585 on: June 06, 2015, 11:43:13 PM »
ITP 59 made its last transmission on June 4th. I reckon I can just about make out what's left of it in the pressure ridge on the extreme left of the picture. Here's how far it got before that fateful day:

You think it was destroyed?
obuoy 9 says it's melting now, by the way. Warmed up quite steeply.

Jim Hunt

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Re: What the Buoys are telling
« Reply #586 on: June 07, 2015, 12:13:38 AM »
You think it was destroyed?

It's certainly no longer where it was, centre stage. It will be interesting to watch the movie once its updated to include the last few days!
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Andreas T

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Re: What the Buoys are telling
« Reply #587 on: June 07, 2015, 05:55:31 PM »
I have tried to mark the position of Obuoy9 on a MODIS image from the lat / long information using the cursor in worldviewhttp://1.usa.gov/1QCehdA
comments please
It is moving along at 26km a day, the azimuth (of the camera?) is given as 150deg which seems measured anticlockwise from north?
temp went above  0 again
« Last Edit: June 07, 2015, 06:02:10 PM by Andreas T »

Rubikscube

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Re: What the Buoys are telling
« Reply #588 on: June 08, 2015, 10:51:58 PM »
I think thats pretty much spot on Andreas, and it looks like it will continue to move pretty fast during this entire week.

Wonder if O-buoy8 is going to be redeployed this year, it was recovered from the arctic in 2013 and has briefly started reporting again such as every O-buoy does before it hits the ice later in the year.

Edit; And 2015b is in trouble, at least there be will one ablation stake left.
« Last Edit: June 08, 2015, 11:03:19 PM by Rubikscube »

Andreas T

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Re: What the Buoys are telling
« Reply #589 on: June 08, 2015, 11:22:01 PM »
I did the same for Obuoy 11
The floe may be recognizable from its shape for a while. It'll be interesting to be able to relate appearance in satellite view with on the ground images.
http://1.usa.gov/1T7TRNO link to worldview

plinius

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Re: What the Buoys are telling
« Reply #590 on: June 09, 2015, 01:50:45 AM »
I did the same for Obuoy 11
The floe may be recognizable from its shape for a while. It'll be interesting to be able to relate appearance in satellite view with on the ground images.
http://1.usa.gov/1T7TRNO link to worldview

I'd contend that this is a hopeless endeavour, since you can see about 100m around a buoy, which is less than the resolution of MODIS. Though it is very interesting to see how that splintering of the flows works from the ground (I never realised how much those flows actually grind each other down).

JayW

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Re: What the Buoys are telling
« Reply #591 on: June 09, 2015, 02:16:35 AM »
I think thats pretty much spot on Andreas, and it looks like it will continue to move pretty fast during this entire week.

Wonder if O-buoy8 is going to be redeployed this year, it was recovered from the arctic in 2013 and has briefly started reporting again such as every O-buoy does before it hits the ice later in the year.

Edit; And 2015b is in trouble, at least there be will one ablation stake left.

Animation of the last couple days

Edit: guess it requires a click, apologies it usually just runs

Darn, I'll try this
http://picasion.com/
« Last Edit: June 09, 2015, 02:24:56 AM by JayW »
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oren

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Re: What the Buoys are telling
« Reply #592 on: June 09, 2015, 07:13:50 AM »
Did that piece just break off? Rotten ice indeed. The whole background looks like it's crumbling, but it's probably giving full extent and area in the stats.

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Re: What the Buoys are telling
« Reply #593 on: June 09, 2015, 12:56:40 PM »
NAOCS  "your buoys took a hell of a beating"    :D


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Re: What the Buoys are telling
« Reply #594 on: June 10, 2015, 04:15:18 PM »
2015B is floating free
If we didn't have the camera images: this is how that shows up in the temperature data.
The snowheight displayed for 2015B has an uptick but again the camera images show this is the floe tilting up as it breaks along the position of 2015B
Ablation stake does show no change in snow height
image link http://ipab.apl.washington.edu/WEB_CAM/USIABP_WEB_CAMERAS.php

At 2015A melt is under way, old ice, darkened by algae melting more strongly despite overcast sky, or is that due to salt content?
« Last Edit: June 10, 2015, 04:22:30 PM by Andreas T »

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Re: What the Buoys are telling
« Reply #595 on: June 11, 2015, 02:48:13 AM »
What time zone do the timestamps on the IMB webcams correspond to?  Given the amount of light at 2015A in the images around 12:00, my guess would be US Pacific, which is the University of Washington's time zone.  Is that right?

Jim Hunt

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Re: What the Buoys are telling
« Reply #596 on: June 11, 2015, 09:33:15 AM »
What time zone do the timestamps on the IMB webcams correspond to?

My understanding is that the clocks on the buoys are all set to UTC, apart from one or two where the raw readings are converted to UTC for the reports.
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Re: What the Buoys are telling
« Reply #597 on: June 11, 2015, 11:22:29 AM »
We could solve it if we knew the orientation of the buoy. I'd suspect it's facing the open ocean, probably to the northwest, which, if I see the position of the Sun right, would place us to Alaskan time.
Other possibility: Daily temperature maximum, if the time in the table is the same as the time in the camera footprint. Looks like sometimes a mild maximum after 12 and a sharp spike around 22 hours. In my trivial mind the first could be daily max, the second would then be sunlight in the buoy sensors...

sedziobs

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Re: What the Buoys are telling
« Reply #598 on: June 11, 2015, 04:01:34 PM »
Looking at these 2015A images, it seems midnight sun is near 0600, which would indicate US Eastern time zone, with the webcam facing approximately north.

2015B is tougher to discern, being farther north, but my guess is that it is also on US Eastern time, with the webcam facing approximately south (June 6th images are mostly clear sky).

My goal was simply to compare the images with weather forecasts.  Knowing the time of each image would be more instructive.

Andreas T

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Re: What the Buoys are telling
« Reply #599 on: June 11, 2015, 09:50:43 PM »
two photos from other threads
Obuoy11 showing beginning of meltpond


obuoy12 after some snowfall
[/img]

It doesn't say explicitly but from lat / long information it looks to me like IMB2014G is colocated with obuoy12 does anybody have information to confirm this? Mind you it doesn't help much to know, top and bottom sounder seem to be out on 2014G
« Last Edit: June 11, 2015, 09:55:59 PM by Andreas T »