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Messages - A-Team

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Arctic sea ice / Re: MOSAiC news
« on: December 11, 2019, 09:58:32 AM »
The Kapitan Dranitsyn is making surprisingly good time and on the S1B  04:00 this morning was only 112 km due south of the Polarstern. On the S1B 0538, the frozen-in Polarstern had passively drifted a slight distance north and west whereas the KD was actively underway as well benefitting from the same drift.

Since we have two lat,lon for the two ships from two satellite images 1.633 hours apart, it can be  calculated (haversine) that the KD has closed in on the PS 10.6 km in that time which suggests it is preceding rapidly in thin ice and would rendezvous in 15.6 hrs except that thicker ice will slow it down but still 24 hrs seems reasonable.

GFS nullschool has a different updated forecast, showing the Polarstern on the edge of an anti-cyclone centered in the Chukchi for the next few days. If so, winds will pick up somewhat and drift will less towards the pole and more (unwanted) drift east (yellow arrow). This represents less than ideal but still manageable conditions for docking and fuel, equipment and personnel transfer.

The KD will likely dock alongside but outside of the Polarstern which is moored with the starboard side along the Mosaic floe. The involves circling around from the east so as not to create a trail of fractured ice that would later affect leads and pressure ridges in the experimental area.

Arctic sea ice / Re: MOSAiC news
« on: December 10, 2019, 04:08:13 PM »
Thx, Jayw! It seems like the second latitudinal circle is not 86º as I thought but maybe 87.5º? (Best to have two  of each labelled for scale.) Indeed the PS has had a strong tailwind from the south.

Is there any meaning to the tumbling of the Polarstern image, or just variable cloud cover obscuring part of the heat source? (The Kapitan Dranitsyn steps are quite big as it is under steam.)

The bottom Lagranian/Eulerian double animation of the 4 S1AB today does not indicate major changes in the ship's orientation that could explain tumbling though the Mosaic floe seems to change quite a bit despite steady conditions.

It can very much be affected by 'action at a distance' elsewhere in the ice pack. That is, the area including the Mosaic floe is seen moving due north for several days but there is already thick ice between it and the CAA -- where does it go?

The 06:45 S1B came in ... it seems to show rapidly disappearing tracks relative to the three S1AB composite back in post #396. How much of the non-linearity is due to the KD following a favorable path through the ice and how much is due to ice shifting and shearing over five hours?

2019 12 10 0635
2019 12 10 0408
2019 12 10 0319
2019 12 10 0140

Arctic sea ice / Re: MOSAiC news
« on: December 10, 2019, 12:58:55 PM »
The white dot seems to be in the wrong location(?). The KD is not preceding due north as shown but rather mostly east on the other side of 120º.

Arctic sea ice / Re: MOSAiC news
« on: December 10, 2019, 11:50:39 AM »
Nice spotting. It is on all three Polarstern S1AB today, including the PolarView plug in with its precision lat lon mouse-over.

Rendezvous weather five days out remains bland. The Polarstern will be more or less in the same position it is now. The personnel there now will have ample time to have equipment deployed on the ice brought back into working order before turnover (to the extent that's possible).,90.00,1100/loc=120.9,86.5

Arctic sea ice / Re: MOSAiC news
« on: December 09, 2019, 11:04:09 PM »

Nice! Note that the GPS is to five decimals, unlike the one that Mosaic shares. Still no history at Sailwx after Dec 3rd. Cruise Mapper only works in certain browsers (such as Mac Chrome but not Mac Opera). Mousing around on the lat,lon bar does move the ship around but the time associated with that move is not shown. What time there is, is "local time" in the middle of nowhere, not utc! That might be either Murmansk or Tromsø.

On a cruise ship, meal times are in local time. The Polarstern also does not keep utc but instead it has been walking it back so as to synch mealtimes when the KD arrives.

This is great that the two ships are already on the same tile at Polarview. I don't see a bright dot yet for the KD but it should be down there. The captain has 35 years of icebreaker experience so is no doubt taking the easiest route.

GFS shows good weather for the rendezvous, the first real break Mosaic has had. No way could they transfer all that diesel with km wide leads opening and closing. The Polarstern is moving north somewhat left of the wind which may be attributable the deflection by the massive ice pack and fixed CAA islands ahead.

Arctic sea ice / Re: MOSAiC news
« on: December 08, 2019, 08:50:43 PM »
This :) was written on Nov 27th but dated Dec 6th and does not address the most damaging storm of the trip on 03-06 Dec 2019. Pulks are sleds being used along with wooden palettes to bridge small leads. Presseisrücken are pressure ridges.

Co-leader Shupe is now over two weeks overdue on his weekly blog. Cires is not blogging the storm, Helmholtz quit in mid-October. Not substantive use is being made of twitter.

No news is a variant on fake news and historical revisionism: if they don't report the Dec 6th storm, it didn't happen. (Those satellites are sooooo annoying: 4 S1AB scenes today + clear Terra Modis.)

we will have an emergency runaway very soon. In the spring we will build it so that even bigger planes like an Antonov can land normally and not only with skis.
I sincerely doubt this looking at increasingly disheveled Mosaic floe which has not stabilized since the Dec 6th storm. Rex doesn't indicate where this runway will be located nor how thick the ice is; in the original plans, this was to be bladed by Piston Bullies in the flat dark areas (former melt ponds). However Mother Nature got there first.

If he is looking for volunteers to drive the bulldozers out on thin ice, like at Borneo, i am opting out. Surely Rex knows how slowly and unevenly ice thickens in the autumn; if not, a quick look over the ship's 100 mbps internet at the nearby Simb3 ice buoy graphs suffices. Those show 1.254 m snow + ice today -- the ice thickness they expected at mooring on Oct 5th some 66 days ago.

The Polarstern is looking at five days of inconsequential wind not strong enough to do any more damage. The ship will drift a bit north from its present record of 85.3º N but also a bit east from 121.2º E. We don't know at this point whether the weather will be calm or windy when the relief icebreaker arrives.

The Kapitan Dranitsyn's call sign is UCJP; the other numbers are IMO 7824405 and MMSI 273138300. We will be following the ship closely to see how much unavoidable damage and ridge/lead preconditioning it does in approaching the Polarstern. However it last reported on Dec-03 at 11:30 UTC, meaning it turned off its new state-of-the art navigation beacon after heading up from Murmansk.

This accomplishes nothing for Mosaic because we can still see the ship's stacks and tracks on Sentinel and RAMMB infra-red.

Contrary to their inept static drift model, this is not favorable for reaching wind fields that would bring them towards the Fram Strait. At high latitude, the ship will never get past that gigantic immobile block of MYI documented in the previous post.

The Polarstern is currently 1477 km from Svalbard whereas at mooring on Oct 4th the ship was 1646 km away on Oct 4th. If this rate keeps up (it won't), it would take 579 days drifting on a WGS geodesic (won't happen) to reach Longyearbyen (won't happen in 2020-22).

I've attached the updated archive of S1AB images of the Mosaic floe. In addition to timestamp, rough and precise lat,lon, wind speed, wind direction and ship temperature each entry has direct links to both GFS nullschool and the jp2 image at The former is built out of the preceding variables; the only technical tricks involve nullschool using lon, lat order and rounding odd times down (eg 02:59 to 00:00) which is easily fixed with modular round-off relative to the 3-hour spacings (eg 01:31 to 03:00). That's MROUND(RIGHT(timestamp,4),300) in your spreadsheet.

It's quite feasible to add thumbnails of the Mosaic floe, P-buoy tracks and regional wind the Polarstern is experiencing to each timestamp row in the S1AB database without growing file size too badly. A better alternative might be to make a mp4 at various scales out of every 3-hour nullschool GFS since mooring and flash those that have associated imagery.

Arctic sea ice / Re: MOSAiC news
« on: December 07, 2019, 06:15:34 PM »
Leave Episode9 to me
Thanks, helpful!
Not so sure about that - no storm but windy enough for discomfort given the parlous state of the floe & environs?
Maybe but there is no double digit velocity in sight on GFS (the hourly ship wx uses m/s). All the major events so far have been at sustained gale force winds, 14 m/s or 50 km/hr.

Since the last S1AB, the ice has presumably had a chance to consolidate because of the calmest conditions yet of the expedition.

  86.2  122.1 19-12-07 10:00  4  120  -21.2  1022.1
  86.2  122.2 19-12-07 09:00  4  110  -21.0  1023.0
  86.2  122.2 19-12-07 08:00  4  100  -20.8  1023.8
  86.2  122.2 19-12-07 06:00  3   90  -21.2  1025.0
  86.2  122.2 19-12-07 05:00  2   60  -20.2  1025.7
  86.2  122.2 19-12-07 04:00  2   50  -18.3  1026.2
  86.2  122.2 19-12-07 03:00  2   70  -21.1  1027.0
  86.2  122.2 19-12-07 02:00  1   80  -21.7  1027.5
  86.1  122.2 19-12-07 00:00  2  120  -22.3  1028.7
  86.1  122.3 19-12-06 23:00  3  100  -23.1  1029.2
  86.1  122.3 19-12-06 22:00  3  100  -23.2  1029.9
  86.1  122.3 19-12-06 21:00  2   90  -23.6  1030.4
  86.1  122.3 19-12-06 20:00  2   80  -24.2  1031.0
  86.1  122.3 19-12-06 19:00  0  360  -24.5  1031.5
  86.1  122.3 19-12-06 18:00  0  360  -24.9  1032.0
  86.1  122.3 19-12-06 17:00  1  280  -25.3  1032.1
  86.1  122.3 19-12-06 16:00  3  260  -25.5  1032.6
  86.1  122.3 19-12-06 15:00  3  250  -25.9  1032.9
  86.1  122.3 19-12-06 14:00  4  260  -26.0  1033.2
  86.1  122.3 19-12-06 10:00  6  260  -25.7  1034.4
  86.1  122.3 19-12-06 09:00  5  260  -25.4  1034.4
  86.1  122.3 19-12-06 08:00  6  260  -25.2  1034.3
  86.1  122.2 19-12-06 07:00  6  260  -25.1  1034.0

That's because wind stress on the ice is not linear but grows roughly as the cube. So upcoming 7 m/s winds forces will provide only 1/27 (4%) the stress of peak 21 m/s winds seen so far.

In order to use 3-hour nullschool wind, the future position of the ship won't be at where it is today so the wind reading will be at the old location isn't applicable unless the new location can be predicted and the green circle repositioned.

However the main thing to look for at GFS nullschool is uniformity of the wind currently coming up in parallel constant-color sprites from the south. It is really abrupt changes in direction, speed and above all, curvature, convergence and divergence of the sprite lines that forecast ice disruption.

In other words, look at time series deltas using the 3000 scale in HD (high density) at the most recent ship wx position. It is these cyclones passing overhead that really check all the boxes.

Right now, the most up to date GFS with known PS position shows elements that would be problematic for the Mosaic floe, just not at very low wind speed.

Best practice with nullschool is to embed the url and popup in the image itself which just takes a couple of clicks past the screenshot.

As we've seen, not a day goes by without some apparent rearrangement of the recently formed ice jumble of the Ice Camp. Some of this may be attributable to satellite viewing angle or changing surface salinity rather than actual ice movement.

Pressure ridges and open leads are not always within satellite resolution. For example, a 10 cm crack and slight shear that took down the met tower guy wire is not observable on Sentinel.

Further, we don't know anything about current sensitivity -- is the floe so damaged now that it is preconditioned to the point that minor ice stress now has an effect?

Sometimes obscure changes at the Ice Camp cause major damage while major upheavals might not actually affect experimental areas. I wonder how much those onboard know about real time floe distortion away from the ship -- we are too high but they are too low for a good view.

They have done two fly-overs with lidar that we know of; only one was released but with flattened overlays. Otherwise it is dark and no one is allowed off the safety perimeter, all the more so since it had to be linearized.

While the ship does have forward-looking ice radar on the bridge, being moored on the starboard side with the Ice Camp at right angles and more to the ship axis may block a full assessment. In any event, none of that radar has been streamed our way despite the ship's fast internet. Mostly they are concerned with continuity of data collection.

That hasn't been great to date despite incredible efforts to keep instruments up and running.

Secondarily, they are concerned about evolution of a single floe over a year. That is already off the table as an attainable objective.

Arctic sea ice / Re: MOSAiC news
« on: December 07, 2019, 01:05:22 PM »
makes sense to have a picture of the site
That one is a mirror image, an old conceptual layout. We do have the original site plan from the 126 page planning document up-forum as well as a later as-built map in radial coordinates centered on the ship. We also have the modified site plan they just released up-forum; it is no longer radial and quite blurry at all the places it has been posted.

None of these maps are at all appropriate to the pending redeployment of the Ice Camp -- if there is one -- after yesterday's big rearrangement.

Arctic sea ice / Re: MOSAiC news
« on: December 07, 2019, 12:13:05 PM »
That would be the 03 Dec 19 podcast though which of several storms is hard to say. Note 'pressure rig' translates to 'pressure ridge'. The follow-up 'Nach dem Sturm' is dated Dec 6th but I am quite certain it does not address the worst storm yet of the same date.

We remained throttled down to 1 Sentinel per day out of the 8 daily orbits passing over the Polarstern. Today the ship was just barely included on the far eastern edge of the 02:45 image. The Mosaic floe is so distorted after the massive lead openings seen at 05:30 the previous day that it is hardly recognizable, though its identity is certain from neighboring floe context.

This event likely undid much their previous ice camp restoration as well as bringing all kinds of new disruptions. The weather will be very mild the next five days so there will be an opportunity to catch up. However, going by past years, there is no reason to believe this will be the last severe anti-cyclone of the winter, on the contrary (see gerontocrat #368 above).

The ice is slowly getting thicker according to the 4 Simb3 buoys which might help subdue ice dynamics at the Ice Camp. As the ice becomes more brittle with deeper cold, that will change the character of disruptive events to less plastic fractures.

The two images below show what has happened. As noted above, the ship was situated at a hairpin of sharp wind curvature; the stress was too high at prevailing wind speeds for rigid ice to go with the flow.

I am seeing a lot of misunderstandings about ice advection in the Arctic Ocean on the part of the atmospheric physicists. Going north will never get them to the Fram Strait on the expedition time frame because a gigantic immobile block of multi-year ice is in the way.

They need to drift west to catch the circumpolar drift ('around') which is too often confused with less frequent transpolar drift ('across'). Flow has largely been zonal in recent years, not meridional (over the pole). Last year's displacement of the FYI/MYi boundary line was somewhat exceptional, with ice on the NP-Wrangel line passing over the pole (but not getting far).

So far this year, ice in the central Arctic is just milling about, the Polerstern's aimless drift is representative of a far larger region. You can see this just animating Ascat masked by Amsr2; we have that on another forum for the last nine complete years.

Arctic sea ice / Re: MOSAiC news
« on: December 06, 2019, 07:34:57 PM »
why we don't get open data from Polerstern / Mosaic?
I looked into a Freedom of Information request for the ship's log, gps location and heading at ten minute intervals and so on. I have done these requests before in the US, followed by successful but time-wasting lawsuits when inevitably they don't comply.

This probably wouldn't go anywhere with NSF grantees like Shupe and Blomquist who are already posting quite a bit of timely disclosure in their realms. The US kicked in $26m; grants will be monitored.
Now a FOIA could get some BS stonewalling such grantees have a right to first use of experimental data, at their leisure (ie 2023 in Mosaic planning documents).

However after much commotion, NIH at least requires immediate disclosure in genomic DNA sequencing. There, a robotic sequencer ftp's its reads directly in real time to a public web archive, just like the 92 Mosaic buoys do today including those of AWI.

Here Mosaic is doing shotgun environmental sequencing and any US grantees would fall under compliance obligations. The original rationale was human health research should not be delayed; the same could be said of planetary health.

Germany/AWI of course does not fall under US domestic law but they may have something similar on the books. AWI presumably owns the navigational instruments on the bridge; on previous expeditions -- but not here, no explanation --  has always published a detailed weekly Polarstern report. It would probably take a filing from a German citizen or reporter to meet the requirement of standing.

What gets me is the deliberate dumbing down of the Polarstern's GPS location. That required a deliberate decision to actively intervene because in factory default mode and in actual onboard use, the instrument would be sending 5 decimal points instead of one. No one navigates through Arctic sea ice on 1 dp.

It all reminds me of the EA189 engine at the center of the Dieselgate scandal that continues even today with the successor EA288.

We are to believe that AWI and 600 polar scientists were surprised to learn upon arrival that the best floe around was only 30-50 cm thick instead of 1.2m. Oh sure.

A satellite unknown to science measured ice thinness during late summer but got it wrong? They made that one up.

A $150m experiment and they didn't have an old tramp steamer out there in late August drilling floes? Not to be believed.

Russianss ran 5 tourist trips to the north pole in late summer but didn't tell AWI partners about ice conditions or why they pulled the plug on Borneo? Highly implausible.

AWI knew perfectly well in advance about the problems ahead, just like VW knew about its NOx problem. Why else would you turn off ship beacons and dumb down its GPS upon leaving port?

Arctic sea ice / Re: MOSAiC news
« on: December 06, 2019, 05:08:52 PM »
Below, a summary of weekly blog posts from Byron Blomquist, CIRES and NOAA. The event this morning appears catastrophic even relative to earlier havoc at the Mosaic floe. An update can be expected Monday. Dec 9th.

The scientists' persistence to stay operational under difficult weather and ice conditions is only to be applauded but as with a poker hand, there is a time to hold 'em and a time to fold 'em.

The event this morning may prove a tipping point. The original plan, conceived eight years ago, is no longer viable in the ice of today. It is time for Plan B.

GFS foresees a lull for the next five day: slow drift north but in the direction of Ellesmere Island, not the Fram Strait.

“December 2. The Dranitzyn left the coast of Norway yesterday to begin the transit to our location and should arrive within a week to 10 days. AWI estimates it will then take about 5 days to transfer ~50 tons of cargo between the two vessels and pump over the fuel, weather conditions permitting. We were not able to accomplish everything we planned for leg 1 having to overcome a series of setbacks related to ice dynamics.

The route to Met City was reestablished over the past week and the main power lines reconnected, so most of the instrumentation there is back on line. The ship's machinists repaired damage to the collapsed 30m met mast and we hope to reinstall it as a 23m mast sometime next week.

Air sampling from the bow is often good for several days running, then unsuitable for several days as the wind direction shifts to the stern of the ship.

The anemometers, CO2/CH4 flux system, fast ozone, slow ozone, NOx, GCMS, and mercury instruments have all been running well. The DMS mass spectrometer ran for a few weeks, but a power supply failure will keep this system off line until leg 4.
Nov 25, 2019. The passage of two arctic cyclones last weekend was a unique opportunity to make atmospheric observations of a poorly understood weather system. There were no major shifts in the ice pack over the last several days but the situation remains dynamic, with leads opening and closing on a daily basis.

The remote sensing site has been dismantled and will be rebuilt at a new site. The ROV site is partially operating on generator power. The Ocean City site was dismantled and moved to avoid an ice ridge, but is mostly operational again.

The situation at Met City is tenuous. Met City is still without a power line but instruments on the tower are operating part of each day on generator power and we've been able to access the site twice daily to refuel. It is sometimes possible to reach Met City by snow machine, but often access is by foot only.

The exact route changes daily, depending on ice conditions. Met City is currently only about 400m from the ship, but the route over ice is probably closer to 1 km. Our measurements there are still shutdown and we don't have a good estimate yet for when the power and data lines will be reestablished.

After the large shift in the ice floe on 19 Nov, the Met City, ROV and remote sensing sites moved about 600m to the SE, across the bow of the ship. Met City is now located directly in front of the bow and the remote sensing site will be reestablished in this same general area. Ice in front of the ship is now a complex system of blocks and ridges. The ROV site is now off the port quarter of the bow.

The formerly compact Central Observatory site now spreads over a much greater area and the bow of the ship is largely surrounded by on-ice infrastructure. If the ice solidifies in this state, this will be the arrangement for the remainder of the project. This will impact the clean wind sector for measurements from the bow of the ship, but there should still be many hours per day with minimal activity on the ice.

November 15-17. A powerful winter storm blew through the scientific cities set up on the ice around the ship. Intense winds tore new cracks in the ice floe next to the ship, sending some ice-based instruments adrift. It’s possible that the floe will drift back together and freeze again. I think about the word “mosaic” and how it implies a breaking in order to be put back together.

Eventually the drift slowed down. The instruments moved in a U-shape around the bow of the ship. ROV Oasis is now off to the left. Remote Sensing not far by. Met City is directly in front of the bow. Ocean City and Balloon Town stayed in relatively the same position, but a long lead opened directly next to their tents.

The Atmosphere Team’s flux stations, part of the distributed network, are doing great, overall, although we had one disruption that involved a polar bear. We have snapped cables and a dismembered exhaust system to repair. We are working to rig new connectors and cables, and have ordered a new exhaust pipe that will hopefully arrive with the next leg of participants in December.

Due to a major storm in the last few days, we have also had lots of cracks around the ice, and one has opened up so wide that in order to get to our instruments, one has to use a kayak to cross to the other side.

The 30 meter tower has tipped over. An assessment of the instruments and damage done to the tower are still on-going. Our other 11 meter tower is still standing tall, but another smaller crack has opened beneath one of the guy-wires that holds up the tower.

Nov 19, 2019. The last several days have seen some dramatic developments and some setbacks.  On Saturday a strong arctic cyclone moved through the area, bringing sustained winds up to 20 m/s for many hours, first in an westerly direction, then veering to northerly. Our drift rate increased to > 0.5 kts to the E and then to the S, at one point up to 0.8 kts. We are now well S of our position a week ago and are once again on a track toward Siberia.

The large multiyear floe which was selected as the backbone of our Central Observatory split in two on Sunday, with a significant shear zone developing just in front of the ship in a port-starboard direction.

This lead has opened and closed a few times over the past 48 hours and the shear between the two halves is currently offset by as much as 70-100 m. The block with Met City, ROV City and the Remote Sensing Site are on the opposite side of the crack and a large ice ridge is developing between Remote Sensing and Ocean City.

The Remote Sensing site was heavily damaged by ice movement and a number of large instruments were moved to safety on Sunday. The site will need to be reestablished at another location when the situation stabilizes.

The power and data links to Met City and all other sites on the opposite side of the lead were severed early AM on Sunday. Further ice movement brought down the 30m met tower at Met City early this morning. Otherwise, most of the equipment installed at Met City is intact and appears to be on stable ice, but only a few instruments are operating, powered by intermittent backup generator supply.

Our CO2/CH4 flux system at Met City is down and will not operate until ship power is restored to the site. Met City was originally located about 800m off the starboard beam of the ship at a 2 o'clock bearing, but as of today is drifting toward the 1 o'clock position. Because the ice is still moving we do not know when power and normal operations will be restored.”

Arctic sea ice / Re: MOSAiC news
« on: December 06, 2019, 12:38:31 PM »
Some large scale north-south extensional fissures have opened up, a long 600m wide crack to the east of the Polarstern and a (so far) smaller one right through the Mosaic floe a few tens of meters west of the ship.

Even a small displacement in Ice Camp disrupts power lines, towers, generators, experimental equipment and repair access. Here the lead is approximately 100m wide (2-3 pixels on S1AB 40m).

This followed 72 straight hours of wind speeds in excess of 10 m/s at the ship's location, attributable to its position in the north-central winds of a persistent anti-cyclone centered in the New Siberian Islands.

On the next post, the relevant GFS nullschool sequence shows that sharp curvature in the applied wind stress from the tightly coiled anti-cyclone was incompatible with increasingly brittle ice, which then shattered along north-south lines to accommodate to applied forces.

The 05:30 scene will apparently be the only S1AB today as the 07:00 orbital pass was either not taken or suppressed. It is hard to believe that both A and B satellites would have higher scheduling priorities at such an obscure location during a dramatic moment in an historic Arctic expedition. Surely AWI has closer connections to schedulers at ESA Copernicus than foreign researchers; eight years of planning went into Mosaic.

In any event, we don't know if the 05:30 caught the beginning, end or middle of the lead opening. It could be growing to the size of the one to the east; alternatively it may have peaked earlier and now be closing. Previous images show that this is not a new fault but rather reactivation of an older lead.

Note a second fissure comes in from the west (3rd image). This too has opened and closed repeatedly over the last two months.

The final image shows a rare cloud-free swath of heat map of the area around the Polarstern a few days back. The white lines are leads that, despite being frozen over, still leak more heat to the atmosphere than surrounding thicker ice and so are brighter when imaged in the infrared.

Neither lead can be attributed to the PS and AF icebreakers maneuvering about during the initial mooring to the Mosaic floe, though we might wonder how the relief icebreaker Kapitan Dranitsyn will get in close enough to refuel the Polarstern.

Insulting official expedition communications from 'Follow Mosaic' feature inane pictures of omelets and baked goods from the Polarstern kitchen, along the lines of arranging deck chairs on the Titanic. Shupe's AGU blog, the only real source of information, has not been updated since November 18th. It has a nine day lag between its writing and its posting.

A new Helmholtz post on PS site mitigation appeared on Dec 4th but seems dated, non-specific and smiley-faced about disruptive floe events, insuperable problems obtaining data continuity over a year and tainting of air quality data by the ship itself. (On past expeditions, the PS stayed pointed into the wind, allowing fresh air to reach bow instruments).  One interesting point however about wastewater:

When it comes to the outlet for our filtered wastewater (technically clean water), a pump system was installed on Polarstern that reintroduces the salt previously removed from it, before discharging the water at a depth of ca. 150 m. The times at which these ‘dumps’ are made are documented, allowing any potential influences on them to be identified after the fact.

By far the best reportage is coming from Martha Henriques at BBC. The Dec 3rd post links back to the others. Byron Bloomquist of CIRES NOAA is also posting detailed damate reports. AWI, the expedition lead, gives out no information whatsoever.

Markus Rex of AWI, expedition leader, shows me the trajectory of the drift so far on a screen in the Red Saloon, one of the ship’s common rooms. There is a pattern in the meandering line on the screen that shows one reason that cracks and pressure ridges have been appearing in the camp.

“You see these cycles here?” he traces a line in the shape of a scalloped edge. “It’s fast here, then it’s always slow, slow, slow.” He stops at a pinch point on the line. “These are the points when we get the high pressure.” That’s when the floe is twisted and pulled in different directions.

At least there is some predictability in these cycles but still, but as Rex watches the screen inside the Red Saloon, it’s clear that there is little the team can do but hope the damage to instruments and infrastructure each time won’t be too great.

Arctic sea ice / Re: MOSAiC news
« on: December 05, 2019, 08:23:00 PM »
The whole ending strikes me as highly contrived, all about filming a meet-up with two buddies and later them eating ribs and french chocolate. The Lance has a helicopter pad but they are not using it so the adventurers will be able to say they went boat to boat per the original plan.

The tent camp is also well within reach and capabilities of the Svalbard helicopter service that extracted the crew from the grounding in the Hinlopen Strait last December.

The Lance does not really have to chops for this job and keeps getting frozen in the 30 cm ice but they are scripted to moor along an ice edge so the two do not have to be seen being picked up from a zodiac even though they are having to be rescued as they don't have the food or fuel to continue under current ice conditions and more weeks of unfavorable floe drift.

There is a Norwegian icebreaker at the scene but they are not using it. The Polerstern's relief icebreaker is not likely to be headed towards Svalbard -- way out their way and through more ice than necessary. These ships have all turned off their GPS beacons; sailwx is only receiving the Polerstern's.

Updates -- and some pointed questions about an actual purpose for the trip -- can be found in the comment section at this Norwegian site which updates almost hourly:

Just before Lance left Longyearbyen, a research ship also left north. I see on Marine traffic that this ship is on standby on the ice (on starboard side of Lance), probably be the new state-of-the-art icebreaker for the Norwegian Polar Institute, "Crown Prince Haakon" a research assignment in the area and can contribute if necessary. The name may be icebreaker Haakon Magnus "is located just to the east of you, can't they break a real trap for you?

How much does it mean for the expedition to go "unsupported", which is not possible with post-supplies? And how do they manage to meet in the icy, dark and snowstorm. Even with GPS and satellite phones, this must be a major challenge. The two teams of polar explorers have agreed on a common point on GPS that they both are heading towards.

Bengt Rotmo and Aleksander Gamme, friends coming on foot to the tent camp, have emergency rockets and a signal gun too, so they can use it to show where they are. There is a doctor on board the Lance though no issues are expected.

Arctic sea ice / Re: MOSAiC news
« on: December 05, 2019, 01:58:38 PM »
The Polarstern continues to drift very rapidly east (ie the wrong way) and slowly north. The winds have been in the double digits for the last 61 hours, averaging a 14 m/s gale force push at~50 km/hr. The direction of the wind has been remarkably steady at 240º.

GFS-null shows this drift will continue for 2-3 days as the anti-cyclone center elongates to the north as it dissipates. Wind vector constancy presents an opportunity to determine the 'Nansen angle' of ice drift relative to wind under these conditions and to predict Polarstern drift a few days out.

The issues here are the ground accuracy of GFS and the optimum scale for angle measurements as nullschool. The url can be fed the nrt position data from sailwx, currently 86.1  121.1  11:00   14  240. At maximum resolution, a rapidly moving Polarstern moves noticeably on GFS nullscape.

Here position-specific daily (or 3-hour) urls at the time of S1AB, say 05:00z can be manufactured by a simple merger of AWImet and any initial GFS url. It would be great to have this back to the mooring date of Oct 4th at a couple of scales as an mp4. Note gimp side panel thumbnails show high velocity winds at a glance. Production at 3 hr intervals would require an automated procedure as 8 per day * 60 days * 2 scales = 960 is out of reach of manual methods.
=-45,90,3000/    Greenland down, north pole centered, scale
loc=121.1,86.100 longitude and latitude of Polarstern

The two new Dec 5th Sentinels show continuing turmoil within the Mosaic experimental area. A relief icebreaker is on its way, sort of. There is currently a 949 hPa cyclone in the north Atlantic between this ship and the Arctic Ocean.

Quite a few scientists from leg 1 will be returning to shore. Leg 2 is seen as the most difficult because of unrelenting cold, darkness and wind. It appears a new communications officer is coming on board; that might help us stay better informed.

Arctic sea ice / Re: MOSAiC news
« on: December 04, 2019, 04:33:17 PM »
take the time to get it right Tor.
Given the very small patch occupied by the three buoys, it would be ok to forget the WGS84 ellipsoid and for that matter the spherical earth and just work on its tangent plane at a buoy triangle centroid. So, using the buoy positions as lat, lon = r,θ of plane polar coordinates = rcosθ, rsinθ (lat in S1AB pixels, lon in radians) = x,y cartesian, it is a matter for high school trigonometry.

What about using mean wind speeds from reanalysis as a proxy for ice motion to make a month on month comparison to Nov 2019? That data is readily available quite a ways back. We could wonder how accurate it is for the Arctic Ocean given the near-total lack of instrumentation but that might not much affect anomaly or trend estimations.

However wx'ers steer clear of near-surface wind wind prediction whereas that is precisely where wind stress on the ice arises. And for that, ridges and floe edges (aka freeboard, thickness) provide the primary frictional surfaces. How much do we know about these even in the Polarstern year? Next to nothing. Assuming they're the same defeats the whole purpose of the wind proxy: more wind but less surface friction would look very similar to less wind and more friction.

Three Sentinel-1B came in this morning. The Polarstern ducks being all in a row already, there wasn't much to do (1st image) except translate them sideways to tomorrow's prediction based on strong steady winds forecast at GFS-null.

The animation of the 3x close-ups do not indicate any rifting or ridging though the turmoil continues on the Mosaic ice camp area (which was a jumble of unconsolidated blocks to begin with). The faint white diagonal indicates the direction of travel to left.

However the ship is entering an area in the anti-cyclone lee of SZ, suggesting ridging if winds converge, or shear if wind speeds differ (4th image). Winds faster than 14 m/s are considered gale force (table below). Use keyboard 'k' to advance 3 hrs, 'shift-k' to advance 24 hrs on GFS:,90.00,3000/loc=118.600,86.100

We have no accurate way of placing the Polarstern (green circle) latitude forward on GFS predictions, a significant issue given sustained wind speeds. Sailwx sishowing the ship a whole degree of longitude east in the 9 hours since the last S1AB):

  86.1  119.1 19-12-04 15:00   16  230    -16.7
  86.1  118.1 19-12-04 06:00   12  240    -14.7

D 2019 12 04 T 0546   86.0937   118.1062 which is 434.4 km from Pole
C 2019 12 04 T 0408   86.0891   117.9333 which is 434.9 km from Pole
B 2019 12 04 T 0230   86.0839   117.7657 which is 435.5 km from Pole
A 2019 12 03 T 0643   86.0017   115.6685 which is 444.6 km from Pole

DC Distance:   1.411 km in 1.633 hrs for 0.864 km/hr or 20.7 km/day
Initial bearing:   248° 20′ 42″
Final bearing:   248° 10′ 21″

CB Distance:     1.397 km in 1.633 hrs for 0.855  km/hr or 20.5 km/day
Initial bearing:   245° 38′ 14″
Final bearing:   245° 28′ 12″

BA Distance:   18.51 km in 19.78 hrs for 0.934  km/hr or 22.4 km/day
Initial bearing:   239° 54′ 19″
Final bearing:   237° 48′ 47″

DA Distance:   21.3 km in 22.55 hrs for 0.945 km/hr or 22.7 km/day
Initial bearing:   242° 31′ 00″
Final bearing:   240° 05′ 05″

Arctic sea ice / Re: MOSAiC news
« on: December 03, 2019, 03:34:04 PM »
Is there some way to indicate how much (if any) the distance between buoys changes over time?
Yes. Put the three buoy lat lon columns in a spreadsheet, making sure their half-hour time stamps are in register. Add the haversine formula ( as 7th-9th columns to calculate sides. Add a 10th column that sums these to a triangle perimeter. Use the SSS formula sqRT (s(s-a)(s-b)(s-c) with s the semi-perimeter for the area. Draw each triangle using an online triangle tool, capture, bin-color in proportion to area, float as otherwise transparent layers and animate. YES YOU CAN

date   hour   lat-P201   lon-P201   lat-P204   lon-P204   lat-P207   lon-P207
01 12 19   03:00   85.9394   113.4152   85.9400   112.7791   86.0074   112.4806
01 12 19   02:30   85.9413   113.3999   85.9420   112.7633   86.0093   112.4640
01 12 19   02:00   85.9432   113.3855   85.9438   112.7479   86.0111   112.4486
01 12 19   01:30   85.9450   113.3719   85.9457   112.7335   86.0128   112.4341
01 12 19   01:00   85.9467   113.3608   85.9474   112.7194   86.0146   112.4214
01 12 19   24:30   85.9485   113.3505   85.9491   112.7078   86.0163   112.4103
01 12 19   24:00   85.9503   113.3405   85.9509   112.6973   86.0180   112.3994

The tool below will put your choice of inter-buoy distance along the bottom rescaled to a constant length. Then you can see the relative shape change in the other two sides.

average the ice motion arrows over a month somehow
In the past we have tried loading the month as grayscale in gimp and using the 'average layers' command on a duplicated stack (image menu). That gives a so-so wind rose at each grid point that could be compared year on year by image subtraction to give a 2015-19 animation.

It may be that OsiSaf ill-advisedly puts the center of the arrow over the grid point (as mosaic_multi does) instead of the tail. So we need to first redraw the arrows with no heads using the OsiSaf netCDF than no one can get to work. Alternatively Panoply (or command line) dumpNC would give numeric x,y values at grid points or regions of interest that could be passed on to Excel which has a good wind rose chart.

The next three days or so on GFS look like more of the same: moderately strong winds at a fixed bearing. Below, the png assumes a mid-range coriolis angle of 25º of ice movement CW to the direction of the wind. Zonal and meridional components r,θ = lat lon are shown for the 05:00Z nullschool of today roughly scaled to the cube of 100 hPa wind speed from comparing response at periods of constancy.

In three days time, my expectation is the Polarstern will drift to 86.2  121.9 (ie on 09:00 on 06 Dec 2019 according to sailwx tables). Thus 1/6th of the trip will be over without any real indication of Fram-ward transpolar drift.

Sentinel coverage of the Mosaic floe has resumed. Daily instability suggests very little of it is fit for purpose.

S1B  2019 12 03 T 0643  17  210  -17.1  86.0017  115.6685

Technical note: nullschool provides a clean 1º graticule over land if wind is set to none. AwiMet provides the green location circle. Setting the scale parameter to 3000 maximizes resolution. Longitude has been increasing by 0.05 deg/day over the last 24 hours but latitude by only 0.005, setting the wind scaling. (Mean recent change or tangent to the PS position curve could be determined more accurately with high resolution S1Ab or buoy data.)

The tangent vector is set by rotating to vertical using the Polarstern's current longitude, drawing a perfect horizontal, then rotating back. The wind direction is drawn as the tangent vector to the radial vector of the osculating circle to the curving wind sprite at the PS. Dropping the perpendiculars then gives the desired breakdown of motion in terms of lat,lon. Here taking the ratio of r,θ component vectors causes the wind scaling factor to drop out.

Arctic sea ice / Re: MOSAiC news
« on: December 02, 2019, 11:33:23 PM »
Mike Horn and Borge Ousland have had and are having an awful time... Perhaps the whole concept of continuous measurements on  a single floe, no longer reflects the polar winter ice reality?
The two adventurers are looking at very unfavorable ice movement for the next four days that will take them north and west faster than they can walk. The same thing happened to Nansen's foot party. The image below plots their nrt position at 08:29 utc 02 Dec 19 over nullschool GFS.

The idea of rescuers reaching them by sailboat or bringing food on skis seems very naive looking at the massively fractured ice leads ( The two are within helicopter range and discussing airborne rescue before the winds worsen as predicted; visibility and pilot safety are additional issues. 

The Polarstern lost a helicopter pilot in Antarctica a few years back with multiple scientists injured.

It's not clear what to measure to show/not show the ice is shearing, compacting and diverging more than it did, to what extents this year is natural and unnatural variation off a weak 2018-19 winter, and whether the mechanical properties of the ice have deteriorated.

We've previously looked at the August, September and early October history of this floe. Basically it was newly formed from collisions and a barely consolidated mess as late as the Oct 2nd S1AB. Still, what were they going to do after eight years of planning and grant-writing. Wait for the ice to freeze solid, then set up in the dark?

Up thread, I laid out Plan B options. The best idea is probably to pull in all the remote equipment, set out more buoys from the relief icebreaker arriving, draw up the ice anchors, squirrel the shp around make an open patch of water, point the bow (where the key instruments are) into the wind to avoid the massive air pollution affecting them now, and change locations under powered drift.

Arctic sea ice / Re: MOSAiC news
« on: December 02, 2019, 05:15:02 PM »
Co-leader M Shupe has an excellent new on-site blog out; note that despite the Nov 27th tag the storm event being discussed only covers the 18-23 Nov 2019. More has happened since then

We could see the damage just looking at S1AB time series but it is great to have confirmation and  specific details beyond satellite resolutioon. Note buoys are not on the Mosaic floe and may be affected differently or not at all.

I don't think things would have gone better had they selected another floe; the ice was garbage everywhere at their latitude on Oct 5th and still is. Had they gone closer to the pole, transpolar drift would have become even more problematic than it is now: the GFS wind forecast translates heuristically to more south and east backtracking of their trajectory.

85.9  113.8 19-12-02 09:00    8  250    -27.1
85.9  113.4 19-12-01 21:00    8  300    -24.1
86.0  113.1 19-12-01 09:00   10  310    -21.8
86.0  112.8 19-11-30 21:00    8  340    -27.0
86.1  112.9 19-11-30 09:00    9   20    -28.0
86.1  113.5 19-11-29 21:00   10   30    -25.8

Postcards from a frozen icebreaker – Part 14
By Matthew Shupe 11/18/19

I was startled by the phone call shortly after midnight. Trouble at Met City. Felix had just arrived on the bridge for his night watch from 12-4am. He always takes a look around camp when arriving for his duties. And there was no 30m mast. Simply gone.

We had seen the crack before, and apparently it got active and pulled on some of the guy lines, ultimately pulling the mast down. The sonic anemometer failed right away, possibly from just being unplugged. Upon later inspection it is bent, can likely be straightened, re-calibrated, and put back into operation.

Our met sensor remained operational the whole time, including [while lying on the ground] after the fall. We will test both of these instruments against others, but it is looking like they will both live to see another field measurement.

The mast itself might also be salvageable. Some bent legs the ship can likely fix and a few damaged sections that will just be taken out of service. Thus, it may become a 25m mast but that would be better than nothing. Now we just need the ice to settle down so we can think about a redeployment.

The chaos has contributed to this feeling. Major ice dynamics running from the northwest to the southeast of us, across the bow of the ship. They have sheared our camp, and the Fortress, in half. This was part of a regional event with lots of ice motion, likely driven by a strong storm with very high winds.

Initially the lead opened many meters across, followed by some shear with the far side of camp moving towards the ship, then away again. In the last days it all moved again perhaps 500m.

Met City is almost directly in front of Polarstern while Ocean City remains approximately where it was (after a slight move to stay away from the ridge). A much longer daily voyage for us to get to Met City, and now it means bringing fuel cans to run generators. Met City is now very dark.

“Continuity” is a very important concept for MOSAiC. But it’s also a huge challenge in the current Arctic conditions. In the last week we’ve had so much ice movement, right out in front of the ship. We watched Met City move back and forth across the view from the bridge.

Intermittently we are able to reach it, going from floe to floe. While at other times there is no access possible. And this limited access impacts the continuity of our measurement on the ice. We are running Met City on a couple of generators but the runtime is such that we must refuel twice per day.

Last night the ice movement left us no route to Met City so the generator fan went out at 4:30 am local time. This limited access is leaving its mark on the Met City data stream but others experiments are also impacted.

Sampling sites have move further away or broken up entirely; the Ocean City hut had to be moved; the whole Remote Sensing installation will need to be relocated, and more. Continuity of the observations has definitely been compromised.
An outdated map of the Ice Camp layout was included, not attached below because it is one we have seen before, now presented at a blurrier resolution. It does not show the layout of the cracks and ridges discussed in the post.

Once again there is nothing but 404's in trying to locate the original full resolution file. Neither the new lidar elevation map nor ice bottom ROV imagery have been released in any form.

Last time I wrote the help desk, they got back to me saying the ship could only be contacted intermittently, even though we know today it had a 100 mbps internet connection ever since leaving Tromsø.

Arctic sea ice / Re: MOSAiC news
« on: December 02, 2019, 04:46:56 PM »
coordinates taken from polarview images in red and collated
Coordinates  were shared earlier from the 106 Sentinel-1AB images available since the Polarstern moored on Oct 4th. These were hand-digitized using the fast and accurate new PolarView plugin.

No new S1AB images have appeared during the last 48 hours, very unusual. It means during all 16 orbital passes over the Polarstern, the sensors were either shut down, malfunctioning, taking scenes in interferometric mode, or taking images but suspending distribution. This happens every time the Mosaic floe is encountering disintegration issues. Coincidence?

The P-buoys give the ship's position 2-3 times a day, always in the early morning UTC hours. The accuracy is about a third of the ship's length. The timestamps refer to nadir or satellite passage over the center of the scene. While these are more accurate than we need (to the second), the minutes can be anywhere between hours.

Like most buoys, the three close-in P-buoys call in their GPS coordinates 24 times a day, every half hour on the half hour. Since 4 dp accuracy is important to measure ice pack deformation, the issue arises of how to best collate them with the erratic timestamps of Polarstern S1AB images.

The Polarstern's lat lon is seldom co-temporal with the buoys, only 15 times out of 106. However the other 91 can be linearly interpolated back to the nearest half hour using the rate of change of lat lon. The ones below are already synched to the buoys and do not need interpolation:

S1B   2019 11 29 T 0400   86.1220   115.0394
S1B   2019 11 22 T 0230   85.7352   120.8192
S1B   2019 11 19 T 0700   85.8011   120.5766
S1A   2019 11 18 T 0530   85.8556   120.8340
S1B   2019 11 17 T 0400   86.0595   122.4405
S1B   2019 11 10 T 0230   85.8219   115.9915
S1B   2019 11 07 T 0700   85.9198   116.7922
S1A   2019 11 06 T 0530   85.9191   117.7247
S1B   2019 11 05 T 0400   85.9509   118.8770
S1B   2019 10 26 T 0700   85.4533   127.4991
S1B   2019 10 19 T 0530   84.9215   133.1910
S1B   2019 10 14 T 0700   84.7783   134.5386
S1A   2019 10 13 T 0530   84.8574   135.0090
S1B   2019 10 07 T 0530   85.0846   134.3174

The Pbuoy dataset has various repairable glitches (shown below) not repaired by the buoy owner; the month-old errors are simply passed on 'as is' to the Meereis and sailwx portals to be ingested into Uniq's animation algorithm.

Since 94 - 12 - 3 = 79 other Mosaic buoys are currently reporting -- and some of these will have glitches of their own -- there is a need to repair the damage and regularize the data.

The best way to go is set up a master clock, say on the half hour back to the beginning, then hang all the data off it to synchronize analysis. Although Mosaic experiments often produce complex data types that don't fit in (below), they still be indexed in if that serves some purpose.

For example, a source like GFS nullschool only reports at 3 hr intervals so has gaps at 5 out of 6 positions, whereas sailwx and awiMet shipboard weather report hourly. Ascat reports 3 times a day but swath timestamps are hard to come by for the concurrent PS location. OsiSaf reports a rolling window of ice movement every two days between 12:00Z. Most satellite products (such as Amsr2 ice concentration or cryo2smos ice thickness) report every 24 hours.

On these forums, we are looking for scalability, transparency, regularization and portability:

Scalability: Any number of buoys or images can be tied to the master clock's indexing field; indeed all put into a single common file. The issue is keeping file size manageable over the course of the Mosaic year. If not, the latency on common operations like 'sort' or 'fill down' becomes unworkable. The key here is keep image collections such GFS weather pictures elsewhere, still indexed though by the master clock.

Transparency: This means suppling the data in human-readable data or image format such as plain txt, comma separated variables, netCDF, kml, gif, png, jpg or mp4 visible in the post itself or as an attachment anyone with an old cheap computer can download, open in free software and process for themselves. More and more climate change sources are using arcane binary formats the average person cannot work with.

Regularization: Errors, gaps and glitches should be repaired just once, rather than 50 people making the same tedious repairs 50 times over. To a certain extent, this is enforced by keying to the master clock. I will post repaired P-buoys, synched S1AB and reconciled sailwx/awiMet in a bit.

Correction and collation of databases can be done very rapidly if you still have a 25 year old Mac running MS Works 1.0; it has gotten much harder since.

Portability: The data should be immediately importable into other open software for specialized projects, such as Excel, Gimp, ImageJ or R for statistical analysis, charting, slide shows, animations and movies.

Arctic sea ice / Re: MOSAiC news
« on: November 29, 2019, 09:12:38 PM »
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 The exact study floe cannot be determined because of the lack of timestamp on the photo.

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

Arctic sea ice / Re: MOSAiC news
« on: November 28, 2019, 06:19:12 PM »
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.

Arctic sea ice / Re: MOSAiC news
« on: November 28, 2019, 12:09:34 PM »
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

Arctic sea ice / Re: MOSAiC news
« on: November 27, 2019, 05:27:20 PM »
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.

Arctic sea ice / Re: MOSAiC news
« on: November 26, 2019, 09:15:46 PM »
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):


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.


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."

Arctic sea ice / Re: MOSAiC news
« on: November 26, 2019, 05:29:54 PM »
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.

Arctic sea ice / Re: MOSAiC news
« on: November 26, 2019, 01:41:23 PM »
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).

 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

Arctic sea ice / Re: MOSAiC news
« on: November 25, 2019, 11:26:21 AM »
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.

Arctic sea ice / Re: MOSAiC news
« on: November 24, 2019, 09:54:43 PM »
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.

Panoply netCDF, HDF and GRIB Data Viewer ... - NASA GISS › 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

Arctic sea ice / Re: MOSAiC news
« on: November 24, 2019, 07:59:48 PM »
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.

Arctic sea ice / Re: MOSAiC news
« on: November 24, 2019, 07:05:36 PM »
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.

Arctic sea ice / Re: MOSAiC news
« on: November 24, 2019, 06:20:38 PM »
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.

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

Arctic sea ice / Re: MOSAiC news
« on: November 23, 2019, 05:20:01 PM »
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.

Arctic sea ice / Re: MOSAiC news
« on: November 23, 2019, 10:30:06 AM »
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.

Arctic sea ice / Re: MOSAiC news
« on: November 22, 2019, 10:38:08 PM »
why netcdf?
It is first about mainstreaming the buoy project. It's such a good one that resistance is futile.

For better or worse, nc and hdf have become the meeting ground for sharing climate data, excel/mysql wrapped in steroids. System integrators -- builders of the immense robotic pipelines of climate science -- do not want to crawl a hundred sites, massage a hundred formats, write a hundred unresponsive sysadmins, nor tweak other people's ad hoc code.

In fact the whole idea is not to look at the raw data at all but assume it is schema-compliant so a remote climate modeler or weather prediction provider can ingest it over and over without further intervention.

It is second about getting out of banks of numbers into bottom-line pictures: working on a more limited scale within Panoply, an open and active low learning curve netCDF data viewer, data type combiner and map-maker that allows the average joe/sephine to put out a decent and original product, for example changing projection to equal area or re-scaling to overlay properly on satellite products, or here correlating ice mobility with say surface wind speed or vertical ice temperature profile.

In other words, it is better to crunch pictures than numbers. Or rather multiple correlated stacks of pictures. Why? Because you can see what you are doing, because there are ten thousand intuitive photoshop-type algos, because the data is inherently indexed by location and timestamp.

It's all about rapid prototyping. Work with the pictures until you know there will be a result, then go back to the numbers and do it right.

Is this a spec for implementing buoy position and sensor data as netCDF? I would say no, it's little more than a vague vision statement looking down the road to better sharing.

Is the priority so high that the weekend should be spent immersed in human-unreadable binary? For me, I would say no to that.

Arctic sea ice / Re: MOSAiC news
« on: November 22, 2019, 06:57:26 PM »
Let's get this right because this is a very serious ongoing event.

Supposing this weekend storm had a causative role in the present troubles at the Polarstern, it might be worth overlaying the 3-hr nullschools over the changing S1AB, using the PS positions in the computed nullschool url as provided for everyone's convenience in an earlier cvs attachment.

The synthetic problem though is the resolution of nullschool maxes out at its '3000' scale whereas the S1AB ROI for Mosaic is just a postage stamp then under the GFS, with vice versa no better. However S1AB still conveys the lead situation zoomed out so there might be a workable compromise that doesn't overshoot the 700 pixel forum width too badly.

Technical note: as above, take whole window screenshots and layer up in Gimp. To avoid jerking the nullschool image with inadvertant mouse-overs, use keyboard commands lik j and k to advance and back the time by 3 hours. Three days is 24 layers; that won't result in an overly large final file. Duplicate the file twice and crop to the url and data box for wind speed. Crop the main file to final size and enlarge the canvas on the duplicates to match. Then tile up as three layers, add the S1AB layers duplicate to match, add transparency to the GFS, flatten over the radar, then slice the tile over in ImageJ, save as animated gif, open and re-save in gimp with good pauses where appropriate. YES YOU CAN.

85   S1B   2019 11 22 T 05:46   22 11 19   05:46   85.7   120.8    4   320   -14.8
84   S1B   2019 11 22 T 04:08   22 11 19   04:08   85.7   120.8    4   320   -15.0
83   S1B   2019 11 22 T 02:30   22 11 19   02:30   85.7   120.8    4   350   -14.9
82   S1B   2019 11 21 T 06:43   21 11 19   06:43   85.7   121.0    4   360   -16.2
81   S1B   2019 11 21 T 03:27   21 11 19   03:27   85.7   121.0    6   30   -16.0
80   S1B   2019 11 20 T 06:02   20 11 19   06:02   85.8   120.5    6   230   -13.8
79   S1B   2019 11 20 T 04:24   20 11 19   04:24   85.8   120.5    8   240   -15.3
78   S1B   2019 11 19 T 07:00   19 11 19   07:00   85.8   120.6    6   240   -11.2
77   S1B   2019 11 19 T 05:21   19 11 19   05:21   85.8   120.5    7   240   -15.4
76   S1B   2019 11 19 T 03:43   19 11 19   03:43   85.8   120.5    8   240   -15.3
75   S1B   2019 11 18 T 06:19   18 11 19   06:19   85.9   120.8   14   20   -10.6
74   S1A   2019 11 18 T 05:30   18 11 19   05:30   85.9   120.9   16   10   -10.2
73   S1B   2019 11 18 T 04:41   18 11 19   04:41   85.9   121.0   16   10   -10.5
72   S1B   2019 11 17 T 05:38   17 11 19   05:38   86.0   122.5   13   320   -15.7
71   S1A   2019 11 17 T 04:49   17 11 19   04:49   86.1   122.5    4   320   -16.2
70   S1B   2019 11 17 T 04:00   17 11 19   04:00   86.1   122.4   14   310   -17.7
69   S1B   2019 11 15 T 05:54   15 11 19   05:54   86.2   118.4   11   170   -26.1
68   S1B   2019 11 15 T 04:16   15 11 19   04:16   86.2   118.3    2   260   -15
67   S1A   2019 11 15 T 03:27   15 11 19   03:27   86.2   118.3    2   260   -14.9
66   S1B   2019 11 14 T 03:35   14 11 19   03:35   86.2   118.2    9   190   -14.5
65   S1A   2019 11 13 T 03:43   13 11 19   03:43   86.1   117.9    9   200   -13.8

AWI communications have been strangely unscientific. The daily 'follow' blog is misdated, a day or more behind events depicted; photos have no timestamps, exifs are stripped; ship time is updated weekly but not provided, we have no idea what UTC the news refers to; the twitter feed is hardly used, no one on board is sharing despite huge bandwidth, the Helmholtz blog has gone dead, ship GPS is obfuscated and so on. It is not a good idea to apply spin templates from political campaigns to scientific matters. Honesty is the best policy.

Arctic sea ice / Re: MOSAiC news
« on: November 22, 2019, 05:07:44 PM »
Why so many big leads during relatively calm weather?
Even though wind speeds have been mild, wind velocity has been very confused in the 200x200 km sector centered to the SE and including the Polarstern. The weak ice of today experiences mechanical failure upon being pulled in different directions even under moderate stress.

The alternative, a delayed reaction to stresses from storm last weekend, doesn't hold water: too many days have elapsed. However that storm was likely a major contributing factor in establishing the initial ice fractures that later became big leads, opening easily under mild divergent winds.

The next cyclone rolling in will brush the Polarstern on Nov 24th before wandering off to Severnaya Zemlya. Winds will be fairly strong (peaking ~32 km/hr) for a day but GFS does not foresee surface winds anywhere near the 51 km/hr of the last storm. Wind stress goes roughly as the cube, so the previous event was 4.3x worse.

Note Uniq's buoy trajectories are in effect a non-gridded replacement for OsiSaf ice motion with a fantastically improved time resolution, an hour vs 48 hours. Given that buoys report location to 4-5 decimal points, whereas OsiSaf is applying AI to low resolution all-Arctic imagery, the accuracy is much higher with the buoy mesh.

The tangent vectors to these curves at the times the S1AB are taken (not marked or paused yet) are then the arrows that should be drawn over the high resolution imagery instead of what we see at mosaic_multisensor. These arrows will be very accurate both in magnitude and direction.

Even if F not quite = ma under the circumstances, it is close enough for citizenry work. Here we want to get at the force acting on the floe in which the buoy is emplaced or rather its rigid body extension. Here you would want go back to an old indian trick called Newtonian Differences rather than differentiate fitted continuous curves.

Set up a column of positions, let the adjacent column subtract t from t-1 and fill down, let the third column do the same for the second, recalling change of position with time is velocity and change in velocity with time is acceleration which with mass fixed amounts to force acting (geometrically the tangent to the velocity curve). These new columns are to be colored differently in supplemental animations though the time steps and positions remain the same.

OsiSaf ice motion is severely biased by the big moves during the 48 hour block; if for example, these might be in the first two hours with the latter 46 providing little displacement, then the image served will not be at all current. This explains the apparent incomparability with GFS 3-hr winds.

Arctic sea ice / Re: MOSAiC news
« on: November 22, 2019, 11:47:17 AM »
The situation has gotten increasingly dire in the immediate vicinity of the Mosaic ice camp as extensional forces have opened multiple km-wide bands. A second Sentinel image of 05:46 has just come in that provides a snapshot of ongoing motion -- the situation has worsened considerably in the last three hours. PolarView has just now posted a third intermediate time, the 04:08, but we won't be able to follow events further until tomorrow morning other than hourly weather and drift which are unremarkable (there's no storm) since the last S1AB:

   Lat  Long  YY-MM-DD  UTC     Wind       T(C)  hPa
  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  120.8 19-11-22 08:00    5   10    -16.1  1015.0
  85.7  120.8 19-11-22 07:00    4  340    -16.1  1014.5

This event will be extremely disruptive to all deployed experimental equipment and effectively destroys the floe for purposes of studying its evolution over a year. Let's hope the Polarstern and all the people aboard stay safe as the event continues to unfold today.

This is a very unfortunate situation ultimately attributable to climate change, its amplification in the Arctic Ocean and the long-term trend to thinner, more mobile ice that cannot resist wind stresses.

The upper two images follow Mosaic convention with north up, the first needs a click to display full size; the lower animation has S1AB orientation of the Pole down the 120º meridian with inverted insets in coordinates attached to the ship at 2x enlargement.  The 4x enlargement is also north down after contrast leveling and light unsharp mask.

Some of the 87 surviving autonomous buoys out of the 100 deployed in the Mosaic project will likely succumb to the same ice pack deformations affecting the Polarstern. So far, they all reported on the 22nd or 23rd with the exceptions below. All but the last two are Chinese buoys that have previously had reporting delays.

300234068118580   SVP    PRIC   MOSAiC   15 11 19   86.19   118.51   
300234010077180   GPS    TUT    MOSAiC   19 11 19   86.08   117.27   
300234065091830   GPS    TUT    MOSAiC   19 11 19   86.01   123.00   
300234065090840   GPS    TUT    MOSAiC   21 11 19   85.51   120.54   
300234065980590   GPS    TUT    MOSAiC   21 11 19   85.73   123.98   
300234065981590   GPS    TUT    MOSAiC   21 11 19   85.61   118.57   
300234065984580   GPS    TUT    MOSAiC   21 11 19   85.95   121.98   
300234065985570   GPS    TUT    MOSAiC   21 11 19   85.92   121.06   
300234067705700   IT      AWI    MOSAiC   21 11 19   85.75   121.63   
.................90094   ITP   WHOI   MOSAiC   21 11 19   85.68   121.98   

Arctic sea ice / Re: MOSAiC news
« on: November 21, 2019, 11:33:41 PM »
that sudden change in direction opened up all the leads
Or whiplash. When the eye of a hurricane/cyclone passes overhead as it kinda did here, the wind reverses direction. Extensional leads rather than compressional ridges because ice on the edges moves centrifugally outwards. But where exactly and what good would advance knowledge do for the Polarstern?

In terms of replacing the white base under your buoy animations with appropriately dated S1AB or nullschool GFS winds (to get at the correlation pictorially), the S1AB go about 20 hours between 3 close coverages and the GFS 3 hours whereas the buoys commonly report hourly. So there is somewhat of a mismatch in time resolution to buoy GPS.

The Simb3 buoys report every four hours. However most buoys can be programmed to call in at whatever interval, from ten minutes on up. Some may be able to take downlink re-programming calls.

Windy gives update intervals and the time of update release (as of 2016 unfortunately) for all the common weather satellites and has stopped providing Arctic ECMWF.

On the four Simb3, call them abcd, retrieving their record of 924 dial-ups back to Oct 6th deployment revealed quite a mix of buoy position reporting combinations that complicate matters for making two delaunay triangles or just one  (or just an inter-buoy line) consistently.

The attached csv database is tricked out with extra sort columns to enable extraction of any desired sub-collection. The Simb3 are key to local ice thickness development, in combination with whole-ocean 25x25 km cryo2smos.

636 abcd   (all buoys reporting)
086 bcd    (buoy a not reporting)
041 cd     (buoys ab not reporting)
012 abd    (buoy c not reporting)
012 acd    (buoy b not reporting)
011 c      (buoys abd not reporting)
006 abc    (buoy d not reporting)
002 ac     (buoys bd not reporting)
002 bd     (buoys ac not reporting)

Uniq and macID have built a better mousetrap. That is, one-hour ice movement is much more refined than two-day OsiSaf as a better match to the intrinsic time scale of winter ice movement.

That is, the PS lat lon changed, in 1026 available hour increments at awiMet as poorly measured by one dp data are distributed as below. Note 0.1 in lon is a lot less distance travelled than 0.1 in lat this far north; the distribution estimate could be refined by using 4 hr windows. The Polerstern is currently moving very slowly south and east.

667 no change lat, no change lon
151 no change lat, westward 0.1 lon
117 no change lat, eastward 0.1 lon
010 0.1 south in lat, no change in lon
004  0.1 north in lat, no change in lon
002 no change lat, 0.3 westward in lon
006 no change lat, 0.2 westward in lon
008 no change lat, 0.2 eastward in lon 
002 0.1 north in lat, 0.1 west in lon
003 0.1 north in lat, 0.1 east in lon
010 miscellaneous

While ice motion so described is limited to inside the buoy envelope, it could give advance notice to the Polarstern of leads and ridges outside their immediate location in advance of the next S1AB. The buoy pattern is in effect an imaging device, resembling the discretized ommatidia of a small invertebrate eye.

OsiSaf uses pattern recognition but those point features (virtual buoys) change from day to day and can be quite sparse. OsiSaf is not currently pointed at S1AB but could be, giving ultra-refined ice motion between timestamps in conjunction with the buoy product.

Clearly uniq could dump the gridded underlying data into netCDF time series format to distribute the underlying numerology though trailing tails (but not colors) would be lost.

Arctic sea ice / Re: MOSAiC news
« on: November 21, 2019, 07:16:32 PM »
Awright! AWI finally posted an updated but already outdated map of the ice camp and its drifting pieces. The bad news is that the map is badly out of focus because designers did not anticipate what 'social media' would do resizing it for phones. This topic will never be trending with millennials; few could even locate Norway on a map.

I have not been able to locate the actual map. Actually it is very affordable to have an ordinary web site and simply post stuff in html 1.0 and upload intact big figures with ftp. In fact they could just use my site for free and get their incompetent graphics fixed to boot. They really shot themselves in the foot with this crazy complex javascript and cascading style sheet eye candy. It doesn't work.

Next we read about how they cannot track locations of their remote equipment. Apparently they don't co-install a buoy, tracker beacon, two-dollar flasher or radar reflector on expensive remote equipment (OPM: other peoples money). They could have just emailed uniq on their 100 Mbps internet to get the current drift.

The fuel cell failure mode is exactly what they would get in Minnesota on a cold day. The rising number of mundane equipment failures makes me wonder about pre-trip testing standards. This is an austere lunar landscape, not a mid-latitude campus.

Reading to end of this blog, it appears one co-leader has a very loose grip on what drives TransPolar Drift (in recent years, not much and very erratically) and on what is going down right now: one cyclone chasing another when TPD anti-cyclones are way overdue. They seem not to look at GFS even 2-3 days out for a drift forecast.

The way things are going -- and given what is coming -- perhaps it is time to consider a staged withdrawal:

-- Forget about fancy remote area deployments, pull back to the ship, put out more autonomous buoys, do helicopter forays to benefit satellite photo interpretation, carry out excursions to measure ice thickness, let the ship loose and motor slowly into the wind to keep the bow air clean. The ship moored to solid ice makes for a poor platform not fit for purpose because unavoidable emissions severely impact atmospheric and other monitoring goals.

-- Wind down Leg 1 in an orderly manner and consider downsizing, repurposing or even eliminating Leg 2. The Mosaic floe as originally envisioned is dead in the water. It is being torn apart and rearranged almost daily; no purpose is served by continued monitoring the core ice jumble-ridge which is atypical and unrepresentative of the Arctic ice pack.

-- Don't admit to planning mistakes but don't continue with them either. Give the redesign a new wrapper called responsive resilient adaptive management (RRAM) or similar.

11/9/19 Another Failed Mission
Postcards from a frozen icebreaker – Part 12 19 Nov 2019
By Matthew Shupe

L1 radiometer flight as high on the agenda today… but kept getting pushed back. Including by a bear visit, which closed down most operations. But finally in the afternoon we were able to hit the air. Loaded our gear on the helicopter….. sled, ladder, shovel, feather duster (great for instrument cleaning), tool box, numerous safety bags, rifle for the bear guard and a spare, personal kits (need those spare gloves), and most importantly our replacement power systems.

It is about 280 lbs…. two big batteries and a fuel cell, all set up in a box. We fired it up for about an hour before the flight to get it all toasty warm inside. Then shut it down, closed the box, and loaded it on the helicopter.

On site the plan is to quickly get it over to the flux station, plug it into a fuel cartridge, and fire it up again, to stay warm while we prepare the station for the power system transplant. Such a great plan…… but unfortunately the remote controlled helicopter landing lights at the remote station did not work, so we flew around for 1.5 hour looking for it.

So tough to find as everything is white (and snow covered) but it is totally dark out. Part of the challenge is that GPS coordinates quickly become outdated due to the ice drift. We get a reading from a buoy from ½ hour before but the whole pack has moved. This unsuccessful search had me really bummed and wondering if/when we would find this site.

It all went off without a hitch or at least without a big hitch on 11/10/19. Well planned in advance, we had the right tools and our specially concocted power system in a box. Beautiful clear skies and cold…. Below -30C for the first time at MOSAiC. The helicopter dropped us off at the L1 site, some 15 km away from Polarstern. Our new power system is getting colder. It won’t start if it gets below the freezing point.

We started up the spare system right away so it could keep itself warm, then opened up the old system, dark and cold, to remove the frozen system. The exhaust system was the culprit, a huge frozen beard extending down from where the water exhaust drips out. Ice extending up the exhaust tube

Arctic sea ice / Re: MOSAiC news
« on: November 21, 2019, 04:27:57 PM »
A lot of movement overnight
This was the worst ice dynamics yet ... and just after they got done laying a bridge over a recurrent lead with scrap palettes and a wooden sled. It is unfortunate that the remote experimental stations have to be tethered to the ship with power, data and fuel lines because these are subject to breakage and burial.

The massive rift chain to the Polarstern's southeast (fresh leads are black on S1AB) shows the response of the ice to to divergent wind stress: extensional faulting resembling NW trending Nevada basin and ranges as the Pacific Plate scrapes past the N American -- and about on the same distance scale. Both play out slowly in time; here the ice failed a couple days after the "84º" wind divergence event pictured in the GFS post above.

A parallel fault zone runs above, below and so far around the Mosaic floe. So far, it has mostly been around because the Fortress is not the path of least resistance for fractures (being thicker). The two Sentinels for the day are in and 'follow-mosaic' :) seems to run a couple days behind events, so unless skies are infrared-clear we won't know until 03:30 utc on Friday what is currently going on.

No question though that the Mosaic floe has experienced some strong ice dynamics even though the wind has been and will be mild short-term. The shifting ice we can see between Sentinel orbits only 3.25 hrs apart may or may not translate to significant damage to remote towers and lines.

The Polarstern itself, forming a barrier much higher than ice, seems to attract ridging, which on the stern side would seem to require daily resetting of slack lines mooring the ship to ice anchors. This recurrent lead/ridge may have originated from the icebreakers maneuvering early on.

Between onboard pollution from the ship's stacks and daily repairs to deployed sensors, scientists may not be getting the steady data streams expected. It would be no better on another floe. Trip leaders said early on that this was probably the last possible year for such an expedition. Maybe it was last year.

It's always been clear that Sentinel radar images, like Ascat scatterometery, arrives at sub-optimal visual contrast but it's never been clear how to best fix a given image, much less make a matching stack for a time series given variations between different orbital angles and nadirs.

Sentinel currently provides 82 images back to mooring on Oct 5th with only five days of missing coverage. The attached S1AB csv database has been merged with sailwx, AwiMet and nullschool GFS to bring in location, wind speed, wind direction, air temperature and links.

The easiest thing to do in terms of small file sizes, convenient format, quick turn-around and pioneering a pipeline for the the ultimate unattended objective fix of the jp2 is use the jpg for now and its intrusive graticule, followed by the Level tool in gimp, as shown in the mini-tutorial attached.

Sentinel images on ice are inherently speckled and while 'there's a app for that'  a slight unsharp mask can bring further small benefits. One size does not fit all however: improving a 100x100 km scene is not optimal for smaller sub-scenes like the Mosaic floe. There we would like to maximally improve the resolution or clarity of the image right around the Polarstern and the Mosaic floe.

Arctic sea ice / Re: MOSAiC news
« on: November 20, 2019, 09:01:12 PM »
Well put, Archi.

I say lay on the amenities, whatever it takes for creature comforts. They have been worried about sustaining Leg 2 morale since the get-go. They'll be beyond the reach of planes, helicopters and even support icebreakers over that time frame.

Mosaic has not released a ship's roster so we don't even know whom to thank. There's crew of 44 and capacity for 80 scientific and technical staff at any given time according to wiki. Most of the people are there to maintain complex instruments at remote sites (no easy job) though scientific team leaders are alongside working too. The breakthrough on internet bandwidth has made a big difference on who needs to be present.

Esther Horvath, photographer and communications manager of the MOSAiC expedition "wants to document the unknown faces on the front lines of climate science. "Who are the scientists? This is what I'm extremely interested in; to show climate change stories through the eyes of scientists, showing how they live in such an extreme remote location."

Chief scientist:
Markus Rex PS122/1: 20 Sep 2019 – 15 Dec 2019
Christian Haas PS122/2: 15 Dec 2019 – 15 Feb 2020
Torsten Kanzow PS122/3: 15 Feb 2020 – 15 Apr 2020
Markus Rex PS122/4: 15 Apr 2020 – 15 Jun 2020
Dieter Wolf-Gladrow PS122/5: 15 Jun 2020 – 15 Aug 2020
Markus Rex PS122/6: 15 Aug 2020 – 14 Oct 2020

The photo today shows some of the damage from recent ice dynamics. We've seen this already on Sentinel but don't know the specifics. However Mosaic has been very cagey about providing a revised map of Ice Camp as-built (and re-built and re-built again) or shareing measured ice elevations above and below.

For example, the open lead necessitating the bridge has itself been cropped out of the photo. We have no idea where the Ocean City and Remote Sensing Site are located today nor how serious the fracture is nor how to follow it on remote sensing.

I don't think this secrecy serves them. The damage control and data hoarding is pure paranoia. No ship radar with 100 Mbps internet? Dumbing down GPS position -- do they fear a cruise missile? What is someone going to do with bearing data beyond a scarcely publishable fourier analysis?

What it boils down to is somebody on the grant committee -- Mosaic dipped deeply into a pot shared with Antarctica and Greenland -- said 'this is never going to work plus it's been done before by N-ICE2015 and SHEBA'. And if they had access to minute by minute floe motion, would now be saying 'I told you so, no way time evolution of a single floe can be followed for a whole year'.

So it seems to be about embarrassment. They are making zero headway on the drift, have no prospects of drifting over the Pole, and the floe is rearranging itself daily if not disintegrating, undercutting the  key talking point about research novelty. This is why Shupe chose the name 'Fortress' for a crummy ice jumble and put it on Mosaic maps.

Today saw the usual turmoil on the Mosaic floe and also some puzzling (since winds have abated) regional torque with the ice no longer moving coherently over the short time frame between two S1AB. Divergent wind stress from yesterday cannot be the attribution because there's not even short term conservation of linear or angular ice momentum because of way too much frictional dissipation.

The two Sentinels are co-registered on the Polarstern (red dot); the faux interferometry that shows complex regional motion in this coordinate frame used the S1AB grayscale average for the 3rd luminance channel of the HSL 'RGB'.

Arctic sea ice / Re: MOSAiC news
« on: November 20, 2019, 11:44:36 AM »
Hefaistos calls our attention to another excellent BBC piece on the Akademic Fedorov trying to get home by Martha Henriques. It is best read in its entirety but a few highlights are being posted below:

How not to get stuck in the Arctic sea ice

News reaches us that boxes of kit and the Polarstern’s large gangway fell into a widening stretch of water.

Odd, no mention of this :( event at 'Follow_Mosaic' :). Possible allusion to it in Shupe's AGU blog. I struggled with 'boxes of kit'. Did the reporter mean boxes of clothes, unloaded scientific equipment or just stuff/things in general? Did they sink to the bottom of the sea or were they retrieved? Ditto the large gangway, loss of that leaves them stranded on or off ship, other than the mummy box chair unloaded by crane.

The Polarstern  is looking at a week of total blah weather ahead according to GFS. I don't expect any significant net drift; there's no indication of when or if the transpolar drift wind pattern will set up. Ice deformation can act from afar but I don't expect that this week because the millions of sq km of weak ice acts as a sponge that limits long range teleconnection of compression and extension.

However the Mosaic floe is looking very beat up after the storms and wind divergence on the two S1AB available for Nov 20th:

S1B   2019 11 20 T 06:02
S1B   2019 11 20 T 04:24

The AK rams the same piece of ice back and forth, maybe 70 times. The drift of the ice meanwhile carries the ship north. During those hours of ramming, the ship drifted so far   that it got back almost to its starting latitude to the north before we finally broke through.

Then the ship gets stuck a second time a few hours later and begins a second period of ramming. That’s when the captain decides to turn on the ship’s reserve engine. The Fedorov has four engines, but rarely uses all at once because this ramps up the ship’s fuel consumption. The fourth engine does the trick, helping the Fedorov break free again.
The captain really really did not want to get stuck for the winter in the ice. The ship is sitting unusually high in the water after the crew shifted scientific cargo onto the Polarstern plus 700 tons of diesel. The loss of weight left the Fedorov sitting so high in the water that the hull reinforcement area is now floating above the ice pack. The Fedorov is not a true icebreaker to begin with.

If the Fedorov were to get stuck, we would have two options: help from the Polarstern or hailing a nuclear-powered icebreaker such as the Yamal. "They are all busy and you don’t know when you will get one. And of course they are very, very expensive.”

The photo below shows how the 25 m wake sealed up almost immediately. The ship was in a compressive regime so ridging was almost immediate.

Arctic sea ice / Re: MOSAiC news
« on: November 20, 2019, 10:59:02 AM »
That's disturbing: not really seeing ice thickening at PS location on Cryo2Smos
Here the time series are using 26 rolling weekly averages according to the Cryosat2 freeboard  / Smos thinness merger of observational ice thickness. There is some thickening over this period in the 0.8 to 1.2 m range. Oddly the ice is thicker to the southeast of the Polarstern's position.

It's hard to say whether that is notably fast or slow relative to past years because there's no long term consistent data set using these satellites and the refined merger algorithm.

Mosaic, in their floe planning, expected to find 1.2m ice here back on October 5th. That is 17 days before the first data frame here and 43 days before the final frame (which has finally attained that thickness). So it's probably fair to say that 1.2 m thickness is quite late.


Technical note: after setting the rectangle bounding the Polarstern's drift over these dates (using locations in the S1AB database from sailwx), set the color picker in Gimp to radius 5 which will fill the bounding box and take the average. Then fill a small overlaid rectangle with this color and pick the whole image with the non-contiguous color selector, capturing the local selection on the palette bar after adding 0.05 m subdivisions from the grid tool. The desired product (ice thickness growth in the Polarstern's vicinity) is then the animation of the palette bar. This could be done on the original png file without the -45º rotation to 'Greenland down' or better still by utilizing the nicely done netCDF file in Panoply which includes error estimates etc and has the option of exporting and analyzing numeric values of the equal area projection pixels. However this won't change bottom-line talking points obtained from much faster image analysis.

Arctic sea ice / Re: MOSAiC news
« on: November 20, 2019, 12:02:57 AM »
There are quite a few impacts from the Polarstern having to run its generator engines all the time ... twitter scrapes from reporters on the AF and PS and a Science commentary piece 0

The bottom line is that it is hard to do large scale science safely and sustainably at such a remote pristine location without observer impacts. But what is the alternative: crappy models, more satellites lacking sufficient resolution, more buoys that break down in the first month, more imagery that cannot be interpreted, no real understanding of ocean-ice-atmosphere couplings or the physics behind Arctic amplification?

How do the Polarstern's impacts stack up relative to commercial shipping, say of anthracite coal being dug out of a Siberian national park today and shipped to China and India?
"The next day they told us not to throw meat over the side again to the polar bears ... The data cables would later become chew toys for the polar bears."

"I've wondered sometimes whether the #Polarstern and #AkademikFedorov could have been 1K cooler, a little less brightly lit? It felt like a lot of the heat was coming from the engines or the incinerator. But it was definitely super warm on board. Don't know about the details of the heating system."

"The Polarstern can't be shut down completely, because it must serve as the expedition's power plant, command center, and hotel—which some might call a five-star. There is a dining room that serves mouthwatering cakes every afternoon at tea time, a sauna, a swimming pool, a gym, a bar, and even small shops where you can buy sweets, tobacco, and alcohol. Although the ship is passively drifting with the ice, it will guzzle 15 tons of diesel fuel per day."

"Aboard the Polarstern at MOSAiC's start, I looked forward to seeing the North Star twinkle close to the top of the sky. But the ship floods the ice with light to enable the researchers to work safely and efficiently, creating a powerful glow that blots out the sky. I did not see a single star during my 2 weeks aboard."

The solid layer of blue ice in between snow on top and mushy rotten ice below, has rarely made it past the 50 cm gradation on the measuring stick. The new layer at the top is the firm ice that can support weight. The older rotten ice below is unreliable, although there is a question about whether a thicker layer of it helps or hinders refreezing during winter.

"For AWI biologist Allison Fong, the glow is a problem. She wants to better understand how microbial plant life survives in the Arctic winter, when there is no sunlight for months on end, but she can't study samples that have been exposed to artificial light. So, once a week she plans to drive a snowmobile to what she calls the "dark zone" hidden behind a fortress of small ridges of snow and ice some 500 meters from the ship. There, researchers will don red headlamps (red light doesn't affect most organisms) and collect ice cores that they will analyze back at the ship."

"Oceanographers, meanwhile, are dealing with the heat, turbulence, and wastewater produced by the Polarstern. "At the main site around the ship, there's sort of a dead zone" for collecting data, says Tim Stanton, an oceanographer at the Naval Postgraduate School in Monterey, California. To avoid the issue, he and others have deployed a handful of autonomous instruments, which sit on the ice or float in holes, far from the ship."

"The expedition's own noises, meanwhile, have forced atmospheric scientists to build special defenses. At a site called "Met City" a half-kilometer from the ship, a barrier nearly as tall as a person shelters an instrument that uses pulses of sound to measure the density of air, and thus gain insight into the structure of the atmosphere. The barrier is designed to deaden any artificial noise that might rumble across the seascape, such as blasts of the ship's horn and the whine of snowmobiles and nearby electronics"

"Then there is the Polarstern's sooty exhaust—a huge problem for the many MOSAiC scientists studying the Arctic's unusually clean air. The researchers want to better understand the sources and fates of aerosols—tiny particles suspended in the atmosphere—that contribute to the formation of small ice crystals within clouds. The number of crystals can determine whether a cloud acts as a blanket to warm Earth or an umbrella to shield it from solar radiation. But scientists aren't sure exactly where Arctic aerosols originate: Are they swept north from land, or are they formed by ocean organisms and sent skyward by breaking waves?"

"To gain some insight, Lauriane Quéléver, a chemist at the University of Helsinki and her colleagues will spend the next year pulling air samples through tubes mounted on a refashioned shipping container that serves as her lab. Instruments will parse the samples, analyzing and counting particles.

"Quéléver was astonished to find that the number of particles soared to 28,000 per cubic centimeter—a few thousand times greater than the typical Arctic level—when a second icebreaker arrived to swap instruments, personnel, and fuel. "I really hope that I'm going to get some very natural and pristine data," she says. "Otherwise I can just go home."

"A snowstorm or strong wind could help her and other scientists by clearing the air, but that rarely happened during my stay. When I visited CU atmospheric scientist Byron Blomquist, he was trying to collect air samples at a tower hanging off the ship's bow. But his instruments weren't sampling anything; they had automatically shut down after an alarm signaled that exhaust from the stern of the ship was enveloping the tower. Inside his container, pumps roared like vacuum cleaners as they pushed clean air out through his instruments, to prevent contamination by the smog."

"Less than 24 hours after the Polarstern settled in, the ship's emissions were smudging the ice. I noticed a black flake as large as my fingernail within the icy floe, removed a mitten and picked it up, rubbing the flake between my fingers. It turned to an oily smear. At the spot where the Polarstern had just spent the night. There hung a thick yellow and brown cloud. "Just think," one researcher said, "if we open the Arctic to shipping it's all going to look like that."

Arctic sea ice / Re: MOSAiC news
« on: November 19, 2019, 05:41:41 PM »
The image below locates the four SIMB3 surface mass balance buoys relative to the Polarstern on Nov 19th. This worked out because S1B took an image at 07:00 at which time all four buoys reported with an exactly matching timestamp. Not all buoys report all the time when they should (see attached databases of quadruples and triples).

The angles and lengths of the position arrows were provided by the side-angle-side tool ( given that 86º latitude is 10843.4 pixels from the pole and the 120º longitude is at a 75º angle on Sentinel images served by PolarView.

There is plenty of opportunity for confusion here but when it is all sorted out and their locations and properties plotted over time with variable values such as ice thickness interpolated within the triangles by kriging, it could be of interest. The Polarstern is measuring many of the same things and sending the data to shore with their high bandwidth internet but is not sharing it until 2023.

Ice movement as predicted above from the GFS-envisioned cyclone resulted in cracks, leads and ridging -- some of them repeats -- and considerable agitation of the whole Mosaic floe Ice Camp as seen on Sentinel despite pushing up against its resolution.

Arctic sea ice / Re: MOSAiC news
« on: November 19, 2019, 01:16:49 PM »
looks like a slowly failing GPS, no? First, you see a delay in updating and then a failure, pinpointing it to a location in the past. GPS accuracy drops quickly when you get down to just a few sats in view
The cadillacs among buoys, the four Mosaic-deployed SIMB3 from Dartmouth, have columns reporting the number of GPS satellites in range, how good an Iridium signal they are getting and how often the buoy calls again if it doesn't get through at first. (They also have pitch, roll and heading but those are not currently activated.)

On average, there are 8.7 GPS satellites within range and these buoys are reporting to phenomenal accuracy, eg 85.739648, 121.329032, which is rounded off to one less decimal by IABP in tracking the 100 buoys of Mosaic.

On land, GPS accuracy greatly benefits from a local tower that supplements satellites that might not have the greatest positions. The Polarstern is moving around too much (drift, jostle, internal wave recoil) for its mast to serve as a fixed local base (see motion below for Nov 18th and 19th).

I don't believe any of the buoys carry radar reflectors or emitters that would allow them to be positioned directly on Sentinel-1AB imagery which is about 41m at PolarView at 85-86º. So there is no way of independently checking reported accuracy even at that level.

source: SIMB3_387850.csv
#gpsSats   iridium_signal   iridium_retries
8.7   4.4   0 averaged over 259 entries

They did have a battery failure on 08 Nov 191/8/19 on the L1 at the remote atmospheric flux station. This turned out to be a defective fuel cell that was no longer charging the batteries. They could not get out there on the helicopter to replace it because of low clouds. This would not be applicable to buoy battery failure: no fuel cells. Ditto polar bears chewing on deployed cables: no cables. Ditto cracks propagating under the foot of the 'swingset' supporting downward looking radiation instruments: no supporting platform for buoys.

Part of their current polar bear problem may be attributable to Mosaic passengers on the Akademik Fedorov feeding them scraps of meat to take selfies.

The Polarstern, contrary to what we have been repeatedly told, has had phenomenal internet service (100 Mbps) the entire way including at its farthest north location, thanks to a new pair of satellites. The PS does not use much Iridium, too expensive for limited bandwidth.

Kepler provides 120 Mbps uplink to Arctic via satellite broadband
by Bevin Fletcher | Nov 8, 2019 11:32am

Toronto-based Kepler Communications said that it demonstrated data rates of 38 Mbps downlink and 120 Mbps uplink aboard the German icebreaker Polarstern to a 2.4m Ku-band Very Small Aperture Terminal (VSAT). The ship is home to the international MOSAiC expedition that involves hundreds of scientists and operations crews examining the effects of climate change on the Arctic.

Kepler is providing high-bandwidth satellite connectivity from low-Earth orbit (LEO) to help the team share large data files between the vessel and shore. Kepler’s satellites are placed around 575 km from Earth, so the closer location helps significantly reduce latency compared to geostationary (GEO) satellites that are 35,000 km from Earth.

“Our Global Data Service provides a cost-effective means to transfer large data volumes that will be gathered over the course of MOSAiC,” said Mina Mitry, CEO at Kepler, in statement. “Rather than only storing data locally and analyzing once physical storage can be sent back with supply vessels, we are giving scientists the ability to continuously transfer test and housekeeping data sets. When its two polar-orbiting satellites pass over the vessel, Kepler is providing 100-times higher data speeds than would otherwise be possible”

Markus Rex said “Kepler's new Global Data Service now enables us to send back bulk data, including key data files for monitoring the status of instruments together with experts at home. This will contribute to the success of MOSAiC."

How many users 100 Mbps internet line can support?  - Quora

I have 100 Mbps internet line at my work. this supports 130 wifi access points, 400 desktops, 5000 wifi users.  My network becomes limited when more are using. Is 100 Mbps line enough?
Is an Internet speed of 100Mbps considered fast? - Quora

Yes, 100 Mbps is considered fast. If you have this connection, it will take only 8 seconds to download a 100MB file at 100 Mbps. This means streaming Netflix, YouTube TV, Hulu, and any other streaming services.

Arctic sea ice / Re: MOSAiC news
« on: November 17, 2019, 08:48:15 PM »
drift speed nov14-16 ~11:30
A keeper! These are fascinating to watch. Below the whole trajectory of each buoy is shown (gimp 'stack average' + level contrast tools; often used to set minimal crop boundaries that don't miss anything).

The Polarstern will be in a very curious situation tomorrow at 15:00 utc: low wind locally but situated in an 84º turn in much higher wind stress which will result (?) in a giant lead opening along the blue band.

Arctic sea ice / Re: MOSAiC news
« on: November 17, 2019, 03:49:28 PM »
The Mosaic floe experienced only moderate ice dynamics during the record winds of Nov 16th (going by the only data of the 15th and 17th); we don't know what effect if any this had on equipment set up at the Ice Camp. Another WHOI buoy is gone; again we lack a causal attribution. Tomorrow will bring further challenging conditions with strong divergent winds.

One surprise initially was the thinness of the ice; neither satellites nor models prepared them for the fragility and thinness of the ice at the selected floe. Next, the mechanical strength of the ice (which cannot be measured remotely) was less than what they needed to plow logistics runways with the Piston Bullys -- that seems unthinkable even now.

Reporters onboard the AF noted a layer of dirty ice sloughing off the bottom of overturned floes; the trip leader spoke yesterday of porous immature ice. How should these be reported at Piomas, how do they count towards Cryosat2 freeboard or SMOS ice thinness? It doesn't work very well to idealize ice from far away because it has become quite heterogenous and very complex close up.

The third surprise has been atypical winds. There is no indication of when trans- or circumpolar winds will set up -- indeed the Fram has been running in reverse. That could change, but at this rate the Polarstern won't get very far on its expected drift. Even if it resumed, the ship won't get near the pole because an enormous impenetrable block of thick MYI ice has occupied that region for close to a year. What would move that out of the way?

It's not really clear how to compare ice dynamics year on year but leads, ridging and deformation may be worse than the expedition had anticipated, again because of seemingly deteriorating ice capacity for resisting wind stress.

I wonder how the guy wires are engineered on the two tall meteo towers. Presumably with very stout springs to take up relative ice motion, yet elasticity would leave the tower swaying in the strongest winds of the trip, 21m/s (75.6 km/hr or 47 mph) on Nov 16th. Recall early on the long crack with legs of the first tower a couple of meters away from doing the splits.

  86.1  122.2 19-11-16 20:00   16  300     -5.2
  86.1  122.1 19-11-16 19:00   16  290     -5.0   994.4
  86.1  122.0 19-11-16 18:00   19  260     -5.2   994.8
  86.1  121.8 19-11-16 17:00   19  260     -5.9   995.7
  86.2  121.6 19-11-16 16:00   20  260     -6.4   997.3
  86.2  121.5 19-11-16 15:00   21  250     -6.6   998.7
  86.2  121.3 19-11-16 14:00   20  250     -6.5  1000.2
  86.2  120.9 19-11-16 12:00   19  250     -6.7  1002.9
  86.2  120.8 19-11-16 11:00   18  250     -6.5  1003.6
  86.2  120.6 19-11-16 10:00   17  260     -6.3  1004.6
  86.2  120.4 19-11-16 09:00   17  260     -6.0  1005.1

The first animation below shows 2.6 km of en bloc motion mostly to the south in the 112 minutes between S1AB timestamps. That works out to 33.9 km/day.

Arctic sea ice / Re: MOSAiC news
« on: November 16, 2019, 12:35:46 PM »
A third Sentinel-1AB came in this morning for yesterday Nov 15th. It shows what appears to be a white pressure ridge appearing between 04:16 and 05:54 right along the axis of the Polarstern. To the west (right) a long dark lead has opened further and shifted towards the Mosaic floe.

Other instabilities can also be seen but we await today's S1AB for confirmation and further developments over the multi-day course of the cyclone which will be massively disruptive for the Mosaic floe and the equipment deployed on it. PolarView is not processing images so far today, perhaps because it is early on the weekend.

The ship added another two tenths of a longitude degree just in the last hour from gale force winds. They originally moored at 85.1, 133.8 on Oct 5th.

  86.2  120.6 19-11-16 10:00   17  260
  86.2  120.4 19-11-16 09:00   17  260

Arctic sea ice / Re: MOSAiC news
« on: November 16, 2019, 03:38:23 AM »
most accurate location of the PS you can get by putting a dot between the closest buoys
Good suggestion. Seemed like one of the buoys was actually fixed on the corner of the selected floe. Still, the floe is ~3000 m whereas 4 dp GPS is ~11 m.

The follow_mosaic PS location (to 2 decimal places) from an unknown time is added as a rough guide. Hopefully they will provide a time with the location at some point.
Questions should be directed to the AWI press officer. No contact information is provided however. Does that answer your question?

AWI press officer Sina Löschke will contribute to the Polarstern-blog from Bremerhaven, Germany. It is going to be her part to answer questions asked by readers and help whenever the expedition team needs a writing hand.

They are really moving. Purely zonal movement (east): 2.3 degree of longitude gained at fixed latitude 86.2 in the last 55 hours, with increasing gale force winds (14+ m/s), dropping pressure and rising temperatures:

  86.2  120.4 19-11-16 09:00   17  260     -6.0  1005.1
  86.2  120.3 19-11-16 08:00   17  260     -5.9  1004.9
  86.2  120.1 19-11-16 07:00   16  250     -6.3  1005.6
  86.2  120.0 19-11-16 06:00   15  240     -7.1  1006.2
  86.2  119.9 19-11-16 05:00   14  250     -7.8  1007.0
  86.2  119.7 19-11-16 04:00   12  240     -8.0  1007.3
  86.2  119.6 19-11-16 03:00   12  240     -7.3  1007.6
  86.2  119.5 19-11-16 02:00   12  250     -6.9  1008.0
  86.2  119.4 19-11-16 01:00   13  260     -6.9  1007.8
  86.2  119.3 19-11-16 00:00   13  250     -7.4  1008.2
  86.2  119.2 19-11-15 23:00   11  250     -8.1  1009.1
  86.2  119.1 19-11-15 22:00   10  250     -8.6  1009.2

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