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Messages - SimonF92

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1
Arctic sea ice / Re: The 2020 melting season
« on: September 11, 2020, 11:28:08 PM »
Hey Freegrass, do what makes you happy, but once a pagophile means always a pagophile :). All the best if you do retire, and thanks for all your useful animations and commentaries

2
Greenland and Arctic Circle / Re: The Nares Strait thread
« on: September 11, 2020, 09:04:50 AM »
Seconded!
Would be great to see him return but let him take his time. He's been to hospital and is recovering from a successful surgery \o/

Ah I was not aware of that! I wish him good health and a speedy recovery!

3
Greenland and Arctic Circle / Re: The Nares Strait thread
« on: September 10, 2020, 04:30:14 PM »
I miss blumenkraft too, they were an active member who made good and valuable contributions to many different threads. As someone who reads far more than they post, they were the kind of person I benefited from.

I really dont know or care what happened, if it was some kind of political thing- but I would like it to be noted that everyone deserves a second chance.

4
Arctic sea ice / Re: MOSAiC news
« on: September 08, 2020, 11:53:29 PM »
Tight clothing being a "safety issue", due to men onboard being at sea for a long time.

I literally dont even know what to make of that statement. Very sad any of this was allowed to happen.

5
Arctic sea ice / Re: MOSAiC news
« on: September 08, 2020, 12:20:48 PM »
     The year dates on the salinity graphic seem to be reversed.  It looks like reverse Atlantification from the first image (2019) to the second (2020).  For example, north of FJF goes from mostly red in 2019 to mostly yellow in 2020.

I think it makes sense, there was a resurgence in ice along the Atlantic side throughout spring 2020

6
Arctic sea ice / Re: The 2020 melting season
« on: September 07, 2020, 01:19:55 PM »
Water between floes beginning to freeze north of Ellef Rignes island

7
Arctic sea ice / Re: The 2020 melting season
« on: September 06, 2020, 08:22:15 PM »
Snow will indeed increase (marginally) but eventually this will transition to rainfall

8
Arctic sea ice / Re: MOSAiC news
« on: September 03, 2020, 03:38:09 PM »

Simon

May I ask what the scale on the left is?

I'm really struggling to see where the base of the ice is!

Would the winter ice be more clearly defined as the freeze causes mixing, the water convecting below the ice layer? As the ice melts the heat is transferred by conduction, leading to a much smoother gradient.

Each value on the left is 2cm (there are sensors in a column every 2cm), so the difference between thermistor50 (Th50) and thermistor150 (Th150) is 1metre.

Heres a very quick image showing you the bottom (and why the temperature method wont work when its warm above the ice):

9
Arctic sea ice / Re: MOSAiC news
« on: September 03, 2020, 02:35:07 PM »
It is very easy to detect and perceive the bottom of the ice in the winter/spring due to the temperature gradient being positive from the top of the thermistor column to the bottom (very cold air: cold ice: warmer ocean).

Between us were setting the ice:ocean thermistor at the -1.8 to -2degC mark.

Unfortunately, during summer this temperature gradient becomes a U-shaped quadratic (warmer air: colder ice: warmer ocean) and eventually normalises to close to 0, which basically creates hell for analysis. Particularly given that the transition between ice and ocean at the bottom is probably muddied by supercooled water.

(the 2nd and 3rd figures represent different thermal conductivity sensors, you can just about perceive the bottom of the ice through summer)

10
Arctic sea ice / Re: When will the Arctic Go Ice Free?
« on: September 02, 2020, 10:35:08 PM »
I could well be wrong but when I thought about BOE, I came to the conclusion that 2027 +/- 2 years would be when an annual BOE would become a permanent feature and that the length of time this would persist would increase perhaps as much as several months by 2050.

Once the inertia of latent heat of melting has been overcome the changes will be rapid and I wouldnt be surprised if the BOE is +2~3 weeks duration for every year after the first one.

11
Arctic sea ice / Re: The 2020 melting season
« on: September 01, 2020, 03:29:16 PM »
It's hard to believe there's no online tool where you can overlay multiple years of the DMI north of 80 graphic.

Zack Labe has done a pretty good job of that (granted you cant select individual years);

https://sites.uci.edu/zlabe/arctic-temperatures/

12
Arctic sea ice / Re: The 2020 melting season
« on: August 31, 2020, 09:58:41 AM »
2020 made it to second place, without extreme weather. Melting momentum.

Quite a sobering melting season.
And a lot of energy that might be stored this winter under the ice for the next one.

Siberian coast going to become a nice place for a warm vacation in 10 years at this rate

13
Arctic sea ice / Re: The 2020 melting season
« on: August 26, 2020, 05:47:26 PM »
Here's todays maps, and a slow animation of the last 3 days.
Still haven't had much time to work on the new colour schemes, hopefully this weekend!

Dont burn yourself out, you are doing great work

14
Consequences / Re: COVID-19
« on: August 26, 2020, 01:35:01 PM »
Ask yourself, if it is indeed all about Vitamin D then why does almost every developed health system offer a seasonal flu jab instead of seasonal Vitamin D supplement?



Furthermore, I am part of a consortium in the UK called Biobank, which uses big data to determine disease susceptibility. Here is a direct quote from a Biobank publication on this matter:

''''''
Our findings do not support a potential link between vitamin D concentrations and risk of COVID-19 infection, nor that vitamin D concentration may explain ethnic differences in COVID-19 infection.
'''''''

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7204679/

I think your employer does not qualify your misinformation as truth. And your post is 100% misinformation.

In fact, if you have to qualify a post with "Well I work for Blah Blah Blah idiots so I am SMART" it is probably a sign it is garbage to begin with. lol

Haha oh my god I wish it were as easy to get a paper past reviewers as it is for bbr2315 to dismiss it as misinformation. With that I am outta here!

15
Consequences / Re: COVID-19
« on: August 26, 2020, 01:23:38 PM »
My original academic background is Immunology and Pharmacology so unlike climate science I feel qualified to comment on this.

Vitamin D levels are one facet of an immensely complicated and subjective biological system. It is a little silly to be commenting so aggressively about this. I have seen a few publications relating Vitamin D to chronic autoimmune conditions and a few relating it to infection susceptibility. However, it is definitely not a silver bullet, and a second wave definitely does not hinge on Vitamin D levels.

Ask yourself, if it is indeed all about Vitamin D then why does almost every developed health system offer a seasonal flu jab instead of seasonal Vitamin D supplement?



Furthermore, I am part of a consortium in the UK called Biobank, which uses big data to determine disease susceptibility. Here is a direct quote from a Biobank publication on this matter:

''''''
Our findings do not support a potential link between vitamin D concentrations and risk of COVID-19 infection, nor that vitamin D concentration may explain ethnic differences in COVID-19 infection.
'''''''

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7204679/

16
Arctic sea ice / Re: The 2020 melting season
« on: August 25, 2020, 02:38:55 PM »
Remember, the only way to verify accuracy would be to actually go out there and drill a hole.

The best way to ensure accuracy is to do multiple testing with multiple algorithms, when drilling a hole isn't possible.

So the reality is most likely an aggregation of individual datasets.

17
Arctic sea ice / Re: The 2020 melting season
« on: August 25, 2020, 02:31:35 PM »
Latest Five Day Forecast
Wind @ Surface
Wind + Temp @ 850hPa
Wind @ 250hPa
Large GiFS!

It looks like winter is coming to town. Temperatures will finally start dropping.

Should I continue posting the Jet Stream? It has less significance now, right?



Hi Freegrass  ;) , It's about time the temperatures started to drop.  :)
But where are the beige pixels going to hide this year?

Scary that over 70% of the ice is just 10cm-30cm thickness

10cm - 3.93 inch
20cm - 7.87 inch
30cm - 11.8 inch

DMI tells an entirely different story, the reality is probably somewhere in between

18
Arctic sea ice / Re: Home brew AMSR2 extent & area calculation
« on: August 24, 2020, 07:29:16 PM »
You have a github A-team?

The ASIF has its very own Developers Corner:

https://forum.arctic-sea-ice.net/index.php/board,24.0.html

Topic #24!

Thanks for this Jim.

Ive worked on a project there before with some of the members. I was just hoping to "pinch" A-team's code for another snow project im working on (the details of which ill share in the developers corner when ready)

19
Arctic sea ice / Re: Home brew AMSR2 extent & area calculation
« on: August 24, 2020, 09:18:29 AM »
Ah, i understand.

That has to be one of the best visualisations of melt progression I have ever seen!

20
Arctic sea ice / Re: The 2020 melting season
« on: August 23, 2020, 03:58:42 PM »
I think that the fact that 2020 seems to be coming in second is almost as scary as if it were heading for a record. 2012 was a freak, but each normal year is getting lower and eventually we will pass 2012, even if there is not another cyclone or something.

+1

Though i do think the Siberian side was pretty "freaky" this year

21
Arctic sea ice / Re: The 2020 melting season
« on: August 20, 2020, 03:44:02 PM »
Wonder how long this 'flat line' will go on for. Because the 10-day air surface temps aren't showing much cold (10-day image not posted because it's a 10-day forecast, which are generally disliked)

22
Arctic sea ice / Re: The 2020 melting season
« on: August 19, 2020, 12:12:06 PM »
My math is crude, don't hold your hopes too high.
In the CAB, average remaining volume loss (2007+) is 750 km3, 800 km3 if you remove low years. Remaining area is now around 2 mil km2. Ergo, average remaining melt is 0.4m.
Overall, average remaining volume loss (2007+) is 1100 km3, 1150 km3 if you remove low years. Remaining area is now around 3 mil km2. Ergo, average remaining melt is 0.37m.
This may be increased somewhat if taking average area from here to minimum.
The calculation is skewed by the fact that when there is no ice left volume loss starts to shrink. That's why I used only 2007 and later.

I would say most of this is bottom melt at this late date.

Thanks, it makes a lot of sense!

23
Developers Corner / Re: Sentinel-Hub custom rendering settings
« on: August 18, 2020, 10:49:49 AM »
Im working on a large project at the moment (Scottish snow, not Arctic stuff), but heres the mask im using;

easy distinction between clouds and ice/snow

https://apps.sentinel-hub.com/sentinel-playground/?source=S2&lat=81.2492016395353&lng=-70.00167832709849&zoom=11&preset=CUSTOM&layers=B01,B02,B03&maxcc=100&gain=1.0&gamma=1.0&time=2020-01-01%7C2020-07-01&atmFilter=&showDates=false&evalscript=cmV0dXJuIFtCMDEqMi41LEIwNCoyLjUsQjExKjIuNV0%3D


You can separate ice (yellow) from clouds (white) in python with;

img = cv2.imread(directory + filename)
hsv = cv2.cvtColor(img, cv2.COLOR_BGR2HSV)
lower_range = np.array([22, 93, 0])
upper_range = np.array([45, 255, 255])
mask = cv2.inRange(hsv, lower_range, upper_range)

'mask' then becomes cloud-corrected ice, with caveats


24
The forum / Re: Suggestions
« on: July 08, 2020, 12:34:55 PM »
A group of "trusted individuals" who approve posts on the main melting thread. Plural because it would be a fair amount of work for just one person.

No posts approved unless they contain either real data or reasonable conjecture.

Lately I dont come on the melting thread due to the signal-to-noise ratio. I decided to pay a visit and once again there are arguments surrounding hyperbole. I love this forum and the efforts people go to to maintain it, but I can name a few people (different each year) who ruin those threads.

25
Arctic sea ice / Re: The 2020 melting season
« on: June 26, 2020, 01:00:58 PM »
Why post month old Hycom?
Sorry. Because of the garlic press discussion.

I thought your contribution was useful, thanks for taking the time to collate data like that for everyone else.

(its an animated gif)

26
Greenland and Arctic Circle / Re: The Nares Strait thread
« on: June 22, 2020, 03:25:11 PM »
It's getting a bit tricky to discern open water and shadows with all that cloud at the moment.

DMI is showing new opening just above Alert in the Lincoln Sea.

Yes, that opening has been visible from the station, it's only a couple hundred metres offshore from us.  We had very high winds (sustained 15-20 m/s) from Thursday through Sunday that did a lot of melting and pushing.  The majority of our snow cover disappeared in that period.

Really appreciating these updates, thanks a lot!

27
Arctic sea ice / Re: The 2020 melting season
« on: June 18, 2020, 02:10:00 PM »
the gfs0600 forecast seems to completely lack a GAC .
The title GAC is something a storm earns after the event , not after a fleeting appearance in a forecast . There may be a GAC ; there certainly will be one sooner or later , but for now I see the 977mb storm has been replaced with a 1025mb high .. b.c.

I feel like there have been imminent GACs for the last 5 melting seasons, at least based on their respective melting threads :)

Big downswing in albedo recently

28
Arctic sea ice / Re: The 2020 melting season
« on: June 15, 2020, 06:24:41 PM »
There have been relentless spring-summer-fall anomalies there for a long time. I suspect this year will be the worst too

29
Might explain why we've been having a really tough time pinning down our "ice:ocean" interface recently.

We've been observing very strange fluctuations in temperature at the bottom of the ice in the raw data, which is bugging the code we used to make;

www.mosaic-ice.com:8501



The raw data can be viewed here;

https://data.meereisportal.de/gallery/index_new.php?lang=en_US&active-tab1=method&active-tab2=buoy&singlemap&buoyname=2019T56

30
PS iv been thinking, the ocean is more saline in the region the buoys are migrating to. This would in theory increase bottom melt, even though to us it would appear not much had changed in terms of ocean temp? Could this be a factor?

I cant find a current figure, but I know you and blumenkraft are pretty keyed in with your maps. Heres where T64 is. Im pretty sure thats close to a sharp salinity gradient

Scrub that i found one :)

31
Arctic sea ice / Re: MOSAiC news
« on: May 27, 2020, 01:55:36 PM »
PS probably struggling to make headway against the drift over the last 2 days. T61 is the Tbuoy on 7m ice. I'll keep monitoring its drift till it stops reporting
animation rotated 45deg

really not a big deal at all but when I had to blow-up ggplot figures for a conference poster I found anti-aliasing hugely useful

Install the R Cairo library and add type=cairo when you render

32
Arctic sea ice / Re: The 2020 melting season
« on: May 26, 2020, 08:15:36 PM »
Figure from the regional miner i wrote. Looks bad pretty much everywhere.

Someone asked me to change the calibration from 2010-2019 to 2012-2019, so I did that

33
Arctic sea ice / Re: DHACSOO - A Durable Arctic Hypothesis
« on: May 26, 2020, 04:38:50 PM »
Quote
Next question. Why does ice adjacent to Siberia begin melting earlier than ice in the CAA which is at the same latitude? Insolation s/b the same +/- some cloud anomaly. Water temp s/b < 0 before the ice begins melting.

I see proximity to heat from land as the trigger to begin melting, preconditioning, etc. Perhaps you see it differently?
I wish you would attempt to quantify your hypotheses.
Does the CAA start melting later than the ESS? I think not, judging by the AMSR2 area graph.
Why does the Beaufort start melting much earlier than the ESS? Same latitude, same proximity to landmasses, and deeper bathymetry.
The answer to all these questions is prevailing currents and ice movement.
Note if the CAA ice was not landfast, it would have been flushed south and melted much earlier every year. So the CAA is a really bad example.

I agree, if you can it would be great to see some kind of data. Most of the time a hypothesis has underlying pilot data. Something other researchers can use to make their own judgements.

I know we all have busy lives outside of ASIF, so please dont interpret this as pushy!

34
Arctic sea ice / Re: DHACSOO - A Durable Arctic Hypothesis
« on: May 25, 2020, 09:10:41 PM »
 Ah okay, so we are talking about an exponential decay in the rate of loss? I agree with this statement, I think many people do.

Im more curious about your DHACSOO. It can be quite difficult to collate data but were you to regress the average velocity/direction of wind coming off the coastlines versus the ice area for the adjacent sea, I think it could be quite interesting. Is the Siberian side terrible at the moment because of current conditions? Or pre-conditioning last year.

Lots to think on.

Occams razor for your working hypothesis is that the ice just follows the mean ocean surface current and accumulates north of the CAA.

35
Arctic sea ice / Re: DHACSOO - A Durable Arctic Hypothesis
« on: May 25, 2020, 06:59:37 PM »
Cool stuff, I enjoyed the read.

Could you sum up your hypothesis in one or two sentences?

36
Arctic sea ice / Re: The 2020 melting season
« on: May 22, 2020, 12:53:22 PM »

We don't know what is going to happen in June but so far we are likely going into June in best modern set up to ravage the inner Arctic basin.

I guess that's a matter of opinion. 2012 and 2016 had very weak freezing seasons which preceded them and set the stage with thinner ice. By comparison, 2020 was a much better freezing season. Hoping for a mid-May PIOMAS volume update which gives us a better idea of thickness.

2012 and 2016 were middle of the pack in terms of their freezing seasons. 2014, 2017, 2018 were just as bad

37
Replaced NaNs with 0s to help with downloading and using csv files.

Rerouting traffic to new website/ domain name (at a very small cost in the region of $0.40 per million lookups):

The port at 8501 is unfortunately a must, and wont be going away any time soon


http://www.mosaic-ice.com:8501/

38
Several improvements to the webapp

1) Better maps
2) Added new buoys
3) Added function to easily change parameters of the code

uniquorn, i see your point, thats going to be pretty difficult to do though  :-[


Webapp will be kept online for 12-hours. Find it here:

http://52.14.65.105:8501

39
Its going pretty well, here is the website- all of this runs on the website itself and not on my actual python environment.

Still about 50hours worth of interactivity to add, but im surprised at how well it seems to be going.

The best part is i can use a free amazon-EC2 to host the server. Im pretty sure those machines have 4Gb ram so it will be relatively slow but beggars cant be choosers :)

40
Arctic sea ice / Re: The 2020 melting season
« on: April 28, 2020, 12:36:52 PM »
According to my mining script regional conditions are poor compared to the last decade.

Would it be more informative if I changed how many years the current year is compared to. Maybe post-2012 instead?

I suggest an automatic ban from this thread after 3-strikes, because its the same every year in the melting/freezing threads. Not going to answer anything re this post that isnt related to the ice.

41
Arctic sea ice / Re: The 2020 melting season
« on: April 14, 2020, 01:05:57 PM »
We wrote a program in the developers-corner that can extract data from the MOSAiC buoys in (essentially) real time.

Ill be posting that data weekly to a dropbox in the format of both raw-numerical and visual data.

It will be interesting to keep an eye on them over the melt-season, it already appears that temps are ramping up over all the active buoys we can monitor.

Uniquorn has been working their magic in making some cartographic visualisations over in the MOSAiC thread.

42
We deliberately cut the start day to Dec 1st, but when you take out that line the changes in growth become more obvious.

We put that line in because not all the buoys start transmitting on the same day so the data-structure gets messy



///////

please ignore the dates, they are now bugged- code is like a house of cards

43
So it would seem. Id say im probably less informed than yourself and uniquorn about this, but its maintained across the buoys

Sorry about the legend clipping here, python is being a real pain



FYI that is an animated gif

44
I wrote a script for plotting individual buoys in a "nice" way. Based on the figure you shared above

45
Policy and solutions / Re: Lessons from COVID-19
« on: March 30, 2020, 03:16:34 PM »
This made me do a sad-smile when i saw it

46
Thinking about those rough charts, it would be easier to compare them if they all started on the same date. I think the shallow gradient was during the warm spell in October, some of the Tbuoy's data don't start till late oct/nov. Of course, if the ice is thin, it thickens quicker.

Good point? I can slice it at a date if you think that would work?

December 1st?


//////

scratch that, you can change it to any date you wish within the code

47
Iv added some new outputs to the console for you also;


48
It wasnt a bug.

Any thoughts? Influx of warm water facilitating bottom melt?

49
So we are getting closer, the ice:snow boundary is now very clear.

Can you see the bump labelled green? Thats something were discussing. That could either be a sharp melting event, or a bug.

As the air temperatures do not rise to facilitate this melt, is probably a bug.

The best way to tell is to slice those dates off the dataframe. If those bumps move with the slice, to a different date, then it is definitely a bug.

If the bumps disappear, then it is not a bug.


SUMMARY: ice thickness is blue-red lines

50
New code coming to you. I feel like this one might underestimate, but it is based on dT120 which has a very distinct and clear ice boundary.

The question is, IS it underestimating or it is that thickness?

Their data here,

https://data.meereisportal.de/gallery/index_new.php?lang=en_US&active-tab1=method&active-tab2=buoy&singlemap&buoyname=2019T56

//Edit//

 having read about it I have to say that I think its the real boundary

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