MOSAiC news

[uniquorn]

Wide area view from Sentinel1AB with merged intermediate frames at 50%, nov17-22. No buoys yet.
click to run
scale=30% to reduce size

[uniquorn]

closer view at full res. Looks like there was a bit of whiplash.

[A-Team]

Here is a stomach-churning zoom centered at the Polarstern to go with that very effective hangover blur above. The last S1B of Nov 22nd has been rotated so that the pole is to the bottom left.

The second image shows a cyclone forming in the upper Fram and wandering up to the Polarstern's location before drifting off to the Kara Sea. The effects on leads and ridging would be fairly minor except for pre-conditioned fissures. Whatever the drift induced in the ship, even if it mimics transpolar drift, has nothing to do with transpolar drift.

The mp4, adapted from Uniq above with the Mosaic floe circled, shows the very unfortunate situation the Polarstern is in relative to large scale failures in the ice pack. Be sure to set on loop so it will rocks back and forth.

The 3x enlargement shows extreme disruption of the Mosaic ice camp over this time frame. Black lines are open water of new leads; white lines are pressure ridges. The Polarview portal to Sentinel imagery is currently badly broken and no files of any kind are available yet for today, the 23rd.

Mp4 are now easy to make in forum-acceptable form by saving ImageJ stacks to avi and then applying cloudconvert. It requires dimensions be even.

https://cloudconvert.com/avi-to-mp4

[uniquorn]

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.

[A-Team]

Right. At first it looks like one of those pen machines putting a personal touch on a massive junk mail campaign. But the trails actually differ quite a bit in their details upon trying to overlay them by a simple translational move. The question is, how to distinguish deformation from shear and discontinuities such as a lead opening.

The long PolarView weekend continues. I wrote them, they are off somewhere not responding. The pink square masking goes away if all but S1 are de-checked; problem is now in the feed. No new images have been ingested since the 22nd.

Mosaic is going to new extremes to keep the world uninformed.

[blumenkraft]

Slightly related, since we had the 'how does the ship influence the environment around the ship' talk.

Satellite tracking shows how ships affect clouds and climate

Link >> https://blogs.agu.org/geospace/2019/11/05/satellite-tracking-shows-how-ships-affect-clouds-and-climate/

[blumenkraft]

60 frames, 51-minute increments via SNPP, Day&Night band.

Click to play

[uniquorn]

helicopter trip?

[blumenkraft]

I thought so too.

[uniquorn]

Do you have a link or much larger single image?

[blumenkraft]

I zoomed the shit out of it for you.

[uniquorn]

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

[A-Team]

The image below takes Uniq's animation #303 above, attaches the hour to each of the 100 frames, then adds the S1AB of that hour when one of the nine relevant ones is available. The png below just looks at frame 77 which had the latest S1.

Relative to buoy tracks, this time was well after the hairpin 180º but close to the final wiggles which were double to the east but triple to the west, at a bad time for the deployed Polarstern equipment.

The ESA/Copernicus could not have picked a worse time to skip two days of coverage of the Mosaic project. We know satellite went overhead at the usual times; we don't know why they shut down the radar that makes EW-format scenes. Maybe it was set to some other mode for some other purpose (?). At any rate, the RAMMB becomes the supplemental tool of choice.

... aims at fulfilling, during the routine exploitation phase, the observation requirements of the Copernicus services and of ESA/EU member states ... a secondary objective is to satisfy other SAR user communities, ensuring continuity of ERS/Envisat, considering requirements from the scientific community, as well as from international partners and cooperation activities.

The elaboration of a pre-defined observation plan necessitates solving, a priori, the potential conflict among users (e.g. different SAR operation modes or polarisation schemes required over same geographical area).Wave Mode (WV) continuously operated over open oceans, with lower priority versus the high rate modes. Interferometric Wide swath (IW) and Extra Wide swath (EW) modes operated over pre-defined geographical areas: over seas and polar areas, and ocean relevant areas, pre-defined mode is either IW or EW. In exceptional cases only, emergency observation requests may alter the pre-defined observation scenario, potentially requiring the use of the Stripmap (SM) mode.

https://sentinel.esa.int/web/sentinel/missions/sentinel-1/observation-scenario

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

The buoy timer is attached; the S1AB csv is a few posts back

[A-Team]

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.

If the Rammb is enlarged 3x but its PS held at the PS S1 location, then the 120's do fall into line which shifts the second location to the magenta half-circle.

Mosaic has not disclosed the location of remotely deployed equipment, only sites within a km of the Polarstern. We are not certain this is a helicopter but it is surely not the icebreaker bringing supplies as that is not due for several weeks.

[uniquorn]

<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.

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

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/

[blumenkraft]

We are not certain this is a helicopter but it is surely not the icebreaker bringing supplies as that is not due for several weeks.

Agreed. You only see it in one frame. If it was a ship you should see it way longer.

[A-Team]

Maybe that should be from the projected PS loc for nov23

Good idea, will implement along with enlarging the underlying S1 and optimizing the contrast for enlargement. Or maybe leave the Rammb as is and shrink the S1 as that is easier to back up to full or even enlarged once the suspect region is identified.

85.7  120.35 19-11-23 06:30    5  220  for location of PS at time of double heat source and wind
85.7  120.8   19-11-22 05:00    for location of the earlier S1B so a decent move

The frames are a whole orbit apart? That is usually a bit over an hour for near-polar, sun synchronous. Says 51 minutes above, so low orbit. Another possibility is heat from a fuel cell starting up. Or burning up -- drain holes were blocking up with refreezing melt water from their process. They were replacing them the other day by the Polarstern. And a remote one in the AGU blog. Of course those would be brought in by a helicopter so go figure.

Given the situation with Sentinels, it's probably worth looking into optimizing the Rammb archive a bit more. The contrast as initially provided uses about a fifth of the histogram. And some of the frames may provide recognizable details in the ice depending on local cloud cover. Bottom line though is the resolution is way worse than Sentinels.

Airplane engine heat maybe possible; is this a flight route between Asian and London?. Polar-5 and Polar-6 are not going out there until the piston bullies can groom an airstrip; the ice ridging  and dynamics make that problematic.

[blumenkraft]

IDK if this makes sense, but could it be an aeroplane also?

[macid]

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.

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....

amazing work on the labels, graticules and dates now, you should put your own name on it I couldn't get frame_along to work with something else, to much headaches in the end. It's easy to make it work one way.. but combine stuff and suddenly you have to play hostage negotiator.

in Panoply I can't see a way to load non-gridded data, and a sensible way to arrange this buoy data into grid format eludes me, use a fine grid and fill non-positions with nulls? Calculated vector values may make sense to put in a grid but I need a few courses to get there.

[A-Team]

put buoy data into netCDF for broader data integration?

Thanks for looking into it. Sure, nulls and fine grid. The thing to look at is OsiSaf .nc to see what they did for sea ice motion vectors, just copy what they did with the buoy data. We're looking for Geo2D file format in Panoply, geo-referenced. Anything less just produces distorted rectangular grids. Panoply will overlay buoy tracks on cryo2smos thickness. Some weirdness from the buoy data covering so little of a whole ocean polar stereographic.

http://www.osi-saf.org/?q=content/medium-resolution-sea-ice-drift-a
https://www.giss.nasa.gov/tools/panoply/download/

Panoply netCDF, HDF and GRIB Data Viewer ... - NASA GISS
https://www.giss.nasa.gov › tools › panoply › download
Sep 30, 2019 - Panoply netCDF, HDF and GRIB Data Viewer. Download Panoply. Panoply requires a computer with Java 8 (or later version) installed

amazing work on the labels, graticules and dates now

I'll second that! Compare it to the very best that this $150,000,000 project seems capable of producing. 0.01% of that budget could have got them first-rate graphics. All those unsecured boxes of kit that sank off the side, how much of the budget went down with them? Flying around 1.5 hr in the helicopter looking in vain for an expensive installation because they didn't track on GPS?

Talking to the spouse (who has ZERO interest in anything scientific) about all the Mosaic breakdowns. Response: the expedition was always just a lark, adventuring.



Going somewhere?

 86.0 120.7 19-11-25 08:00 11 130 -20.8 1003.1
 86.0 120.8 19-11-25 06:00 12 140 -18.5 1001.7
 86.0 120.9 19-11-25 03:00 12 140 -18.6 1000.1
 86.0 121.0 19-11-25 02:00 12 140 -18.8 999.7
 86.0 121.1 19-11-24 22:00 12 150 -19.7 998.0
 86.0 121.2 19-11-24 21:00 12 150 -19.3 997.7
 85.9 121.3 19-11-24 14:00 11 160 -16.7 996.0
 85.9 121.4 19-11-24 07:00 15 170 -17.2 995.6
 85.8 121.3 19-11-24 04:00 15 180 -16.0 996.2
 85.8 121.2 19-11-24 02:00 15 190 -15.4 997.2
 85.8 121.1 19-11-23 23:00 15 190 -15.6 999.9
 85.8 121.0 19-11-23 22:00 15 180 -15.8 1000.8
 86.0 121.2 19-11-24 21:00 12 150 -19.3 997.7
 85.9 121.2 19-11-24 20:00 12 150 -19.2 997.5
 85.9 121.3 19-11-24 16:00 12 160 -17.8 996.3
 85.9 121.4 19-11-24 07:00 15 170 -17.2 995.6
 85.9 121.3 19-11-24 06:00 15 170 -16.6 995.7
 85.8 121.2 19-11-24 02:00 15 190 -15.4 997.2
 85.8 121.1 19-11-23 23:00 15 190 -15.6 999.9
 85.8 121.0 19-11-23 22:00 15 180 -15.8 1000.8
 85.8 120.9 19-11-23 20:00 13 190 -15.9 1002.8
 85.8 120.8 19-11-23 18:00 11 190 -17.5 1004.7
 85.8 120.7 19-11-23 16:00 11 200 -19.3 1007.1
 85.8 120.6 19-11-23 15:00 11 190 -19.9 1007.9
 85.7 120.5 19-11-23 12:00 10 190 -21.0 1010.7
 85.7 120.4 19-11-23 10:00 8 200 -20.9 1013.3
 85.7 120.3 19-11-23 06:00 5 220 -19.1 1016.1
 85.7 120.3 19-11-23 05:00 4 220 -18.8 1016.6
 85.7 120.4 19-11-22 22:00 4 30 -17.5 1019.1
 85.7 120.4 19-11-22 17:00 8 60 -22.4 1018.2
 85.7 120.5 19-11-22 16:00 8 50 -21.2 1017.9
 85.7 120.6 19-11-22 13:00 7 50 -14.9 1016.9
 85.7 120.7 19-11-22 10:00 5 50 -16.3 1016.0
 85.7 120.8 19-11-22 09:00 4 40 -17.0 1015.5
 85.7 120.9 19-11-21 22:00 4 340 -15.0 1011.5
 85.7 121.0 19-11-21 06:00 4 360 -16.2 1003.8
 85.7 121.1 19-11-21 01:00 5 20 -17.4 1002.2
 85.7 121.2 19-11-20 23:00 6 10 -18.1 1001.9
 85.8 121.3 19-11-20 21:00 7 20 -18.5 1001.7

[uniquorn]

3 closest buoy comparison. Animations created separately, note the time differences. Well within an hour, but need watching. ctr

[Tor Bejnar]

Somebody could write some (classical styled?) music to which those buoys could dance to.

[A-Team]

One Sentinel has come in so far this morning, the 02:54 of Nov 25th. It just barely captured the Mosaic floe. The previous S1, the 05:46 of Nov 22, means a 3-day gap in coverage unprecedented back into September. Polarview is now ingesting mid-morning images so no more coverage of the Polarstern for today.

All the open leads have sealed so we will never know what happened during the chaos in the early morning of the 22nd other than what is in the three images available. However the weaknesses created by divergent wind stress will stay weak for the remainder of the winter and may re-open later. The red line in the final frame below may be a persistent lead or ridge associated with swaths early on made by the two icebreakers. 

The version below of Uniq's most excellent three-buoy comparison is squeezed to increase the separation of the tracks and runs back and forth as an mp4. Be sure to set controls to loop. The file size is so small on these because all the blank spaces compresses dramatically; the forum could show 50x the time period within its 10 MB limit.

On the 3rd animation, I've collected 16 of the 344 frames of Uniq's 3-buoy animation that have Sentinel scenes at the same time. There's enough empty space to add an actual thumbnail from the S1AB inventory of Mosaic floe images.

The bottom image shows the track of the Polarstern as adapted from the Rammb infrared sequence above.

Technical note: It is easy to add a dimmed out rest-of-track to each of the earlier frames to make it clear what is coming next. That is done by desaturating the final frame, excising the date and scale, duplicating 16x, tiling, lowering opacity and setting to 'darken only' in gimp, then reslicing the 'make new layer from visible' to the final animation.

[uniquorn]

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

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

[blumenkraft]

60 frames, 51-minute increments.

Yes, baby, that's the right direction.

[rog]

Buoy movement with music.

[A-Team]

Very nice addition, rog!

Smooth sailing ahead? The rifting episode of 22 Nov 2019 is over but the last four Sentinel-1 images (blue lines) are still show quite a bit of turmoil in the main experimental area. The Polarstern has been very slowly moving north but mostly moving west the last two days under moderate wind speed (5th column), winds direction swinging around (6th column) under cold temperatures and unremarkable barometric pressure.

Here the tenth of a degree of latitudinal shift from 86.0 to 86.1 represents a distance of 11.1 km whereas that distance requires a degree and a half of longitudinal change (at 86.0). So over the time frame of the table below the Polarstern has moved 17.7 km. They are currently 1472 km away from their destination of Longyearben, Svalbard which would be ~180 days away if this pace kept up (it won't).

https://www.movable-type.co.uk/scripts/latlong.html

 86.1  119.0 19-11-26 14:00 7 70 -27.0 1011.1
 86.1  119.0 19-11-26 13:00 9 70 -26.3 1011.1
 86.1  119.1 19-11-26 12:00 7 70 -26.5 1011.2
 86.1  119.2 19-11-26 11:00 7 70 -27.1 1011.9
 86.1  119.2 19-11-26 10:00 7 60 -27.8 1012.1
 86.1 119.3 19-11-26 09:00 8 70 -26.9 1012.3
 86.1 119.4 19-11-26 08:00 7 70 -26.3 1012.2
 86.1 119.5 19-11-26 06:00 8 70 -25.4 1011.8
 86.1 119.5 19-11-26 05:00 8 80 -24.1 1011.8
 86.1 119.6 19-11-26 04:00 7 80 -23.5 1011.6
 86.1 119.7 19-11-26 03:00 8 90 -22.7 1011.6
 86.1 119.7 19-11-26 02:00 8 80 -22.0 1011.6
 86.1 119.8 19-11-26 01:00 8 90 -21.7 1011.6
 86.1 119.9 19-11-26 00:00 8 90 -23.1 1011.5
 86.1 119.9 19-11-25 23:00 9 100 -23.8 1011.3
 86.1 120.0 19-11-25 22:00 8 100 -24.1 1011.2
 86.1 120.0 19-11-25 21:00 9 110 -24.2 1010.7
 86.1 120.1 19-11-25 20:00 8 110 -24.8 1010.4
 86.1 120.2 19-11-25 19:00 9 120 -23.7 1009.9
 86.1 120.2 19-11-25 18:00 9 120 -24.1 1009.4
 86.1 120.3 19-11-25 17:00 9 120 -23.7 1008.9
 86.1 120.3 19-11-25 16:00 9 120 -23.4 1008.2
 86.1 120.4 19-11-25 15:00 10 130 -23.5 1007.3
 86.1 120.4 19-11-25 14:00 10 130 -23.6 1006.7
 86.1 120.5 19-11-25 13:00 10 130 -23.6 1006.0
 86.1 120.5 19-11-25 12:00 10 130 -23.5 1005.5
 86.0 120.6 19-11-25 11:00 10 130 -23.2 1005.0
 86.0 120.6 19-11-25 10:00 11 130 -22.4 1004.4
 86.0 120.7 19-11-25 09:00 11 130 -22.2 1004.0
 86.0 120.7 19-11-25 08:00 11 130 -20.8 1003.1
 86.0 120.8 19-11-25 06:00 12 140 -18.5 1001.7
 86.0 120.9 19-11-25 05:00 12 140 -18.4 1001.0
 86.0 120.9 19-11-25 04:00 11 140 -18.2 1000.7
 86.0 120.9 19-11-25 03:00 12 140 -18.6 1000.1
 86.0 121.0 19-11-25 02:00 12 140 -18.8 999.7
 86.0 121.0 19-11-25 01:00 11 140 -19.1 999.2
 86.0 121.0 19-11-25 00:00 10 140 -19.8 998.7

[psymmo7]

...Buoy movement with music.

Thank you Rog. ---much appreciated

[blumenkraft]

Buoy movement with music.

Well done, Rog! Love it.

Now, when can we expect the dubstep version?

[macid]

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

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

Coordinate conversion uses Proj4js, no rotation option for stereographic projections. Manipulating the longitude in the dataset prior to conversion would achieve something similar (as long as there's no terrain height in the plotted area) or a there use rotate functions for x,y datasets after conversion.

But next is rotating the map and graticules, Plotsvalbard map would be messed up.. may as well go to raw ggplotting at this point. Which I should do anyway, because I can't get PSvalbard to work in Ubuntu (trying to take developing a bit more seriously)

Now, when can we expect the dubstep version?

drop at 11-23 please

[blumenkraft]

drop at 11-23 please

Exactly!

[uniquorn]

that drop has potential for development

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

[A-Team]

There is a golden opportunity to study how ice drift correlates with wind direction during an unusual period of steady wind speed and direction in in late October. As Nansen observed during the voyage of the Fram, motion of the ice was almost always offset from the direction of the wind. However he lacked the big picture that we have today (eg basin-wide cyclone).

The response of the Polarstern is shown in the two-frame animation and the csv of its variables below. Note both the zonal and meridional drift components were linear, with moderate drift to the north but a strong component to the east, forming a large angle to the wind direction (which is counter-intuitive but expected).

The ship presents a very large target to the wind but is of a negligible mass compared to the larger ice pack. Mosaic has declined to make public the ship's bearing (ie alignment with wind) over time, presumably to reserve for themselves (in 2023) the capability of using the GFS forecast to make a few days of ice motion forecast.

Attached also are the wind roses for wind direction and wind speed during the 229 hours of this low variability event.

[uniquorn]

<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

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.

[uniquorn]

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

[Tor Bejnar]

Thanks Rog!  Music makes it easier to actually watch the path of ice movement (and multiple times, to boot!).

Decades ago a classically trained friend did lots of improv playing, sometimes like (for example) being influenced by the way leaves blew around outside during blustery weather.  I imagine a computer program today basing 'music' (okay, sound) on buoy movement direction, speed, changing buoy relations (opening leads/growing ridges) [pitch, note duration, scale direction, volume, other variables, other aspects of sound], put to harmonic (or at times dis-harmonic) scales/chords.

[A-Team]

Snow at the Remote Sensing Site at 86.13, 118.58 on Nov 26th, is still barely over the birkenstocks and looking very susceptible to wind re-distribution. Thermal insulation? Not really but maybe keeps the wind from sweeping heat off the ice surface.

Meanwhile, back at the AGU blog collection, co-leader Matthew Shupe writes about earlier equipment disruptions (but not about the big one on the 22nd):

https://blogs.agu.org/thefield/2019/11/26/postcards-from-a-frozen-icebreaker-part-13/

https://polarbearsinternational.org/news/article-polar-bears/polar-bear-questions-do-polar-bears-drink-water/

"11/14/19

But then in the following day, just after we performed the major power system transplant on our L1 site, our L2 site failed. I examined all of the available information, and it told me a story: The inclination of the system changed abruptly by an angle that was ~3 times larger than the change from when Dave and I climbed on a station together; at about this same time the sonic anemometer instrument quit. The rest of the system’s communications went out about 8 minutes later, just after a couple spikes in one of the shortwave radiation sensors.

I speculated that this was a bear because the force exerted on the system must have been about 3 times that of Dave and I, and the fact that things were operating fine before and parts failed over the course of multiple minutes instead of all at once. With our brief visit by helicopter today, it appears that this speculation is true. It looks like the bear walked around the station and first yanked on a cable to the sonic anemometer, shattering a metal connector. He then jerked on a few other cables, totally pulling them apart and breaking another connector that was inside our main box. He pulled on our met mount, up at 2m height so he must have been standing on hind legs; this bent it down to one side.

And then he found the good stuff: the exhaust from the fuel cell power system is water. (As an aside, I wonder how bears drink water at all? I guess they must melt snow). It looked like he was sucking on the exhaust, pulled it out and chewed on a heat cable, mangling the copper outlet tube. This last part may be the hardest to fix as we have spares of all the instruments and cables, but will need to figure out a solution. All-in-all, it appears that, after another major field surgery, we should be able to resuscitate this system and get it operational again.

11/17/19 

It started small, as they all do. About 1m across at the point where the spine road leads past Ocean City out towards Met City. The crack meandered and there were places to easily just step across. No major changes over the day. We went on with our daily work at Met City.

In the afternoon a couple of us went out to do some power line maintenance. As it was there was little slack in our power network to accommodate cracks, so we disconnected some of the power line straps and pulled available slack to the area around the crack. Loops of heavy power cable sitting near the edge.

I estimated that it could absorb a widening to perhaps 20m. It held out well beyond that, but in the end it still wasn’t enough. Saturday evening the crack opened to >20m in places, then made a lateral shift of as much as 100m.

Met City, Remote Sensing site, and the ROV Oasis all moving more forward towards the centerline of the Polarstern from the starboard side. A bit reminiscent of the bid lead we had 22 years ago at SHEBA; that one moved our camp 500m to the side and made it necessary to power the camp on generators for the rest of the project.

But here, at MOSAiC, with this big shift, somehow Met City survives. It appears to be crack free, all instruments standing, and amazingly the power is still on! By Sunday morning there was a shear in the other direction, back beyond the original connection point, opening, closing.

And finally coming to a rest at nearly the original starting point. Met City power was finally interrupted at about 7am local time, its characteristic green light going out. Sunday was a planned day off so no science activities on the ice but the logistics team was still busy; they work very hard in support of this mission.

By the end of Sunday, Met City is still standing but dark, and the 30m mast has an odd tilt to it. Will have to explore that tomorrow."

[blumenkraft]

Wait, what?

Could that be Starlink satellites?

[Archimid]

Fascinating.

[blumenkraft]

New Arctic Drift podcast!

Link >> https://overcast.fm/+UIoJTFRRM

[A-Team]

The first product below montages five fragmentary scenes from AWI mosaic_multisensor that suffice to show the entire drift to date; the composite is then set over the S1B from today.

The motion can be described as two stalls connected by a rapid linear drift. The Polarstern is continuing to drift 0.4º west at constant latitude in the nine hours following the hour of the S1B scene. However it has not exited its box into new lat/lon territory. Winds remain moderate at 9 m/s.

GFS sees retrograde motion for next 5 days: more tangling of the trail, no poleward motion, west yes but south with that. Overall drift will be not Fram-ward but rather towards western Siberia but not dramatically so. And that's been the case for the subsequent 15 hours (though lat is not provided to sufficient accuracy to follow southerly drift).

The actual latitude as measured on 41m resolution Sentinel is 86.16621 which rounds to 86.2 but is notably less, namely 6 km to the south. The longitude is 117.09º which rounds to 117.1º so the AWIwx is wrong, probably from just cutting off digits instead of rounding to nearest tenth.

  86.2  117.0  19-11-28  06:00  6  30  -28.5  1011.9
  86.2  117.0  19-11-28  05:00  6  40  -30.2  1012.3
  86.2  117.1  19-11-28  04:00  7  50  -30.9  1012.8  S1A 04:08
  86.2  117.2  19-11-28  03:00  7  50  -31.1  1013.0
  86.2  117.2  19-11-28  02:00  8  60  -31.1  1013.1
  86.2  117.3  19-11-28  01:00  7  50  -31.2  1013.3
  86.2  117.3  19-11-28  00:00  7  60  -30.8  1013.4
  86.2  117.4  19-11-27  23:00  7  60  -31.2  1013.5
  86.2  117.4  19-11-27  22:00  8  70  -31.1  1013.7
  86.2  117.5  19-11-27  21:00  7  70  -31.1  1013.7
  86.2  117.5  19-11-27  20:00  7  60  -31.1  1013.7
  86.2  117.6  19-11-27  18:00  7  70  -31.0  1014.0
  86.2  117.7  19-11-27  17:00  7  70  -30.5  1014.1
  86.2  117.7  19-11-27  16:00  7  80  -30.2  1014.1
  86.2  117.8  19-11-27  15:00   

The close-up continues to show rapid evolution of the Mosaic floe. It appears a lengthy lead has opened in front of the bow and partly frozen over. Challenges continue in keeping off-ship equipment collecting data.

[A-Team]

The diagram and spreadsheet below show a second method for accurately measuring latitude and longitude of the white dot on S1AB that represents the location of the Polarstern at the timestamp of the satellite image.

In the case of ship position near 86,120, the canvas is extended 4x 2713.6 pixels (1º of latitude) so that the North Pole is now in the image after rotating -15º to bring the 120º meridian into the vertical. The distance and angle are then measured from PS to NP which then provide, after some spreadsheet trivia, the desired location results. The circle of latitude of the ship can be drawn as well as supplemental meridians.

If the stack of 91 S1AB images from floe mooring to the present are aligned to 86,120 using the difference mode in Gimp, then all the high resolution lat,lon can be read off in one operation from a common fixed center at the pole which largely eliminates relative error. While the measure tool is fast and easy, it is limited to 2 dp in angle measure accuracy.

Thus a better alternative is simply to record the x,y position of the Polarstern relative to x,y  of 86,120 along with a virtual north pole. Then the lat,lon can be calculated to arbitrary precision from basic trigonometry without further photogrammetric measurements on the images and error assessed by probing the effect of bumping x,y by a pixel each.

The main source of error is ambiguity of position of the point 86,120 within the broad red geolocation swath provided by PolarView. The GeoTiff scene variant provided would have precise geo-referencing but the file size of these is enormous: 128 MB compressed which would likely scale to a terabyte for the growing S1AB archive.

Better still would be hourly (or ten minute) GPS readings from the ship itself, rather than 8 hr S1. All that has to be done there is for Mosaic to stop obfuscating its release.

Update:  another image has just been posted, S1B 2019 11 28 T 0635

[uniquorn]

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.

[A-Team]

Mosaic news is a big yawn. Ineffective. People want excitement.

Right, Mosaic is putting people to sleep with boring staff photos. A web cam of ridges crashing against the ship and scary leads opening and closing by the gangway, time lapse with an inset of the captain's instrument panel (GPS, pitch, yaw, bearing). Even an iPhone 6 can stream time lapse video with sound, I have one set up at the bird feeder. A live cam would not make a dent in the ship's excellent bandwidth.

Does that mean you've already done it so we don't have to?

Yes it does (because it turns out to be rather easy).

PolarView does this very accurately in an unpromising display option called 'jpeg2000 file (lossy)' that does not download the selected scene to disk as the icon suggests but rather opens a new tab running a plug-in (no installation required) called NSJSView 1.0. It is reminiscent of Nasa Worldview but better done.
 
While the ground resolution of S1AB is ultimately limiting, the remaining measurement uncertainty now is where to put the dot on the fuzzy Polarstern reflector. Here the ship beam axis and bow2stern crosshairs define a consistent center and provide an estimate of error associated with mouse position being off a pixel or two.

Nothing more is involved than finding the PS dot in each of the 91 S1AB and capturing it with a screenshot that includes the lat lon to four decimals. There seems not to be text capture in the contextual menu nor url change with mouse position (unlike nullschool) so those numbers have to be entered manually in the S1AB spreadsheet. (OCR will have problems with the '/' separator.) Gross typos can be caught by comparing round-off to one decimal data already in the db.

Rows will look like this (86.1642 116.9532 is the location of the 06:35 image):

S1A   2019 11 28 T 04:08 86.2   117.1   7   50   -30.9 86.1665 117.0933

So now we know where to put the dot and how big to make it on the Polarstern viewed as a big buoy (not seeing). 

The 91 S1AB do not quite jib with the 1392 hourly buoy GPS data points. Here the question is not how to interpolate -- R is statistical software offering every conceivable interpolation method and goodness of fit evaluation -- but whether to use the mosaic_multisensor track provided a couple of posts back, as AWI may have used secret high precision PS location data in drawing the red line.

In any event, it will be interesting to see how animated close-in P-type buoy triangulations relate to these high accuracy S1AB location points. Outer buoys will be affected to a greater extent because of additional remote transitory leads and ridging. The attached csv provides the high precision lat lon collected to date.

http://bslmagb.nerc-bas.ac.uk/iwsviewer/?image=DataPolarview/111_S1jpeg2000_201911/S1A_EW_GRDM_1SDH_20191128T040828_28AD_N_1.8bit.jp2

[uniquorn]

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

[uniquorn]

drift update, 3 Pbuoys closest to PS - see below

[blumenkraft]

RAMMB-SLIDER's not updating -.-

[A-Team]

Rammb down, line of dots?

IT will be back in Monday after a long weekend.

'Follow Mosaic' was better today but long is the transect, on what floe is it located, what is its history and initial thickness, what have they found so far -- none of your business apparently.

Hippocrates once said, you cannot walk the same Arctic sea ice transect twice ... was this floe representative, what commotion has the site undergone in the last 60 days?

The location and date (but not the time, the exif was stripped) are given as 86.08 113.73 on the 29th. That would be well south of anywhere the Polarstern has been recently. However if the Polarstern persists in using "ship time" and changing that every Saturday (they say to better party with the incoming icebreaker at its meal times), the date itself becomes problematic.

The last few days have seen a brisk sub-gale force wind (2nd column, m/s) from a consistent direction pushing the ship steadily east with a touch of south. The ship is at a record easterly position at 113.8 but at an unexceptional latitude. Again, this is a great opportunity to study ice pack movement at a constant stress vector.

Assuming the work party photo was taken at the same time as the last of the four Sentinel-1AB this morning, the work site can be located approximately using the fabulous new PolarView plug-in from bslmagb.nerc-bas.ac.uk. The exact study floe cannot be determined because of the lack of timestamp on the photo.

http://bslmagb.nerc-bas.ac.uk/iwsviewer/?image=DataPolarview/111_S1jpeg2000_201911/S1B_EW_GRDM_1SDH_20191129T053813_F681_N_1.8bit.jp2

86.1   113.8   29   17:00   09   40
86.1   113.9   29   16:00   10   40
86.1   114.0   29   15:00   11   40
86.1   114.0   29   14:00   11   40
86.1   114.1   29   13:00   12   50
86.1   114.2   29   12:00   11   50
86.1   114.3   29   11:00   12   60
86.1   114.4   29   10:00   12   50
86.1   114.5   29   09:00   13   60
86.1   114.6   29   08:00   13   50
86.1   114.8   29   06:00   12   40  05:38   86.0079   114.8607
86.1   114.9   29   05:00   14   40  04:49   86.1120   114.9497
86.1   115.0   29   04:00   13   50  04:00   86.1220   115.0394
86.1   115.1   29   03:00   12   50
86.1   115.3   29   02:00   13   50  02:22   86.1262   115.2108
86.1   115.4   29   01:00   10   40
86.1   115.5   29   00:00   11   50
86.1   115.6   28   23:00   12   50
86.1   115.7   28   22:00   12   50
86.1   115.8   28   21:00   13   50
86.1   115.9   28   20:00   12   40
86.1   116.0   28   19:00   13   50
86.1   116.1   28   18:00   12   50
86.1   116.2   28   17:00   11   40
86.2   116.3   28   16:00   10   40
86.2   116.4   28   15:00   11   40
86.2   116.5   28   14:00   9   50
86.2   116.5   28   13:00   9   40
86.2   116.6   28   12:00   8   30
86.2   116.7   28   11:00   8   30
86.2   116.8   28   10:00   9   30
86.2   116.8   28   09:00   9   30
86.2   116.9   28   08:00   8   20
86.2   117.0   28   06:00   6   30  0635   86.1642   116.9532
86.2   117.0   28   05:00   6   40
86.2   117.1   28   04:00   7   50  0408   86.1665   117.0933
86.2   117.2   28   03:00   7   50
86.2   117.2   28   02:00   8   60
86.2   117.3   28   01:00   7   50
86.2   117.3   28   00:00   7   60
86.2   117.4   27   23:00   7   60
86.2   117.4   27   22:00   8   70
86.2   117.5   27   21:00   7   70
86.2   117.5   27   20:00   7   60
86.2   117.6   27   18:00   7   70
86.2   117.7   27   17:00   7   70

[SteveMDFP]

Hippocrates once said, you cannot walk the same Arctic sea ice transect twice ... 

I think you're paraphrasing Heraclitus, actually.  Rivers, though, of course.

[uniquorn]

drift update, 3 Pbuoys closest to PS, ~8days in 50frames
updataed below