Support the Arctic Sea Ice Forum and Blog

Author Topic: MOSAiC news  (Read 137092 times)

uniquorn

  • Young ice
  • Posts: 2760
    • View Profile
  • Liked: 1249
  • Likes Given: 247
Re: MOSAiC news
« Reply #1200 on: September 21, 2020, 08:17:44 PM »
<>has uniqorn been showing us animations of tidal oscillation or inertial oscillation? And does that mean that there is no (or at the very most negligible) tidal movement in the Arctic?
You may be right binntho. The drift paths from the F Gimbert paper look very similar to the buoy animations except for a larger possible component of inertial oscillation this year. The maths is above my pay grade also but I may work up to it in time. I think tides have a part to play in the arctic, more importantly at the shelf breaks. An increase in inertial oscillation due to thinning and fractured ice cover adds another (previously unknown to me) feedback loop that deserves more consideration from the forum.

Also shown is P163 drift speed. Calculating the time between 12 peaks in the centre gave an average of 23.29hrs/peak which is too short for a lunar cycle so I'm open to other explanations.
P163
09 06 2200 to 09 12 1330
279.5hours, 12peaks = 23.29hrs/peak

I may take a look at north Atlantic buoys on another thread though a comparison of some in the central arctic from previous years would be more interesting. Meanwhile here are some of the remaining Mosaic buoys in the Greenland Sea. awi amsr2 inset to show rough ice location. (graticule belongs to the animation)


A-Team

  • Young ice
  • Posts: 2705
    • View Profile
  • Liked: 649
  • Likes Given: 33
Re: MOSAiC news
« Reply #1201 on: September 21, 2020, 10:03:15 PM »
Quote
inertial oscillations
These papers go back to the 1960's if not earlier. I added some classics over at the wave forum.
https://forum.arctic-sea-ice.net/index.php/topic,2417.msg287387.html#msg287387

The Polarstern has left its second floe for Bremerhaven, escaping the encroaching pole hole of darkness but also missing a lot of the early freezing system, not completing a full cycle which would take staying until Oct 4th.

The ship's progress can be followed by pasting lat lon data from awiMet into the excel template containing the haversine distance formula, the elapsed time between reports (hrs are commonly skipped), and a velocity column as we do for buoys.

However since the accuracy provided is poor, it is easier for eyeball estimates just to count the hours between 0.1 drops in latitude which represent 11.1 km of progress to the ice edge. Over the last 24 hours, those are 3,2,6,3,3,2,5.2,1,1,1,2,1,1 so the speed has been running at 2-11 km/hr.

In other words, there has been some 2m ice but lately favorable leads and lower compression ice where the ship can make rapid progress. The PS is rated at 28.7 km/hr for calm open seas so 11 km/hr indicates very insubstantial ice for the last 80 km despite the very high latitudes.

They are dropping longitude as opportunity presents as this gives a shorter path to the unconsolidated ice north of the the edge, as well as representing the homebound direction. The ship should emerge from the WorldView and Sentinel-1B pole holes late tomorrow.

The AMSR2_AWI shows the averaged concentration (relative to the palette) for the last 16th days. The red line shows its envelope, areas outside have been entirely open water the entire time. (This is a gimp trick to determine minimum crop boundaries for long time series.)

There's no significance to this unless the ship gets stuck or stops for a few days to observe conditions near the ice edge.
 
Update: The ship is making much faster time now, with only one hour between 88.2 and 87.5. Will they share any of the transiting data on ice thickness and condition? (No.)

Update: The Polarstern has covered 206km  in the last 24 hours ending 20-09-22 21:00 for an incredible average speed -- through 'solid ice' of 8.6 km/hr perhaps aided by a 17m/s gale force tailwind that may be diminishing ice compression. Just paste the two lat lon in the first two columns and rows of any spreadsheet and the haversine formula in R1C3...

=ACOS(COS(RADIANS(90-A1)) *COS(RADIANS(90-A2)) +SIN(RADIANS(90-A1)) *SIN(RADIANS(90-A2)) *COS(RADIANS(B1-B2))) *6357.444

   Lat  Long  YY-MM-DD  UTC     Wind       T(C)  N  h  VV  wwWW  ICE  Pnn(hPa)
  87.5    99.6 20-09-22 04:00    6   90    -15.0  /  /  //  //// ///// 1013.3
  87.6  100.8 20-09-22 03:00    6  100    -13.9  1  9  98  4011 58/98 1013.1
  87.7  100.8 20-09-22 02:00    6  110    -13.5  /  /  //  //// ///// 1013.3
  87.7  100.6 20-09-22 01:00    6  110    -12.4  /  /  //  //// ///// 1013.1
  87.8  100.1 20-09-22 00:00    6  110    -11.4  /  /  //  //// ///// 1013.0
  87.9    99.7 20-09-21 23:00    5  120    -10.9  /  /  //  //// ///// 1013.0
  88.0  100.4 20-09-21 22:00    5  130    -10.8  /  /  //  //// ///// 1012.7
  88.1  100.8 20-09-21 21:00    4  130    -10.8  /  /  //  //// ///// 1012.6
  88.2  100.6 20-09-21 20:00    4  130    -10.8  /  /  //  //// ///// 1012.5
  88.2  102.3 20-09-21 19:00    3  110    -10.9  /  /  //  //// ///// 1012.6
  88.3  103.2 20-09-21 18:00    3  120    -11.0  /  /  //  //// ///// 1012.4
  88.3  103.9 20-09-21 17:00    3  150    -11.2  /  /  //  //// ///// 1012.5
  88.3  105.7 20-09-21 16:00    3  150    -10.9  /  /  //  //// ///// 1012.4
  88.4  105.9 20-09-21 15:00    3  140    -10.6  7  7  99  0222 58/98 1012.3
  88.4  105.0 20-09-21 14:00    3  160    -10.7  /  /  //  //// ///// 1012.1
  88.5  104.8 20-09-21 13:00    3  150    -10.6  /  /  //  //// ///// 1011.8
  88.5  105.1 20-09-21 12:00    2  150    -10.9  7  2  99  4022 58/98 1011.6
  88.5  105.5 20-09-21 11:00    1  170    -11.3  /  /  //  //// ///// 1011.4
  88.5  105.7 20-09-21 10:00    3  190    -11.3  /  /  //  //// ///// 1011.3
  88.5  106.2 20-09-21 09:00    3  180    -11.2  7  2  99  4022 58/98 1011.2
  88.5  106.5 20-09-21 08:00    2  160    -11.1  /  /  //  //// ///// 1011.1
  88.6  105.5 20-09-21 05:00    1  200    -11.0  /  /  //  //// ///// 1010.8
  88.6  106.4 20-09-21 04:00    2  180    -11.0  /  /  //  //// ///// 1010.6
  88.6  106.9 20-09-21 03:00    3  180    -11.9  7  9  98  4042 58/98 1010.3
  88.7  107.5 20-09-21 02:00    3  150    -11.6  /  /  //  //// ///// 1010.3
  88.7  108.0 20-09-21 01:00    2  140    -11.9  /  /  //  //// ///// 1010.3
  88.7  108.5 20-09-21 00:00    1  140    -12.7  /  /  //  //// ///// 1010.3
  88.8  108.8 20-09-20 23:00    2   80    -11.8  /  /  //  //// ///// 1010.2
  88.8  107.8 20-09-20 22:00    1   90    -11.7  /  /  //  //// ///// 1010.2
  88.9  107.1 20-09-20 21:00    1   80    -11.6  /  /  //  //// ///// 1010.0
  88.9  105.7 20-09-20 20:00    1  350    -11.3  /  /  //  //// ///// 1009.6
  88.9  106.5 20-09-20 19:00    1  310    -11.3  /  /  //  //// ///// 1009.2
  88.9  108.2 20-09-20 18:00    1  310    -11.5  /  /  //  //// ///// 1008.8
« Last Edit: September 23, 2020, 12:47:56 AM by A-Team »

Latent

  • New ice
  • Posts: 13
    • View Profile
  • Liked: 7
  • Likes Given: 0
Re: MOSAiC news
« Reply #1202 on: September 21, 2020, 10:20:53 PM »
BBC seems to have some inside info.  I have looked back on this Forum but have found no mention of this in particular. 
You need to read further down the article to see the quotes from Julienne Stroeve on her Mosaic mission:
https://www.bbc.co.uk/news/science-environment-54211760

Sorry if I have attached this incorrectly, not a techie ;)

A-Team

  • Young ice
  • Posts: 2705
    • View Profile
  • Liked: 649
  • Likes Given: 33
Re: MOSAiC news
« Reply #1203 on: September 22, 2020, 03:42:00 AM »
Quote
news in the BBC piece?
We've been considering two new articles from J Stroeve that appeared in The Cryosphere in the the last month. This sounds like a third Mosaic-specific version is coming soon. The news (?) is that Cryosat has a significant thickness bias that cannot properly account for a snow cover.

Was 4.5 months out in the cold and dark, cut off from internet productivity, a good use of Stroeve's and other principal scientists' time? I would say it was not.

So here we go with yet another satellite (Cristal) that promises to do it better, in part using new measurements from the Mosaic year. Here it sounds like it will measure reflectance of two simultaneous microwave frequencies in the Ku and Ka bands. That is WWII terminology for 12–18 GHz and 33.4-36.0 GHz.

While ice thickness and volume have always been the Achilles heel of Arctic remote sensing, it is necessary to get at it by satellite observation because models can't do it satisfactorily and  ships cannot always be out there. Indeed even supplemented with buoys, plane overflights and touch-and-go sampling, they cannot provide comprehensive sampling.

Indeed Cryosat takes a month of orbits to get one round of swath assembly. So I would guess design of Cristal is not just accurate freeboard but equally about getting a wider swath so fewer orbits are needed to build a picture (done in part by having two satellites). 

Freeboard does not give thickness except with the assumptions of ice density and buoyant equilibrium. How well does that work with under-ice melt ponds, porous ice, incomplete brine exclusion, undrained deep melt ponds, flooded negative freeboard floes, repeatedlymelted and refrozen snow and so on?

It is still years away from launch in 2027 so the question could be raised whether the Arctic ice of its time will be a good match to the design indicated by Polarstern research of ice of last winter.

'Thickness' alone may not really characterizes critical properties of the ice even today -- there were too many surprises this melting season. Will snow depth be the focus or will we be wishing we had a rain-on-snow satellite -- or just ordinary rain gauges on a giant fleet of buoys that could be deployed any time for far less expenditure?

https://forum.arctic-sea-ice.net/index.php/topic,2906.msg287133.html#msg287133

Trends and spatial variation in rain-on-snow events over Arctic Ocean during early melt season
https://tc.copernicus.org/preprints/tc-2020-214/

"CRISTAL -- Copernicus polar ice and snow topography -- will carry a multi-frequency radar altimeter and microwave radiometer to measure and monitor sea-ice thickness and overlying snow depth. It would also measure and monitor changes in the height of ice sheets and glaciers around the world thanks to its interferometric radar mode.

IRIS will significantly improve the measurement accuracy of its predecessor SIRAL-2 (a Ku band only altimeter on board ESA’s CryoSat-2 Earth Explorer mission) thanks to the dual frequency operation and by adding the measurement of sea surface height as part of the mission objectives.

The drifting polar orbit is 760km above the Earth. Its on-board memory will be able to store up to 4 terabits of science data during its 7.5 year lifetime."
« Last Edit: September 22, 2020, 03:52:08 PM by A-Team »

binntho

  • Nilas ice
  • Posts: 1521
    • View Profile
  • Liked: 528
  • Likes Given: 119
Re: MOSAiC news
« Reply #1204 on: September 22, 2020, 07:24:10 AM »
I think tides have a part to play in the arctic, more importantly at the shelf breaks.
I agree. But perhaps it is a part that is not easily visible to us.

Quote
Also shown is P163 drift speed. Calculating the time between 12 peaks in the centre gave an average of 23.29hrs/peak which is too short for a lunar cycle so I'm open to other explanations.

But fits well with an inertial oscillation (IO) at slightly less than 2 per day this close to the pole. From my reading I gather that the IO goes from 2/day at 90N to 0 at the equator.

Quote
Meanwhile here are some of the remaining Mosaic buoys in the Greenland Sea.
Not really possible to discern any tidal oscillation, perhaps the scale is too large. We know that there is a larger tidal effect here than in the Arctic, although not all that large (you need to go south of the Greenland-Iceland-Scotland line to get into proper tidal movement). The maximum tidal movement in Longyearbyen is around 2m, in Reykjavik it is almost 5m. Out in the open ocean, the movement is signifcantly less, perhaps 0.5m in the Greenland sea, 1 - 1.5m just south of Iceland.
because a thing is eloquently expressed it should not be taken to be as necessarily true
St. Augustine, Confessions V, 6

uniquorn

  • Young ice
  • Posts: 2760
    • View Profile
  • Liked: 1249
  • Likes Given: 247
Re: MOSAiC news
« Reply #1205 on: September 22, 2020, 10:45:22 AM »
Any volunteers to keep an eye on a new snow buoy, 2020S98, close the the pole?

Also 2020S106, 2020S107 and Also 2020S108
The ever improving meereisportal makes it visually simple.

For latest lat/lon it is still necessary to look at the data tables.
meereisportal here

or the iabp daily table here
though you need to know the buoyID
for example
  300234066087160   NA   2020   Snow_Buoy   AWI
   MOSAiC   09/21/2020   89.16   109.45
« Last Edit: September 22, 2020, 11:18:46 AM by uniquorn »

uniquorn

  • Young ice
  • Posts: 2760
    • View Profile
  • Liked: 1249
  • Likes Given: 247
Re: MOSAiC news
« Reply #1206 on: September 23, 2020, 11:28:22 AM »
No interest in snow then ;)

PS just north of 80N 86N on Polarview S1B at 03:19 this morning, track history from sailwx
weather at the moment
24 -- freezing rain
-0.2C
ice:
5 -- Very close pack ice 7/8 to < 8/8 concentration
5 -- All thin first-year ice (30-70 cm thick)
yesterday's fomo pic.
« Last Edit: September 23, 2020, 11:47:35 PM by uniquorn »

OffTheGrid

  • New ice
  • Posts: 64
    • View Profile
  • Liked: 34
  • Likes Given: 31
Re: MOSAiC news
« Reply #1207 on: September 23, 2020, 11:40:55 PM »
I think you mean just north of 86 north old boy?
That slush pic in their wake was at 88.3 just after they left on the 20th btw.
I think the Cap'n thunk the kids needed a bit of a reality check by scaring them to think they were going to run head on into a Beaufort 9 storm front with wave and swell chaos in the shelf fragments and skyscraper sized  Bergs on the edge of the ice front.
Instead he has turned ninety degrees due West to run with it.
They've copped the force nine thunderstorm hot front on the butt. But so far have no idea what force 9 sea states near coasts look like. He may blood them with that experience in the next few days.
This auld Ships Cap'n do. Me bin coastal on sail in force twelve Gustin to 180kmph. And experienced the site of 100+ ft rolling breakers from one horizon to the other coming in from the southern ocean at 60 second period all day long. Wavelength some 3km and velocity over 200kmph in the deep where they spawned, the beasties!

uniquorn

  • Young ice
  • Posts: 2760
    • View Profile
  • Liked: 1249
  • Likes Given: 247
Re: MOSAiC news
« Reply #1208 on: September 23, 2020, 11:51:29 PM »
I think you mean just north of 86 north old boy?
aye aye capn, merci
Should have mentioned wind at 75km/hr
86.1N   88.0 20-09-23 00:00   21(m/s)
« Last Edit: September 24, 2020, 12:21:39 AM by uniquorn »

A-Team

  • Young ice
  • Posts: 2705
    • View Profile
  • Liked: 649
  • Likes Given: 33
Re: MOSAiC news
« Reply #1209 on: September 24, 2020, 10:37:04 AM »
The Polarstern continues to hug the 86th parallel for the last 28 39 hours, holding at 86.0  59.5. This cannot be because of thick ice as they have come 214 km at an average speed of 7.6 km/hr at mild temperatures, mist/drizzle and moderating winds after the brush with the first Barents cyclone. Daylight is fading fast right at their location, 3rd image below.

Note this is just great circle haversine(first,last) distance and not on the ellipsoid; parallels are not great circles for either datum; adding up track segments would give a greater distance in fewer hours of actual movement and so considerably higher speed, implying little resistance from the ice despite its 100% concentration.

Presumably the ship is now moored or at least idling at a floe of interest after doing some unscheduled study of weather, water and ice at constant longitude. FOMO mentions sending up weather balloons at six hour intervals up to 35km on each of the 370 days of the trip but nothing specific to the 86º. FOMO today is a week back, showing the massive open lead out of all context.

GFS is showing precip bands associated with the cyclones; going by the temperatures, these are an undifferentiated mix of rain, freezing rain and snow; which matters quite a bit for the ice.

They could angle down later through the gap between FJL and Sv to reach Bremerhaven which seems likelier than going down the Fram to the bad weather of the North Atlantic but that means continuing west to the 45th meridian or so.
« Last Edit: September 24, 2020, 07:05:12 PM by A-Team »

uniquorn

  • Young ice
  • Posts: 2760
    • View Profile
  • Liked: 1249
  • Likes Given: 247
Re: MOSAiC news
« Reply #1210 on: September 24, 2020, 12:24:28 PM »
  Lat  Long  YY-MM-DD  UTC     Wind       T(C)  N  h  VV  wwWW  ICE  Pnn(hPa)
  86.0   59.5 20-09-24 09:00    8  130     -0.3  8  2  96  7872 57/9/  985.1
  86.0   59.5 20-09-24 08:00    8  120     -0.6  /  /  //  //// /////  985.5
  86.0   59.5 20-09-24 07:00    9  120     -0.4  /  /  //  //// /////  986.1
  86.0   59.5 20-09-24 06:00    9  120     -0.4  8  1  94  1052 57/9/  986.9
  86.0   59.5 20-09-24 05:00    9  110     -0.4  /  /  //  //// /////  987.8
  86.0   59.5 20-09-24 04:00   10  110     -0.4  /  /  //  //// /////  988.5
  86.0   61.4 20-09-24 02:00   10  110     -0.3  /  /  //  //// /////  990.1


edit: jp2 (some gamma alteration)
overview with rough PS location highlighted
« Last Edit: September 24, 2020, 12:42:19 PM by uniquorn »

uniquorn

  • Young ice
  • Posts: 2760
    • View Profile
  • Liked: 1249
  • Likes Given: 247
Re: MOSAiC news
« Reply #1211 on: September 24, 2020, 12:51:30 PM »
@interstitial - Many of the new buoys have thickness and some additional information like 'placed on ridge' listed under buoy info here

interstitial

  • Grease ice
  • Posts: 609
    • View Profile
  • Liked: 213
  • Likes Given: 76
Re: MOSAiC news
« Reply #1212 on: September 24, 2020, 02:01:25 PM »
@interstitial - Many of the new buoys have thickness and some additional information like 'placed on ridge' listed under buoy info here
That is great. Even if it ends up proving me wrong I like more information.

A-Team

  • Young ice
  • Posts: 2705
    • View Profile
  • Liked: 649
  • Likes Given: 33
Re: MOSAiC news
« Reply #1213 on: September 25, 2020, 12:17:12 PM »
The Polarstern is proceeding again along its 86º transect in newly graduated SYI after pausing for 16 hours. The ship is due north of western FJL so could cut over later today to the gap with Svalbard. Possibly they wish to intersect their previous drift location with the original floe before heading home.

Bow radar shows a surprising amount of open water consistent with the ice showing limited sub-100% concentration on AMSR2_AWI. The patches are small relative to the 3x3 km pixels but still seem to contribute. Smos-SMAP over OsiSaf shows ice less than 0.5m thick not recently moving much at the PS location.

Update: they've stopped again at 86.0 35.5 on 20-09-26, must be taking some samples along  this preferred parallel, interesting concept.

Update: they've stopped again to award themselves another award:

  Lat  Long  YY-MM-DD  UTC     Wind       T(C)
  86.0   48.4 20-09-25 13:00    4  140     -1.8

   Lat  Long  YY-MM-DD  UTC     Wind       T(C)  N  h  VV  wwWW  ICE  Pnn(hPa)
  86.0   48.7 20-09-25 08:00    7  140     -1.6  /  /  //  //// /////  988.1
  86.0   49.2 20-09-25 07:00    8  140     -1.7  /  /  //  //// /////  987.9
  86.0   49.7 20-09-25 06:00    9  150     -1.4  /  /  //  //// /////  987.9
  86.0   50.2 20-09-25 05:00    8  150     -1.3  /  /  //  //// /////  987.9
  86.0   50.5 20-09-25 04:00    9  160     -1.4  /  /  //  //// /////  987.8
  86.0   51.3 20-09-25 03:00   10  160     -1.5  8  3  98  0272 56/92  987.8
  86.0   52.6 20-09-25 02:00   10  170     -1.2  /  /  //  //// /////  987.9
  86.0   53.5 20-09-25 01:00   11  170     -1.2  /  /  //  //// /////  988.0
  85.9   54.7 20-09-25 00:00   10  160     -1.2  /  /  //  //// /////  987.8
  85.9   55.8 20-09-24 23:00   10  170     -1.1  /  /  //  //// /////  987.6
  86.0   57.1 20-09-24 22:00   10  170     -1.1  /  /  //  //// /////  987.6
  86.0   57.7 20-09-24 21:00   12  180     -1.1  /  /  //  //// /////  987.2
  86.0   59.0 20-09-24 20:00   12  190     -1.1  /  /  //  //// /////  986.8
  86.1   59.7 20-09-24 19:00   12  190     -1.0  /  /  //  //// /////  986.4
« Last Edit: September 26, 2020, 02:04:37 PM by A-Team »

A-Team

  • Young ice
  • Posts: 2705
    • View Profile
  • Liked: 649
  • Likes Given: 33
Re: MOSAiC news
« Reply #1214 on: September 26, 2020, 10:01:08 PM »
Because the ice is so thin and mechanically weak, the Polarstern is able to make very good time. The ship needs to stick to its Bremerhaven arrival schedule of Oct 4th but is thus able to make additional stops at ice stations, which they are able to schedule along the 86th parallel.

None of the data will be shared, even routine observations like ice thickness along the long transects, because informing the current melt/freeze season in nrt has never been a priority. Indeed, disclosure is verboten. Some data types, like L25 in sea ice diatoms, aren't suitable for sharing as they need to be measured back at land labs.

In theory, the PS could continue along 86.0 until the Greenwich meridian which would involve another 2-3 days of travel including brief ice station stops from their current longitude of 31.5º. Winds are picking up though and possibly blowing them somewhat south. It's not clear the ship will exit through the Fram or have time for observations if they do.

Update 1: the ship has turned south under steam, attaining ~33 km in 4 hours along the 32nd meridian. They could reach Bremerhaven in 4-5 days if they don't stop at the ice edge for another station.

Update 2: the Polarstern has advanced 111 km south in the last 10 hours to 84.3  32.1 so will be crossing the ice edge into open water in a couple of hours. Bow radar is already showing large patches of open water as of midnight on the 26th. The weather is unfavorable for a final ice station given the 14m/s wind, cold, precip and low light conditions so this is effectively the end of the Mosaic expedition (except for working up the data into publications).

Update 3: they have stopped right at the ice edge for 5-6 hours, 20-09-28 at 01:00, 4th image.


The ice photo is apparently from Thursday, Sept 24th. The melt ponds are frozen over enough to stand on but do not have a coat of snow. Bootprints can be seen in 5cm snow that seems mushy. Bow radar caught ice motion at one of the ice stations.

It's worth pondering whether a future expedition could make complete loops at fixed latitude in August, say at 85-87º. This might require a dedicated contract icebreaker for the CAB portions with the Polarstern following close behind to spare fuel. What though would be the scientific rationale for doing constant latitudinal circuits?

The top-of-cloud insolation would be held constant though it would vary down on the ice, along with air temperature. The coriolis effect would also be constant in magnitude but then it varies very little at high latitudes (it goes as the sine of latidude; the sine function barely budges at large angles). Wind patterns and origins would vary greatly. On the whole, it does not seem holding one variable constant really helps isolate the others for study.
« Last Edit: September 28, 2020, 04:34:47 AM by A-Team »

uniquorn

  • Young ice
  • Posts: 2760
    • View Profile
  • Liked: 1249
  • Likes Given: 247
Re: MOSAiC news
« Reply #1215 on: September 28, 2020, 10:02:40 PM »
  Lat  Long  YY-MM-DD  UTC     Wind       T(C)  N  h  VV  wwWW  ICE  Pnn(hPa)
  82.9   22.6 20-09-28 18:00    6  300     -8.1  8  5  93  4842 52/91 1012.1

48 -- fog, depositing rime, sky visible

Wispy bow radar

PS in pancake ice

A-Team

  • Young ice
  • Posts: 2705
    • View Profile
  • Liked: 649
  • Likes Given: 33
Re: MOSAiC news
« Reply #1216 on: September 29, 2020, 01:00:54 AM »
This is quite creative use of the last week before heading for port, in some ways more interesting than just studying a single possibly unrepresentative floe. The Polarstern can do CTD casts, ice thickness, and water temperature while on the move.

With periodic stops on the the 86º transect, the various teams can go out and take cores, water samples and weather parameters in the boundary layer and above. The new twist is going back and forth across the marginal ice zone (ice edge) to study conditions allowing new ice formation (which as usual takes place laterally along the periphery of the existing ice side.

The "position buoys" that coordinate with the Polar5/6 overflight campaign haven't been mentioned before. Normally, the teams out on the ice try to coordinate with the time of the overflight but that could not happen this year as access to the base airport in Svalbard only became available at the last moment (because of virus).

Update 1: 81.6  11.6 20-09-29 14:00  14m/s -2.9ºC. The ship has left the ice edge for good and is heading down the Fram to study the position buoy floes before heading to the destination fjord in Svalbard. FOMO is showing engine room pictures again. The wind up the Strait is strong but there is no ice above it to be imported.

Update 1: 81.7 1.6 20-09-30  09:00 12m/s -5.7ºC. The PS is in the middle of the Fram west of Svalbard doing another 24 hour constant-latitude transect to synergize with Polar 5/6 flights earlier this month. Winds are still blowing north at near gale force..

By AWIPEV, they mean the joint German-French portion of the large research station at Ny-Ålesund, Alfred Wegener and Institute Paul Emile Victor (a Greenland explorer). Some eleven countries do field and lab work there on the ocean, ice tundra, glaciers, troposphere, stratosphere, magnetosphere where there is a benefit (or necessity) to be so far north at 79º.  It's not clear what's involved with Mosaic to 'exchange material" with AWIPEV.

The links below describe some of the research going on. One study is looking how to protect GPS accuracy at high latitude from ionosphere disturbance.

https://www.awi.de/en/expedition/stations/awipev-arctic-research-base.html
https://www.awipev.eu/
https://en.wikipedia.org/wiki/AWIPEV_Arctic_Research_Station
https://www.ursi.org/proceedings/procGA20/papers/YSASummaryJin.pdf
https://www.andoyaspace.no/the-grand-challenge-initiative/
https://www.grandchallenge.no/project-cusp/
« Last Edit: September 30, 2020, 01:52:19 PM by A-Team »

A-Team

  • Young ice
  • Posts: 2705
    • View Profile
  • Liked: 649
  • Likes Given: 33
Re: MOSAiC news
« Reply #1217 on: October 01, 2020, 12:25:22 PM »
Some interesting detail has emerged about the Polar5/6 flights out of Svalbard that could have been a major component of Mosaic had they been fully executable as initially planned.

The idea with these Arctic-adapted planes which can fly as low as 100m is to close the resolution gap between detailed but very costly ground exploration and large-scale remote sensing from satellites (whose view is often obscured by cloud tops).

The MACS camera mounted underneath Polar 6 is an amazing device that captures high resolution ice detail simultaneously in the visible, near infrared and thermal infrared. Some 300,000 images at a frame rate of four per second have been taken in the first flights, meaning serious AI is necessary for processing and interpretation.

The camera was developed and operated by DLR (Deutsches Zentrum für Luft- und Raumfahrt) which is similar to NASA and a separate organization from AWI/Helmholtz but participating in Mosaic.

DLR provides a single example on their web page for 84ºN 6ºE in September; there is no link to an archive. This would be truly massive given the number of scenes at the ground resolutions mentioned. No serious description of scene or camera specs is given. A DLR image on twitter has dimension 4096 x 2722 pixels.

https://www.dlr.de/content/en/articles/news/2020/03/20200915_studying-ice-at-the-centimetre-scale.html

The visible is said to measure roughness of the ice and snow; elsewhere this unit has been run as stereo triples which could map pressure ridges but here seems to rely on low angle sun shadows. The near-infrared images provide automatic discrimination of water from floe at 2 cm resolution; the thermal infrared images show temperature differences between ice and freezing fissures at 40 cm.

The conventional thermal palette does not seem optimal for interpretation as a glasbey palette more clearly shows geometric rim features of some of the melt ponds.

Meanwhile, Polar 5 is outfitted quite differently to do cloud and atmospheric research such as determine droplet size distribution, analyze ice crystal shapes, ice and liquid water content of mixed phase clouds and factors relevant to cloud formation. Again the route follows the Polarstern ice station route to synergize with field data. No sample data is available.
« Last Edit: October 01, 2020, 12:43:15 PM by A-Team »

A-Team

  • Young ice
  • Posts: 2705
    • View Profile
  • Liked: 649
  • Likes Given: 33
Re: MOSAiC news
« Reply #1218 on: October 02, 2020, 11:17:42 PM »
The Polarstern seems to be moored in a Svalbard fjord for the exchange of material (ice cores?) with the AWIPEV lab in Ny-Ålesund. No purpose would be served by following the expedition back to Bremerhaven.

Nothing new emerged looking today for published expedition research at The Cryosphere preprints and Google Scholar (for 'Mosaic Arctic'). Articles will be dribbling in for 3-4 years, thus not terribly helpful for nrt understanding of 2019-20.

It is possible that some areas of the big central database will open earlier than 2023 or at least be discussed on Meereis forums or insider twitter accounts.

Three new blogs have appeared on the ticker site:
https://www.meereisportal.de/en/mosaic/sea-ice-ticker/

'Non-Sentinel-1AB high-resolution satellite SAR images had to be ordered two days in advance with precise lat lon information for floe 2.0. To provide that information, drift forecasts relied on the Sea Ice Drift Forecast Experiment SIDFEx  [[despite its total failure in predicting the very rapid TPD drift last spring that ruined the Mosaic program design] That did ok on a 7-day spaghetti forecast for 19 – 26 September zonally but missed the meridional as wind forecasts are only good 3-4 days out.]. For the 120-day forecast, we largely expect to see a southwest drift that generally follows the Transpolar Drift Stream [[duh]]".

https://swift.dkrz.de/v1/dkrz_0262ea1f00e34439850f3f1d71817205/SIDFEx_Graphical/SIDFEx_Polarstern_Graphical_floe2_latest.pdf

"On 21 August the MOSAiC Team set up a new Ice Camp for the fifth leg of the expedition at ca. 87° 43’ N and 104° 30’ E. On 20 September we then left (were forced to leave) the second floe. Here, too, a network of autonomous buoys, smaller than the first, was deployed on the main floe and in its vicinity, and was once again left behind. 

On the central floe, the Sea Ice Team deployed three sets of buoys, outfitted with complex systems for observing various parameters: in Met City there are snow and ice buoys, as well as a buoy for monitoring flows and turbulences, from the ocean to the atmosphere. A second station, set up on level ice, focuses on energy flows and optical properties, as well as the mass balance for snow and sea ice.

We also installed buoys in the pressure ridge near the ship’s bow, which are above all used to compare the distribution of snow there to the distribution on level ice. There are also three cameras among the buoys, which offer us a daily record of the conditions on site. [[no links provided to cam archive]]

Beyond the main floe, 28 buoys were installed on smaller individual floes: 20 in its immediate vicinity (up to 10 km away) and the remainder as far as 40 km away. One of the buoys was deployed at the North Pole itself, and another near the sea-ice edge."

Extent on 31 August was 4.19 million km² and had declined by ca. 1.85 million km² – an area roughly the size of about 5 times the size of Germany. In the second half of August and until mid of September, a strong ice retreat was observed in the Canadian Basin, which led so far to the lowest ice extent of 3.784 million km² on 09 September this summer.

Meteorological conditions in July and August included a distinct temperature anomaly over the Central Arctic producing fluctuations in air temperatures at 925 hPa (~760 m; note they make no use of DMI 80 or its 2m temperatures) of more than 6°C above the long-term average for the years 1981 to 2010 notably in July, when the high-pressure cell was directly over Siberia. A detailed assessment of this year's sea ice minimum is given here:

https://www.meereisportal.de/en/archive/2020-kurzmeldungen-gesamttexte/arctic-sea-ice-extent-on-an-extremely-low-course/

=-=-=-=-=-=

What becomes of all these thousands of weather balloons? They burst in the upper atmosphere after two hours of reporting and fall to earth with their instrument package, usually far from the launch site and unrecoverable.

Some latex ones are said biodegradable but that seems highly implausible at Arctic temperatures; many would just sink to the ocean bottom along with their ewaste. A staggering number are released each year by various countries, 22,630 in 2018 just from Canada. Birthday balloons are coated mylar (not biodegradable) and found everywhere in parks, deserts and wilderness of the US.

https://www.cbc.ca/news/politics/balloon-weather-environment-canada-radiosondes-ewaste-toxic-batteries-1.4897720
« Last Edit: October 02, 2020, 11:47:17 PM by A-Team »

oren

  • Moderator
  • First-year ice
  • Posts: 6313
    • View Profile
  • Liked: 2319
  • Likes Given: 1964
Re: MOSAiC news
« Reply #1219 on: October 03, 2020, 10:32:26 AM »
Big thanks for all the Mosaic updates.

A-Team

  • Young ice
  • Posts: 2705
    • View Profile
  • Liked: 649
  • Likes Given: 33
Re: MOSAiC news
« Reply #1220 on: October 03, 2020, 02:42:58 PM »
And thx to Uniquorn for getting this forum off the ground and contributing so much to buoy and other visualizations!

The wartime secrecy surrounding mundane data such as ship location, ice thickness, experimental layout, timestamps on photos, weather balloons etc etc was astonishing -- who was the enemy?

Not our melt and freeze forums. The enemy was the rest of the scientific community who might, most implausibly, steal data and publish first or worse, publish better. Wars always bring civilian casualties -- here the collateral damage was to public understanding of climate change.

They missed a great opportunity at the north pole, dropping memorializing trash and passing out souvenir water instead of doing scientific work, then rushing on for a short stay at a meaningless secondary floe. This year's ice mobility and melt ponds were especially auspicious for reaching the public, that didn't happen.

The public paid for the entirety of this expedition (includes $25 million from US public). If these scientists wish to do private science, let them pay for it out of their own pocket. In terms of ducking responsibility for public understanding of climate change (stale papers published in 2023 have zero impact), silence from scientists simply does not work.

Mosaic floated the preposterous notion that policy makers will read these 2023 papers and make the needed inferences about climate change abatement. Mosaic is an extreme version of controversy avoidance and seeking the least drama -- the scientists involved are fully aware it's already too late for the Arctic.

AWI is not an educational institution; even though everyone on staff lists themselves as professor, there are no students. Outreach was self-promotional and mis-directed, not overseen by anyone with a scientific background and often wrong.

Anything that went amiss -- and inevitably a lot did given the unexpected drift and floe shifts -- was strictly sanitized to present an unrelenting smiley face to the world. Information did emerge but was scattered all over Twitter and institutional blogs with no central directory.

I've attached their final weather summary. Like all graphics to date, it's done ineptly (eg scaling, wind rose, summary stats). The data going into is attached as a text file if someone wants to work on it. The source web page could disappear with the end of the expedition; the data will be retained but as a deep dive into archival petabytes.

https://www.awi.de/fileadmin/user_upload/MET/PolarsternCoursePlot/psobsedat.html
« Last Edit: October 04, 2020, 03:20:55 PM by A-Team »

Niall Dollard

  • Grease ice
  • Posts: 762
    • View Profile
  • Liked: 296
  • Likes Given: 71
Re: MOSAiC news
« Reply #1221 on: October 04, 2020, 12:56:03 PM »
And thx to Uniquorn for getting this forum off the ground and contributing so much to buoy and other visualizations!

+1

A somewhat grainy screenshot from the Zeppelin Station webcam at NY-ÅLESUND, showing the Polarstern.


uniquorn

  • Young ice
  • Posts: 2760
    • View Profile
  • Liked: 1249
  • Likes Given: 247
Re: MOSAiC news
« Reply #1222 on: October 07, 2020, 11:32:37 PM »
from https://twitter.com/seaice_de



Quote
Lead openings and deformation caused by the wind shear are rather abrupt events than continuous processes.

FishOutofWater

  • Grease ice
  • Posts: 873
    • View Profile
  • Liked: 501
  • Likes Given: 179
Re: MOSAiC news
« Reply #1223 on: October 13, 2020, 10:02:42 AM »
Thanks, Uniquorn and A-Team for all the images that you were able to pull out of this award winning expedition.

Update: they've stopped again to award themselves another award:

To those of us who have worked to communicate the science and stories of the climate crisis to the public, this mission was bitterly disappointing, but that was never the goal or even a concern. They did what they intended to do and are proud of it.

castaway

  • New ice
  • Posts: 2
  • https://mountaineerbr.github.io/
    • View Profile
    • Biologist Blogger
  • Liked: 1
  • Likes Given: 17
Re: MOSAiC news
« Reply #1224 on: October 13, 2020, 06:26:22 PM »
Congratulations for all that helped in this thread with data and opinions.
Specially uniquorn and A-team (because these are the ones I remember the most).
I read most of the posts over the last year, and it was great to know the insides and outs of this expedition thanks to you guys.
Everyone is going to try and make sense of the generated data, most amiss conclusions will be contaminated with fear.

A-Team

  • Young ice
  • Posts: 2705
    • View Profile
  • Liked: 649
  • Likes Given: 33
Re: MOSAiC news
« Reply #1225 on: October 14, 2020, 12:34:58 AM »
Quote
Expedition leader Markus Rex returned with a warning. "The sea-ice is dying," he told a media conference in Bremerhaven on Oct 12th "The region is at risk. We were able to witness how the ice disappears and in areas where there should have been ice that was many meters thick, and even at the North Pole - that ice was gone" ...BBC
It's looking now like early Mosaic abstracts will emerge at the EGU meeting this spring (and AGU too in Dec 2021). In past years, neither professional society has shared poster session material much less recorded talks for non-attendees.

That could change as meeting mingling is out of the question with covid19 resurgent everywhere in the EU.  Indeed they are saying 22nd EGU General Assembly will be held online 4-8 May, 2020. It's not clear if only paid registrants can hear the talks nor if they will be archived say on youtube with separate poster session or ppt graphics.

Looking at google scholar under 'Mosaic Arctic', quite a few EGU abstracts emerge. Some of these are 'works in progress' that don't have any results, only indicate later inclusion. Others address complex issues that cannot be effectively communicated in brief text.

It might make better sense to check in regularly at The Cryosphere for preprints and reviewer comments. However, not all Mosaic articles will be published there. Twitter sites often have links to new releases but that is difficult to follow systematically.

https://tc.copernicus.org/preprints/  nothing new through Oct 12
https://os.copernicus.org/  oceans
https://twitter.com/sthendric
https://twitter.com/seaice_de
https://twitter.com/lavergnetho
https://twitter.com/CKatlein
https://twitter.com/IlkerFer

Large Eddy Simulations of the Arctic atmospheric boundary layer around the MOSAiC drift track
Littmann, Daniela; Dorn, Wolfgang; Bresson, Hélène; Maturilli, Marion; Rex, Markus

The present study focuses on the influence of the surface conditions on the atmospheric boundary layer by applying the large eddy simulation model configuration of the icosahedral non-hydrostatic model.. ICON-LES is used here with a grid spacing between 50 m and 800 m and set up to a domain with radii of 10 km to 100 km around the MOSAiC drift track. The model is driven by output data from weather forecast simulations for selected stormy and calm days. Results of simulations with various spatial horizontal resolutions and with different surface conditions such as ice fraction, ice thickness, snow cover will be compared and evaluated against observational data.

Precipitation isotope (δ1⁸O, δ2H, d-excess) seasonality across the Pan-Arctic during MOSAiC
Mellat, Moein; Bailey, Hannah; Mustonen, Kaisa-Riikka et al

Stable isotopes of oxygen and hydrogen in precipitation (δ18OP, δ2HP, d-excess) are valuable hydrological tracers linked to ocean-atmospheric processes such as moisture source, storm trajectory, and seasonal temperature cycles. However, characteristics of δ18OP, δ2HP and d-excess and the processes governing them are yet to be quantified across the Arctic due to a lack of long-term empirical data. The Pan-Arctic Precipitation Isotopes Network (PAPIN) is a new coordinated network of 24 stations aimed at the direct sampling, analysis, and synthesis of precipitation isotope geochemistry in the north. Our ongoing event-based sampling provides a rich spatial dataset during the MOSAiC expedition and new insight into coupled climate processes operating in the Arctic today. Using back-trajectory analysis, we attribute these nuances to divergent moisture sources and transport pathways into, within, and out of the Arctic, and demonstrate how atmospheric circulation processes drive changes in isotope geochemistry and climate that are linked to sea ice concentration.

For example, Alaska moisture derived from the North Pacific Ocean, Sea of Okhotsk, and the Bering Sea remains relatively enriched in 18OP/2H due to higher sea surface temperatures, whereas moisture originating from ice-covered seas to the north is characterized by relatively depleted values.

Variability of Lagrangian pathways and coherent structures in the Arctic and its effect on the predictability of MOSAiC drift and material transport
Wilson, Chris; Rynders, Stefanie; Vredenborg, Myriel; Kelly, Stephen; Aksenov, Yevgeny

Since operational ocean forecasts have a limited time horizon (~weeks), we focused on hindcast to examine typical sea ice/ocean circulation scenarios for 2005-15. We applied off-line ARIANE particle tracking in an eddying 1/12 deg. global NEMO sea ice-ocean model to estimate the most likely drift pathways. Over 10,000 trajectories were initialised in October each year, started at the best estimated MOSAiC location, advected for one year and analysed for key coherent drift structures. The advection and deformation of the initial particle cluster provided information about MOSAiC drift predictability, but also elucidated transport processes of the biogeochemical tracers, such as nutrients and carbon, and spread of pollution and microplastics.

We analysed observations from a newly curated dataset of the Arctic to examine various water mass properties, their origin, fate and connectivity.The MOSAiC surface drift trajectories depend on release time and location, but to leading-order, they are governed by the interannual variability of the wind and of the underlying ocean circulation. Mesoscale flow deformation is linked to a spreading of the cluster of particles and is associated with reduced potential predictability of separation of particles within the cluster (~ 450 km after 12 months).

Gyre-scale flow affects the ensemble drift path over long times and influences whether particular coherent structures are encountered by the particles, their location and strength (in terms of velocity magnitude and gradient). Saddle-type structures play a major role in bifurcation of particle trajectories. In the examples studied, saddles north of Nares Strait, near Northern Greenland and Northern Iceland, topologically associated with streamline connectivity between gyres, coastal boundary currents and inflow/outflow at the Arctic gateways, were significant.

Fine scale motion tracking of sea ice over central Arcticusing TerraSAR-X data
Anja Frost, Suman Singha, Stefan Wiehle, Sven Jacobsen
https://elib.dlr.de/135033/2/FROST_interactive_Poster_CRSS2020.pdf

MOSAiC's Pan Arctic Water Isotope Network: Sea ice-water vapor isotope interactions and transport processes within, into and out of the Arctic
Kopec, Ben et al

Our MOSAiC project is focused on how the Arctic Basin's water cycle behaves throughout the year, especially now that sea ice loss allows for a new source of moisture to the atmosphere during times when this basin was formerly frozen over. These massive changes in open water and corresponding fluxes in conjunction with significant shifts in atmospheric circulation, are altering how moisture is transported into, within, and out of the Arctic Basin. In order to help quantify these Arctic hydrologic cycle variations, we have established the AWIN (Arctic Water Isotope Network) that uses continuous water vapor isotope measurements (δD, δ18O, and deuterium excess) at eight land-based stations from Barrow in Alaska to Ny Alesund in Svalbard, as well as on board the Polarstern.

For this analysis, we focus on the first months of the expedition (October-December 2019) to closely examine cases of critical events including a major low-pressure system in mid-November that impacted much of the Arctic Ocean basin and three key repeating transport regimes - 1) transport into the Arctic from the North Atlantic via the Greenland Sea, 2) transport into the Arctic via Baffin Bay, and 3) transport out of the Arctic via the Greenland Sea, as well as transport within the Arctic during each of these regimes. For example, in the scenario of transport into the Arctic via Baffin Bay, at our site in Thule, Greenland, we see significant reductions in deuterium excess each time the southerly flow initiates, suggesting significant moisture evaporating from nearby in Baffin Bay. We then can track that moisture to another site to observe how much of that locally-sourced vapor is transported to a given downwind location, allowing us to quantify vapor fluxes and isotopic fractionation processes across the Arctic.
« Last Edit: October 14, 2020, 01:37:44 AM by A-Team »

uniquorn

  • Young ice
  • Posts: 2760
    • View Profile
  • Liked: 1249
  • Likes Given: 247
Re: MOSAiC news
« Reply #1226 on: October 14, 2020, 01:28:33 PM »
T78 and T81 update.
T81 taking a long time to cool(thicken). There are some deployment notes for T78 but nothing for T81.
« Last Edit: October 14, 2020, 01:45:17 PM by uniquorn »