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OffTheGrid

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Re: The 2020 melting season
« Reply #6250 on: September 27, 2020, 01:18:53 AM »
Oh jeez...
We've got two new itp buoys in the North Beaufort. The fresh surface layer is thin enough to be raised to the salinity of the over 100 m below it by brine released from less than half a meter of ice. The heat content in that 100m is enough to melt 3-4m of ice. Itp120  is on the NorEast edge of the last thick blob that's now pushed against the garlic press over high salinity and heat outflowing warm water.
The Halocline looks bust.

uniquorn

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Re: The 2020 melting season
« Reply #6251 on: September 27, 2020, 12:22:44 PM »
Nice charts but I don't agree with the interpretation. The halocline doesn't appear to be bust yet.
Data shown starts at 7m depth.
The halocline in that location looks similar to previous years. Beaufort temperatures at 50m depth are a concern for the future that have been well noted on this thread and others.

@interstitial - more thickness data
SIMB  https://www.cryosphereinnovation.com/443910  (no charts yet. edit: working with chrome, not firefox)
Quote
ITP120 was deployed on a 1.15 m ice floe in the Beaufort Sea on September 21, 2020 at 78° 54.0 N, 142° 21.2 W as part of the Beaufort Gyre Observing System (BGOS) during the JOIS 2020 cruise on the CCGS Louis S. St. Laurent. On the same icefloe, a US Army Cold Regions Research and Engineering Laboratory (CRREL) Seasonal Ice Mass Balance Buoy 3 was also installed. The ITP is operating on a standard sampling schedule of 2 one-way profiles between 7 and 760 m depth each day.
SIMB  https://www.cryosphereinnovation.com/441910
Quote
ITP121 was deployed on a 2.3 m ice floe in the Beaufort Sea on September 20, 2020 at 77° 22.3 N, 137° 16.4 W as part of the Beaufort Gyre Observing System (BGOS) during the JOIS 2020 cruise on the CCGS Louis S. St. Laurent. On the same icefloe, a US Army Cold Regions Research and Engineering Laboratory (CRREL) Seasonal Ice Mass Balance Buoy 3 was also installed. The ITP is operating on a standard sampling schedule of 2 one-way profiles between 7 and 760 m depth each day and includes a fixed SAMI PCO2 with PAR and SBE-37 microcat with dissolved oxygen at 6 m depth.

Added whoi itp121 microcat1 at 5m depth
« Last Edit: September 27, 2020, 02:08:02 PM by uniquorn »

OffTheGrid

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Re: The 2020 melting season
« Reply #6252 on: September 27, 2020, 08:55:27 PM »
I not sure how you could say that with a straight face Uni.
That "past buoy for comparison was only last year. When it was measuring 50+ m of fresh surface shield at this time of year. This year it's about 15m.

The heat content was never even half the current measurements in the top 100m from 120 and even more so 121. Measured as total degrees above freezing point of seawater x volume of parcels. And it's now centered at under 50m depth. Used to be over twice as deep.
121 is recording big pockets to surface above the scale of the chart. Those white blobs.
Every washing machine clockwise/anticlockwise cycle of those loosely bound slush puddles is an Ekman pumping/suction cycle mixing away the surface shield into the Halocline below. The Beaufort is covered with short 2 m waves from Bering to past 80 nth right out into the ice off CAA. Mixing the fresh away, as we speak. Pacific summer water incoming, was able to shelter under insulating ice in the Beaufort for longer than usual in spring, early summer, so has lost much less energy by evaporation and wind cooling. Hence the danger that 20g/ litre of salt expelled from seawater freezing on the surface can raise salinity of the surface shield at 2 psu per 10 litres. And mixing remove the rest.

uniquorn

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Re: The 2020 melting season
« Reply #6253 on: September 27, 2020, 10:26:21 PM »
Occasional sharp peaks above 2C are not uncommon at 50m in the Beaufort over the last year but you have a point, today's broader peak at 48m-56m on itp121 does look significant. I would wait a few days before claiming that the halocline is bust though, particularly at the beginning of the freezing season.

%ITP 121, profile 13: year day longitude(E+) latitude(N+) ndepths
2020  271.00141  -138.6742  77.2639  374
%year day pressure(dbar) temperature(C) salinity
<>
2020  271.03226   42   -1.0367   29.9797
2020  271.03216   44    0.3501   30.0927
2020  271.03207   46    1.5122   30.3881
2020  271.03199   48    2.0639   30.5199
2020  271.03191   50    2.2932   30.6454
2020  271.03182   52    2.2169   30.7789
2020  271.03172   54    2.1873   30.8761
2020  271.03163   56    2.0021   30.9866
2020  271.03154   58    1.6610   31.0456
2020  271.03146   60    1.6165   31.1104
2020  271.03138   62    1.5137   31.1871
2020  271.03128   64    1.2485   31.2670
2020  271.03119   66    1.1310   31.3255
<>
Quote
And it's now centered at under 50m depth. Used to be over twice as deep.
I don't think so. The composite plots overwrite many of the profiles. I find it more useful to look at them individually as an animation. Beaufort peaks are normally at 50-70m imho. Maybe I will have time to run some older buoy profiles for comparison.
« Last Edit: September 27, 2020, 10:36:11 PM by uniquorn »

OffTheGrid

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Re: The 2020 melting season
« Reply #6254 on: September 27, 2020, 11:59:39 PM »
Yes, didn't mean to imply it's bust today. But it should have it's thickest fresh lid of the year right now.  Instability sets in as it starts to freeze and multiple mechanisms such as large over turnings, as muddy the composite plots as you point out, set in.   
Also in play are osmotic diffusion of salt upwards, freshwater downwards across the fresh/saline boundary, and algae blooms sinking, entraining fresh water, taking it down to mix with the salty stuff, and thermal conduction and radiation upwards into the shield of the heat in that summer water layer. Once there it will convect to surface.
All these processes have been steadily ratcheting up in mutually reinforcing mixing effects. And weakening the shield stability since the earliest Beaufort ITPs in 2005.
In TrekSpeak:
Shields are at 20% and worse still, they and structural reinforcement fields and the warp core are suffrin from wild an unpreductable instubilities since tha last exotic energy wave swept through the quadrant.
Ah dinae ken how the ship could survive another like it.
« Last Edit: September 28, 2020, 12:38:59 AM by OffTheGrid »

uniquorn

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Re: The 2020 melting season
« Reply #6255 on: September 28, 2020, 12:08:30 PM »
whoi itp33 was deployed in 2009 in a similar location to itp121 but 15 days later. The animation compares the first 16 profiles.
In that location the salinity gradient was steeper in 2009, temperature was clearly much, much lower.
Depending on itp121's future drift path, this could be a combination to follow further.

oren

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Re: The 2020 melting season
« Reply #6256 on: September 28, 2020, 12:30:15 PM »
Great find.

uniquorn

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Re: The 2020 melting season
« Reply #6257 on: September 28, 2020, 09:44:17 PM »
2020, 2018, 2015, 2012, and 2009. Roughly the same days, similar location.

El Cid

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Re: The 2020 melting season
« Reply #6258 on: September 28, 2020, 10:42:18 PM »
2020, 2018, 2015, 2012, and 2009. Roughly the same days, similar location.
Conclusion?

oren

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Re: The 2020 melting season
« Reply #6259 on: September 28, 2020, 11:29:05 PM »
Uniquorn, is there an easy way to download the  raw numbers behind the animation? Hopefully I will have time to play with it in my Excel.

uniquorn

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Re: The 2020 melting season
« Reply #6260 on: September 29, 2020, 12:26:22 AM »
itp121 is here     https://www.whoi.edu/page.do?pid=166917
The older buoys can be found in completed missions. whoi provide a .dat file for each profile. I load them all and make a chart for each profile using octave in this case. I haven't converted it to R yet.

Every profile will make a nice chart in excel or open source libreoffice if the first 2 lines are removed (then space as separator) so a day273 comparison shouldn't be too arduous. The biggest step is downloading the data and actually looking at it. It's only a text file labelled as .dat
Quote
is there an easy way
maybe.
download and install notepad++
Download the buoy .zip file (I have to right click and open in new tab)
extract all
right click on one .dat profile and open in Notepad++
delete the first 2 lines
save as test.csv
open in excel with 'space' as separator
make chart


SimonF92

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Re: The 2020 melting season
« Reply #6261 on: September 29, 2020, 12:52:54 AM »
This is nice, area-under-points might be a nice way to get a comparative quantitative metric for these plots, im also going to have a look at this data
Bunch of small python Arctic Apps:
https://github.com/SimonF92/Arctic

uniquorn

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Re: The 2020 melting season
« Reply #6262 on: September 29, 2020, 01:53:33 AM »
2020, 2018, 2015, 2012, and 2009. Roughly the same days, similar location.
Conclusion?
More people should assess the data.

El Cid

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Re: The 2020 melting season
« Reply #6263 on: September 29, 2020, 08:13:01 AM »
2020, 2018, 2015, 2012, and 2009. Roughly the same days, similar location.
Conclusion?
More people should assess the data.

Sorry, I only asked because I can't come to any solid conclusions by myself and would like to know what others make of it.

uniquorn

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Re: The 2020 melting season
« Reply #6264 on: September 29, 2020, 12:15:08 PM »
It's a fair question but for me also it is too early to come to a conclusion. Too much movement and not enough data. Next analysis will be yearly paths with 50m temperature to see what that shows. It's likely to be warm pacific incoming from the Chukchi plateau as there is no rough topography at ~78N-140. Maybe the buoys will show us how 'wide' the warmer area is. Mercator at 34m and 92m depth misses the peak. Maybe Aslan can help with that.

OTG has plenty of suggestions ;)

edit: latest data from itp121 is a bit cooler at 50m

%ITP 121, profile 18: year day longitude(E+) latitude(N+) ndepths
2020  273.25141  -138.1066  77.2762  375
2020  273.25303   44   -0.0354   30.0949
2020  273.25311   46    0.3879   30.2224
2020  273.25319   48    0.4206   30.3668
2020  273.25328   50    0.4183   30.5225
2020  273.25336   52    0.2941   30.6820
2020  273.25345   54    0.5035   30.8875
2020  273.25353   56    0.5986   31.0057
2020  273.25361   58    0.5534   31.1116
2020  273.25369   60    0.6788   31.2080
2020  273.25377   62    0.7504   31.2909
2020  273.25385   64    0.9152   31.3495
2020  273.25394   66    0.8092   31.3845
2020  273.25403   68    0.6351   31.4414
2020  273.25411   70    0.3613   31.5064
2020  273.25419   72    0.2022   31.5450
2020  273.25427   74    0.0279   31.5973
2020  273.25435   76   -0.0417   31.6361
« Last Edit: September 30, 2020, 12:11:23 AM by uniquorn »

OffTheGrid

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Re: The 2020 melting season
« Reply #6265 on: October 01, 2020, 07:45:55 PM »
If you look at the buoy status charts, eg drift speed and engineering charts, and the composite plots temp and salinity you can see that the less than 12hr Ekman turbine cycle is going at full noise on all Beaufort buoys. Also seems to have a ~4day slush puddle washing machine cycle overlayed. I think from the near zero buoy temp, and a rise in pressure at the microcat that 120 has melted out. It's been freaky watching the mixing down to over 200m that's visible in the Ekman resonances showing on the composite temp chart particularly. Since that wave event. The only reason there's still a surface shield is the ongoing melt and current flushing the bottom melt out from under the thicker blob off South CAA.
I'm stunned by this Ekman turbine resonance mixing phenomenons power it's quickly working to flatten the salinity curve. It's obviously tidally influenced but at about 1.5 hour shorter period it's obviously deriving mechanical energy that's phase leading, and beat harmonics are clear to see when the peaks and troughs add or cancel with the tidal cycles. Perhaps they set the size of the 4 day cycle larger slushpuddles full of 5.5 hour smaller ones
And maybe there's larger ones on a monthly tidal cycle. That they are embedded in.
There's much worse wave and wind events building right now.
Unlikely to improve.

oren

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Re: The 2020 melting season
« Reply #6266 on: October 01, 2020, 07:52:50 PM »
OTG, it would be nice if you could substantiate your analysis by showing it using the actual charts, for your own rigor and for the education of the forum. Else it might read like a lot of speculation.

OffTheGrid

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Re: The 2020 melting season
« Reply #6267 on: October 02, 2020, 09:17:01 PM »
Sure Oren, I agree that would be ideal. Anyone can see this for themselves with the currents and temperatures settings on nullschool, Windy's wave and swell settings, the itp charts at https://www.whoi.edu/page.do?pid=20781

Though I love to present these hypothesis in Beautiful Animations, and have images to make them from, my laptop hours are limited it's setup in a house, and my amphious 6m x 2.2m 2m standing hight solar electric mobile home, while comfortable to live in and energy independent, and capable of going all day long at 10-39kmph without out even drawing battery power on a single 100w solar panel, is not yet a risk free environment for a computer. Especially in a supervolcano caldera in winter.
I have some twenty gigabytes of satellite imagery and volcanic gas surface concentration data to process into videos small enough to share before our next international Greenland Emergency videoconference in a
Others here have better infrastructure and image processing skills than me.
I have to prioritize. Marveling at the mayhem asi is displaying, though interelated is a distraction that is escapism and light relief from the far bigger and more dangerous problem that we are trying to develop a feasible technological response for blunting the damage to be rapidly deployed.
This forum is a valuable resource, and the many hours put   in in near-real-time analysis and presentation by the gurus here, and your level headed moderation are most appreciated, thank you all.

oren

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Re: The 2020 melting season
« Reply #6268 on: October 06, 2020, 12:55:13 PM »
itp121 is here     https://www.whoi.edu/page.do?pid=166917
The older buoys can be found in completed missions. whoi provide a .dat file for each profile. I load them all and make a chart for each profile using octave in this case. I haven't converted it to R yet.

Every profile will make a nice chart in excel or open source libreoffice if the first 2 lines are removed (then space as separator) so a day273 comparison shouldn't be too arduous. The biggest step is downloading the data and actually looking at it. It's only a text file labelled as .dat
Quote
is there an easy way
maybe.
download and install notepad++
Download the buoy .zip file (I have to right click and open in new tab)
extract all
right click on one .dat profile and open in Notepad++
delete the first 2 lines
save as test.csv
open in excel with 'space' as separator
make chart
Thank you uniquorn. I finally managed to find a browser that downloads ftp links, and to locate all the download links for the five buoys in question.
I do wonder now, why they break up the data file so that each profile is in a separate file. Very weird. My first item of interest is to generate a plot of temperature and salinity for a given depth, comparing all five buoys. Turns out I need to import 150 files into Excel... I will look into automating the process somehow. I can program using VBA but this is a bit outside my expertise.
If anyone has any tip, or knowledge of a combined file that exists somewhere, please share.

WildFit

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Re: The 2020 melting season
« Reply #6269 on: October 06, 2020, 09:26:54 PM »

I finally managed to find a browser that downloads ftp links,........


If you are on a Mac you can use the print menu in any browser to:

"Save as PDF"

instead of printing.

I can check whether PCs can do the same just let me know or you try it out.

Don't be confused by the interface, the shown interface is from "BIG SUR DEVELOPER BETA 9"
and therefore it will look different on "Catalina" or earlier operating systems while the feature is there as well. Worst case would be to switch from browser print menu to system print menu which is a button to click as well.

uniquorn

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Re: The 2020 melting season
« Reply #6270 on: October 06, 2020, 11:30:40 PM »
If anyone has any tip, or knowledge of a combined file that exists somewhere, please share.
whoi itp33 data in one file. I'm slowly working my way through them. Rename .txt to .zip and extract. It will need sorting.

Data comes in profile by profile, they probably started with that format and, thankfully , they haven't changed it much over the years.

oren

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Re: The 2020 melting season
« Reply #6271 on: October 06, 2020, 11:42:59 PM »
Thanks wildfit (and welcome!). No mac.

Thanks uniquorn, this will be very handy. It gives me the idea to write a VBA macro to merge multiple dat files into a single one. Should be doable I think.

WildFit

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Re: The 2020 melting season
« Reply #6272 on: October 08, 2020, 02:39:07 AM »
Thanks wildfit (and welcome!). No mac.



Should work under windows 10 as well

oren

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Re: The 2020 melting season
« Reply #6273 on: October 08, 2020, 05:46:19 AM »
Thank you wildfit. Looking at it again, this is not what I am trying to do. I was trying to download files from ftp, and my browser would not download anything. Finally I installed Firefox and it downloaded successfully.

For example the link ftp://ftp.whoi.edu/whoinet/itpdata/itp121grddata.zip

Anyway, that is already solved.

oren

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Re: The 2020 melting season
« Reply #6274 on: October 08, 2020, 06:44:48 AM »
to write a VBA macro to merge multiple dat files into a single one. Should be doable I think.
Turns out the helpful Internet has already given thought to the matter, and while VBA is doable there is a much simpler solution.
Run command line (DOS), navigate to the directory where the files are, and type:
copy *.dat onefile.txt
So simple...
In the itp case I actually used "copy itp121g*.dat onefile.txt" to avoid concatenating the rest of the dat files in the directory.

Edit: The other four files are attached, itp 121, 110, 88, 62. Rename each file to zip by removing the .txt, and then extract.
« Last Edit: October 08, 2020, 07:07:13 AM by oren »

oren

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Re: The 2020 melting season
« Reply #6275 on: October 08, 2020, 09:15:27 AM »
A couple of graphs for 50dbar (roughly 50 meters depth), covering the same period as in uniquorn's animation upthread. I haven't compared the locations of the various buoys.
Click to enlarge.

uniquorn

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Re: The 2020 melting season
« Reply #6276 on: October 08, 2020, 12:34:38 PM »
Nice, the DOS or (power)shell solution is quick if you don't need to bind the lat/lon to the list. It's interesting that 2020 salinity, which may be a signature of pacific water, is a closest match with 2012. It could just be coincidence.

Rough location overlay

Tor Bejnar

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Re: The 2020 melting season
« Reply #6277 on: October 12, 2020, 05:57:43 PM »
...
I do wonder how much of the Beaufort's scorpion tail will melt before that sea is ice covered.  Some bottom melt can happen near surface freezing, I've been led to believe.  ...
I think the answer was, "much of it."
Arctic ice is healthy for children and other living things because "we cannot negotiate with the melting point of ice"

uniquorn

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Re: The 2020 melting season
« Reply #6278 on: October 14, 2020, 11:01:49 PM »
Beaufort 50m temperatures from whoi itp buoys, 2006-2020
edit: adjusted buoy sizes so newer year overlay is easier to identify
edit2: mp4 is smaller
« Last Edit: October 14, 2020, 11:46:40 PM by uniquorn »

oren

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Re: The 2020 melting season
« Reply #6279 on: October 14, 2020, 11:05:13 PM »
Amazing animation. And there does appear to be a warming trend.

uniquorn

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Re: The 2020 melting season
« Reply #6280 on: October 14, 2020, 11:12:31 PM »
@Oren, the static chart is a valuable addition to the analysis.

csv data as text file attached. conversion from day numbers/year may need checking.
« Last Edit: October 14, 2020, 11:21:02 PM by uniquorn »

HapHazard

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Re: The 2020 melting season
« Reply #6281 on: October 17, 2020, 08:29:35 AM »
I guess this thread is still relevant.

I am on my way out the door, just checked in before I stepped away from the computer. Curious now, though - what is the latest extent drop on record?

[ADS NIPR VISHOP (JAXA)] Arctic Sea Ice Extent.

October 16th, 2020:
     4,928,965 km2, a drop of -9,602 km2:o
If I call you out but go no further, the reason is Brandolini's law.

grixm

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Re: The 2020 melting season
« Reply #6282 on: October 17, 2020, 10:23:21 AM »


Depending on what you mean by latest, 2012 saw a drop on December 31st. It can happen year-round.

I guess this thread is still relevant.

I am on my way out the door, just checked in before I stepped away from the computer. Curious now, though - what is the latest extent drop on record?

[ADS NIPR VISHOP (JAXA)] Arctic Sea Ice Extent.

October 16th, 2020:
     4,928,965 km2, a drop of -9,602 km2:o

HapHazard

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Re: The 2020 melting season
« Reply #6283 on: October 17, 2020, 10:18:32 PM »
Thanks, grixm. My ol' bean counter couldn't remember how common it is, even though I've been lurking here for 6 years or so.
If I call you out but go no further, the reason is Brandolini's law.

oren

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Re: The 2020 melting season
« Reply #6284 on: October 19, 2020, 05:34:03 AM »
@Oren, the static chart is a valuable addition to the analysis.

csv data as text file attached. conversion from day numbers/year may need checking.
Thanks for the data uniquorn. But what to do when Excel fails you? Except for showing that 2020 is literally off the chart, this graphic is not useful for much else. I have filtered the data for location between 137-150 longitude and 73.5-78 latitude, based on the animation showing a more or less uniform behavior for that sub-region. Issues I have tried to grapple with:
* Excel insists on assigning a "soft" and similar-looking palette to all lines.
* Periods of no data for a given year (gaps between different buoys) are shown with a visually disruptive connecting line.
* Each day has several measurements of varying temperatures, because of intra-day variations -and/or the combination of data from multiple buoys. This causes many annual "lines" to overlap.

If I ever get the inspiration and the time I might do some intra-day averaging to reduce noise and somehow separate the data parts of each year from the connecting periods. And manually fix the palette so that each year gets a visually different color.

And of course, click and click again to enlarge.

Tor Bejnar

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Re: The 2020 melting season
« Reply #6285 on: October 19, 2020, 03:52:13 PM »
Oren,
That chart looks like cacophony incarnate until looking at the enlarged (embiggened) version, where the grey (gray) 2020 data has mostly risen to the top (like nitrogliceran floats on top during its preparation, so I was once told).  The quasi-horizontal lines make since, too (non-continuous data). 
Arctic ice is healthy for children and other living things because "we cannot negotiate with the melting point of ice"

uniquorn

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Re: The 2020 melting season
« Reply #6286 on: October 20, 2020, 12:50:10 AM »
itp121 has hardly moved. Temperature at 50m remains relatively high. Both temperature and salinity suggesting turbulence. Day 264-293.

uniquorn

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Re: The 2020 melting season
« Reply #6287 on: October 20, 2020, 11:10:45 AM »
A closer look at itp121 drift path. Small signs of inertial oscillation or tidal movement. It shares a floe with SIMB441910 (https://www.cryosphereinnovation.com/441910), thickness 210cm at deployment. (click for more data)

forum software behaving strangely today.

uniquorn

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Re: The 2020 melting season
« Reply #6288 on: October 20, 2020, 12:44:04 PM »
a closer look at itp121 drift, oct18-19

gerontocrat

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Re: The 2020 melting season
« Reply #6289 on: October 29, 2020, 11:02:39 PM »
You gotta watch it

"Para a Causa do Povo a Luta Continua!"
"And that's all I'm going to say about that". Forrest Gump
"Damn, I wanted to see what happened next" (Epitaph)

Sebastian Jones

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Re: The 2020 melting season
« Reply #6290 on: October 30, 2020, 05:51:49 AM »
You gotta watch it


Yes.
It's not as if I have not followed this story for 15 years almost daily, but this little video really brings it home.
3/4 of the ice in the Arctic has melted away.