MOSAiC news

[Tor Bejnar]

Obviously I was turned upside down, and maybe backwards, too.

Unicorn's GIF shows the trace of buoys moving over a period of time, with a 'running commentary' of the 'current' location's Lat-Long.  The lines of longitude get closer in the lower left corner, so "North" is in that direction.  From the perspective of (or watching from) the North Pole, something traveling eastward will be going from right to left, England to Russia, and westward will be going left to right, Russia towards England.  Traveling westward on the Eurasia side of the Earth the ("E") longitude numbers go down.

Clearly the buoys are going left to right so they are going westward, and as the longitudinal number are going down, the Kara Sea is off to the upper right of the map.  We can also determine that the latitude parallels are at 0.1º intervals and the longitudinal lines are at 1.0º intervals in this presentation.][/li]
[/list]

Got it (for now). [And no wonder my tectonics professor once claimed I must be a member of Flat Earth Society!]

[gandul]

Furious winds in seven days according to ECMWF

[psymmo7]

Here is an English transcript of the latest podcast from the MOSAIC website that is otherwise only available in German.
MOSAIC_AUDIOLOG BOOK12

 
Posted last Sunday (February 9. 2020) at 9:02 AM

Installment 12 – little snow, lots of new findings & “Gurki”

In this installment expedition leader Christian Haas reports lots of new findings that have been gathered in various scientific areas of the  MOSAIC expedition. One finding among them concerns the  formation and original provenance of the various ice types. In addition, during the last few days, various living organisms have been found in the ice. Haas describes the current status of the programme for  building a landing strip and gives an insight into various  kinds of methods and  measurement techniques.

Commentator: Arctic Drift – the Audio Logbook.

Christian Haas: Today is one of the coldest days that we have experienced till now, about minus 34 degrees. But luckily the wind is not particularly strong, only about force 3, so that the wind chill temperature is only about minus 45 degrees.
 
Commentator: Very low temperatures continue to prevail in the Arctic. Despite this the researchers on the MOSAIC expedition observe similar climate alterations to those that are currently occurring in Europe. There is also comparatively little snow in the Arctic. The expedition leader Christian Haas explains why this change has consequences for the ice and why the researchers welcome any change in the condition of the snow.

Christian Haas: During the last few days we even had Strong Wind event, with force 5 to force 6 winds. That isn’t exactly a storm but, of course, given the temperatures that we have here, it felt very, very cold. What was fantastic about it, was that the snow was redistributed: that means that it was blown away from some places and piled up in other places in deep drifts. These drifts were several decimeters deep and several meters wide and long. As a result, the landscape quite clearly changed in the course of the last few days. However, just as before, there is still very little snow: on average between 9 and 12 centimetres, which is really a lot less, about half the amount that we would expect from long term climate records. That leads to the ice being able to grow thicker than it would be able to if the snow was deeper. This follows from the fact that snow has very good insulating qualities and very low heat conductance. Therefore a thin snow covering has the effect that the ice can lose more heat and can grow faster as a result. If the snow were deeper, the ice would grow significantly more slowly.

Commentator: In the previous installment Christian Haas already told us at some length about the various kinds of instruments that were being placed in the pressure ridges. The first measurements and observations from the so-called Pressure Ridge Observatory are bringing results.

Christian Haas: Yes, a few weeks ago we set up the Pressure Ridge Observatory. That meant that we installed a large number of measuring instruments in a large pressure ridge to observe how the ice grows in  the cavities and under the thickest ice and how the pressure ridges affect turbulence under the ice. Currently we are making the first investigations with our ROV, our remote-controlled unmanned submarine that is equipped  with cameras and is able to take samples. And, just as we hoped,  we found fish, even now in winter, in the cavities - the openings in the ice keels that occur in the pressure ridges between the ice blocks. Small codfish that spend the winter hiding there. We also found the remains of algal mats that will start to grow as soon as the light returns and will serve as a food source for these fish.

Commentator: Intensive research is also going on in other scientific  fields. As the result of new ice movement and a split in the ice inside the camp new insights could be gained into ice formation.

Christian Haas: During the last few days we had a lead opening event and a strong ice deformation event even though the wind wasn’t particularly strong. However, because the ice is drifting continuously  there are always  local differences in drift speed and drift direction. That happened now in our vicinity about 2 kilometres south of the ship where a lead opened and an open water surface about 20 metres wide and several hundred metres long was exposed in a relatively short period of time. This event was very welcome, because it enabled us to investigate the processes that occur when water is exposed in this way, how quickly it loses heat and how ice forms on it  and how thick it gets. So, several teams rolled out on the day it occurred and set up their instruments around the lead and made measurements for hours and in some cases days. They measured the water vapour above the  lead and how this affected the warming of the air. They also measured how new ice came into being in the form of  so-called frost flowers and the chemical processes that accompany it.

Commentator: In addition, the results of the ice-core-drilling programme  have provided information about the place where the ice floe originally came from.

Christian Haas: Once a week we have an extensive ice core drilling programme where we drill ice cores from different types of ice to examine their chemical and biological properties. This week for the first time we found a core that was full of sediment from the sea floor. At the moment we have 4000 metres of ocean beneath us, so it’s a fairly natural question to ask how the sediment got into the ice. But this sediment is a clear indication, if not proof, that that our ice floe was formed in the very shallow water of the Siberian Shelf. The water there is only 20 metres deep and if the wind is strong while the ice is being formed sediment can get trapped in the ice. The sediment then drifts with the ice and we can use it as a reliable tracer for identifying the origin of our  floe.

Commentator:  Research doesn’t only take place on the ice.  Airborne  missions with helicopters help the crew work more effectively by allowing regular maintenance of automatic monitoring stations that are several kilometres distant from the ship.

Christian Haas: One aspect of our activities here that’s very successful, although we haven’t said much about it yet, is helicopter flights. It wasn’t clear how well it would be possible to fly in the dark. Flying in darkness is very challenging. We took a lot of effort to prepare the helicopters for it by providing them with the right equipment for night flying. The pilots and mechanics also had to undergo special training in order to be able to undertake night flights here.  Fortunately, the effort has paid off. Because we have had really very good weather conditions, we have been able to carry out a large number of flights. We not  only made survey flights with the laser scanner in the neighbourhood of the ship, but we also have a network of automatic monitoring stations in an area between 10 and 50 kilometres from the ship and we have been able to visit some of these locations and in some cases to land there. We installed lights on them that can switched on by remote control, to save battery power, and in this way we were able to visit them and carry out maintenance tasks such as cleaning them, replacing batteries or reactivating them. 

Christian Haas: Another important aspect of the helicopter flights is that we carry out measurements of the thickness and  surface roughness of the ice. We do that with a laser scanner that measures the height of the helicopter over the ice with a rotating laser beam so that we cover a roughly 300 metre wide track along the flight path. By flying criss-cross over the ice in a grid pattern we can use this track to map large areas and can get a good impression of the type of ice  and its surface properties.  The maps that we produce in this way are our most important tools for being able to navigate through the ice, because otherwise we have neither photographs nor high resolution satellite data. An important feature of these freeboard and roughness maps is that we have used them to identify possible locations for siting the landing strip that we are going to construct during the next few weeks.

We need this airstrip for the crew exchange between the third and fourth legs of the expedition, because we can only accomplish this  using larger aircraft that land on wheels.   

The  landing strip will have to be one and a half kilometres long and on ice that that is one metre thick. We have already begun to look for such possible sites and the laser scanner maps were an important tool for doing this, because we could distinguish between areas that were relatively flat and those that were uneven because of pressure ridges. Of course we like to construct the landing strip on a relatively flat area, because it would be very laborious to have to try and remove and flatten humps and pressure ridges with the Pisten Bullys. Unfortunately the recent deformation- and lead-opening- events have destroyed some of the potential sites so that we must now wait until the situation has stabilized and then make new survey flights to confirm whether the sites we identified earlier are still suitable before we can begin with the construction of the landing strip.

Commentator:  The laser data and the survey flights aren’t just important for the construction of the airstrip and the maintenance of the automatic monitoring stations. The movement of the ice can also be followed and analyzed using aerial data. 

Christian Haas: At the moment the  laser scanner data are the most important way for us to be able to observe the movement and deformation of the ice. For instance, to see exactly where leads open, where pressure ridges occur and where floes are colliding.  . During the lead-opening event that we already mentioned we were successfully able to survey the area with the laser scanner for several days and to follow how the ice opened up in some  places but was pushed together in others until leads were completely closed   and the last strong convergence event took place. A convergence event is one where ice floes collide and are pressed against each other with such force that they break up and pressure ridges are formed.

Commentator:  Whereas the helicopter pilots work at an altitude of several kilometres [Ed. sic – this is really what he said – I know it’s nonsense], the marine biologists are researching at a depth of several kilometres and made a rather remarkable discovery.

Christian Haas: A special highlight of each week are the net catches of the biologists, who lower their nets several thousand metres deep into the ocean from the side of the ship and catch a variety of living organisms including algae, zooplankton, small amphipods and jellyfish.   The shrimp-like amphipods are the most numerous.  But this week we had a rather special surprise, because we caught a ca. 10-centimetre-long animal that was a very bright red. We haven’t  identified it yet, because there are so many different species that not every  biologist can be expected to identify them all immediately, but because it looked like a cucumber we called it “Gurki” [Ed. “Gurki” is a diminutive form of the German word for cucumber  “Gurke”]

Commentator:  You will be able to find out whether a suitable site can be found for building the landing strip and what new findings there are from the various scientific investigations  in the next installment of Arctic-Drift the  Audio Logbook.

Commentator: AUDIO NOW.

[uniquorn]

drift speed increased yesterday, mostly west, a touch north, feb10-13. Data for P204(middle) stops earlier than the others at 00hrs

[blumenkraft]

A MOSAIC timelapse video showing the time between 05. and 21. Oktober 2019.

[A-Team]

MOSAIC_AUDI L G B K

Weird that they don't provide the date of the interview. A couple of weeks old?

Furious winds in seven days according to ECMWF

That gradient would give rise to a strong CCW cyclonic push towards the Fram. The last of the CW circulation right now is sending the Polarstern that way at a rapid clip. GFS foresees another 18 hours of this before the ship is becalmed and even moves back the other way. Bow radar has been uneventful so far during this run towards Svalbard.

The new SIC-Leads product gives a considerably more nuanced picture of ice pack motion than gridded OsiSaf. The lead images are difficult to adjust though 'equalize' the grayscale histogram gives a quick over-exposed look that doesn't overlook the small cracks.

[Jim Hunt]

Via Stefanie Arndt on Twitter:

https://twitter.com/arndt_st/status/1228021694012547074

Today’s afternoon we crossed 85N but couldn’t see the grid line due to heavy snow storms. However, the ridged second-year sea ice and its thick snow layer on top slows us consistently down.

[A-Team]

If so, the KD is still 3º of latitude away from the PS so 330 km plus some longitude; going will be slower in thicker ice and 15 m/s wind so maybe 1 km/hr or ~336 hrs which is 14 days, a lot later than planned. The KD was held up by Barents waves for a week or more. Leads cannot be assumed to stay open under conditions of compressive stress and pressure ridges are everywhere this year. Both ships will be in the pole hole of most satellites for weeks.

2h @CKatlein
Today we had a short power blackout in the Central Observatory of
MOSAiC, anyways all heaters are running and all systems are warm and
cozy again. Strong winds mostly kept us inside the vessel for the day.
 
Feb 12
While our supply icebreaker is still 200 miles away making 1-2 knots [2.8 km
hr], we get to experience the first twilight at 87.8° N. The  icedrift takes us
further north with a speed of 0.3 knots [0.6 km/hr]

The buoy array data is already being used, as it should, to study error in various sea ice motion products. Is TL is aware of or using the Sic-Leads product yet?

What we have discovered so far, which is something really new, is how salt from ice gets into snow. We knew that snow can be very salty, but now we have pictures of pockets of brine water in snow. This is important for how snow looks from space. It means that it looks more similar to sea ice.We might think that the ice is getting thicker where, in reality, there's just more (salty) snow on it. Then we have an error in estimates.

Please. This was known and published long ago, just google upward extrusion of brine pockets in maturing sea ice. Yes, this could improve satellite interpretation if only we knew where and how much.

[blumenkraft]

German biggest public media reported on MOSAIC.

Video at link.

Link >> https://www.tagesschau.de/ausland/polarstern-arktis-101.html

[A-Team]

Decent offering today at FoMo -- a top and bottom DEM of the Mosaic floe and surroundings on youtube which is converted to mp4 below (because the the youtube controller is so annoying in not looping and moving on to unwanted material ... take the spaces out of https://youtu.be   /KJf5XOkB5m0 to see).

Nothing is labelled; no distance or height scale or Ice Camp locations are shown. The Polarstern is the dark squiggle. This is not expert use of display software by any means but it is a good start and a breakthrough for FoMo in terms of an interesting post.

It would have been better simply to have done an annotated slide show of the best views rather than the clumsy fly-through. That could include a plan view grayscale of the two DEM data layers. Every frame is angled though. Two screenshots are shown below.

Question is, if the floe is in hydrostatic equilibrium shouldn't the bottom be predictable from the top (apart from density altering inclusions). That is, with a free-floating ice berg, 10% is above the water and 90% below. Here though the overall contiguity of the ice pack and resultant mechanical strength over-ride the buoyant tendencies of individual pieces.

[uniquorn]

Now, where to put that airstrip?
Here showing most Mosaic IABP buoys that report on the hour. Some report only on the half hour. Inset is nullschool wind isobaric at 1000hpa. Frames are repeated twice to match the hourly buoys. Projection is done using PlotSvalbard in R. Delaunay triangulation in Octave.
 

[A-Team]

Given the lack of scales, it is very difficult to make out what is what on the surface and undersides of the Mosaic floe from the youtube provided. In particular, the top priority area is really in front of the bow radar, covered every six hours since 01 Nov 19 but not yet interpreted. Met City etc aren't located; the sensor area is already illuminated by nautical twilight.

This would have been better done as side by side hill-shaded digital elevation models or as user-controlled joy stick as done for surface and basement rocks of some Greenland glaciers. One issue is the very different scales -- the surface heights being about a ninth of underwater keel depths. This alone is a good reason for just providing unadorned grayscale DEMs and letting users take it from there. The attached mp4 reverses colors as the blue is harder to follow than its orange.

The Polarstern, after a prolonged episode of high winds and rapid motion, is now becalmed at 88.0 80.3 at noon on 20-02-14 UTC. The passage across the outer arm of the Chukchi anti-cyclone at about midnight on Feb 14th may have resulted in shearing but that won't show until tomorrow. The bow radar is swinging wildly suggesting that one or more sea ice anchors have come undone in the prolonged 14-15 m/s winds.

Looking ahead to the extreme low pressure in FJL, that is not foreseen to result in extreme winds at the Polarstern's position. A sharp gradient to nearby high pressure is needed for strong winds.

showing most Mosaic IABP buoys

The overlay of 14 days of Sic_Leads to Feb 13th  shows the sea ice motion over the buoy triangulation...

[Jim Hunt]

In related news:

https://www.awi.de/en/about-us/service/press/press-release/call-for-tender-procedure-for-the-construction-of-a-successor-to-the-icebreaker-polarstern-has-been.html

The Federal Ministry of Education and Research (BMBF) today cancelled the Europe-wide call for tenders for the procurement of a new polar research vessel, Polarstern II, for legal reasons. In times of unresolved climate issues, the research mission of the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI) can only be fulfilled in the long term with a modern icebreaker. This understanding is also shared by the BMBF. Therefore, we will work intensively with the BMBF to find a solution, which also aims to set up a new award procedure. Among other things, the experiences from the current MOSAiC expedition will be incorporated into the planning process in order to develop an icebreaker that is as future-proof, powerful and sustainable as possible.

[A-Team]

cancelled procurement of a new polar research vessel, Polarstern II  for legal reasons

Perhaps the language was such that only a German firm could win the contract?

@CKatlein 5h  [20-02-14 13:00 UTC]

Exchange between #MOSAiC leg 2 and 3 was planned for tomorrow (15 Feb).
However the supply icebreaker is still 168 miles away [270 km] and in the last
hour moved less than 1000m. #naturewins

In other words, the KD is practically stuck with 270 km of much thicker ice to cross (though pressure ridges may be the problem this year, not the thermodynamically thickened). At this rate, the KD is 270 hours away (15.4 days) except that's optimistic since the Polarstern drifted 20.4 km away in the last 29 hours.

S1AB today should show the KD's track, except there may not be one if the previous track has sealed over and they are not making a new one. We know more or less where to look from S Arnd's post the other day about crossing 85ºN. Believe that's it's track below 85.1461 80.6331 at 05:47 on 14 Feb 2020. The Polarstern was at 88.0 80.9 at that hour.

If abrupt wind stress gradients matter for disruption of the ice pack, the PS bow radar tomorrow could be interesting in terms of shear.

Technical note: despite the PS not disclosing its position and no S1AB coverage, when there is a break from in the latitude decimal, it means the ship crossed 87.9000 and 88.0000 parallels, though in the latter instance, the PS didn't transmit its weather for 3 hours.

88.0   84.8 20-02-13 08:00   13  110    -28.9
87.9   85.3 20-02-13 05:00   13  110    -28.8

87.9   88.3 20-02-12 03:00    9  110    -31.9
87.8   88.4 20-02-12 02:00    9  110    -31.7

[uniquorn]

.

[Jim Hunt]

I haven't got time to make a video. Storm Dennis has arrived!

However I believe this currently reveals KD top left and PS bottom right:

https://rammb-slider.cira.colostate.edu/?sat=jpss&z=5&im=12&ts=1&st=0&et=0&speed=130&motion=loop&map=1&lat=1&opacity%5B0%5D=1&hidden%5B0%5D=0&pause=0&slider=-1&hide_controls=0&mouse_draw=0&follow_feature=0&follow_hide=0&s=rammb-slider&sec=northern_hemisphere&p%5B0%5D=day_night_band&x=15118.7998046875&y=15407.1005859375

[A-Team]

KD yellow circle, PS magenta circle

Looks about right. The KD may be aiming east of the PS in order to catch the transpolar drift (instead of fighting it). If the ships are drifting in opposite directions, the KD could struggle all day with the ice but end up farther away from the Polarstern than when it started.

[psymmo7]

If anyone is good in Danish - then Rasmus Tonboe is reporting from the Kapitan Dranitsyn at this site.
https://www.dmi.dk/?id=1255
Apparently  the ship passed through a snowstorm last Sunday (9th Feb) picture attached

[A-Team]

If anyone is good in Danish

So bizarre: providing routine blog text only as a png image. It just takes a second though to run it through free online Danish OCR (https://convertio.co/ocr/danish/) and then google-translate.

"Tomorrow there is a general clean-up and a single trip out on the ice to drill cores in the EMIRAD measurement area near the ship.

The other morning, when I was with the chemistry team at the "dark site" and taking samples, I saw a slight light to the south on the horizon. "Dark site" is so far from the ship that there is no light pollution, and therefore you can see even the faintest shades of light.

I took a picture of the horizon with my mobile camera, but when I got home and looked at the picture, it looked like I had turned off the phone. It was completely black and there was no hint of light. The sun is still far below the horizon, and it's not even twilight, but we've got the moon back and it gives some light when we're out.

Last weekend we had a strong low pressure with strong winds and temperature fluctuations. Saturday morning started with blizzard and 20 m / s and temperature of about -12 degrees.
During the day the wind subsided while the temperature dropped to -38 degrees towards evening.

The captain had forbidden going out on the ice in the morning, and I spent most of the day in the "cold lab" working with ice samples from our measuring range. "Cold lab" is a container on the back deck which is designed for laboratory. The laboratory has -15 degrees, so you can work with your snow and ice samples without melting. Compared to the outside temperature, it feels warm in the lab.

I am working on mapping the composition of the ice cream; the size and distribution of air bubbles and the distribution of salt in the ice. It affects what we measure with our satellite instruments, which is why it is important to be able to develop computer models.

There is still some wind, but the temperature was only -15 degrees when we were out digging our instruments out of the drivers."

R Tonboe has an English language twitter site but has not posted anything since 27 Nov 19. His interests with Mosaics are remote sensing, ice team and ESA radiometer. His 2019-20 papers:

Version 2 of the EUMETSAT OSI SAF and ESA CCI sea-ice concentration climate data records

In situ observed relationships between snow and ice surface skin temperatures and 2 m air temperatures in the Arctic

Estimating the snow depth, the snow–ice interface temperature, and the effective temperature of Arctic sea ice using Advanced Microwave Scanning

Will low primary production rates in the Amundsen Basin (Arctic Ocean) remain low in a future ice-free setting, and what governs this production?

Estimating sea ice parameters

Satellite passive microwave sea-ice concentration data set intercomparison: closed ice and ship-based observations

SMOS-HR: A high resolution L-band passive radiometer for Earth science and applications

The Kapitan Dranitsyn is not making much forward motion today. It is visible on the animation up to about 06:00 on Feb 16th. It is a challenge to meet up not only because of the ice but because the  two ships experience different (and changing) drift trajectories.

[colding]

So bizarre: providing routine blog text only as a png image. It just takes a second though to run it through free online Danish OCR (https://convertio.co/ocr/danish/) and then google-translate.

I've sent a short mail to DMI asking them to please publish the diary in English or at least as text only.

[A-Team]

publish diary as text

The concept: a hardy explorer pecking out a diary on a courier typewriter like in days of olde? Nansen had electric lights already on the Fram. The PS has two bars, a sauna and a swimming pool.

Meanwhile, the Kapitan Dranitsyn has advanced 34.7 km in the last 21 hours. Not all of it was in the direction of the Polarstern,  only about 14 km. The zigzag route yields an effective linear approach speed of 16 km/day which means 18 more days till docking with the Polarstern, say early March. And delays will be similar or worse for those returning to Tromsø.

Because the ice is drifting, getting to the Polarstern is like crossing a river: start quite a ways upstream, not right across. That's not an easy calculation though, a lot of imponderables:

If the KD is moving at x(t) m/s at bearing a(t) under steam but the ice around it is drifting y(t) m/s at bearing b(t), how many days does it take, given the GFS wind forecast f(t) to reach the PS which is not under steam but has been drifting at z(t) m/s at bearing c(t)? Nansen's rule of thumb was the icepack drifts at 2% of the wind speed at an angle of 20-40% to it from the Coriolis effect.

The KD is probably not doing the math here but instead just seeking a pragmatic route that avoids thickest pressure ridges. Those could be more prevalent than in the past because ice pack motion has gotten measurably worse.

Meanwhile, the current Polarstern scientific team is still deploying equipment 4.5 months after mooring. These instruments have to installed far from the lights of the ship which would disturb what they are trying to measure. The location has not been disclosed. The acronyms ITBOB, ENVI-POPE and AZFP stand for:

-- Ice-tethered bio-optical properties and radiation
-- Platform  cluster for Optical,  Physical and Ecological sensors
-- Acoustic Zooplankton Fish Profiler

https://www.sciencedirect.com/science/article/pii/S2405896316320742

[A-Team]

The KD has been making better progress north, aided by ice pack drift. A long section of track is outlined in yellow in the gif below, needs click. Meanwhile the Polarstern is drifting west. The extreme low pressure system coming to the Barents will have little effect on winds which will remain sub-gale force.

[uniquorn]

New Snowbuoy 2020S99. A touch south east of p207.

[A-Team]

New snowbuoy 2020S99. A touch south east of p207.

"This buoy replaces 2019S92, which was crashed during a ridging event." Does that mean inactive 82, 83, 85, 88-91, 95, 97, 98 met similar fates?

On the inactive snowbuoy setting, they only show 2019S95 which was operative for 6 days at the M7 site co-deployed with 2019O7 and 2019T71:

2019S79   86.00   119.17   07.10.19-28.11.19 (52)    
2019S80   85.96   122.71   08.10.19-02.11.19 (26)
2019S92   86.04   117.73   07.10.19-26.11.19 (50)
2019S95   84.62   133.29   11.10.19-17.10.19 (6)

2019S81   88.25   85.17   07.10.19
2019S84   86.49   109.32   07.10.19
2019S86   88.16   69.44   10.10.19       
2019S87   88.40   81.98   09.10.19       
2019S93   88.04   80.39   07.10.19       
2019S94   88.20   74.00   10.10.19    
2019S96   88.08   77.50   29.10.19
2020S99   87.96   75.37   10.02.20

"2019S92 was at the L1 site, co-deployed with 2019R9, 2019W4, 2019I1, 2019F1, 2019T67, one ASFS, one MARC" so we could determine from S92 where the mysterious L1 site is relative to the Polarstern.

Ditto 2019S93 which was co-deployed at L2 with 2019R8, 2019W2, 2019I2, 2019T63, 2019T65, 2019F2, ASFS, MARC

The ASFS (Shure's sonic atmo sled, see above) that "got eaten by a pressure ridge" was at L3. They got that unburied on 15 Feb 2020 according to FoMo but it is not yet functioning. At the L1-3 sites, they are trying to do air, ice, ocean in coordination so it hurts to have a major component down.

2019S94 was co-deployed at L3 with 2019M30, 2019W3, 2019T70, 2019I3, 2019F3, ASFS, UNMANNED-ICE-PRIC

Today at 03:00 the L2 site was at lat lon 88.0420  80.3936 whereas the PS was at 88.1  77.9 per awiMET which is 11.4 km away. The PS can be located slightly better using RAMMB (at 03:27 at 88.074  77.85) which is 10.21 km away but the last known precise location for the PS from S1AB was on 2020 02 02 at 05:46 87.3446   95.4993.

Given a similar calculation for L1 and L3, the three lines could be visualized on GoogEarth where they would not quite radiate out consistently from the PS location because of error but be very close to displaying the overall configuration. Following the L123 triangle over time would show rotation.

Although difficult to see on Sentinel, the KD is still 263 km away from the Polarstern but winds remain moderate (despite the nearby 953 hPa low) and ice pack motion is favorable for trajectory convergence. It's not unusual for ships and explorers get caught on a treadmill where despite a whole day's effort, they make no progress towards their goal. That's not happening here (to the extent the KD can make headway).

[paolo]

Earthquake M 5.2 - North of Svalbard
•   2020-02-18 07:29:39 (UTC)
•   85.740°N 22.699°E
•   10.0 km depth

[uniquorn]

Hopefully PS and KD are ok in deep water.

Given a similar calculation for L1 and L3

Tbuoy gps appear to be struggling somewhat. Wbuoys didn't last long. I and Fbuoys??
An equal combination of R8(L2), R9(L1) and S94(L3) gives the estimated PS location below. It looks a bit too far west. I'll run it back to known location points, it could work.

added jan5-15 as a test. Red dots are S1 calculated PS locations (timing not checked)

[A-Team]

Earthquake M 5.2 - North of Svalbard  2020-02-18   85.740°N 22.699°

This site is called the Sparsely Magmatic Zone (SMZ) of the Gakkel Ridge. Only one large volcanic center at 19° E has been noted over the entire extent of this segment.

JD calculated years ago on another forum that even when the volcano field erupted a bit east in the Eastern Volcanic Zone (EVZ), the amount of heat released was utterly inconsequential as far as melting Arctic Ocean ice or even for turbulent disruption of the salinity and thermal layers.

Did the 1999 earthquake swarm on Gakkel Ridge open a volcanic conduit?https://link.springer.com/article/10.1007/s10950-009-9179-6

In 1999, a seismic swarm of 237 teleseismically recorded events marked a submarine eruption along the Arctic Gakkel Ridge, later on also analyzed by sonar, bathymetric, hydrothermal, and local seismic studies... We find event locations scattered around 85°35′ N and 85° E at the southern rift wall and inside the rift valley of the Gakkel Ridge.

https://sci-hub.se/https://doi.org/10.1016/j.jog.2015.11.002 seismic station on FJL

https://sci-hub.se/https://doi.org/10.1016/j.polar.2014.10.001 35 year earthquake record

[A-Team]

FoMo released a new map of the area around the ship today! It is reproduced below as their enlarged view 1696 x 1620 pixels (at which text is readable) so needs a click and large device screen. A dozen or two acronyms are not explained in the Legend.

No map scale is provided; however the PS measures 118 m, indicating the large squares are 500 m and the dotted smaller squares 100m.

There is no labelled lat lon graticule and north is not indicated as it varies with drift but is more or less at the top, going by recent S1AB with graticules. A near-vertical line of the grid system runs through something called nav(0,0) but the horizontal lines have no special relationship to nav(0,0). The grid appears set to be parallel / perpendicular to the Polarstern's bow-stern axis, which makes some sense the ice camp is accessed off the starboard side.

The map only includes 1000 pixels of the area mapped daily by the ice radar which points out 1310 pixels (2.5 km) from the bridge. Oddly an overlay of the bow radar does not have any features matching the runway.

The bluish-white base map appears to be heights determined by the laser altimeter patched together from helicopter overflights on different days. No scale (z axis) is provided but generally white indicates pressure ridges and surface ice jumbles. Some of these represent summer floe-building collisions and were already present at mooring back on Oct 4th; others are newer (not indicated despite symbols for leads and ridges in the legend).

Starting at the top left, the text overlays can be assigned png mouse-over x,y pixel coordinates and analyzed in a sortable database, sampler below and full csv attached.

The Remote Sensing site (RS on the map) acknowledged the loss of three instruments yesterday: KuKa, X-Scat and Elbara (a passive L-band 1.4 GHz smos-type radiometer). No spare parts are available on board, none are coming with the KD and implausibly by air on leg 4. (L Kaleschke's research involves Elbara; he is on the KD.)

No explanation has been given for three devices all failing (unsuitable connectors? power supply is from the PS). UWBRAD, an ultra-wideband 0.5–2GHz radiometer, is still working as is the SSMI radiometer (19, 37, 89 GHz) and the GNSS-R.

This is a major loss for remote sensing improvement. No summary of total trip up-time been provided. J Stroeve wrote about problems back on Dec 1st, tweeting "Our radar is once again connected to the power while some instruments are still awaiting connection."

The map term GNSS occurs in three places. Probably GNSS-R was intended for reflected GNSS signals from snow/ice  which relate to ice thickness, altimetry and scatterometry of various types of satellite GPS-like signals.

https://epic.awi.de/id/eprint/50082/1/Expeditionsprogramm_PS122_leg2.pdf pg 87

Technical inspection of the new map establish it as a disturbingly amateurish product given its importance to operation planning and communications. Surely a shipload of scientists on a $150,000,000 budget stuck on board for days at a time by weather could muster up someone onboard or ashore with basic graphics skills (such as editable layer compositing). They will need a journal-quality map later ... and this is not it.

[uniquorn]

PS continued drifting north west. With the current cyclone, perhaps the two teams will share the most northerly location in a few days time.
updated below

[A-Team]

@CKatlein 6h Finally our resupply icebreaker is so much delayed, that Polarstern has reopened the bar! #MOSAiC

That storm coming up from the Caribbean has morphed into a strong cyclone that is now predicted to drift across the FJL line into the Arctic basin and past close to the Polarstern as it gradually dissipates, even as a new system comes in.

This will significantly complicate the rendezvous of the KD and Polarstern as their drifts will be affected differently. At these stronger wind stress gradients, the Ice Camp experimental area may have more problems with pressure ridges, opening leads and shear lines. So far ice motion has been limited to shears on the periphery. (Much higher winds occurred earlier on the drift: 20-02-01 20 m/s.)

The KD appears to be at 86.4771  89.8613 at 05:55 this morning though the track on Sentinel is ambiguous and Rammb is cloudy. If so, with the Polarstern at 88.25  74.4 and moving rapidly west, the two ships are separated by 211 km with a rendezvous maybe ten days off.

Temperatures have already risen by 15º and winds are quite a bit stronger than GFS had foreseen yesterday (or rather, the discrepancy between observed shipboard winds and GFS winds has widened). These temperatures per se are still too cold and transient to melt ice but the Kara/Barents/FJL ice will be greatly dispersed and disrupted.

   Lat  Long  YY-MM-DD  UTC     Wind       T(C)   hPa      GFS
  88.3   71.6 20-02-19 19:00   14  110    -13.1  978.3
  88.3   71.8 20-02-19 18:00   13  110    -13.3  978.8  10.5  120
  88.3   72.0 20-02-19 17:00   13  100    -13.6  979.1
  88.3   72.2 20-02-19 16:00   13  100    -14.0  979.5
  88.3   72.4 20-02-19 15:00   14  100    -14.3  979.9  11.0  115
  88.3   72.6 20-02-19 14:00   14  100    -14.6  980.3
  88.3   72.8 20-02-19 13:00   14  100    -14.7  980.6
  88.3   73.0 20-02-19 12:00   15  110    -14.8  980.8  12.7  115
  88.2   73.5 20-02-19 10:00   16  110    -14.3  981.4
  88.2   73.7 20-02-19 09:00   16  110    -13.6  981.5  12.8  115
  88.2   73.9 20-02-19 08:00   16  110    -13.2  982.1
  88.2   74.4 20-02-19 06:00   16  100    -12.7  982.5  13.9  115
  88.2   74.6 20-02-19 05:00   14  110    -12.9  983.4
  88.2   74.8 20-02-19 04:00   15  100    -13.4  983.7
  88.2   75.0 20-02-19 03:00   14  100    -13.7  984.6  12.1  100
  88.2   75.2 20-02-19 02:00   12  100    -13.9  985.2
  88.2   75.4 20-02-19 01:00   12  110    -13.9  985.6
  88.2   75.5 20-02-19 00:00   12  110    -13.6  986.0  10.1  125 most recent bow radar
  88.2   75.7 20-02-18 23:00   12  110    -12.9  986.3
  88.2   75.8 20-02-18 22:00   12  110    -13.2  986.5
  88.2   75.9 20-02-18 21:00   12  110    -13.4  986.7  10.3  115
  88.2   76.1 20-02-18 20:00   13  110    -13.4  986.7
  88.1   76.3 20-02-18 18:00   11  110    -14.3  986.9  10.1  115
  88.1   76.4 20-02-18 17:00   11  110    -15.4  987.2

[uniquorn]

Longitude dropping quickly as they continued north west yesterday.
updated below

[A-Team]

The Polarstern continues to drift rapidly north and west in high winds and driving snow associated with the warm wet cyclone moving slowly across the Arctic Basin from FJL. Staff is confined to the ship under these conditions which will persist for the next couple of days.

FoMo is reporting hazardous ice motion (creating snow-covered open water) but these leads are not yet showing on the PS bow radar. These will worsen because of the ice pack cannot follow the sharp curvature of the wind. Meanwhile on-ice instruments may need repair but cannot be serviced. On Feb 13th, the whole Central Observatory experienced a brief (unexplained) power blackout.

The KD is not showing on RAMMB because of cloud cover though the PS has been visible at times. Its location is not known because it does not post a weather report nor turn on its beacon. It is seeing similar weather to the PS and drifting along the same streamline. It may be possible to pick up on its Sentinel track from yesterday and find a current position.

Uniq provides the AMSR2 view on the freeze forum today #929:

The Polarstern continues to fly north and west under the cyclone. It is visible on RAMMB but the KD is not (nor does it provide its location).

Iain provides a WorldView visible animation of the CAA Perry ice bridge and compared to earlier years #925. That area has been monitored with an observatory of moorings for years.



The Barrow Strait Real Time Observatory: Under-ice Monitoring in the Canadian High Arctic
https://dl.acm.org/doi/10.1145/3148675.3152195 Nov 2017

These can also be visualized using the new SIC lead product from L Kaleschke, the last 60 days below. Unfortunately it does not going any farther west than shown. He is on the KD and seemingly unreachable.

[johnm33]

I find it particularly interesting that the leads and apparent wave structures move through the ice rather than with it, the PS' slow progress is the best indication of this I've seen. The emergent double features indicates an acceleration?

[A-Team]

leads and apparent wave structures move through the ice rather than with it

OsiSaf gives another view, more along the lines of wind-induced. Ascat over 81 days gives yet another perspective, of smooth flow.

The Polarstern will continue to move rapidly poleward and towards the Fram this week under the influence of cyclones passing over Greenland. If it does reach the pole, it may be stuck in that area for quite a while as that ice is off the transpolar drift in most years.

The ship is currently at record lat lon of 88.5 66.2 on 20-02-21 at 15:00 with warm persistent winds in the 13 m/s range which are borderline for outdoor work. The Kapitan Dranitsyn is 184.1 km (still a week away) as of noon today at 87.06 89.1, with progress reported slowed by the same storm. Neither ship will be visible on Sentinel over the next weeks though the wavy KD track is available at 04:50 this morning.

[uniquorn]

drift as noted above - see below

[uniquorn]

Verifying those large low concentration leads north of Greenland.
https://go.nasa.gov/2PvaB6T, feb21-22, Kaleschke sic leads inset. ctr

drift update. Below 45E they start drifting away from the pole. At the recent rate of ~3degrees/day that's maybe 5-6days away. KD might just make it.

[A-Team]

A steady tailwind bearing for 56 hours produced the incredible straight drift of the proxy buoys for the Polarstern seen in Uniq's #635 animation above. Chasing down the stats, the ice pack moved at 2.1% the speed of the 1000 hPa wind (confirming what 'they' have been saying for years).

This wouldn't be possible without unresisting exits for the ice such as Fram, Nares and SV-FJL gap because the ice pack cannot compress further against land. (Over-rafting pressure ridges provide too much pushback when the ice is thick.)

Data from awiMet should someone wish to refine the estimate by providing the std error:
wind m/s,bearing 12,110 12,110 12,110 11,110 11,110 12,110 12,120 13,110 12,110 12,110 11,110 12,100 12,100 12,110 13,110 14,110 14,110 13,110 13,100 13,100 14,100 14,100 14,100 15,110 16,110 16,110 16,110 16,110 16,100 14,110 15,100 14,100 12,100 12,110 12,110 12,110 12,110 12,110 13,110 11,110 11,110 9,110 10,110 10,100 10,110 11,100 10,90 9,90 9,90 8,90 9,90 8,90 

Both ImageJ and Gimp offer image enhancement by convolution kernels, both canned (Process -> shadows) and roll-your-own DIY. They have a very beneficial effect on the Kaleschke SIC lead product (and downstream overlays), enhancing lead visualization without blowing up the grayish white interstitial background like linear contrast change, local adaptive (clahe) or histogram equalization.

To the extend the leads are anisotropic -- and they will be from TPD or during passage of a cyclone -- the choice of convolution 'direction' matters. The mp4 below used 'northeast'. No rocket science is involved automating out from the canned convolution to converge onto a quasi-optimal element of GL(3,R) wrt to frame average and that extends to a rolling window of GFS winds.

While some people are twittering from the KD, others are not. Kaleschke did not have time to describe productions methods but it is clear from Uniq's remarkable match-up in#635 of microwave leads with WorldView infrared that SIC leads just takes a longer radar wavelength approach to heat escaping through the ice. The images can't help but agree.

In other words, low Ghz radar meets up with long wavelength infrared in the electromagnetic spectrum, the difference being WV infrared is at the mercy of cloud cover while low Ghz sees through them better (in winter). It benefits from processing to darken warmer regions (ie the leads). We don't know what processing steps were taken but clearly they can be improved for the purpose of overlays on GFS weather,  Ascat scatterometry etc etc which don't see the leads but have other, complementary strengths.

The tripods have proven a planning and operational fiasco. Just drill through the ice, freeze in some 5 m fiberglass poles with no guy wires, hang slack electric and data cables off them, your pressure ridge problems are over. And where did Mosaic get their no-go snowmobiles, out of a museum?

[uniquorn]

Thanks for those calculations. Here looking a little closer at the direction change to close to due west. Drift speed picking up again after the turn.
edit: updated, p207 grazing along the 88.6 line. Wind fairly constant.

[blumenkraft]

From the Polarstern-Blog

A successful ROV day

Link >> https://blogs.helmholtz.de/polarstern/en/2020/02/a-successful-rov-day/

[A-Team]

Although RAMMB has been showing the Kapitan Dranitsin closing in on the rapidly drifting Polarstern by the end of February, visibility from above is often obscured by clouds. It now appears that the KD is stuck in the thicker colder ice nearer the pole (as predicted above), still 100 km from the PS.

That is not an impossible distance for helicopter exchange of leg2/leg3 scientists and for transfer of experimental matériel but flight conditions are currently far from acceptable: gale-force 15m/s at 15:00 at 88.6 53.3 on Feb 24th. The KD was able to un-stick itself returning last time by shifting fuel from port to starboard tanks.

Follow-Mosaic speaks of multiple Twin Otter landings maybe being feasible on unprepared airstrips at both the KD and PS sites but that potentially doubles down on catastrophic risks without resolving the underlying issues.

The KD was supposed to bring extra fuel to the PS but now it seems if the KD does that, it won't have enough fuel of its own to get back to Tromsø, so a relief icebreaker for the relief icebreaker has to be considered.

Both ships are provisioned for up to a year so scientific work can continue at least at the PS. Despite conditions, the ROV has been able to log over 80 km of undersea ice mapping, even photographing that ringed seal investigating another misaligned thermistor cable. (Because they couldn't find a suitable 'thermodynamic' floe back in October, the PS moored on a pressure ridge jumble.)

Something has gone wrong at the ice radar archive. The heavy white scale bar is now lying over the image, causing loss of data. This bar should never have been placed here as ample black space was available in the masked region. It has never been clear whether this represented compass NS; better had digital lat, lon and ship axis bearing been placed above a km length scale bar. All that was provided on the device screen but cropped out. The ice pack (and the embedded PS) may be rotating more than anticipated.

Meanwhile the PS is moving west at an extraordinary rate of 0.4 ºlon/hr, bringing it into an extreme fracturing zone caused by cyclones barreling in through the SV-FJL gap instead of the usual winter path up the Fram. This pattern has greatly enlarged the Fram intake funnel out beyond the north pole (as noted here last week), with even the Lincoln Sea ice being drawn in. The Polarstern will be located just to the right of the pole hole (ie 50º at nullschool) later this afternoon.

[blumenkraft]

From the MOSAIC web-app:

Severe ice conditions in the Arctic currently delay the approach of
the Russian supply vessel Kapitan Dranitsyn towards the
Polarstern. Ideally, the vessel should reach Polarstern in the coming
days, but weather and ice conditions are still difficult. That dense
winter pack ice could delay the exchange phases between legs two
and three was part of the expedition planning from the beginning
and is thus not a surprising situation. Already in the planning phase
we took into account that the supply vessel may not be able to
reach Polarstern during the polar night. In such case it was planned
to exchange personnel and cargo via the on-board helicopters of
Polarstern. However, there are no suitable flight weather conditions
at the moment. In parallel the feasibility of operating two polar Twir
Otter aircraft is evaluated at the moment to ensure a faster
exchange. Under certain conditions a Twin Otter is able to land on
unprepared sea ice next to Kapitan Dranitsyn, but needs a safe
landing strip at Polarstern and also flight weather conditions.
Additionally, the possibility of support by another icebreaker is
evaluated, that could steam towards Kapitan Dranitsyn to provide
additional fuel on the way back when the same ice conditions will
be encountered. In the meantime, scientists and crew onboard both
vessels remain patient and wait for easing conditions in the next
days. But most importantly: safety is not affected and there are
enough supplies on both ships. The scientific activities continue on
board Polarstern and are not affected by the situation. The picture
of the day shows that the atmosphere on board Dranitsyn is good
despite the delay. It is not clear yet when the exchange can be
completely finished and which additional delays will arise for the
future exchanges of scientific teams and the ship's crew. The
options are well prepared and also discussed with the participants
of leg 4 of the expedition. The necessary patience and flexibility
needed by everyone to plan expeditions in unknown territory and
under unknown weather conditions could not be described better as
summed up by Berthold Brecht: "Ay, make yourself a plan, they need
you at the top, then make yourself a second plan, then let the whole
thing drop."

[A-Team]

The KD has gotten itself stuck and unstuck multiple times before. The question here is if they could, would they continue north to the Polarstern without enough fuel for the return trip in thick ice? They could perfectly well moor alongside the Polarstern and await the melt season.

This would be better for the scientific program. The KD itself does not carry the Pistenbullys necessary to plow an 1800 m wheeled airplane runway but an opportunity might arise for staff and crew exchanges.

If the KD cannot get itself unstuck, it might take several months to lease a heavy duty nuclear icebreaker that could escort the KD to the Polarstern or more likely back home. Most capable icebreakers are contracted out months or even years in advance; the KD is not in an emergency situation.

In the last few years the Kapitan Dranitsyn has been modified as a passenger vessel, with 49 outside cabins for 100 passengers. Public accommodation includes spacious lounges, bars, a heated swimming pool, gym, sauna, library and a small hospital. wiki

Air drops for both the KD and PS could bring in lighter essentials; these are a whole lot safer than multiple landings on ungroomed airstrips which could bring on emergencies for which there is no response.

One option not yet mentioned is for the more capable icebreaker Polarstern to fire up its engines, go free up the KD and perhaps escort it south a bit, do the exchanges, and return to wherever its current position has drifted. This would leave the power (and data collection) off for a prolonged period at deployment sites so more likely the many tons of irreplaceable scientific equipment would have to pulled in first.

This would entail an enormous amount of de-installation and re-installation work in high wind chill (but not dark) and seriously undermine the scientific mission. Alternatively a skeleton crew and generator could be left in a lifeboat equipped as shelter to keep things repaired and going.

[uniquorn]

Latest rammb view of KD apparently ceasing northward movement and drifting west. Will be interesting to see how the two drift paths compare (maybe there is a buoy nearby..)
heavy contrast

[A-Team]

On Rammb, the 60 frame time series is needed, color the dot pairs you're sure of. The PS also responded to a change in wind bearing around the same time. The longitude of the KD can be estimated easily enough but latitude retrieval depends on including the outer 85º circle in the time series (on the extremely flighty Rammb display) so that the number of pixels to 87.5º can be measured to proportion the KD's location.

Since GFS nullschool gives the same wind speed and direction wherever you click (within reason), the KD and PS will have the same drift as long as neither is under steam. The short cut is just to count pixels between the two Rammb dots over time: if constant, the KD is still stuck.

It's interesting to read people onboard the PS are hoping the KD can get closer, needn't actually get to the PS. Presumably that makes multiple round trips a lot easier for the helicopters. The PS has two and the KD a larger one. Closer though means more problematic for the KD crew and leg2 scientists in terms of returning home, though possibly the outbound broken swath could be re-used.

Update: persistent strong winds over the last 36 hours are pushing the local icepack rapidly west, taking the Polarstern with it at a record clip of 0.4º lon/hr. More of the same is forecast for the  next 72 hours with an increasing southerly component.  The KD is no longer on a streamline to the PS but rather on a parallel one heading to the the FJL gap.
 
This will leave the PS at perhaps 88.3 20.0 by the first of March, leaving the ship 857 km from its 15 Oct 2020 final destination in near-prime transpolar drift position that could end the mission by the first of June some 4 1/2 months early.

[uniquorn]

The PS also responded to a change in wind bearing around the same time

Agreed, I should have taken account of that.

drift update. Mostly west, edging south. With the present forecast it's likely that feb23 ~20:45 was as far north as they go. An accurate PS location is not disclosed but here is p207 data. (recent data attached as txt)
p207,2020-02-23 20:30:25,88.5921,57.8164
p207,2020-02-23 21:00:26,88.5921,57.6921

[Jim Hunt]

Via Stefan Hendricks on Twitter, a new discussion paper:

https://www.the-cryosphere-discuss.net/tc-2020-64/

The MOSAiC ice floe: sediment-laden survivor from the Siberian shelf

We show, using a Lagrangian tracking tool and a thermodynamic sea ice model, that the MOSAiC floe carrying the Central Observatory (CO) formed in a polynya event north of the New Siberian Islands at the beginning of December 2018. The results further indicate that sea ice in the vicinity of the CO (< 40 km distance) was younger and 36 % thinner than the surrounding ice with potential consequences for ice dynamics and momentum and heat transfer between ocean and atmosphere.

[A-Team]

We're getting mixed signals at the moment: is the KD stuck or just proceeding slowly, has it already exhausted so much fuel it cannot get back to Norway, is another icebreaker passing by in the vicinity capable of refueling it? Both bloggers onboard have gone silent.

The Rammb frames on which both ships are visible do not show the KD closing on the PS. That is consistent with either the KD being stuck or just making very slow progress.

The "Kapitan Dranitsyn" supply icebreaker is barely making any progress. "The mood on board the Polarstern is very tense," said Chief Scientist Professor Christian Haas. "There is uncertainty as to how to proceed. The colleagues are disappointed that there is no foreseeable return soon.

But since mid-December the sea ice in the winter arctic has grown steadily, it is up to 160 centimeters thick and provided with many dense press ice ridges by stormy winds. Open and thin jobs are rare. And so the KD is struggling slowly - with such high energy consumption that the fuel will not be enough to return to Norway. 

Ideally the KD will reach PS in the next few days, the expedition blog led by the Bremerhaven Alfred Wegener Institute (AWI) says: "However, the weather and ice conditions are still adverse."

Markus Rex expects the KD to reach Polarstern in the next few days. It is only 50 nautical miles away.  She had made good progress in the past 24 hours. Rex says planes are also available in Canada. But better weather is also needed for their use.

Chief Christian Haas says  it was presumptuous to believe that in mid-February a conventionally operated ship would get to the central Arctic. There is no experience with it, not even with the "Kapitan Dranitsyn".

Haas believes that the winter journey should have been planned for a longer period than the two months planned. "Of course we have a luxury problem," he admits. Researchers today did not want to be away from home for longer than two or three months. "We are happy and excited to be here," emphasizes Haas. The food is also good. But the team is now very exhausted from work and is longing for a more relaxed time.

Will the PS reach the North Pole?
No. Forget the spaghetti models, just look at GFS wind. The ship is already below the pole and proceeding west and south where the transpolar drift will take over. Nothing in the recent past is relevant to the ice thinness and wind patterns this year. The circumpolar drift from the Laptev to Fram has been going on for many millennia.

https://t.co/DC5NfoNfSB?amp=1

Is it surprising the Mosaic floe contains sediment from the Siberian shelf?
No. Where else could the ice have formed, given its posted track from Ascat? If there is no dueling hypothesis, there is no information content.

On WorldView, the Laptev Sea can be seen to be awash in algal bloom and fine sediment (from between islands, from melting coastal and submerged yedoma, from Lena Delta) in late August (see early locked posts on this forum). The only surprise would be coarse sediment too dense to have been suspended long, indicating a role for land-fast ice.

https://t.co/DC5NfoNfSB?amp=1

As explained some years back by Pink Floyd, we don't need no education to answer such questions ("Another Brick in the Wall").

[echoughton]

Thanks for the updates! A-Team talks about their predicament being a "luxury problem". Indeed, all on this forum should have mandatory reading of "The Kingdom of Ice" about the De Long party in the Jenette. (Spelling may be wrong) One of the best books I ever read, it shows to what incredible lengths humans are able to go in order to survive. When De Long and company finally make it to land, it happens to be the most remote place on earth...unbelievable

[Tor Bejnar]

In The Kingdom of Ice: The Grand and Terrible Polar Voyage of the USS Jeannette
(Doubleday), 2014, by author and historian Hampton Sides.

Per Wikipedia:  The book tells the true story of the 1879–1881 arctic voyage of the USS Jeannette and the crew's struggle to survive after having to abandon their ship in the polar ice.

I read it a few years ago:  extremely intense in places, and worth the read.

[blumenkraft]

Shopped the audiobook! Thanks, guys, for the recommendation!