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Messages - SimonF92

Pages: [1] 2 3 ... 6
1
Arctic sea ice / Re: MOSAiC news
« on: September 12, 2020, 07:34:26 PM »
I think we may be too harsh on mosaic. We have had loads of buoy data but it seems few are interested in it (or are willing to share their analysis). 1.4% of viewers can be bothered to look at recent ice temperature data to estimate thickness when it is practically spoon fed to them.
We need to up our own game and get some planks out of our eyes.

Im working on the stuff from last season but the data is pretty poor to be honest. There are 4 'active' thermistor buoys, but only T78 is providing reliable data at this point. The thickness for that one seems to be 90cm-1m.

2
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

3
Antarctica / Re: arctic.io / antarctic.io
« on: September 11, 2020, 04:14:04 PM »
Its possible they are updating their site to a new production at the moment, in which case try back in 24hours.

4
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!

5
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.

6
Arctic sea ice / Re: MOSAiC news
« on: September 09, 2020, 05:10:29 PM »
drift update using T78.
Tbuoy temperature data. Not long to wait till core temp drops to allow us to get a clearer idea of where the ice/ocean interface is.
P234 drift speed update

Thinking overnight about the Pbuoy deployment, we know that there were many more local buoys on the first floe. Perhaps they are sharing even more buoy data this time. I haven't had time to calculate any distances yet, but a close array of buoys might be useful for documenting reduction of motion during the early stages of the freeze cycle in relation to other measurements being taken.

Agreed, possibly a missed opportunity with the north greenland gap. Maybe they thought they had to get through it before it closed up.

I have been thinking about it too, I know that covid19 has disrupted some of their operations. Is it possible that there was some sort of disruption to crew operation that forced them to deploy the Pbuoys in such a way? Doesnt say much on their twitter.

7
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.

8
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

9
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

10
Arctic sea ice / Re: The 2020 melting season
« on: September 06, 2020, 10:33:15 PM »
Thanks stjuuv, i should have provided a link!

11
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

12
Arctic sea ice / Re: The 2020 melting season
« on: September 04, 2020, 03:44:22 PM »
I think this is ice

lat=80.14909531134998&lng=-94.69253540039062

13
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):

14
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)

15
Arctic sea ice / Re: MOSAiC news
« on: September 03, 2020, 01:07:53 PM »
Once the ambient air temps get cold enough to not destroy our (imperfect) algorithm, ill update the code and start posting those thickness figures we were able to produce during the spring season

16
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.

17
Arctic sea ice / Re: MOSAiC news
« on: September 01, 2020, 03:44:40 PM »
I'm surprised by the data from T78. Thermistors 85-94 dropped to -1.5C in the last two days. That's 18cm. It's unclear from temperature alone whether this is ocean or 'rotten ice' but a few more days data should verify which is which.
It could be a good thing if the ice is cooling.

Im still convinced salinity has a role to play at the ice:ocean interface thermistors

18
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/

19
Arctic sea ice / Re: When will the Arctic Go Ice Free?
« on: August 31, 2020, 01:10:50 PM »
Peter Wadhams again?  When does he predict the Arctic will be ice-free this time?

As of August this year, he said this year is still a possible BOE... and if not this year, next year.

While I respect him, he really needs to stop making predictions like that... he complains about people not being scientific in one sentence then makes a prediction that isn't supported by facts (as in, where will all the energy come from to melt out this years remaining ice?)


2020 declared Blue Ocean Event
The area of the Arctic is 14.06 million km², we are already under 4 million km² of sea-ice. Look at the ratio of blue water to white sea-ice, the blue so outweighs the white that I'm declaring 2020 a BOE year, the second (after 2012). All it took in 2012 was a storm, this year it took bugger all. Because the remaining ice is nothing but a vestigial skin, next year, only freakish cold will prevent another one. Wadhams was wrong because he was late, not early.

I wonder how many people said 2013 would be a BOE

20
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

21
Arctic sea ice / Re: Arctic Image of the Day
« on: August 28, 2020, 02:33:45 PM »
I think the Petermann is gearing up for a large calving event, the main crack is roughly 12km from the terminus

22
Arctic sea ice / Re: The 2020 melting season
« on: August 27, 2020, 07:17:29 PM »
This is the furthest south Fram export has been in 20 years of Worldview data for this week

(Actually its tied with 2007)

23
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

24
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!

25
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/

26
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.

27
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

28
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)

29
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!

30
Arctic sea ice / Re: Home brew AMSR2 extent & area calculation
« on: August 24, 2020, 12:48:57 AM »
You have a github A-team?

31
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

32
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)

33
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!

34
Developers Corner / Re: Sentinel-Hub custom rendering settings
« on: August 19, 2020, 12:04:50 PM »
Some data iv generated with this "bluebird" technique on a well known Scottish snowfield

Delta is number of days from April 1st each year (these fields melt before winter)

35
Developers Corner / Re: Sentinel-Hub custom rendering settings
« on: August 19, 2020, 12:03:22 PM »
Im still improving this, but I think it will come in pretty handy when I get it working, for tracking the area of small ice caps

Real
Ice
Clouds
Open-ground


Will post a link to the github when done

36
Arctic sea ice / Re: The 2020 melting season
« on: August 19, 2020, 11:45:44 AM »
Looking at this around 70% of remaining ice is 0.5m-1.5m Thickness.
Indeed. But at this late atage there is less than 0.5m of average melt remaining. Probably 0.3m on average (can do the math later). Of course this can be distributed unequally and there can be upside surprises as well.
OTOH, remaining thickness in each grid cell is an average, and there is lots of ice below the average. The distribution is highly skewed with a lot of the volume in a small fraction of the area. (Wipneus' gice chart)

If you do ever get round to doing that math I would very much like to see one does those kinds of calculations

37
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


38
Arctic sea ice / Re: The 2020 melting season
« on: August 13, 2020, 10:34:33 AM »
I'm trying to get a good look at the patterns I saw in the lower resolution image. This one is a better look. Same date, from the northwest passage directory. What is with all the lines and arcs?

click for full resolution

Rain clouds moving over the ice, causing surface water to affect the sensors differently to adjacent drier areas?

39
Greenland and Arctic Circle / Re: St. Patricks Bay Ice-caps are gone
« on: August 10, 2020, 02:28:29 PM »
Wow, thanks very much!

These two are yesterdays image of the Simmons and Murray ice-caps discussed in this 2001 paper;

https://www.researchgate.net/publication/252553821_Mass_Balance_and_Area_Changes_of_two_High_Arctic_Plateau_Ice_Caps_1959-2001

They also discuss the St Patrick Bay ice-caps and estimated they would melt out after 2040.

*edit: though they didn't consider positive feedback in their estimation

40
Arctic sea ice / Re: The 2020 melting season
« on: August 10, 2020, 12:30:28 PM »
Below is the change in concentration from the 8th to the 9th of August. The second is the absolute change, where sea ice was lost or gained for the same dates.

Don't know what magic you are conjuring to make these but they are really interesting, great stuff

41
Greenland and Arctic Circle / Re: St. Patricks Bay Ice-caps are gone
« on: August 10, 2020, 12:18:35 PM »
Its poignant and scary that these last vestiges of the Laurentide ice-sheet are disappearing right before our eyes in real-time.

I spent many hours trying to find those ice caps in Worldview but never could due to the resolution of the images. Does anyone have any links to higher-res imaging sites?

42
Greenland and Arctic Circle / St. Patricks Bay Ice-caps are gone
« on: August 07, 2020, 02:26:07 PM »
I remember reading about these in 2017 and hoping they might be making a cyclical recovery, but no, they are officially gone

https://nsidc.org/news/newsroom/st-patrick-bay-ice-caps-canada-have-completely-disappeared

43
Arctic sea ice / Re: The 2020 melting season
« on: July 29, 2020, 02:46:45 PM »
Current temp Up 0.1 C from July 27th 1.7 C, July 28th 1.8 C

Im interested in how quickly this normalises. Could this be an 'artifactual' effect of large amount of rain on the ice? Bremen clearly showing rain all over the ice.

44
Arctic sea ice / Re: 2020 Melting Season Predictions
« on: July 28, 2020, 12:05:00 PM »
I will guess 2M KM^2 extent and 1.2M KM^2 area.

I think 2021 and 2022 will rebound a la 2013 and 2014. But this summer is going to be terrible. The worst impacts of the aerosol and contrails will result in worst-ever melt ponding this spring, and worst-ever melt this summer. However, they will also result in an excellent refreeze come winter 2020-21, and a brutal winter across the mid-latitude and well-populated areas of the continents.

The ice will survive this summer in a belt close to the CAA and Beaufort. Hudson Bay will melt out very late. Everything else will go early and quickly.

B+, you dropped a few points on your Hudson claim- but seemingly well done otherwise


45
The forum / Re: Suggestions
« on: July 08, 2020, 01:32:06 PM »
Simon, how are your PHP skills? Wanna update the forum software? ;)

point taken blumenkraft  :-X!

46
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.

47
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)

48
The forum / Re: Forum Software
« on: June 22, 2020, 06:59:18 PM »
Out of curiosity, why would anyone bot an amateur scientist arctic forum?

49
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!

50
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

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