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Messages - Freegrass

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1
Arctic sea ice / Re: The 2019 melting season
« on: Today at 02:40:43 PM »
Updated full-size versions available in the Nullschool Animations thread:
https://forum.arctic-sea-ice.net/index.php/topic,2905.msg228895.html#msg228895

Hindcast: 9/12 to 9/16, Forecast: 9/16 to 9/20. Wind + IWPD @ 850hPa (tiny version)

2
Arctic sea ice / Re: Nullschool Animations
« on: Today at 02:25:50 PM »
Hindcast: 9/12 to 9/16, Forecast: 9/16 to 9/20.
IWPD @ 850hPa, Wind + IWPD @ 850hPa (full-size versions)

[Instantaneous Wind Power Density: air density ρ, wind velocity v: ½ρv3]

3
Arctic sea ice / Re: The 2019 melting season
« on: Today at 12:37:10 AM »
Well it's funny when bbr of all the prople, starts talking (read attacking) about somebody else's false predictions, which are according to his words not just honest mistakes (btw nothing the guy said at that point looked like trash that doesn't make any sense, CAB numbers weren't weak, but July was hot and we are still practically tied with 2016.) but trolling. Man you are literally famous for that on this forum, with much more ridiculous "predictions". Every time you see something you "like", you post these 10 day forecasts of every single run that helps your "case".

@aperson
It's not a denialist mistake to be wrong. Everybody is wrong sometimes with their predictions. It's just a mistake. What do we call people who voted for BOE option THIS YEAR, during this melting season. Or do you think that was more realistic than weatherdude's prediction. They were just wronglike him. That is it. No conspiracies or hidden meanings behind every false prediction. Some are more realistic, some are less.

Please guys stop attacking and bullying people every time there is somebody who has different prediction, compared to yours, even if they are wrong.  Cause you also are wrong a lot., like many people here, including me. Nobody could have predicted such a strong HP during the first half of the summer, especially after last few years (there was a talk last year or 2017 I remember very well, that because of the warming, cloudy cool summers are a new norm). And after all of that, nobody could have predicted such a slow August melt. It was proven dozens of times to all of us that Arctic is almost impossible to predict and full of surprises.

4
Arctic sea ice / Re: Nullschool Animations
« on: September 15, 2019, 01:53:48 AM »
some people here don't like it when new members...

I'm a thick-skinned relic. I don't mind getting extra hassles from others here -- nobody knows me and why would they suspect my psychedelic swirls are actually concerned with scientific content? Call me names, swear at me, whatever... but this professorial snarky-hints style (as if I'm just an undergraduate, so it's my job to figure out what the hell they want), it can nettle me -- refreshing my memory about why I hated school!

A godfather quote comes to mind: "What have I done to cause you to disrespect me so?"

Anyhow, I'm sorry to drag you back into this silly argument -- when people can just adjust their browser settings or site preferences and not have to act so unpleasant to us, when there are plenty more deserving candidates for accusations of abusing this site. If you'd forgive just a half-tsp of unsolicited advice from me, I'd urge you not to waste a moment's mental energy diagnosing the bizarre syndromes of haters. We got other stuff to do!

5
Arctic sea ice / Re: The 2019 melting season
« on: September 15, 2019, 01:11:03 AM »
I think you both can continue to post 1 post a day of videos. It is a good contribution. Make them a size so they don't autoload.
If someone doesn't like them and it really bothers them, this forum has a block feature, were you can select to hide posts from a certain user (then it says post is hidden, click to show).
There have been alot of people posting this season, you can't like what everyone contributes.

6
Arctic sea ice / Re: The 2019 melting season
« on: September 14, 2019, 09:49:26 PM »
I check nullchool every day, several times a day. I find these nullschool posts very insightful and  often generate insightful discussion. Aleph Null's hindcast/forecast animations are specially nice for me because I often only look at nullschool's forecast. Having the hindcast in a very quick animation right on time and often generating comments is very useful to me.

And it is right on topic. Animations of models of the current status of the melting season couldn't be more on topic.

There are advantages to linking videos instead of uploading, for example, having a broader audience, but it is more work.

This off topic. Complaints have been a common recurrence on this thread this season. Perhaps we need a "Complaints" thread where forum users can voice their dislikes and find acceptable solutions without polluting this thread?

7
Arctic sea ice / Re: The 2019 melting season
« on: September 14, 2019, 06:19:30 PM »
Animated gifs are roughly 3 times larger for the content I prepare.


Is that so? When an MP4 autoloads in backgroud no matter what (as i recently learned - thanks Oren!!), and everyone opening the thread causing IP traffic, the 'click to play' GIF (>700px) would save a shitton of traffic.


That said, i do enjoy your and Freegrass' animations and i do find them valuable. :)

8
Arctic sea ice / Re: Nullschool Animations
« on: September 14, 2019, 08:02:13 AM »
I hope others like it like i do! :D

9
Arctic sea ice / Re: Nullschool Animations
« on: September 13, 2019, 07:35:36 PM »
This one is awesome Aleph_Null! I've been wanting to do this also, but I still have to figure out how.

Sincere thanks to you & blumenkraft for the initial feedback. Maybe this place is a good graphic test bed. I'm still a bit skeptical of information overload here -- like there's so much going on it's impossible to take it all in. (A complication for me with some layered views I see.)

I'm an old graphic pro from a couple of incarnations ago, hacking about with my prehistoric version of Photoshop. The basic approach: two or more layers are merged into one, over and over, then the merged layers are output as jpegs, thence to EZGif. To pirate Aluminium's artwork I needed a little help from their splitter: https://ezgif.com/split

[EDIT: To be clear: I'm not worried about information overload here in the greenroom, I was referring to my own product -- trying to keep it simple enough to grasp.]

10
Arctic sea ice / Re: Nullschool Animations
« on: September 13, 2019, 01:36:01 PM »
I'm not sure if this is comprehensible, or just confusing.

It is really awesome. !!

11
Arctic sea ice / Re: Nullschool Animations
« on: September 13, 2019, 12:42:00 PM »
I'm not sure if this is comprehensible, or just confusing. I've combined Aluminium's last with the IWPD layer of my previous hindcast-forecast.

12
Arctic sea ice / Re: Nullschool Animations
« on: September 13, 2019, 08:43:15 AM »
This one is most useful. If you could merge the temps in there that would be perfect.

13
Arctic sea ice / Re: The 2019 melting season
« on: September 12, 2019, 01:35:13 PM »
Further illumination can be found in the Nullschool Animations thread (where, they say, Freegrass is available to all):
https://forum.arctic-sea-ice.net/index.php/topic,2905.0.html

Hindcast: 9/8 to 9/12, Forecast: 9/12 to 9/16.
Wind + IWPD @ 850hPa [Instantaneous Wind Power Density: air density ρ, wind velocity v: ½ρv3]

14
Arctic sea ice / Re: meaningless freezingseason/melting season chatter.
« on: September 12, 2019, 01:00:42 AM »
Yes I could see the dog, Freegrass, better viewed zoomed out on an average quality phone !

Reminds me a bit of this guy  ;)

15
Arctic sea ice / Re: Nullschool Animations
« on: September 11, 2019, 09:57:22 PM »
On guessing games and interpretation of data animation

The architects of the weather-data detection, assimilation, and prediction frameworks culminating in GFS & EURO might bristle at the suggestion that theirs, the most expensive and sophisticated stretch to play the odds in human history (not to mention humankind's premiere scientific accomplishment, imho), amounts to a guessing game. A super smart guessing game: a half-dozen interlocking differential equations conceived as an impossible dream by Vilhelm Bjerknes -- how could this work when it takes an army of human "computers" more than a year to figure out tomorrow's weather?

Somehow it all came together, with a little help from supercomputers, and from visionaries wild enough to see what happens if you fly into the eye of a hurricane. That's Harry Wexler, who bestowed my mantra: "The atmosphere is indivisible." From this mantra emerges all understanding. It'll take you clear through Climate Science to general enlightenment. Everyone's allowed one foolish hope. I've got dibs on that one...

Regarding the Arctic this summer, I hear consternation about continual disagreement between models in the 2019 melting-season thread. (Lurkers like me have been kindly re-christened "new ice" -- I don't know if this level of forecasting churn is unusual or not.) Lurking Dorian raises the question: given that a model's basic function is to project forward from past events, is it reasonable to expect a model capable of predicting the unprecedented?

So there are a couple of things my swirly suite of IWPD animations are meant to keep an eye on: the health of the planet, and how well the calculus of GFS holds up today, under apparently burgeoning chaotic factors. In particular, these animations intend to sharpen questions about the model to inquiries such as "What, where, when, and how did the forecast miss, in this hand of the guessing game?"

16
Arctic sea ice / Re: Nullschool Animations
« on: September 11, 2019, 05:16:27 PM »
I just need to figure out now how to make the transitions smoother between the frames.

Attached please find a brief test of EZGif's crossfade (I always convert to mp4 before downloading), with frame-delay set to 100 and crossfade-delay set to 20. This is the first ten frames of my jitter test, above, slowed down a lot.

I seem to recall attaining a BA degree (fwiw!) in painting & animation. Somehow I gravitate to the non-lucrative pursuits. At any rate, perhaps it's interesting that my current focus (the swirly suites of IWPD) calls for an intentionally jerky look (because I want to scrutinize each 3-hour guess as it crosses my screen), while you aspire to the naturalistic feeling of the unforgettable COsc videos you posted. We both explore graphics to understand how weather works, but from different angles, at the moment -- with regard to crossfade, at least!

Note: This test of ten frames with crossfade makes a larger file than 50 frames without.

17
Arctic sea ice / Re: Nullschool Animations
« on: September 11, 2019, 05:15:13 PM »
When I was posting videos, I used ffmpeg to convert GIFs to MP4s. I just took a quick look on Google and there are all kind of options for smoothing videos by interpolating frames.

https://www.google.com/search?q=ffmpeg+smoothing

18
Arctic sea ice / Re: The 2019 melting season
« on: September 11, 2019, 04:31:57 PM »
What's the official minimum then?

Currently, according to JAXA data, it is 4,158,349 km^2. Achieved on September 4th.

The extent data is misleading, at best.  The rank matters little - what matters is the sea ice thickness and the condition of the ice in general.

Unfortunately, the sea ice extent graphs are given the most attention rather than sea ice thickness and fragmentation (and sea surface temperature).

The sea ice extent is a dubious measurement, as highly fragmented slush should not be considered "extent", but it does seem to get included.  Therefore, the "extent" of the low quality single year ice of 2019 is compared against the "extent" of the multi year ice of, say 1995 - which is incorrect - it's comparing apples to oranges.

We need to be focusing on the multi year ice, sea ice thickness  - not the "extent" data.

On that note, how's that multi-year ice doing in 2019?

19
Arctic sea ice / Re: The 2019 melting season
« on: September 11, 2019, 10:03:19 AM »
September 6-10.

Looking at this, one might think there was an increase on the Atlantic side.

Big nope though. It's due to widening gaps.

20
Arctic sea ice / Re: Nullschool Animations
« on: September 11, 2019, 06:25:55 AM »
This thread is a good idea.
In any case, better a smaller audience but that of of willing users who choose to participate and appreciate the effort.
+1

I'm one of the regulars and appreciate the effort!

21
Arctic sea ice / Re: Nullschool Animations
« on: September 11, 2019, 03:22:15 AM »
This thread is a good idea.
In any case, better a smaller audience but that of of willing users who choose to participate and appreciate the effort.

22
Arctic sea ice / Re: The 2019 melting season
« on: September 10, 2019, 05:20:45 PM »
Nah, what's that face Simon? Being corrected on something doesn't vindicate such a face. It's all good mate. :)

And thanks a lot for the 'veteran' compliment. Very kind of you. :D

23
Arctic sea ice / Re: Nullschool Animations
« on: September 10, 2019, 05:11:42 PM »
The A-team really went for it...

I came across this interesting reply in the animated gifs thread:

One of these days I'm going to read through this thread again from start to finish, and will then hopefully fully understand what it is you guys are doing with what, and maybe then I can be a target user who is able to express what he needs.

Sorry for not understanding already. My head is too full. I know you're doing awesome stuff, grade A citizen science.

At the moment, I'm having similar difficulties. Perhaps I'll remain a modest admirer of such works for now. I just hope not to come out with a meteorological projection as mistaken as the Sharpie Over Alabama (wasn't that a Billie Holliday song?)! My "target user" is me. I just make what I want to see, selfish as hell.

Incidentally, Freegrass: Thanks again for reminding folks of this thread in the main thread. I'll do the same from now on. No point sprucing up the place if we never get any company.

24
Arctic sea ice / Re: Nullschool Animations
« on: September 10, 2019, 02:55:44 PM »
I really need to learn more about GIMP, and how to create great animations with it.

You may wish to peruse the "Creating Animated GIFs" thread?

25
Arctic sea ice / Re: Nullschool Forecast Graphics
« on: September 10, 2019, 10:07:51 AM »
Oops, I got so relaxed in your nice den here, Freegrass, I forgot to say why I like hindcasts. Watching the smoothed-out choreography of the hindcast versus the toggling, increasingly uncertain-looking movement quality of the forecast... that's what interests me. When I realized that Dorian was playing the same guessing game we've seen in the Arctic all year, I wanted to find out more about how models work, and whether chaotic factors are noticeably rising.

Thanks for listening!

26
Arctic sea ice / Re: Nullschool Forecast Graphics
« on: September 10, 2019, 09:59:08 AM »
I also thank you, Freegrass, but I'm also interested in hindcasts. Perhaps this is an appropriate place for me to explain why -- without spawning an OT clog in the main thread where angels fear to tread? (Speaking of chatter: I must say I am continually blown away that technology at the level of Nullschool is freely available. The more I learn about atmospheric science, the more amazed I am.)

With my production technique (using a Photoshop doc to stack up screengrabs -- what the hell) I'm seeing a lot more volatility in hindcasts than might be expected. I mean, this is supposed to be past-tense, but it hasn't settled down, evidently, because data assimilation continues for awhile.

That was my impression, but I wanted proof. So I put together the following to illustrate the jitter of data assimilation -- with 24 hours between screengrab runs (the more recent, with the same timestamp, appearing second). Sorry this one has to be so jittery.

27
Arctic sea ice / Re: Nullschool Forecast Graphics
« on: September 10, 2019, 04:03:19 AM »
Good job on making this thread Freegrass. :)

28
Arctic sea ice / Re: Nullschool Forecast Graphics
« on: September 09, 2019, 07:39:09 PM »
Thank you for these, Freegrass!

29
Arctic sea ice / Re: The 2019 melting season
« on: September 09, 2019, 03:52:04 PM »
Up-thread, the remnants of Hurricane Dorian are forecast to be south of Svalbard by Saturday. An alternative forecast from the BBC Weather site shows it arriving a little earlier and a little to the south-west of Svalbard. Following this it's forecast to move west and climb onto the eastern parts of Greenland until Sunday where, presumably, it would drop a ton of snow.
I'm not sure how this website below works outside the UK. If you home out the forecast map, it cover the entire globe bar the poles.
https://www.bbc.co.uk/weather/map

30
Arctic sea ice / Re: Nullschool Forecast Graphics
« on: September 09, 2019, 03:27:12 PM »
That's a good idea, Freegrass. :)

31
Arctic sea ice / Re: The 2019 melting season
« on: September 08, 2019, 09:57:13 PM »
I suspect that the famous bottom melt, as kind of a negative feedback, is not anymore what it used to be.

As luck would have it the NSIDC discussed surface versus bottom melt in the the latest Arctic Sea Ice News:

"Summer’s not over until bottom melt ends"

Quote
Although Arctic air temperatures are now falling below freezing, sea ice loss will likely continue for several weeks as heat stored in the ocean melts the underside of sea ice.

Here's the accompanying graph. The caption reads:

Quote
This 2005 to 2006 time series from the Beaufort Sea shows ice thickness (red line), growth rate (blue bars with negative values), bottom melt (blue bars with positive values), and surface melt (dark blue line with points). Both surface and bottom melt started on June 10. Surface melt peaked on August 1, and peak bottom melt was two weeks later on August 15. Surface melting ended on August 24, while bottom melting continued until October 24.

32
Arctic sea ice / Re: The 2019 melting season
« on: September 08, 2019, 01:25:52 PM »
Welcome. :)

33
Arctic sea ice / Re: The 2019 melting season
« on: September 08, 2019, 12:32:41 PM »
Freegrass, i made a GIF for you. Click it.

34
Arctic sea ice / Re: The 2019 melting season
« on: September 07, 2019, 02:55:37 PM »
the ice spreading out more is likely a sign of its weakness over past years.  the eratic/collapse-like behavior of berring sea is definitely a sign of a step change, get another two or three seas acting like this and it likely would be over; down 500k right-at/shortly after the year's max!  Regardless of min. the arctic seems broken and falling far faster than just increasing average melts would suggest.

35
Arctic sea ice / Re: The 2019 melting season
« on: September 06, 2019, 06:44:43 PM »
NASA put a nice animation of arctic ice loss online

Two take-aways for me: The Fram export starting up is nothing less than expected and the persistent arm in the ESS is a tail of MYI that made a full clockwise circle on the edge of the Beaufort Gyre, snapped off in the summer.

36
Arctic sea ice / Re: The 2019 melting season
« on: September 06, 2019, 02:07:19 PM »
Hindcast: 9/2 to 9/6, Forecast: 9/6 to 9/10.
Wind + IWPD @ 850hPa [Instantaneous Wind Power Density: air density ρ, wind velocity v: ½ρv3]

Some improvements, I hope, over my previous effort with Nullschool. A timestamp makes it more legible. Greenland is now oriented at the bottom to accord with Worldview.

37
The forum / Re: ASIF Statistics
« on: September 06, 2019, 11:18:51 AM »
I started making and posting my graphics on August 15. Can it be?

The F in ASIF from now on stands for Freegrass.  ;)

Amazing stats these past few weeks and days...

38
Arctic sea ice / Re: The 2019 melting season
« on: September 06, 2019, 10:25:02 AM »
That's a low pressure system so it causes dispersion -- the opposite of compaction.

On your figure, I suggest you redraw your arrows at 45 degrees to the right of the actual wind directions displayed -- which is the direction the ice goes (Coriolis) -- and then you will see the dispersion.

It's pretty trippy how a low-pressure system which should intuitively drag stuff inwards to fill the void, actually ends up pushing things away instead.
It actually isn't... A low pressure system creates a bulge on the ocean surface, so ice would have to travel up a slope to get to the center of that bulge. High pressure systems create a dent in the ocean surface, so the ice falls into that pit towards the center...

I'm pretty sure this is completely inaccurate, but can there be some truth to this?


Try reading this article about Ekman Transport https://en.wikipedia.org/wiki/Ekman_transport

Movements on a spinning sphere aren't always intuitive

39
Arctic sea ice / Re: The 2019 melting season
« on: September 06, 2019, 01:16:08 AM »
The weakest ice under full (90° Angle) attack

Windspeeds around 50km/h at a bit of a distance to the "Eye"

Some compaction will be the least impacting extent numbers, some melt still ongoing could
keep area drops in line with extent losses, despite higher concentration.

That's a low pressure system so it causes dispersion -- the opposite of compaction.

On your figure, I suggest you redraw your arrows at 45 degrees to the right of the actual wind directions displayed -- which is the direction the ice goes (Coriolis) -- and then you will see the dispersion.

40
Arctic sea ice / Re: The 2019 melting season
« on: September 05, 2019, 06:53:41 PM »
Dorian's track:

https://www.nhc.noaa.gov/refresh/graphics_at5+shtml/151958.shtml?cone#contents

It will be interesting to see what effect of heat inputs from two hurricanes and (currently) two additional tropical disturbances will be in about a weeks time.

There may be no effect except to hinder freezing.  It is possible the heat may permit bottom melt to continue with a resulting late minimum.  I don't expect the numbers to be dramatic.  If melt does continue it will likely be at a trickle of 10-15K/day; at least that's my expectation.

42
Consequences / Re: Hurricane Season 2019
« on: September 05, 2019, 07:32:39 AM »
Not a psychiatrist, but when a guy looks up to the sky and sais 'i'm the chosen one', i can see how there must be some detachment from reality and narcissism involved here. Or that time when he bragged about his building now being the tallest after 9/11.

Now he is clearly demented. Can't even speak anymore.

People who think there is a need for a psychiatrist to asses if the POTUS is mentally ill are in need of a psychiatrist.

43
Arctic sea ice / Re: The 2019 melting season
« on: September 04, 2019, 09:40:55 PM »
I've been watching Lingling and Dorian recently, and I'm interested that they both undergo extratropical transition and integrate their momentum into the jet stream around the same time:



Dorian and Lingling are the symmetrically opposite 968mb lows here. Their angular momentum seems to enhance a dipole pattern, and the timing of their momentum transfer will be critical to how it sets up here. Regardless of the exact configuration, it looks like this will split the initiating tropospheric polar vortex into two lobes and allow a major heat/moisture intrusion from the Pacific



As we enter peak hurricane season, it's important to remember that one of the major heat engines that moves heat from equator to pole are tropical cyclones, so watching their activity will be critical to see how the freezing season initiates (or fails to)

This to me indicates that the melting season is not over yet and way may see losses for the next two weeks. I would be stunned if the AO does not go negative again in the next two weeks, but then again I'm just a naive observer and not a pro meteorologist.

Edit: And after looking at this month's PIOMAS, I really wonder if this will push the Sept 15 update into first place.

44
Arctic sea ice / Re: The 2019 melting season
« on: September 03, 2019, 01:09:36 AM »
I'm not sure if things will get ugly as the low will be a cold one and I be surprised given the area numbers stabilising we will see any huge surprises in extent(i'm leaning more and more extent will stay above 4 million now). It would seem the more compact looking CAB may of played a role why extent is not worse than it is now but as some others have said, the conditions in the 2nd part of August was perfect for ice retention as no doubt the end of August 2016 pattern would of lead to a much lower extent with that mega dipole that occured then(the total opposite to what happened in the last 2 weeks).

Weather patterns don't look too favourable for any early refreeze or anything that may suggest a significant cool down of the Arctic SST's to the next couple of months could well be interesting for different reasons!

45
Arctic sea ice / Re: The 2019 melting season
« on: September 02, 2019, 05:23:17 PM »
@Freegrass: When every other post is a forecast animation, it might be a bit much. It takes a lot of space. Maybe you can just post links to the animations hosted at a different place?

Respectfully disagree, Grixm. Seeing them on a daily basis has value to me.

Freegrass, i hope you keep them coming. :)

46
Arctic sea ice / Re: The 2019 melting season
« on: September 02, 2019, 04:30:19 PM »
@Freegrass: When every other post is a forecast animation, it might be a bit much. It takes a lot of space. Maybe you can just post links to the animations hosted at a different place?

It's not much, how could it?

Many come here to see as "much" as possible.

Just use a computer instead of a mobile phone and it won't matter.

47
Arctic sea ice / Re: The 2019 melting season
« on: September 02, 2019, 02:43:01 PM »
Fram export looking fairly extreme this evening? (Depicting surface winds at 30 to 60 km/h southbound.)

48
Arctic sea ice / Re: The 2019 melting season
« on: September 01, 2019, 08:23:54 AM »
August 27-31.

2018.

Additionally: August 1-31 (fast).

49
Arctic sea ice / Re: The 2019 melting season
« on: September 01, 2019, 07:17:47 AM »
The ice looks like shit!

Scientifically speaking.
How not to agree.

50
Arctic sea ice / Re: The 2019 melting season
« on: August 31, 2019, 08:15:30 PM »
Huge swathes of CAB ice clearly visible today in Worldview. Most of it looking pretty much like this (at 85.75, 19.57):

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