MOSAiC news

[oren]

Thanks for these wonderful resources uniquorn. Interesting that 2020R11 has a much lower albedo than R12. Where are they located? Can you link to coordinates?

[uniquorn]

R11 and R12 are quite close together so probably older snow on R11. Perhaps wind drove it off.
Here is a slow animation of mosaic radiation and snow buoys. click to run
A quick look didn't find a time where none of the details were obstructed. Text repel can only do so much

[Niall Dollard]

Are S96 and R11 located very close together ? Co-ords today are same. (to 2 decimal places)

S94 and R12 are also quite close.

R11 has the higher lower albedo. The data for corresponding nearest Snow Buoy (S96) says "distance to initial snow/ice interface" as 0.024

R12 has higher albedo. Nearest Snow Buoy (S94) has "distance to initial snow/ice interface" much higher at 0.38.

Could R12 be protruding well above the surface and R11 practically on the surface ?

[max_123]

First talks of MOSAiC data at EGU2020

MOSAiC goes O2A - Arctic Expedition Data Flow from Observations to Archives
 https://meetingorganizer.copernicus.org/EGU2020/EGU2020-17516.html

Thermal Infrared Imaging of Sea Ice During the MOSAiC Expedition
 https://meetingorganizer.copernicus.org/EGU2020/EGU2020-4871.html

Variability of Lagrangian pathways and coherent structures in the Arctic and its effect on the predictability of MOSAiC drift and material transport
 https://meetingorganizer.copernicus.org/EGU2020/EGU2020-6748.html

MOSAiC’s Pan Arctic Water Isotope Network: Sea ice-water vapor isotope interactions and transport processes within, into and out of the Arctic
 https://meetingorganizer.copernicus.org/EGU2020/EGU2020-12445.html

Large Eddy Simulations of the Arctic atmospheric boundary layer around the MOSAiC drift track
 https://meetingorganizer.copernicus.org/EGU2020/EGU2020-18102.html

[uniquorn]

Thanks for alerting me to R12. Some replies are within quote with added links to the data

Are S96 and R11 located very close together ? Co-ords today are same. (to 2 decimal places)
>Yes
S94 and R12 are also quite close.
>Yes
R11 has the higher lower albedo. The data for corresponding nearest Snow Buoy (S96) says "distance to initial snow/ice interface" as 0.024
R12 has higher albedo. Nearest Snow Buoy (S94) has "distance to initial snow/ice interface" much higher at 0.38.
Could R12 be protruding well above the surface and R11 practically on the surface ?

Possible. S94 data has changed significantly recently
R10,R11,R12,S94,S96 locations. click to run
example of radiation and snow buoy deployments

[uniquorn]

Never sure of the date the photographs are taken but I suppose this must be recent. fomo may7

[uniquorn]

Data from the mosaic Tbuoys suggesting that thickening has stopped with possible thinning in some cases, confirmation of the image above (if it is recent) click to run
data has stopped from T63 and T72

[Steven]

From the Norwegian Meteorological Institute:

Strong sea-ice drift for MOSAiC in 2020
https://cryo.met.no/en/mosaic-drift2020

Since January, Polarstern has drifted much faster than the ice drifted in the previous ten years.

...

The animation shows the trajectory of the MOSAiC drift campaign (red) from its beginning in October 2019 and 10 simulated trajectories (other colors) from recent years. The drift of Nansen’s Fram from January to April 1896 is also shown. The simulated trajectories are initiated at the position of MOSAiC on January 1st, and continued until May 1st. They are based on the EUMETSAT OSI SAF sea-ice drift product (OSI-405).

[uniquorn]

For comparison with previous post, 3 Pbuoys (Surface velocity profilers), jan1-may9. Svalbard bottom right. Click to run
km/h = m/s x 3.6, drift speed is not averaged

[uniquorn]

Edited the estimated thickness charts to make it easier to see small changes. Could do with some data from Mosaic to verify but maybe today's image is enough

[uniquorn]

Return from MOSAiC expedition: Kapitan Dranitsyn breaking southwards through the ice
A timelapse of a period where Kapitan Dranitsyn had an easy time breaking through the ice along a bigger lead structure

[Niall Dollard]

Forecast models are indicating a big storm to move in over Svalbard later Tuesday.

East or Northeast winds gusting to 90 or 100 km/hr are expected to affect the area where Polarstern is currently located early Wednesday.

The highest windspeed from the hourly synops reported from Polarstern was 76 km/hr at 15 UTC on 16th November 2019 with winds from a WSW direction. I wonder could this be exceeded ?

Incidently atmospheric pressure records reported by the ship since expedition began were :

lowest pressure : 974 hPa at 16 UTC on 14th March 2020
Highest Pressure : 1034.4 hPa at 10 UTC on 6th December 2019

[Niall Dollard]

Return from MOSAiC expedition: Kapitan Dranitsyn breaking southwards through the ice
A timelapse of a period where Kapitan Dranitsyn had an easy time breaking through the ice along a bigger lead structure

Mostly easy going, although I did notice at 1:20 into the video they had to reverse a couple of times and make a few attempts to bash through !

[uniquorn]

Yes, it also begins with 3 reverses to break into the lead.
Drift update. Unfortunately it looks like we are saying goodbye to P207 which stopped sending data 2 days ago. I'll find another Pbuoy close by.
Some pictures from https://twitter.com/arndt_st and https://twitter.com/CKatlein giving some examples of fairly recent snow depth.

[uniquorn]

Delaunay triangulation on Mosaic IABP buoys that report on the hour. Day 91-130
Quite a lot of dropouts, probably best full screen at 2x speed

[Frivolousz21]

So the weather looks like it might grab them and haul their ass to the fram?

[uniquorn]

For a while there was a small chance PS would exit between FJL and Svalbard but an early Fram exit looks highly likely for the buoys now. PS will probably steam further north, after the Svalbard fjord crew change, to prolong the expedition.

[Niall Dollard]

Polarstern reported a windspeed of 83 km/hr at 3UTC this morning from a NE direction.

This is the highest windspeed reported by the ship in its hourly synop reports since the expedition began.

In Beaufort terms it is strong gale force 9.

[uniquorn]

drift speed is certainly picking up a bit.

More activity in the last few frames of bow radar
https://data.meereisportal.de/maps/animations/Iceradar/Radar_Animation_Polarstern_seaiceportal(20200430_20200513)_grid.m4v

[blumenkraft]

Looking forward to the bow radar movies when the Polarstern is going to travel through the ice on it's way to Svalbard.

[uniquorn]

A crop of today's bow radar. PS appears to be changing orientation again.
updated below

[blumenkraft]

Perhaps someone would be interested in a daily check on 2020R11 and 2020R12 and let us know when albedo drops.

Some lower readings at R12 today.

[uniquorn]

So maybe 20hrs above salt water freezing temps and we get a small albedo drop (in one location). Thanks.

Since PS is likely to weigh anchors next week, here is a comparison of the floe from oct8 and today using S1 jp2 from https://www.polarview.aq/arctic

[uniquorn]

Wild swings on bow radar over the last few days.
De-icing the hull before they set off? Cleaner atmo readings?
That's the first sight we've had of that quadrant.

[uniquorn]

today's fomo pic
probably not taken today

[uniquorn]

Sonne and Maria S. Merian, probable PS supply ships, are on the move.
updated below

[blumenkraft]

Trivia:

Sonne is the German word for 'sun'.

The Maria S. Merian is named after

"Maria Sibylla Merian (2 April 1647 – 13 January 1717) [who] was a German-born naturalist and scientific illustrator, a descendant of the Frankfurt branch of the Swiss Merian family. Merian was one of the first European naturalists to observe insects directly.

[uniquorn]

Following up on yesterday's fomo:

https://meetingorganizer.copernicus.org/EGU2018/EGU2018-7443.pdf

Surface classification and melt pond characterization using aerialphotography of Arctic sea ice during summer meltNiels Fuchs, Gerit Birnbaum, and Wolfgang DierkingAlfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, Climate Sciences, Germany(niels.fuchs@awi.de)The surface of the Arctic sea-ice cover changes dramatically with the onset of melting: the highly reflective snowcover disappears, absorptive melt ponds evolve, and the albedo drops. Images with high spatial resolution acquiredwith airborne cameras are an important data source to understand this summery sea-ice surface transition. Thedata  is  used  as  reference  to  describe  and  evaluate  the  transition  in  model  simulations  and  to  develop  retrievalmethods for satellite remote sensing products aiming at evaluating the stage of melting.We  use  a  comprehensive  airborne  image  data  set,  collected  over  melting  sea  ice  in  the  Arctic  since  2008,  tocompile contemporary reference data of Arctic sea-ice surface classes during summer melt. To this end, we usethe  open  source  sea  ice  classification  algorithm  “OSSP”  (Wright  and  Polashenski,  2017,  in  "The  CryosphereDiscussions") with several modifications to separate the ice image area into snow covered and bright ice, shadowsfrom ridges, wet snow and dark ice, submerged ice and melt ponds, and open water. Based on the large data set weobtain statistics of surface parameters such as melt pond coverage for first-year ice and multi-year ice conditionsat different regions for different melting stages. An advantage of our analysis is the use of a constant camera setup.In this poster, we give a brief overview about the available data and the OSSP algorithm, which is based on asegmentation and random forest classifier approach, and present more in detail our modifications of the OSSP,which include orthorectification of the image data, changes in the input feature list and an improved segmentation.Our primary focus here is a thorough study of classification errors for sea ice under melting conditions. Further-more, we provide classified images from a 2017 measurement campaign north of Svalbard with derived geometricparameters such as, for example, melt pond fraction and pond size distribution.

Perhaps we get an example of 'floemosaic' later

[uniquorn]

drift update, abrupt direction change. west to south.

[blumenkraft]

Wild swings on bow radar over the last few days.
De-icing the hull before they set off? Cleaner atmo readings?
That's the first sight we've had of that quadrant.

From the web-app:

Now it is done, team 3 is leaving. The floe is cleanly tidied up and it
doesn't remind us much of the MOSAiC floe we arrived at over 11
weeks ago. The floe that was selected as home floe for the MOSAiC
drift over 7 months ago. A floe that has been explored and sampled
from all imaginable sides in the last months better than any floe
ever before. During the last days the ice around us has broken up
even more. On Tuesday evening we were hit by a strong
storm with
wind peaks of more than 9 Bft, and the ice has lived up to the
project name: A mosaic of
many cracks has formed around
Polarstern. Because the storm was well predicted, the important
and large installations were removed from the ice floe and brought
to the safety of the ship before. As the ice does not seem safe
enough at the moment, it was decided to further reduce the
instruments remaining on the ice during Polarstern's absence. On
Thursday, our old lady's machines were turned on for this purpose.
With great sensitivity, the ship was moved to a new parking
position through the systems of channels in the ice. Thanks to
countless helping hands on the ice and on the ship, the ice floe was
then "tidied up" for 1.5 days in sunshine and temperatures around
freezing point. All that remains on the ice is a variety of
autonomous measuring systems, which continue to measure above,
in and under the sea ice, even while Polarstern will not be here for
the next three weeks. These systems will also help the next
research team to find our mosaic again. On Saturday at 11 a.m. the
crane brought the last hard-working helpers back on board - an
emotional moment for all involved. Afterwards, an area next to the
floe was washed free of ice for CTD and net work. This work was
also completed in the evening hours. So our work here is done. We
say goodbye and now break our way south. Soon team 4 will take
over our work.

[uniquorn]

https://www.sailwx.info/shiptrack/shipposition.phtml?call=DBBE

[uniquorn]

A chart from mosaic buoy T58 showing how ice temperatures change with air temperature.
click for full resolution.

[Niall Dollard]

It makes a pretty graph Uniquorn.

I am trying to examine the plot/colours using the right vertical axis.

It looks like brown is predominantly coldest and that corresponds to T21. Then blue T26 and so on down. I presume the increasing T numbers correspond to increasing depth ? I wonder do the Tnumbers correspond to cm is that too simplistic? ie is T121 at depth 121cm ?

Given that T21 or T26 show up on the graph as coldest, where are T1,T6,T11,T16 ? I cannot see those colours on the graph but maybe they are all on top of each other, on top of the T21 brown colour and the brown overshadows these lower number colours ?

[uniquorn]

Probably best to download the csv file and view a selection of charts to make a more detailed analysis but yes the first ~20 thermistors record very similar temperatures, after which proximity to snow/ice begins to have an effect.
The gradient within the ice is quite smooth but rises quite rapidly with rising air temperatures.
The snow layer is more difficult to describe.
Thermistors are spaced at 2cm intervals

Graph above is a static way of looking at the animation below.
Air on the left, ocean on the right.

[SimonF92]

Thats smashing uniquorn, id like to add it to the webapp, can you send me the source code?

[uniquorn]

Drift update, may1-22 with sailwx overlay of latest 240hrs of PS location. The buoys match the overlay from may12 onward.
PS looks to be taking the shortest route to open water.

Yesterday's S1 showing her route to just north of 83N. cffr

Sonne making good progress.

[uniquorn]

No updates on sailwx for PS, Sonne or MSM today. No S1 yesterday or today so far.
We do have an overview of ship positions from uni-Bremen/AWI

Today's S1. The Central Observatory (mosaic floe) top left, PS bottom right.
jpg is smaller

[uniquorn]

Really good shot from S1 today showing the old mosaic floe (central observatory?) top left, PS roughly 1/5th left (bright dot) and how far they have to go to reach open water (right). It's still possible to make out the path PS has taken so far, clearly having to pick her way through the ridges.
click for full size
well the dot is very bright when you click twice for full resolution

[uniquorn]

buoy 26569 registered with sailwx overlaid with latest sporadic PS location.
buoy has 6 times better resolution than PS

[Niall Dollard]

The temperature on the Polarstern went positive today (25th May) at 14 UTC and has remained above zero since.

First hourly value above zero this year. (It came close to zero (-0.1) on 20th April)

At 82.4 north.

[uniquorn]

update on amateur Tbuoy ice thickness estimates.
T61 is included as a test for the software calculations. It was 7.05m thick at deployment

added Tbuoy drift, may1-26. 2 Pbuoys showing drift speed are mostly obscured.
PS location in purple.

[uniquorn]

A look at the ice temperature gradient flattening out as air temperatures rise above 0C, T73-T79. Once again, air on the left, snow/ice at the gradient change, stable ocean temperature on the right. click to play ~6MB

[shendric]

For your information:

360 degree photos from the Polarstern panorama camera are now partially available here:

https://www.mosaic-panorama.org/?cu=en-GB

The scans are taken every 10 minutes, but stored on the ship due to data transfer limits. The website therefore mostly contains images from past cruise legs that came back with the supply vessels. A few more recent ones are also available though on a one image per day basis.

Cheers, Stefan

[uniquorn]

Thanks Stefan. Nice to see photos with dates.
Continuing with temperature profiles of T65-T70. T69 had a trauma at the end of january, possibly ridging, damaging the thermistor chain at ~thermistor100. Near surface temps are interesting with differing characteristics. click to play

[Frivolousz21]

update on amateur Tbuoy ice thickness estimates.
T61 is included as a test for the software calculations. It was 7.05m thick at deployment

added Tbuoy drift, may1-26. 2 Pbuoys showing drift speed are mostly obscured.
PS location in purple.

There has to be a lot of blowing snow.   Or just melting. 

[uniquorn]

The temperature profile animations above  suggest most Tbuoys have ~20cm snow and also give an indication of how difficult it is to estimate snow thickness from temperature readings alone. Total ice+snow thickness is likely to be more accurate. The method is described fully as it developed here

Mosaic snow buoys that survived into 2020 are shown below

[uniquorn]

PS probably struggling to make headway against the drift over the last 2 days. T61 is the Tbuoy on 7m ice. I'll keep monitoring its drift till it stops reporting
animation rotated 45deg

[SimonF92]

PS probably struggling to make headway against the drift over the last 2 days. T61 is the Tbuoy on 7m ice. I'll keep monitoring its drift till it stops reporting
animation rotated 45deg

really not a big deal at all but when I had to blow-up ggplot figures for a conference poster I found anti-aliasing hugely useful

Install the R Cairo library and add type=cairo when you render

[uniquorn]

anti-aliasing: I'll take a look. I think I'm cramming too much movement into too few frames.

[SimonF92]

anti-aliasing: I'll take a look. I think I'm cramming too much movement into too few frames.

I dont think thats it, its a known issue with using the native renderer- antialisaing really helps those jagged lines that pop up

https://stackoverflow.com/questions/6023179/anti-aliasing-in-r-graphics-under-windows-as-per-mac