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Messages - uniquorn

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1
Arctic sea ice / Re: MOSAiC news
« on: Today at 11:53:06 AM »
Drift update.

2
Arctic sea ice / Re: The caa-greenland mega crack
« on: Today at 11:31:22 AM »
Lincoln sea still mobile. Lift off again from NW Greenland coast.
https://go.nasa.gov/2PsDJe3  dec1-8 ctr

3
Arctic sea ice / Re: MOSAiC news
« on: December 07, 2019, 02:07:30 PM »
Rapid drift to a grinding halt for direction change. Almost a handbrake turn.

edit: added a drift comparison. Spatially quite similar though one or more buoys appear to temporarily race ahead during the more rapid drift. It's possible that could be an artifact of generating the animations separately though.

4
Arctic sea ice / Re: MOSAiC news
« on: December 06, 2019, 08:40:31 PM »
Drift comparison of p201, p204 and p207 setting the start of each track in the same place on oct11. An attempt to show distance change between buoys over time until something better comes along.
ctr
tech note: data missing on oct31 as mentioned upthread

5
Arctic sea ice / Re: The caa-greenland mega crack
« on: December 06, 2019, 07:41:49 PM »
Fast ice still lifting off the mclure strait, https://go.nasa.gov/38fCYxy

6
Arctic sea ice / Re: The caa-greenland mega crack
« on: December 06, 2019, 01:38:35 PM »
significant shear, https://go.nasa.gov/38eGIiQ   cffr

7
Arctic sea ice / Re: MOSAiC news
« on: December 05, 2019, 10:49:40 PM »
drift update, 3 buoys close to PS, ~8days in 70frames.

8
Developers Corner / Re: Test space
« on: December 05, 2019, 08:59:14 PM »
nullschool ani, marker gets a bit lost going to gif

9
Arctic sea ice / Re: MOSAiC news
« on: December 04, 2019, 03:27:36 PM »
drift update, 3 close Pbuoys, ~7days in 50frames. Retracing at speed.
small steps, Tor, small steps :)
edit: updated below

10
Developers Corner / Re: Test space
« on: December 03, 2019, 10:47:57 PM »
testing polygons - got nowhere today

11
Arctic sea ice / Re: MOSAiC news
« on: December 03, 2019, 02:25:41 PM »
Quote
It's not clear what to measure if the ice is shearing, compacting and diverging more than it did
Had a look at osisaf for today but it only goes back to 2015 and wouldn't be representative (ctr). Is there a monthly drift somewhere that might give an overview of possible increase in mobility over the years. (or average the arrows over a month somehow?)

A month of meandering mosaic drift, nov2-dec3. Another acceleration yesterday. ~31days in 150 frames.

Woods Hole Oceanographic Institution, owners of itp102, part of the mosaic buoy network, give a nice overview of drift on their site and at the moment mosaic align quite well with annual drift. https://www.whoi.edu/page.do?pid=165676

12
Arctic sea ice / Re: MOSAiC news
« on: December 02, 2019, 09:51:39 PM »
Perhaps the new reality is continuous change as ice moves, breaks up, reforms into different patterns?
Indeed. Late refreeze and rapid extent gain maybe has it's own problems. More obvious stretch marks perhaps.  https://go.nasa.gov/35U33jv  nov27-dec2, ctr

13
Arctic sea ice / Re: MOSAiC news
« on: December 02, 2019, 09:21:27 PM »
drift update, 3 close Pbuoys and PS estimated location, ~10days in 50frames

14
Greenland and Arctic Circle / Re: The Nares Strait thread
« on: December 02, 2019, 01:59:02 PM »
Agreed, the arch struggling to form with so much mobility and change in direction further north.
https://go.nasa.gov/2ODuA2Z nares/lincoln  oct27-dec2 ctr

15
Arctic sea ice / Re: The 2019/2020 freezing season
« on: December 01, 2019, 10:34:14 PM »
Baffin perhaps missing some MYI intake, or maybe it's just weather. Either way, quite a step change into new territory.

16
Arctic sea ice / Re: MOSAiC news
« on: December 01, 2019, 04:07:01 PM »
drift update, 3 Pbuoys closest to PS, ~9days in 100frames.
This ani includes an estimate of PS location based on 10/17 distance between p201 and p207. Some coordinates taken from polarview images have been added in red to verify the rough path. The timing of the path passing close to the polarview points still needs to be verified.
Tech  note: PS points in red taken from a list collated by A-Team using the method here

17
Developers Corner / Re: Test space
« on: December 01, 2019, 01:07:43 AM »
Ran a 2000px with latlon labels for checking. Took out the two obvious S1 errors. Possibly 2 more. Also testing the limits of label repel. EdV next

18
Developers Corner / Re: Test space
« on: December 01, 2019, 12:13:36 AM »
added some PS coords from S1AB on polarview, some of which look like they need checking. Half way is not bad, but a bit too far west. Need to check times too etc....

19
Developers Corner / Re: Test space
« on: November 30, 2019, 11:31:35 PM »
PS test, half way between p201 and p207, inherits most other things from p201, small steps

20
Arctic sea ice / Re: The 2019/2020 freezing season
« on: November 30, 2019, 08:50:34 PM »
Barents and Greenland seas pushing towards previous recent upper limits, Chukchi and Baffin finding new lows.
Wipneus regional extent for nov28.  https://sites.google.com/site/arcticseaicegraphs/regional

21
Arctic sea ice / Re: Arctic Ocean salinity, temperature and waves
« on: November 30, 2019, 06:37:51 PM »
uni-hamburg amsr2-uhh overlaid onto mercator temperature 34m at 60% transparent. amsr2 0% concentration, normally dark blue, has been set to fully transparent. sep21-Nov29, Large.
Posting temporarily

22
Arctic sea ice / Re: The 2019/2020 freezing season
« on: November 30, 2019, 03:32:43 PM »
Here using mercator (model) salinitytemperature at 34m to show currents at 34m that may help to explain the resilience of the extended Chukchi bite. Sep21-nov29. Turbulence along the edge of the chukchi plateau is likely to increase mixing of shallow water.

23
Arctic sea ice / Re: MOSAiC news
« on: November 30, 2019, 02:46:59 PM »
drift update, 3 Pbuoys closest to PS, ~8days in 50frames
updataed below

24
Arctic sea ice / Re: MOSAiC news
« on: November 29, 2019, 01:26:58 PM »
drift update, 3 Pbuoys closest to PS - see below

25
Greenland and Arctic Circle / Re: The Nares Strait thread
« on: November 29, 2019, 01:21:18 PM »
https://go.nasa.gov/33xyper  nov27-29, ctr

26
Arctic sea ice / Re: MOSAiC news
« on: November 28, 2019, 10:56:37 PM »
Quote
A live cam would not make a dent in the ship's excellent bandwidth.
Maybe they're paying by the MB ;) Those Obuoy.org cams were interesting though, and quite popular here. Who is going to be interested in 2023?

Thought about posting more buoy data but after a classic facebook breakfast shot on https://follow.mosaic-expedition.org/ I'm going with this from bbc.
https://www.bbc.co.uk/news/world-europe-36475672




27
Arctic sea ice / Re: MOSAiC news
« on: November 28, 2019, 12:49:59 PM »
Quote
a second method for accurately measuring latitude and longitude
Does that mean you've already done it so we don't have to? ;) I need one accurate starting point on, say, oct4 for a drift comparison test.

Looking at the close up S1AB's I think mosiac have really missed an opportunity to engage an audience in real time. It looks like quite exciting ice movements happen close to Polarstern. The sort of thing that interests webcam watchers worldwide (waterholes, peregrine falcons etc). There's plenty of light around the ship, where's the webcam???

Today's drift in slowmo so you can read the lat/lon and I dont have to label anything.

28
Arctic sea ice / Re: Arctic Ocean salinity, temperature and waves
« on: November 27, 2019, 10:23:15 PM »
uni-hamburg amsr2-uhh overlaid onto mercator temperature 0m at 80% transparent. amsr2 0% concentration, normally dark blue, has been set to fully transparent. Chukchi, sep21-Nov26, Large.
Posting temporarily - removed

29
Arctic sea ice / Re: The 2019/2020 freezing season
« on: November 27, 2019, 10:04:48 PM »
uni-hamburg amsr2-uhh overlaid onto mercator temperature 0m at 80% transparent. amsr2 0% concentration, normally dark blue, has been set to fully transparent. Chukchi, Nov1-26

30
Developers Corner / Re: Test space
« on: November 27, 2019, 09:18:42 PM »
grat white

31
Developers Corner / Re: Test space
« on: November 27, 2019, 09:08:38 PM »
grat

32
Developers Corner / Re: Test space
« on: November 27, 2019, 08:53:40 PM »
testing large close pbuoys with tails ctr

33
Arctic sea ice / Re: MOSAiC news
« on: November 26, 2019, 08:55:11 PM »
The polarstern position may possible be estimated to a higher degre of accuracy than 1dp by calculating the mid point of p201 and p207. The correction to the animation above(deleted) includes those calculated coords, shown in red. I haven't been able to animate them along with the buoys yet.
Note how the drift track crosses over a similar area 3 times. Perhaps itp102 data correlates with that crossover point.
Tech note: Lat/Lon data is to 3 or 4 decimal places, rounded here for visual reasons. There are still some overlaps.
interest level=1/10?
edit: cropped to less than 580px for better display

34
Arctic sea ice / Re: MOSAiC news
« on: November 26, 2019, 08:24:47 PM »
<how ice drift correlates with wind direction>
For future reference, what was the offset angle during that period? It looks a bit less than 45deg.

Looking under the ice, whoi itp102 is part of the mosaic buoy array, though not currently featured in any animations yet, but it can be expected to experience similar drift. The detail on the drift track is just about good enough to make out the path we are all familiar with, also reminding us of the overall scale of movement. Note the small change in temperature and senility as the buoy possibly passes over roughly the same area. An enthusiast may want to look into that ;)
The microcat is mounted at only 6m below the surface.
https://www.whoi.edu/page.do?pid=165676
Quote
ITP102 was deployed on a 0.7 m thick ice floe in the Transpolar Drift on October 10, 2019 at 85° 7.9 N, 135° 34.1 E in collaboration with the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition from the Russian Research Vessel Federov. On the same icefloe, a Naval Postgraduate School Arctic Ocean Flux Buoy (AOFB) and Seasonal ice mass balance buoy were also installed. The ITP includes a second generation prototype MAVS current sensor operating on a pattern profiling schedule including 2 one-way profiles between 7 and 760 m depth each day and SBE-37 microcat fixed at 6 m depth.

35
Arctic sea ice / Re: MOSAiC news
« on: November 26, 2019, 05:09:24 PM »
that drop has potential for development :)
Quote
Manipulating the longitude in the dataset prior to conversion
Went with lon = (data$longitude..deg. +45), lat = data$latitude..deg.    from the line before which appears to have the desired effect, though doesn't affect the underlying map, as you say. Should be ok till they hit land (and no bathy)

So, we have rotation and lat/lon labels. You wait ages for a lucky click and then 3 come along at once. And then music.

That manually placed 86N label is at 86.1 Will fix it and repost later(see below)

Tech note: Lat/Lon data is to 3 or 4 decimal places, rounded here for visual reasons. There are still some overlaps.
Forgot to change lon lines so 120E is not shown. Check the numbers


36
Arctic sea ice / Re: The caa-greenland mega crack
« on: November 26, 2019, 04:18:12 PM »
crack comparison, Peary-PGAS, nov26 2017-2019   https://go.nasa.gov/2DoNgwR
map courtesy of ossifrage

38
Arctic sea ice / Re: The 2019/2020 freezing season
« on: November 26, 2019, 01:57:33 PM »
That wind over the chukchi is almost certain to be mixing the relatively shallow water there. Whether that raises the SST or increases heat loss I'm not sure, but for a while, with air temps of ~-2C, probably not so much heat loss yet.
edit: unless it's the heat loss keeping the air temps higher

39
Arctic sea ice / Re: Arctic Ocean salinity, temperature and waves
« on: November 25, 2019, 11:22:47 PM »
whoi itp103 (both microcats stopped recently) popped back out of the amundsen gulf and 116 now heading for the fram

40
Arctic sea ice / Re: MOSAiC news
« on: November 25, 2019, 06:06:02 PM »
Nice, the mosaic floe images give a bit more meaning to the movement info.
Today's update, still retracing. It should be noted that the buoy animations are rotated -45deg from Greenland down. Similar to the mercator default image.

The secret to rotation may be in here somewhere
Quote
proj.og = "+proj=longlat +datum=WGS84",
proj.out = "+proj=stere +lat_0=90 +lat_ts=0 +lon_0=0 +k=1 +x_0=0 +y_0=0 +datum=WGS84 +units=m +no_defs +ellps=WGS84 +towgs84=0,0,0",
or maybe not ;)

41
Arctic sea ice / Re: The 2019/2020 freezing season
« on: November 25, 2019, 02:02:22 PM »
 <effect of bathymetry on melt>
worldview brightness temperature image of the saline water north of Svalbard sinking and/or mixing. This persistent lower concentration ice area is getting easier to spot as the export ice gets thinner. Click for full res. https://go.nasa.gov/2DbiRCm

Maybe the extra buoy data from PS and mosaic are already improving the models in that area.

42
Arctic sea ice / Re: MOSAiC news
« on: November 25, 2019, 02:16:50 AM »
3 closest buoy comparison. Animations created separately, note the time differences. Well within an hour, but need watching. ctr

43
Arctic sea ice / Re: MOSAiC news
« on: November 24, 2019, 07:29:32 PM »
<If the Rammb is enlarged 3x but its PS held at the PS S1 location>
Maybe that should be from the projected PS loc for nov23

A major breakthrough for the buoy animations today. We now have dates! Though please see below for a view on how accurate they may be. This one goes back to nov17 to show todays movement retracing the previous path. We also have minimal manually added lat/lon labels.

Tech note: Best efforts are made to make the frame count the same as the number of hours, so the time should be accurate to the hour, probably much closer.
Quote
transition_along makes the following variables available for string literal interpretation, in addition to the general ones provided by animate():
    frame_along gives the position on the along-dimension that the current frame corresponds to
https://rdrr.io/github/dgrtwo/gganimate/man/transition_reveal.html
I would never have guessed 'frame along' in a million years, but, eventually, after asking the right question....



Some background on the method used for the buoy animations
Quote
When we animate data visualisations we often do it by calculating intermediary data points resulting in a smooth transition between the states represented by the raw data. In gganimate this is done by adding a transition which defines how data should be expanded across the animation frames. Underneath it all most transitions calculate intermediary data representations using tweenr and transformr — so far, so good.

What we have glanced over, and what is at the center of the problem, is what state of the data we decide to use as basis for our expansion. If you are not familiar with ggplot2 and the grammar of graphics this might be a strange phrasing — data is data — but if you are, you’ll know that data can undergo several statistical transformations before it is encoded into a visual property and put on paper (or screen).
https://www.data-imaginist.com/2018/what-are-we-plotting-what-are-we-animating/

44
Developers Corner / Re: Dev library
« on: November 24, 2019, 07:19:11 PM »
I just know everyone is going to want to try this for themselves ;)

Steps and rationales in placing an S1 image under its buoy time frame:

rotate S1 of 05:46 22.11.19 cw 45º in ImageJ
measure scale between 85-86 at 2712.46 pixels or 813.7 pixels per 0.3 deg of lat
animation scale between 85.6 and 85.9 which is 0.3 deg of lat is 369.6 pixels
consequently the S1 needs to be downscaled by 45.42% to fit under animation frame 77 need to find 85.6 120 on the S1 to know how far to drag it.
given 85.0 and 86.0 corners, it will be 0.6 * 2712.46  = 739.2 pixels down from 85.0
add a blank layer and put a green dot there.
put a big red * over the Polarstern on the image
add frame 77 and final frame 100 overlays and co-slide to 85.6 120
autocrop to get rid of S1 that is not under frame 77.
note PS is 53 pxl left and 6 pxl down relative to buoy P204 on frame 77
for future PS put a magenta star 53 pxl left and 6 pxl down relative to buoy P204 on frame 100
sailwx is saying PS is at 85.7 120.3 on frame 100 which is at 04:30 on 11.23.19
put a orange star 27.4 pxls up from 85,7 (in a blank layer, don’t cover up data).
copy out P204’s route, color it cyan and translocate it from PS f77 to PS f100 for
that gives hypothetical intermediate drift that we can test with RAMMB
ship GPS is only 1 dp so has a large uncertainty orange box
save a new-from-visible png enlarged to ~700
 
repeat for all the frames that have a nearby S1 time and post to forum later
most of the steps are the same for all S1 and
steps vary simply if Uniq changes buoy animation scale and orientation

05:46   22 11 19
04:08   22 11 19
02:30   22 11 19
06:43   21 11 19
03:27   21 11 19
06:02   20 11 19
04:24   20 11 19
07:00   19 11 19
05:21   19 11 19

45
Arctic sea ice / Re: MOSAiC news
« on: November 24, 2019, 05:22:20 PM »
Thanks. Quite a big lead in that rough location. Maybe they had to move some gear. The overlay is on to nov22 S1B as there were no images yesterday, so the 120 lines don't match up. click to run

46
Arctic sea ice / Re: MOSAiC news
« on: November 24, 2019, 04:26:42 PM »
Do you have a link or much larger single image?

47
Arctic sea ice / Re: MOSAiC news
« on: November 24, 2019, 02:55:08 PM »
helicopter trip?

48
Arctic sea ice / Re: The caa-greenland mega crack
« on: November 24, 2019, 10:50:30 AM »
Some lift off to feed the Beaufort arc

49
Arctic sea ice / Re: The 2019/2020 freezing season
« on: November 23, 2019, 10:00:16 PM »
Comparison of nov22, 2016-2019 using unihamburg amsr2uhh.
That chukchi little bit bigger bite would seem to be getting more resilient as the years go by. As noted already, some welcome early ice in the Bering.

50
Arctic sea ice / Re: MOSAiC news
« on: November 23, 2019, 01:16:16 PM »
update on close buoys, nov19-23. The diagonal to the legend is 120E with 2deg intervals, the line top right is 85.5N, with 0.1deg intervals. No labels. Testing semi transparent buoy markers.
Westerly buoys get two northerly lurches, the easterlies only one.

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