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Pmt111500

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Re: What the Buoys are telling
« Reply #1250 on: March 02, 2017, 03:31:08 PM »
Up in the sky Venus keeping company to the buoy.
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Oddmonk

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Re: What the Buoys are telling
« Reply #1251 on: March 02, 2017, 05:13:28 PM »
Up in the sky Venus keeping company to the buoy.

Yes.

Andreas T

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Re: What the Buoys are telling
« Reply #1252 on: March 04, 2017, 11:49:04 PM »
The photovoltaic panels seem to be charging the batteries enough now to keep the buoy running through the hours of darkness. But clear skies also mean heat loss with little downward IR as seen in the temperature readings.

jdallen

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Re: What the Buoys are telling
« Reply #1253 on: March 05, 2017, 01:28:43 AM »
The photovoltaic panels seem to be charging the batteries enough now to keep the buoy running through the hours of darkness. But clear skies also mean heat loss with little downward IR as seen in the temperature readings.
Temperatures that low is good.  If the ice itself is chilled as well, that's 1-2CM/day of growth potential, assuming ice of at least 2M thickness.  The $64 question is how long we'll have these wonderful temperatures, and if we're getting similar elsewhere over large enough stretches of the basin.
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Gray-Wolf

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Re: What the Buoys are telling
« Reply #1254 on: March 05, 2017, 10:36:34 AM »
The photovoltaic panels seem to be charging the batteries enough now to keep the buoy running through the hours of darkness. But clear skies also mean heat loss with little downward IR as seen in the temperature readings.
Temperatures that low is good.  If the ice itself is chilled as well, that's 1-2CM/day of growth potential, assuming ice of at least 2M thickness.  The $64 question is how long we'll have these wonderful temperatures, and if we're getting similar elsewhere over large enough stretches of the basin.

Shame it's not October?
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jdallen

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Re: What the Buoys are telling
« Reply #1255 on: March 05, 2017, 06:57:37 PM »
The photovoltaic panels seem to be charging the batteries enough now to keep the buoy running through the hours of darkness. But clear skies also mean heat loss with little downward IR as seen in the temperature readings.
Temperatures that low is good.  If the ice itself is chilled as well, that's 1-2CM/day of growth potential, assuming ice of at least 2M thickness.  The $64 question is how long we'll have these wonderful temperatures, and if we're getting similar elsewhere over large enough stretches of the basin.

Shame it's not October?
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Eli81

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Re: What the Buoys are telling
« Reply #1256 on: March 06, 2017, 10:26:28 PM »
Indeed, a nice stretch of operation - going on 5 days now. Being a battery person, you can actually "see" the cold temperatures in the battery voltage - peaking at 16V! That's a tad high for a lead acid. That will come down as the temperatures and therefor battery internal resistance drops.

Almost -50C last night again.

Does look quite chilly...

Lord M Vader

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Re: What the Buoys are telling
« Reply #1257 on: March 07, 2017, 07:06:57 PM »
Hey folks, do you have this site showing at least 8 bouys temperatures over the Canadian Arctic? Zoom in and out and you will find mintemps ranging from -2F to -40F over the open Arctic basin! And also info about the bouys temps over the last 7 days!

http://www.wrh.noaa.gov/map/?&zoom=6&center=62.451405884537564,-155.6982421875&basemap=OpenStreetMap&boundaries=true,false&obs=true&obs_type=weather&elements=temp,wind,gust&obs_popup=false&obs_density=3

Andreas T

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Re: What the Buoys are telling
« Reply #1258 on: March 12, 2017, 11:47:33 PM »
The latest blast of (relatively) warm humid air which entered  the arctic from across east siberia has reached Obuoy14.
Temperature is up above -15degC.
By the way: checking temperatures at Resolute suggest that the low temperatures seen when the buoy "woke up" were the lowest of the winter.

Andreas T

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Re: What the Buoys are telling
« Reply #1259 on: March 13, 2017, 11:57:41 PM »
clearer sky today brings a slight drop in temperature. Cloudiness can also be seen by lower battery voltage when PV panels don't deliver much charging current.

Eli81

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Re: What the Buoys are telling
« Reply #1260 on: March 15, 2017, 01:34:09 AM »
Woohoo! They have updated the movie. 2017 starts at about 14:10.

Sunset in the Arctic...

Watching_from_Canberra

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Re: What the Buoys are telling
« Reply #1261 on: March 16, 2017, 09:20:01 AM »
What's the second colour on the battery graph?  Lithium batteries starting to take charge?
http://obuoy.datatransport.org/monitor#buoy14/batteries

Eli81

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Re: What the Buoys are telling
« Reply #1262 on: March 17, 2017, 05:56:24 AM »
The lithium banks are primary (non-rechargeable) batteries.

I'm thinking it's temperature related. The lithium bank is dead, but it's voltage will vary based on ambient temperature. Colder temperatures will lower cell voltages, and warmer temperatures will raise them.

Either that or it's due to bank loading - over the winter, the systems would have been trying to draw from the lithium bank, but as mentioned its dead, so the voltage would collapse rather than support any load. Now that the lead-acid is taking a charge, they're completely unloaded.


epiphyte

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Re: What the Buoys are telling
« Reply #1263 on: March 29, 2017, 07:02:34 PM »
There's been discussion in more than one thread touching on the <1M Beaufort ice thickness currently being reported from IMB 2017A. Looking for some enlightenment as to whether the buoy's single-point measurement is representative of the general area I looked back a few days on Polarview until I found a Sentinel 1 image covering its location.

The latest I could find was taken on 3/23/17 at a time when the buoy was at 146.60701W, 72.81730N. Unless I've messed up that should be just about in the center of the boxed crosshairs in the graphic below. For reference as to scale, the box is ~2.5KM on a side.

I'll refrain from too much amateur analysis of the image because I probably don't know what I'm talking about, but for what it's worth I'd hazard that the surrounding neighborhood -

 - has not been subjected to significant stress in the time since it became a contiguous sheet. (since there are no frozen-over cracks)

 - Contains at least some ice which is more than a year old. (since there are rounded, pebble-shaped, darker areas suggestive of heavily melted "rubble" floes)

« Last Edit: March 29, 2017, 07:11:40 PM by epiphyte »

woodstea

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Re: What the Buoys are telling
« Reply #1264 on: March 30, 2017, 03:24:08 PM »
Nice shadow from O-Buoy 14 this morning.

Jim Hunt

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Re: What the Buoys are telling
« Reply #1265 on: April 04, 2017, 11:40:39 AM »
An intriguing artifact at the top of this webcam image in the dead of night:
Reality is merely an illusion, albeit a very persistent one - Albert Einstein

DrTskoul

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Re: What the Buoys are telling
« Reply #1266 on: April 04, 2017, 12:31:20 PM »
An intriguing artifact at the top of this webcam image in the dead of night:

The light at the end of the tunnel?

A bear with a flashlight?
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Andreas T

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Re: What the Buoys are telling
« Reply #1267 on: April 04, 2017, 02:43:10 PM »
My guess would be the moon, but it'll take me a while to work out where the moon was at that time.

gerontocrat

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Re: What the Buoys are telling
« Reply #1268 on: April 04, 2017, 03:13:12 PM »
My guess would be the moon, but it'll take me a while to work out where the moon was at that time.

On April 3 the Moon was half full.  Corresponding well with the image.

magnamentis

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Re: What the Buoys are telling
« Reply #1269 on: April 04, 2017, 11:43:16 PM »
An intriguing artifact at the top of this webcam image in the dead of night:

that's the moon [just kidding of course]
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Andreas T

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Re: What the Buoys are telling
« Reply #1270 on: April 05, 2017, 12:43:42 AM »
An intriguing artifact at the top of this webcam image in the dead of night:


that's the moon [just kidding of course]

????
or, applying knowledge and understanding courtesy of "Stellarium" http://www.stellarium.org/en_GB/
the view at 74.25N 103W at 6:30UTC 4. 4. 2017

Jim Hunt

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Re: What the Buoys are telling
« Reply #1271 on: April 05, 2017, 10:32:13 AM »
A couple of previous moonshots:
Reality is merely an illusion, albeit a very persistent one - Albert Einstein

magnamentis

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Re: What the Buoys are telling
« Reply #1272 on: April 05, 2017, 10:53:43 PM »
An intriguing artifact at the top of this webcam image in the dead of night:


that's the moon [just kidding of course]

????
or, applying knowledge and understanding courtesy of "Stellarium" http://www.stellarium.org/en_GB/
the view at 74.25N 103W at 6:30UTC 4. 4. 2017


it was cowerdice LOL and after 16 hours of work i just didn't have to energy to verify, thanks for the link and i hope the "part-quote" was made with a smile and not an evil grin haha.....
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DrTskoul

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Re: What the Buoys are telling
« Reply #1273 on: April 06, 2017, 12:40:22 AM »
An intriguing artifact at the top of this webcam image in the dead of night:


that's the moon [just kidding of course]

????
or, applying knowledge and understanding courtesy of "Stellarium" http://www.stellarium.org/en_GB/
the view at 74.25N 103W at 6:30UTC 4. 4. 2017


it was cowerdice LOL and after 16 hours of work i just didn't have to energy to verify, thanks for the link and i hope the "part-quote" was made with a smile and not an evil grin haha.....


Or just being in a playful spirit and making up silly answers...
“You can know the name of a bird in all the languages of the world, but when you're finished, you'll know absolutely nothing whatever about the bird... So let's look at the bird and see what it's doing -- that's what counts.”
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magnamentis

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Re: What the Buoys are telling
« Reply #1274 on: April 06, 2017, 05:06:55 PM »
that had to be expected after my last one, very informative but it's ok, can live with it :-)

just have a look at the time stamp and you'll easily see that it was much later that i was seeing that post, without knowing the later posts, hence when i wrote mine i was not aware of how old the post i replied to was and did not know that there were many replies referring to the moon. it was well meant and by no means silly, can happen, it's called ninja-post for experience multiple forum participants, a totally normal thing to happen.
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stonedwaldo

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Re: What the Buoys are telling
« Reply #1275 on: April 12, 2017, 05:04:00 PM »
All does not appear to be well with the battery system on Buoy 14.
From my experience, it appears that the AGM batteries are becoming unstable under load due to age. I have seen some blizzard conditions on the camera, so maybe it's just lack of sunlight.... but that voltage behavior appears to be increasingly unstable.

I manage large battery systems for a living, and as they get old, you begin to see issues where the battery voltage will suddenly drop under load, even though the battery should still be at ~30 or 40% capacity.

As full day sun returns, my hope is that these batteries will spend less time in the low charge range and old age stability issues will be less of an issue. They still seem stable when fully charged at least :-|

Neven

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Re: What the Buoys are telling
« Reply #1276 on: April 12, 2017, 06:29:07 PM »
Welcome to the ASIF, stonedwaldo. Your profile has now been released, so you can comment freely.
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Andreas T

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Re: What the Buoys are telling
« Reply #1277 on: April 12, 2017, 07:36:46 PM »
@stonewaldo, I noticed the "battery voltage" during sunshine hours is higher than last summer. Would that be an indication that the batteries are not charging properly, i.e. drawing less current from the PV panels?
We have to hope that the buoy can function intermitendly until 24h sunlight arrives, on 5th of May I think. https://en.wikipedia.org/wiki/Midnight_sun#/media/File:Midnight_sun_dates_svatlas.png

stonedwaldo

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Re: What the Buoys are telling
« Reply #1278 on: April 14, 2017, 03:37:30 AM »
That's hard to say, this is a slightly different type of battery than I use and mine usually operate at 30C, not -30C. However, it's possible.

Another theory I have is that the supervisory computer appears to select what sensors and equipment to run based on how much power it thinks is available. If the batteries are starting to get weak, it might not be running the Iridium transmitter or ozone sensor as often and that is allowing more voltage to build up in the pack.... That doesn't necessarily mean the battery can support as many amps of load though.

As long as the battery remains electrically conductive, things should work when full sun returns May 5th like you mention.

Is it possible that the computer is starting to crash due to corrosion or the rough environment? Computers usually last for 10+ years, but mine don't live in the ocean :-)

stonedwaldo

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Re: What the Buoys are telling
« Reply #1279 on: April 14, 2017, 03:49:16 AM »
Is buoy #14 different from all the other buoys? Looking at all of the other histories, they seem to have only run for a single season, dying sometime in mid winter and never coming back online. Is there something special about #14 that allowed it to run so much longer and even come back online again this spring? Different hardware or a totally different buoy system?

(sorry if this has been asked and answered already)

DrTskoul

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Re: What the Buoys are telling
« Reply #1280 on: April 14, 2017, 04:06:47 AM »
The little buoy that could....
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oren

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Re: What the Buoys are telling
« Reply #1281 on: April 14, 2017, 07:39:00 AM »
I don't think there is anything inherently different. Luck I guess.

Jim Hunt

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Re: What the Buoys are telling
« Reply #1282 on: April 14, 2017, 09:49:55 AM »
Several other O-Buoys have previously managed to survive the winter. Number 9 for example:

http://GreatWhiteCon.info/resources/arctic-sea-ice-images/winter-201314-images/#OBuoy9
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Andreas T

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Re: What the Buoys are telling
« Reply #1283 on: April 14, 2017, 10:38:15 PM »
posted by Jim on another thread but worth keeping here where its doesn't get buried so quickly:
There's no sign of any activity on the North Pole Environmental Observatory web site, but nonetheless there is now an ice mass balance buoy in situ near the North Pole:


[url=http://GreatWhiteCon.info/resources/ice-mass-balance-buoys/winter-201617-imb-buoys/#2017B]http://GreatWhiteCon.info/resources/ice-mass-balance-buoys/winter-201617-imb-buoys/#2017B][/url]

To celebrate I've updated the IMB buoy temperature profiles slightly. The dotted lines at the left show maximum and minimum air temperature over the preceeding 24 hour period. The thermistor 1 reading is now in column 2.

As also reported by the the [url=http://greatwhitecon.info/2017/04/2-degrees-north-pole-expedition/]2 Degrees North Pole Expedition[/url], it's warming up in the area.

Current Buoy Data (04/12/2017):

Pos: 89.19 N, 30.07 E
Air Temp: -15.56 C
Air Pres: 1020.69 mb
Snow depth : ? cm
Ice thickness : 172 cm
[/url]
« Last Edit: April 14, 2017, 10:43:16 PM by Andreas T »

stonedwaldo

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Re: What the Buoys are telling
« Reply #1284 on: May 02, 2017, 02:08:04 AM »
There have been some epic arctic snowscapes and sunsets lately as the days get longer. I hope this buoy keeps going just for these incredible images, not to mention the scientific data.

I know this is the last of the O-BUOY Project units still operating, but are there other arctic buoys with real time web feeds and such?

Watching_from_Canberra

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Re: What the Buoys are telling
« Reply #1285 on: May 03, 2017, 10:44:41 AM »
Look, a UFO!  :P


Andreas T

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Re: What the Buoys are telling
« Reply #1286 on: May 06, 2017, 08:31:32 AM »
those clouds have kept overnight temperatures up. Not sure what to make of those spiky temperature readings, they usually don't jump up and down so rapidly and air temperatures shouldn't.
CO2 and Ozone sensors have stopped working and wind speed did not "wake up" after the winter, so pictures and temperatures and GPS is all it is sending.

Pmt111500

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Re: What the Buoys are telling
« Reply #1287 on: May 07, 2017, 08:52:31 AM »
Is buoy #14 different from all the other buoys? Looking at all of the other histories, they seem to have only run for a single season, dying sometime in mid winter and never coming back online. Is there something special about #14 that allowed it to run so much longer and even come back online again this spring? Different hardware or a totally different buoy system?

(sorry if this has been asked and answered already)

The forces involved with ice compaction and general freezing fog formation in autumn/early winter are likely to destroy either the buoyancy material, gaskets protecting the onboard computer, or the batteries might be destroyed in the general cold. Salty icing fog in an early winter storm would be quite bad. Compare this f.e. to sinking a modern car to the ocean for couple of days and then freezing it up. Will it start once it unfreezes and dries? Good luck I'd say. Could be the Buoy was just in time to enter NW passage to avoid the worst of it.
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Bruce Steele

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Re: What the Buoys are telling
« Reply #1289 on: May 07, 2017, 08:39:06 PM »
Andreas, I was wondering if you have seen this site? It shows IMB type data for some of the buoys on the poster you linked. It's new to me and an additional 4 or 5 real time data sets should be useful once I get used to using the new platform.

http://data.seaiceportal.de/gallery/index_new.php?active-tab1=measurement&ice-type=snowthickness&satellite=SB&region=n&resolution=all&showMaps=y&submit2=display&lang=en_US&active-tab2=snowthickness

This plot for buoy S45 deployed 2016 shows ice cover at about .81 meters and air temps approaching zero.

http://data.seaiceportal.de/download/buoys/2016S45_TS_addout.png
« Last Edit: May 07, 2017, 09:19:24 PM by Bruce Steele »

woodstea

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Re: What the Buoys are telling
« Reply #1290 on: May 09, 2017, 08:31:41 PM »
Brief spike above 0 degrees this afternoon at O-Buoy 14 in the CAA. That's the first time this year. Approximate location : 74° 12' N, 103° 3' W.

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Re: What the Buoys are telling
« Reply #1291 on: May 12, 2017, 08:33:35 PM »
I produced a plot of ice temperatures last year, so I have done the same for buoy2017A starting from 10.March.
Xaxis are days counting from 10.March  i.e. 60 = 9.May
Y axis are temperatures at the thermistor string  numbered downwards from the top , about .5m above the ice down into the sea below it. Horizontal lines are at -5 -10 ... -25 C
The temperatures at the thermistors above the snow are the lowest during winter and the temperature of all thermistors below the ice are nearly the same at -1.6
It shows large daily fluctuations when clear skies in April brought high daytime and low nighttime temperatures, but more steady higher temperatures when moist warmer air inflow brought clouds.
« Last Edit: May 12, 2017, 08:38:46 PM by Andreas T »

JayW

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Re: What the Buoys are telling
« Reply #1292 on: May 13, 2017, 01:38:57 PM »
IMB 2017A

Credit to Jim Hunt
http://greatwhitecon.info/resources/ice-mass-balance-buoys/winter-201617-imb-buoys/#2017B

First attachment is the temperature profile

Second is its location
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Re: What the Buoys are telling
« Reply #1293 on: May 14, 2017, 02:09:20 PM »
I produced a plot of ice temperatures last year, so I have done the same for buoy2017A starting from 10.March.
Xaxis are days counting from 10.March  i.e. 60 = 9.May
Y axis are temperatures at the thermistor string  numbered downwards from the top , about .5m above the ice down into the sea below it. Horizontal lines are at -5 -10 ... -25 C
The temperatures at the thermistors above the snow are the lowest during winter and the temperature of all thermistors below the ice are nearly the same at -1.6
It shows large daily fluctuations when clear skies in April brought high daytime and low nighttime temperatures, but more steady higher temperatures when moist warmer air inflow brought clouds.

Is there enough information to estimate the thermal conductivity / heat capacity of the ice, by thickness there -- you have the time series of top/bottom temps, it feels like it won't be too hard to calculate the estimated energy flows between each sensor, as you have the oscillation at the surface, being damped at each layer, combined with the long term trend from the weather ..

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Re: What the Buoys are telling
« Reply #1294 on: May 14, 2017, 07:55:27 PM »
If thermal conductivity of the ice is constant, the heat flux through the ice is given by the temperature gradient. In this graph closer lines mean less steep temperature gradients vertically through the ice (i.e. temperature sensors which are spaced at regular 10cm steps report temperatures which are less different)
This means less heat is transferred from the bottom to the top, less freezing, thickening of the ice

Because heat is taken up to warm ice,  gradients are different near the top and bottom when the temperature of the ice changes, particularly when these changes happen rapidly.

Around the 27th march (day17) there is an odd lowering and then raising of temperature near the ice bottom while higher up the changes are in reverse. Possibly this is a change in conductivity most plausibly I think because of movement of brine, possibly due to deformation/ cracking of the ice, but that is a guess based on basic principles.
« Last Edit: May 14, 2017, 08:15:07 PM by Andreas T »

seaicesailor

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Re: What the Buoys are telling
« Reply #1295 on: May 16, 2017, 11:02:19 AM »
Making use of the same code as last year, but for 2017A.
I have placed the origin in what I believe is the thermistor at the ice surface, but I may be wrong. Anyway, that discontinuity is pretty clear.
I am afraid we'll have fun for less than one month with this one...

Jim Hunt

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Re: What the Buoys are telling
« Reply #1296 on: May 16, 2017, 12:05:50 PM »
I am afraid we'll have fun for less than one month with this one...


It takes more than a month to melt a meter of sea ice, especially at this time of year. However that doesn't preclude the buoy freeing itself from the floe long before the ice melts away completely:

"Seasonal ice mass-balance buoys: adapting tools to the changing Arctic

Reality is merely an illusion, albeit a very persistent one - Albert Einstein

seaicesailor

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Re: What the Buoys are telling
« Reply #1297 on: May 16, 2017, 12:10:46 PM »
I am afraid we'll have fun for less than one month with this one...
It takes more than a month to melt a meter of sea ice, especially at this time of year. However that doesn't preclude the buoy freeing itself from the floe long before the ice melts away completely:

Yes that's what I meant Jim. And it is getting located in such a bad place, with the heat coming. Like a bullfighter waiting for the bull in front of the gate (bad example, usually the bullfighter wins)
Anyway I am still in mourn for 2015F , lol

slow wing

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Re: What the Buoys are telling
« Reply #1298 on: May 16, 2017, 12:17:10 PM »
Making use of the same code as last year, but for 2017A.
I have placed the origin in what I believe is the thermistor at the ice surface, but I may be wrong. Anyway, that discontinuity is pretty clear.
I am afraid we'll have fun for less than one month with this one...

Great plot!

So maybe it began with nearly 20 cm of snow but had lost several cm of that by the end?


(Safe) Prediction: that remaining snow isn't going to see out the month!



EDIT: but wait..

Thermal conductivity of ice = 0.005; of water = 0.0014.

So ice has about 3.5 times the thermal conductivity of water.

Conversely, the same depth of water will show about 3.5 times the vertical displacement between the thermistors as ice. There must be some densely packed snow - almost ice but with some trapped air - that shows similar. And maybe that's what we are seeing from 2017A in March? How do we know if it melts? It just gets a little more compact in turning into water, with a similar displacement between thermistors. Perhaps that's what has already happened here - an alternative explanation?

Now I'm uncertain what is going on in that plot, but my apologies for the stream-of-consciousness post!
« Last Edit: May 16, 2017, 01:08:50 PM by slow wing »

seaicesailor

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Re: What the Buoys are telling
« Reply #1299 on: May 16, 2017, 02:41:39 PM »
Making use of the same code as last year, but for 2017A.
I have placed the origin in what I believe is the thermistor at the ice surface, but I may be wrong. Anyway, that discontinuity is pretty clear.
I am afraid we'll have fun for less than one month with this one...

Great plot!
So maybe it began with nearly 20 cm of snow but had lost several cm of that by the end?
(Safe) Prediction: that remaining snow isn't going to see out the month!
EDIT: but wait..
Thermal conductivity of ice = 0.005; of water = 0.0014.
So ice has about 3.5 times the thermal conductivity of water.
Conversely, the same depth of water will show about 3.5 times the vertical displacement between the thermistors as ice. There must be some densely packed snow - almost ice but with some trapped air - that shows similar. And maybe that's what we are seeing from 2017A in March? How do we know if it melts? It just gets a little more compact in turning into water, with a similar displacement between thermistors. Perhaps that's what has already happened here - an alternative explanation?
Now I'm uncertain what is going on in that plot, but my apologies for the stream-of-consciousness post!
Thanks!
I don't know, I just tried to separate what varies smoothly to the right to what cannot explain its noise to the left. As said, might be wrong by centimeters but I don't think too much as there is a discontinuity in that y-axis, or the thermistor next to it.