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blumenkraft

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Re: MOSAiC news
« Reply #50 on: October 01, 2019, 03:56:19 PM »
That must be it! ;)
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uniquorn

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Re: MOSAiC news
« Reply #51 on: October 01, 2019, 05:47:23 PM »
FRAM workshop nov2018. Everyone is doing their best. More data will turn up eventually :)
https://epic.awi.de/id/eprint/48526/2/T31_FRAM_workshop_20181122.pdf
Quote
Task 3.1   Short- and midterm Activities and Goals 19/20/21:
•Better implement ROV data flow!
Buoy data flow needs to be improved (MOSAiC!)    Current progress too slow. Needs additional manpower! 
•Concept for data costs! This is expensive for the sections!
•Personnel: Christian is in Canada until mid 2019, then contract runs out. Mario is 50% FRAM until mid 2019.
•Continuation as LKII: 520+260 kEUR, 3+2 FTE, Arc+Ant
•Manage SPOT & MOSAiC
•Continue developments, transfer all knowledge to AWI
My bold :)
edit:a daily copy into /maps/latest/ would do me
« Last Edit: October 01, 2019, 08:42:15 PM by uniquorn »

blumenkraft

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Re: MOSAiC news
« Reply #52 on: October 02, 2019, 09:36:11 AM »
--- NEWS ---
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blumenkraft

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Re: MOSAiC news
« Reply #53 on: October 02, 2019, 07:15:57 PM »
Slideshow with the latest images.
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ghoti

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Re: MOSAiC news
« Reply #54 on: October 02, 2019, 07:37:37 PM »
Quote
This search for a suitable floe is ongoing

This has become a common problem for placing instruments on the Arctic ice. It also means measurements are being done under unrepresentative conditions.

Using sampling to ultimately estimate the conditions of the entire Arctic via statistical analysis requires representative (usually random) sampling but this is no longer possible. The result is likely over estimation of sea ice thickness and stability.

A-Team

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Re: MOSAiC news
« Reply #55 on: October 03, 2019, 12:06:18 AM »
Mosaic is a fantastic endeavor that will provide a massive amount of observational data via an incredible array of modern instrumentation (relative to the last go-round, SHEBA, of 1999). Results will dominate the scientific literature on the Arctic Ocean for years to come because the interior basin has heretofore largely gone un-instrumented.

Mosaic will greatly improve the interpretability of satellite imagery and provide a reality check on model predictions never regularly confronted with observation. Just having real weather assimilated into daily ECMWF initializations is a huge step forward over meagre shoreline inputs, for example measured 2m winds responsible for icepack motion and export.

Ice-atmosphere couplings (eg radiative balance, boundary layer turbulent flux, cloud properties) depend on location and weather, not on the floe selected. While the Polarstern provides the center of observation, the secondary deployments go out a radius of 40 km. With drift, this generate a swath of measurements nearly a degree of latitude wide (111 km) wide, rather than point data (mooring) or line data (buoy).

The second study component is the ice itself. It has not yet proved possible to determine ice mass balance issues (thickness, bottom growth, melt ponds) year-round with any accuracy from remote sensing, much less modeling, so the comprehensive thicknesses will be a real breath of fresh air.

The third focus is water column under the ice. The anticipated drift across the Eurasian Basin does not seem ideal for the study of encroaching Atlantification (like N-ICE2015 or the PS's recent visit to the upper Fram), though the northern Laptev is an area of very active concern for mixing of thermal and saline stratifications.

It's never been clear what provides the vast volumes of return water to the East Greenland Current because the Waddell Sea and points north have been under thick ice for ages. Mosaic has an acoustic tomography experiment going relative to new moorings that can address this.

Mosaic planners knew from the outset that finding a suitable floe would be mission-critical. They allocated a full week for that search; as I write, the ship has been at N 85°12' E 134°18' for eight hours. They are looking for 1.2 m or thicker ice, a port-side mooring for logistics, and a large enough floe so that electricity and LAN data lines can reach remote instrumentation.

The safety issues involve pressure ridges heaving experimental set-ups, leads opening suddenly, nearby floes over-rafting, patches of very thin ice, strong swells from remote storms, aggressive penguins walruses and bears, plus working long hours in cold, dark and possibly very windy conditions. (The PS serves alcohol at two on-board bars.)

I am skeptical -- based on the multi-satellite September time series below -- that they will find the perfect floe at 85ºN because the Laptev is in such poor condition but if they go much farther towards the Pole, there may not be notable net drift towards the Fram.

The gif below shows Osisaf, Ascat and Smos embedded within a novel differential AMSR2. The complex palette is provided in the lower left corner. The Polarstern search wedge, called a spherical rectangle or section double frustrum, is shown as an overlay (map adornment) for each satellite. The base resolution is 6.25 km/pxl for AMSR2 unchanged from archive.

With so much data coming in so many forms, synchronized integration becomes increasingly important in science-retaining visualizations. While this one was easy enough to make, it doesn't roll forward because of the differencing wrt a fixed final day, 30 Sep 19.
« Last Edit: October 04, 2019, 04:22:08 AM by A-Team »

oren

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Re: MOSAiC news
« Reply #56 on: October 03, 2019, 02:45:45 AM »
Hello A-Team! Your posts are always welcome. Astounding visualization.

I was wondering if Mosaic might make their thickness measurements available. I am more interested in the many floes they skip, rather than the one floe they finally select (if they even manage to find a suitable one). I see this a a very rare opportunity to compare direct local measurements to SMOS remote sensing and to PIOMAS modelling.

uniquorn

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Re: MOSAiC news
« Reply #57 on: October 03, 2019, 08:31:57 PM »
That pallette highlights another fracture along the Lomonosov ridge from sep24-26 which I hadn't noticed before. These are not frequent, but not uncommon either. It's possible that they'll be drifting in that direction.

update on PS location and temps, looks like more buoys, 29 currently on the iabp table
http://iabp.apl.washington.edu/maps_daily_table.html
https://www.sailwx.info/shiptrack/shipposition.phtml?call=DBLK

uniquorn

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Re: MOSAiC news
« Reply #58 on: October 03, 2019, 09:53:26 PM »
By the way, does anyone recognise this buoy from the mosaic image upthread?

A-Team

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Re: MOSAiC news
« Reply #59 on: October 04, 2019, 03:47:42 AM »
Not real helpful to tweet a buoy picture without furnishing its identifying number and capabilities.

Here is a very nice site hosting SIMB3 buoy data. The founding engineers were graduate students with Don Perovich at Dartmouth so it is safe to assume robust design standards were used in manufacturing these buoys. The Polarstern has not yet deployed its four. There is one just launched in the Beaufort (IMEI: 386840), that is showing just 90 cm of ice well in from the periphery. The first figure shows condensed hightlights of this site. Hopefully someone here can explore the embedded graphics option that they offer.

https://uploads-ssl.webflow.com/5ce41274c00488a72c34a503/5d5eac596e0dbc1338aad5f6_SIMB3_Data_Sheet.pdf
https://www.cryosphereinnovation.com/data

The Polarstern is carrying 14 other buoys with tracking csvl provided by APL at UW. These are active but have not yet gathered much data.
http://iabp.apl.washington.edu/maps_daily_table.html

@Zlabe has some great new summary graphics for the Arctic which I combined with an Ascat and Polerstern location wedge.. These show that the air and water are anomalously warm for September.

A good way to keep current: set up your web browser to open a tab set for this list of links:

http://osisaf.met.no/p/osisaf_hlprod_qlook.php?year=2019&month=10&day=01&action=Today&prod=LR-Drift&area=NH&size=100%25
ftp://ftpsrv2.awi.de/sea_ice/mosaic/jpg/large/
ftp://ftpsrv2.awi.de/sea_ice/mosaic/jpg/large/mosaic_multisensor_map_2019-10-02_hr_NoOverlay.jpg
ftp://ftp-projects.cen.uni-hamburg.de/seaice/AMSR2/3.125km/
ftp://ftp-projects.cen.uni-hamburg.de/seaice/AMSR2/3.125km/Arc_20191002_res3.125.png
https://manati.star.nesdis.noaa.gov/ascat_images/ice_image/msfa-NHe-a-2019271.sir.gif
https://seaice.uni-bremen.de/data/smos/png/20191002_hvnorth_rfi_l1c.png
https://seaice.uni-bremen.de/data/smos_smap/png/north/ (has not resumed as of Oct 3d, still on 31 July 2019)
https://seaice.uni-bremen.de/data/smos_smap/netCDF/north/2019/  (has not resumed as of Oct 3d, still on 31 July 2019)
sailwx.info/shiptrack/shipposition.phtml?call=DBLK hourly coordinates for Polarstern
« Last Edit: October 04, 2019, 04:24:03 AM by A-Team »

A-Team

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Re: MOSAiC news
« Reply #60 on: October 04, 2019, 04:00:09 AM »
Here is that active SIMB3 buoy in the Beaufort. It is not exactly part of the Mosaic expedition though it seems Perovich is sailing steaming dieseling on the Polarstern. As noted, the ice plus snow is not yet a meter thick. meaning the ice alone is thinner still.

Buoy data are better plotted in polar stereographic than mercator-like projections. The meridian is very easy to find using AMSR2 UHH because it has a 1º longitude graticule on its outside, easily exposed by picking land-red and deleting to alpha in a blank floating layer.

To intersect with the latitude, the base map has a scale of 839 pixels out to 75º which pencils out to 59.33 pixels per degree. So just multiple by buoy latitude and draw a circle out that many pixels, fill the boundary. Then place the star on the actual AMSR2 layer according to the floating layer.

Quote
Oren: wondering if Mosaic might make their thickness measurements available. I am more interested in the many floes they skip, rather than the one floe they finally select
I had that same question because we have long been starved for real ice thicknesses. I wrote the help desk but the 'Send' button wasn't operative. Those EMbirds measure distance to the surface and distance to the saltwater very accurately and with excellent horizontal resolution. On N-ICE2015, they timed the flights to coincide with the satellite overpass and spot surface drilling.

They may not retain the data after rejecting the floe, not feel it is properly  calibrated, or not have the bandwidth to send it ashore. Iridium data packets from buoys are a few hundred bytes (if you can remember what those were).

On the selected floe, which will likely be a fused composite of floes with different histories, they are planning a comprehensive 4D study of its thickness and freeze thaw cycle from above and below. So hopefully an interactive 3D model like we see for some of the Greenland glaciers.

The PS has still not found its floe but must be in a promising area because they have been lingering along 85º for several days. They haven't missed much TPD; OsiSaf had a couple of days of that but today the ice is back floundering about as it did all summer.

@zlabe attributes this to the persistent negative (N)AO and lack of seasonal polar vortex transition. Useful references as the atmosphere transitions to the NH wintertime circulation:

+[Polar Vortex] https://t.co/pDd73GKvxd
+[Sudden Stratospheric Warming] https://t.co/T5kyOBO2vC
+[Quasi-Biennial Oscillation] https://t.co/XVqccdx5jd
+[Atmospheric Coupling] https://t.co/3yttvdHeLy

Can someone here explain what significance the dew point has in these circumstances? Or do they just collect it because that's easier than not collecting it?
« Last Edit: October 04, 2019, 04:51:51 AM by A-Team »

Jim Hunt

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Re: MOSAiC news
« Reply #61 on: October 04, 2019, 11:36:04 AM »
The Polarstern has not yet deployed its four.

I am still anxiously awaiting data from those four. However Polarstern does at least now seem to have found a floe to get frozen in next to:

http://GreatWhiteCon.info/2019/09/the-mosaic-expedition/#Oct-04

Quote
We finally found the piece of ice that will be the home for Polarstern for the next year. It’s a floe a few kilometers in diameter and with thickness ranging from half a meter to a few meters.

Quote
Hopefully someone here can explore the embedded graphics option that they offer.

I'll see what "Snow White" and I can come up with!
« Last Edit: October 04, 2019, 01:14:40 PM by Jim Hunt »
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uniquorn

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Re: MOSAiC news
« Reply #62 on: October 04, 2019, 12:40:44 PM »
A quick look at mosaic aibp buoy locations up to oct4, just lat/lon, no projection.
5 buoys listed are not in this area 84-86N 120-140E
http://iabp.apl.washington.edu/maps_daily_table.html

uniquorn

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Re: MOSAiC news
« Reply #63 on: October 04, 2019, 01:13:38 PM »
A closer look at 4 of them. Dates A time series will be useful when it's a bit clearer what is happening. Some of this looks like drift, some of it delivery. All the scales are different here to maximise the image size.
edit: slower gif
« Last Edit: October 04, 2019, 01:26:46 PM by uniquorn »

gerontocrat

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Re: MOSAiC news
« Reply #64 on: October 04, 2019, 02:42:44 PM »
Hello A-Team! Your posts are always welcome. Astounding visualization.

I was wondering if Mosaic might make their thickness measurements available. I am more interested in the many floes they skip, rather than the one floe they finally select (if they even manage to find a suitable one). I see this a a very rare opportunity to compare direct local measurements to SMOS remote sensing and to PIOMAS modelling.

I am also wondering if and when IceSat-2 data is going to be part of an integrated data suite.

http://www.spacedaily.com/reports/Laser_precision_NASA_Flights_satellite_align_over_sea_ice_999.html
Laser precision: NASA Flights, satellite align over sea ice
Quote
In April, instruments aboard NASA's Operation IceBridge airborne campaign and the Ice, Cloud and Land Elevation Satellite-2 succeeded in measuring the same Arctic sea ice at the same time, a tricky feat given the shifting sea ice. Scientists have now analyzed airborne and spaceborne height measurements, and found that the two datasets match almost exactly, demonstrating how precisely ICESat-2 can measure the heights of the sea ice's bumpy, cracked surface.

Sea ice height profiles from ICESat-2 can tell scientists whether the ice is a newly formed, smooth surface or an older, rougher section. The key measurement from ICESat-2, however, is how high the ice surface is above the open water, called freeboard. If scientists know that number, they can calculate the thickness - which isn't directly measured from satellite data. When Kwok and his colleagues compared freeboard measurements from ICESat-2 and Operation IceBridge's Airborne Topographic Mapper instrument for the April flights, they were within 0.8 to 1.6 inches (2 to 4 centimeters) of each other.

With additional flights over land and sea ice in both Greenland and Antarctica this fall, Operation IceBridge is continuing to help assess ICESat-2 data, along with other efforts including the third year of an Antarctic ground traverse along a section of the 88 degree South line of latitude.
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A-Team

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Re: MOSAiC news
« Reply #65 on: October 04, 2019, 03:21:02 PM »
Nice spotting, Jim. Now if we only had a list of all urls from the people on board tweeting or posting to home institution blogs, we could keep up a lot better.

https://www.bnl.gov/mosaic/ collects posts from Brookhaven NL and posts some very nice photos. They are going to have a huge problem initially with polar bears because those are highly concentrated near the Laptev sea ice edge where the food is, rather than swimming around in 1000 km patch of open ocean.

Hopefully they can scare the bears off and not shoot them the way drilling projects on Greenland have done. Walrus have been in the news lately too, sinking a Russian zodiac near FJL. The Oden photographed a walrus messing with scientific gear last summer at the North Pole. A walrus thrashed Nansen's kayaks on the return trip. I don't anticipate any problems with penguins.

I have belatedly realized that a changing hourly PS position report from sailwx doesn't mean the ship is underway because sea ice drift is of comparable magnitude to them poking about looking for the perfect floe.

They have fixed the daily ice obliteration on the Sentinel radar; the heavy triangle is gone and replaced by a too-small circle. It's still opaque though. The problem is working with one layer; the red route should be done in a second layer with a transparency slider (a capability offered already in Feb 1990 by Photoshop 1.0).

The reason I bring this up is we need a very clear radar image of the floe in order to match it with Sept 21-24 visible Worldview (the last clear sunlit days) to allow traceback of its origin to early June when Ascat can pick up its motion back to formation in the fall of 2018.

As Uniq noted earlier, this is best done using the unadorned jp2 file served by polarview.aq/arctic. It sounds though that the floe can still be photographed from above in the visible even though WV's growing pole hole blacked out this latitude and north about ten days ago.

That is, the PS will determine all its current and future properties such as healed leads, pressure ridges, underwater keels, brine pockets, bottom algae, sunlight transparency, snow layers, fire soot etc etc.

My expectation is this floe formed as FYI on the periphery of the ice pack maybe two hundred km north and a bit east of Kotelny Island (NSI). It is not a piece of MYI from the Beaufort arm, nor related to thick ice between the Pole and CAA, nor broken-off landfast Siberian ice. It then drifted over the last 11 months, initially along its parallel (ie zonally) but with an admixture of south meridional this spring, to its current position, graduating to SYI on Sept 15.

Note the primary floe at 3 km diameter is far short of the 30-40 radius necessary for the secondary deployments. The adjacent floes, whose leads are now freezing up, will have a similar provenance. These will thicken but never attain the structural strength of the main floe. Thus the Polarstern is thus moored on a future shear line.

I've attached a bit of Norwegian maritime humor because the main Mosaic planning document shows the PS moored starboard. It is customary for the captain to be given a green and red sock as mnemonic to avoid collisions with other transiting vessels.

Following up on earlier observations of FishooW and Zlabe on the unusually persistent negativity of the North Atlantic Oscillation (NAO) this summer, I graphed the last 12 months of daily readings. The onset in late May coincided very closely with the cessation of Fram/Nares export and TransPolar Drift, per Ascat and OsiSaf. No return to positive winter values is foreseen this month.

https://www.cpc.ncep.noaa.gov/products/precip/CWlink/pna/nao.shtml

TPD drift would be nice but most research programs on the Polarstern don't require it. A lot of this is Nansen nostalgia (or should I say Sverdrup nostalgia as he captained the Fram after Nansen abandoned ship).

The Akademik Fedorov is named after a distinguished early participant Yevgeny Fyodorov (Фёдоров) in the first of many Russian sea ice drift experiments. (These 'don't count' as not conducted by westerners, any more than Alfred Wegener, not an American, counts as the 1912 discoverer of plate tectonics despite a whole book on continental drift.)

Russian scientists landed a plane (no runway) at 89°25′N 78°40′W in May 1937 and drifted 2,850 km over nine months to mid-Greenland where they were miraculously picked off by icebreakers before the floe melted out. (They carried a hand-cranked radio so did not depend on a battery charge lasting.) The PS carries two Piston Bullies to plow airport-smooth runways, along with innumerable creature comforts, yet millennials on board complain every day about perceived hardships.

https://en.wikipedia.org/wiki/Yevgeny_Konstantinovich_Fyodorov
https://en.wikipedia.org/wiki/Drifting_ice_station

Some of the AWI documents conflate ice drift on the ocean (entirely wind-driven) with ice floating down a river (eg annual breakup of MacKenzie). Surface currents in the central Arctic Ocean are entirely negligible (discounting keel-induced local advection). AO tides and tidal currents are very minor and also irrelevant.

Think of a dry leaf skittering along the sidewalk. It's the wind that carries the leaf along. The sidewalk itself is not moving. For the Arctic Circumpolar Boundary Current see:

https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2010JC006637
« Last Edit: October 05, 2019, 11:15:43 PM by A-Team »

Jim Hunt

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Re: MOSAiC news
« Reply #66 on: October 04, 2019, 03:56:02 PM »
The Oden photographed a walrus messing with scientific gear last summer at the North Pole.

In a fortuitous face to face meeting with Helen Czerski at Silverstone earlier this year I asked her how it might have got there.

She said that whilst it wasn't her speciality she believed that in extremis Walrus have been known to eat seals.
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blumenkraft

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Re: MOSAiC news
« Reply #67 on: October 04, 2019, 04:12:23 PM »
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A-Team

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Re: MOSAiC news
« Reply #68 on: October 04, 2019, 04:43:24 PM »
Walrus eat all kinds of stuff besides shellfish. Here are some published accounts:

-- 2008 BBC footage of walruses hunting spectacled eiders overwintering in the Bering Sea
-- thick-billed murres taken time and again by walruses off Coats Island in Hudson Bay
-- successful walrus attacks on molting pink-footed geese off  Svalbard
-- walrus catching bearded seals
-- stomach of walrus filled with large pieces of sealskin with the blubber attached,
-- walrus shot with floe seal in its mouth which it had just captured;
-- walrus killing and eating a wounded polar bear
-- group of walruses eating a narwhal

https://esajournals.onlinelibrary.wiley.com/doi/pdf/10.1890/1540-9295-12.5.312
« Last Edit: October 04, 2019, 07:44:31 PM by A-Team »

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Re: MOSAiC news
« Reply #69 on: October 04, 2019, 06:07:18 PM »
AWI blog post:

A fortress of ice and snow

Link >> https://www.awi.de/en/about-us/service/press/press-release/a-fortress-of-ice-and-snow.html
According to GFS there is a plume of very warm air heading their way from the North Atlantic in around 5 days or so.
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be cause

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Re: MOSAiC news
« Reply #70 on: October 04, 2019, 06:42:27 PM »
'I hope there will still be a floe for them to attach to come the fall ' .. my thoughts when this expedition was reported in the 'what's new thread back in June . Seems my concerns are being realized . I really wish every success to everyone involved ; in the Arctic , elsewhere and of course here on ASIF .. and it is a joy to once again welcome A-team back among us .

  .. still free b.c.  :)
 
2007 + 5 = 2012 + 4 = 2016 + 3 = 2019 ...

gerontocrat

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Re: MOSAiC news
« Reply #71 on: October 04, 2019, 07:52:42 PM »

  .. still free b.c.  :)
 
and not on the run from Mr. Plod?
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SteveMDFP

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Re: MOSAiC news
« Reply #72 on: October 04, 2019, 08:47:41 PM »

  .. still free b.c.  :)
 

Very happy to hear that!!

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Re: MOSAiC news
« Reply #73 on: October 04, 2019, 10:36:13 PM »
This is currently the top story on the bbc science page.

https://www.bbc.co.uk/news/science-environment-49941340

Hopefully this means the expedition is going to be broadcast to a wider audience.

Also some good photos of the state of the ice around the ship.

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Re: MOSAiC news
« Reply #74 on: October 04, 2019, 11:12:17 PM »
Polarview this morning

A-Team

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Re: MOSAiC news
« Reply #75 on: October 05, 2019, 12:20:37 AM »
Some good material on that BBC page above. Some highlights are captured below:

"After a brief but intensive search, we've found our home for the months to come," said expedition leader Prof Markus Rex, from AWI. 

"It may not be the perfect floe but it's the best one in this part of the Arctic and offers better working conditions than we could have expected after a warm Arctic summer."

Sixteen locations were scouted with the aid of satellite imagery and helicopters. A floe measuring 2.5km by 3.5km was eventually chosen.

The ice looks very fractured but that can largely be attributed to two icebreakers coming in. Freeboard looks fairly minimal but that is hard to estimate from oblique photos. The snow depth is again ankle-deep (15cm). That is still enough to insulate the ice somewhat from the cold of the air which has been running -8 to -12ºC in recent hours.

"Snow is an insulator. Its R-value varies depending on moisture content and density of the snow granules; but on average snow has an R-value of 1 per inch — about the same as wood. Twelve inches of snow have roughly the same insulating value as a 2x4 wall filled with fiberglass insulation." [R value is a US spec; I don't know what it corresponds to in Euro-land.)

In theory, there should be a timestamp, GPS location, direction of view, etc in the exif metadata buried in the photo file. However that is routinely scrubbed or altered during production. The online tools below could not find anything of interest. Sept 30th dates are indicated but those might be spurious.

The cost of €130m ($150m) of the enormous MOSAiC scientific mission is fairly modest, very similar to the reported cost of a single RQ-4A Global Hawk BAMS-D surveillance drone like the one Iran downed in June. The US military budget for the 2019 year is $693,058,000,000 or enough for 4620 Arctic Mosaic expeditions.

https://www.verexif.com/en/index.php
https://www.get-metadata.com
« Last Edit: October 05, 2019, 12:34:41 AM by A-Team »

A-Team

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Re: MOSAiC news
« Reply #76 on: October 05, 2019, 12:56:35 AM »
Thanks to Uniq at #74, we can compare the Sentinel-1 images being archived by Mosaic for ice motion to the originals served at https://polarview.aq/arctic. (Note #74 includes essential photo ID parameters unlike the Mosaic archive which is blending multiple dates.)

The image below needs a click to display at its 1190 x 584 pixels 'native' resolution. The Mosaic image had to be enlarged 300% to more or less match features which pixelated them terribly.

I found the blue ice motion arrows to be way off the mark both in direction and speed in comparing 3-4 Oct; they may just be dumbed down OsiSaf which span 48 hours and are not nearly of the needed resolution. Overall ice pack motion is better followed in Ascat from late Sept to early June.

Mosaic may just have made a temporary archive merely for floe-finding; hopefully they will settle in soon to better characterization of drift (for which they plan a large array of GPS units that also measure local pack deformation). There are quite a few compressible spaces now not fully frozen over, yet the motion in a 1º x 1º rectangle about the ship is mostly cohesive (uneven wind stress? weaker ice to the south?).

Sailwx only reports PS position to one decimal degree (~11km) and does not provide stern-to-bow azimuths needed for tracking ship+floe rotation. The PS knows very accurately where it is located and pointed but so far we don't where/if that data is being shared in nrt. However sailwx is hourly whereas S1AB has at best twice daily temporal resolution.

It's easier to track floe motion in the visible though WorldView has gone dark and will stay dark into March. However for provenance of the selected floe, summer dates are needed. Taking some cloud-free days, it proves feasible to match up Terra to S1 features -- which appear very different at different wavelengths. If the ice hasn't moved too much, it should still be possible to find the selected floe in visible. Needs click to enlarge.
« Last Edit: October 05, 2019, 01:38:27 AM by A-Team »

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Re: MOSAiC news
« Reply #77 on: October 05, 2019, 02:10:48 PM »
Take an inside tour of the Polarstern?

"During the historic meeting of USCGC Healy and Germany's RV Polarstern at the North Pole on 07 Sept 2015 we had the opportunity to exchange visits.  Both ships were conducting Arctic GEOTRACES cruises."

http://www.geotraces.org/news-50/news/116-news/1134-geotraces-arctic-expeditions-successfully-completed

Goddard Institute assembled the last cloud-free visible satellite mosaic of the Arctic Ocean over Sept 17-23. The PS is shown by a red dot at its selected floe on 01 Oct 19.

“We’ll have to wait and see if it’s also stable enough to withstand the autumnal storms that are now brewing,” PI Markus Rex said, adding that the team is “prepared for all scenarios.”

Right. The ice in the northern Laptev has not really set up yet. They have made the best possible decision under the circumstances. A lot of laboriously deployed instrumentation and infrastructure would have to be pulled back on board in the event of swells, flooding of the floe, ridging or shearing.

I worked out the scale on the Polarview imagery Uniq posted in #74 using the distance between 85º-86º as 111.67 km in WGS84 ellipsoid which all GPS devices reference. From the approximate dimension of the selected floe 3.5 x 2.5 km, it is possible to identify the object as a dark oval on S1 radar.

When the next image surfaces on Polarview, we can use the pair to compute real non-gridded velocities because the PV file name provides the UTC time the image was taken to the second.
« Last Edit: October 05, 2019, 10:37:49 PM by A-Team »

uniquorn

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Re: MOSAiC news
« Reply #78 on: October 05, 2019, 02:24:32 PM »
Here looking at freezing indicated in the Laptev further south by both uni-hamburg amsr2 and uni-bremen SMOS with Mosaic buoy iabp300234068312210. The labels are temperature and day number with hour. Rough location is ringed just on the edge of worldview terra modis visible today.
https://go.nasa.gov/35cKcRd
buoy type is SVP=surface velocity profiler http://iabp.apl.washington.edu/Acronyms.html
« Last Edit: October 05, 2019, 05:53:33 PM by uniquorn »

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Re: MOSAiC news
« Reply #79 on: October 05, 2019, 10:05:14 PM »
Right, the big issue now is how fast the Polarstern's safety zone will grow to the south (towards New Siberian Islands). A buffer for long reach swells would really improve their situation, as would solidified adjacent ice.

Sept 2019 is an especially unfavorable for late open water/slush in the northern Laptev mooring area as the PS team is well aware (3rd and 4th graphics). The latter appends Oct 2018, though that scarcely provides a prediction for this autumn.

I found some trackable features for Oct 04 back to Sep 21 enveloping the Chosen Floe (which itself is not so trackable) and was able to follow them back into Modis/Worldview daylight. The ice has been going around in an aimless circles with no sign of TransPolar Drift onset. Despite leads opening and closing, this region of ice has been moving mostly like a rigid block.

Last May, we found the best way to quantify deformation was via Delaunay triangulation. That is, if three features form a triangle, its changing lengths and angles -- whose values ImageJ conveniently tabulates in CSV -- describe ice deformation since triangles unlike quadrilaterals etc are rigid. This method was used in a recent N-ICE2015 article for the same purpose.

https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2016JC012387

Sentinel-1 does not fly over every day by any means. They seem to be using other sources of imagery in a mix-and-match manner. For example, Sept 25th is a just an exact copy of Sept 26th in the region shown.

The satellite usage table below from Mosaic's main planning document shows the options (needs a click to be readable; color legend is screwed up). Naturally, they have a budge gto buy commercial coverage as needed.
« Last Edit: October 05, 2019, 11:19:57 PM by A-Team »

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Re: MOSAiC news
« Reply #80 on: October 06, 2019, 12:28:48 AM »
Only marginally off topic, after successfully surfing the meat of ex Hurricane Lorenzo's swell at Bude, North Cornwall this morning I wandered into the middle of an art installation:

https://twitter.com/jim_hunt/status/1180548568903499778

Perhaps Neo is scanning the horizon for hungry walrus?
Reality is merely an illusion, albeit a very persistent one - Albert Einstein

Jim Hunt

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Re: MOSAiC news
« Reply #81 on: October 06, 2019, 12:39:44 AM »
Meanwhile here's a very crude initial version of the GWC winter 2019/20 Ice Mass Balance buoy page:

http://GreatWhiteCon.info/resources/ice-mass-balance-buoys/winter-2019-20-imb-buoys/#MOSAiC-1

Now including MOSAiC IMB buoy #1:
« Last Edit: October 06, 2019, 08:30:49 AM by Jim Hunt »
Reality is merely an illusion, albeit a very persistent one - Albert Einstein

uniquorn

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Re: MOSAiC news
« Reply #82 on: October 06, 2019, 01:29:50 PM »
Polarview this morning. PS and AF quite close to each other.

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Re: MOSAiC news
« Reply #83 on: October 06, 2019, 02:24:20 PM »
Below are some floe tracking images that tie precise lat/lon positions into the WorldView visible dates when floes are more intuitively portrayed in clear weather. The first provides 16 days of daily displacements of the PS Floe based on their archived mix of radar images. Based on a fairly strong anticyclonic OsiSaf today, I expect Floe movement to the 'right' overnight.

The Floe is embedded in a larger context that moves as a semi-rigid block; indeed the whole ice pack is still exhibiting coherence but daily morphological plasticity as can be seen in the translucent greenish animation from earlier in Sept. (Ascat arrives as grayscale but two other channels for color can be made from fourier bandpass filtering that emphasize different scales of contrast variability.)

Sentinel imagery that Uniq has been posting is far higher quality but involves handling large initial files in unpopular jp2 format. The 16bit depth provides much more latitude in contrast adjustment though the gains are not as phenomenal as with 8bit Ascat. At the end of the day, everything has to be posted in 8bit x 3.

In the file names, 20191004T064336 parses out to 2019 Oct 04 at UTC time 06:43.36. The two images are then 06:27 - 06:43 apart or 16 minutes short of 48 hours, critical to accurate measurement of floe motion. It's possible to make 'interferometric' color images from just two frames in ImageJ; these have excellent prospects for displaying deformation over the whole region. As always we are very dependent on satellite providers for spot-on pixel geo-registration.

S1B_EW_GRDM_1SDH_20191004T064336_49AC_N_1.16bit.jp2
S1B_EW_GRDM_1SDH_20191006T062717_2BFE_N_1.16bit-2.jpg

The dark blob in the center corresponds to the ice oddity in the first image of #77. It has stood out for since last autumn out as a relatively white region in plain Ascat; it is one of the last regions of thick MYI; it barely experienced TPD last winter.

The third image illustrates tracking of an unrelated floe in Modis Terra. Note daily or better coverage is needed to define motion as the 'shortcut' shown does not capture details of multi-day motion.

The fourth image shows the all-weather forward view from the bridge. The dark triangle is aft. While the floe shapes seems terribly distorted, publications have used it in the past to measure floe jostling and ice deformation. This clip is from an earlier voyage. The PS may have it turned on while moored but is not uploading it to a public archive as far as I know.

https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2016JC012387 ship radar N-ICE2015
« Last Edit: October 08, 2019, 01:09:50 PM by A-Team »

uniquorn

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Re: MOSAiC news
« Reply #84 on: October 06, 2019, 03:14:09 PM »
I made some headway with buoy tracking. This visualisation may be useful. Still no projection, just lat/lon. iabp buoy type is IT=Ice tracker, maybe it is on a snowmobile/helicopter?
edit: 36km in 30min, according to the NOAA calculator https://www.nhc.noaa.gov/gccalc.shtml, maybe helicopter.
« Last Edit: October 06, 2019, 05:15:22 PM by uniquorn »

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Re: MOSAiC news
« Reply #85 on: October 06, 2019, 06:18:28 PM »
The mosaic multisensor map is improving all the time, from large opaque pointer and path to semi transparent for both. :) sep28-0ct5 crop. Maybe it will go to higher resolution as the movement slows down.
I'm not able to match the buoy path above with PS movement so far. Maybe helicopter flying between boats?? I realise the buoy map needs to be inverted and flipped.

edit:added latest polarview sentinel1 jpeg with graticule, showing the position of both boats. Mosaic insert top left
« Last Edit: October 06, 2019, 06:47:47 PM by uniquorn »

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Re: MOSAiC news
« Reply #86 on: October 06, 2019, 08:12:27 PM »
I thought it was accurate buoy placement, but I think sailwx latitude chart resolution is struggling this far north. Probably not much value in posting further.
edit: apologies to the chart creator, the saliwx lat/lon data is only 1 decimal place.

Off the map for ecmwf windy also. ~50km windswesterlies forecast further south on tues.
edit:added the drift path for whoi itp116 close the the pole which is stubbornly refusing fram export at the moment. (grey arrows are the annual drift track)
« Last Edit: October 07, 2019, 03:00:06 PM by uniquorn »

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Re: MOSAiC news
« Reply #87 on: October 07, 2019, 12:06:23 PM »
Smos/Smap has fired up its daily archive at U Bremen again as of Oct 4th, having ceased production on July 31. This provides an improved thin ice prediction map relative to plain vanilla Smos (which archives all year despite accuracy deterioration in summer) by using complementary input from a second satellite instrument.These are both passive microwave sensors that provide brightness temperatures at 1.4 GHz.

https://www.the-cryosphere.net/13/675/2019/ Feb 2019 free full Smos/Smap
https://www.mdpi.com/2072-4292/10/4/553 Apr 2018 free full Schmidt Kaleschke
https://zenodo.org/record/1631856#.XZr_GOnmBQY Nnov 2018 tech spec Schmidt Kaleschke

Smos/Smap runs two days behind rather than one day late like Ascat, Smos, OsiSaf, Amsr2 etc. The cut-off is 0.5 m; all ice thicker than that is shown in the same palette color (even though some value remains in the 0.5 to 1.0 m range).

Thus it is most useful right now for Mosaic, near the ice edge during freeze-up.

The 'pole hole' is larger for Smos/Smap (out to 87º) than for Smos. That's just as well because that of Smos is almost always ringed with artifacts. Both use the same thickness palette. Ground resolution is not great but the png's are released at a much more generous size (1173 x 2170 pxl) than Smos (624 x 757 pxl).

It is generally better for enlargements to be done in-house from the raw numerical data than done later from postage-stamp products. For example, the data-obliterating graticule need not be so badly dithered in. Note though that some netCDF tools like Panoply use linear interpolation whereas bicubic probably gives better results.

The first image below shows the two are nearly identical on Oct 5th. This means that Smos was likely quite accurate earlier in Sept contrary to popular opinion.

In terms of the Polarstern, the <0.5m thin ice of the Laptev anomaly starts just to their south. This doesn't have the resolution to speak to individual floes that might be thicker (or practically open water).

The Sep-Oct time series of Smos shows thickening is preceding quite slowly, with thin ice not clearing the pole hole at 87.5º until Sept 22nd. The Polarstern is parked at 85º. This means a lot of ice between the ship and Pole is still quite thin, well less than a meter.

Since one degree of latitude is 111 km, the PS is currently some 555 km south of the pole. The Great Laptev Bight of thin ice reaches up another 555 km from the south. Above Banks Island in the Beaufort, the ice has thickened beyond 0.5m for 1839 km. More typically, thicker ice extends out 1100 km from the pole, the FJI-SV line being another exception like the Laptev. These asymmetries probably reflect the location of the cold pole vs direction of proceeding Atlantification.

Measuring the distances ccw from pole to Smos/Smap thin ice edge on 05 Oct 19 using the 15º graticule, the average distance pencils out to 881 km. Adding up the areas of all the triangle by side-angle-side method using sin(15º) = 0.259 for included pole angle between sectors gives 5,633,429 sq km.

The velocities at which these are expanding would give some idea of when the deployed Polarstern experiments gain a margin of safety; see #79.

lon   pxl   km          lon   pxl   km
  0   266   1107        180   291   1212
 15   209    870        195   260   1083
 30   210    876        210   267   1113
 45   196    816        225   389   1620
 60   172    717        240   347   1446
 75   183    762        255   257   1071
 90   192    801        270   193    804
105   173    720        285   171    711
120   160    666        300   211    879
135   137    570        315   178    741
150   145    603        330   137    570
165   149    621        345   186    774

229   441   1839 farthest ice edge in Beaufort

mage archives:
https://seaice.uni-bremen.de/data/smos_smap/png/north/2019/
https://seaice.uni-bremen.de/data/smos/png/20191006_hvnorth_rfi_l1c.png
« Last Edit: October 08, 2019, 12:04:32 PM by A-Team »

Jim Hunt

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Re: MOSAiC news
« Reply #88 on: October 07, 2019, 12:35:12 PM »
Hot off the MOSAiC news feed:

http://GreatWhiteCon.info/2019/09/the-mosaic-expedition/#Oct-07

Quote
On Friday evening at 9:30 p.m. boat time the team of MOSAiC Expedition reached their destination: the floe which had been chosen some days before.
Reality is merely an illusion, albeit a very persistent one - Albert Einstein

uniquorn

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Re: MOSAiC news
« Reply #89 on: October 07, 2019, 04:17:41 PM »

RoxTheGeologist

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Re: MOSAiC news
« Reply #90 on: October 07, 2019, 06:24:10 PM »

I find the water temp line very satisfying for some reason. It's good to know the universe is working as intended.

Thank you A-Team and Uniquorn. It's going to be a very exciting winter for all scientists, including those of us firmly seated in our armchairs.



A-Team

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Re: MOSAiC news
« Reply #91 on: October 07, 2019, 10:19:20 PM »
Safety is a huge issue: a lot of things can go wrong with so many people deploying so many experiments over a remote and harsh location during the course of a year. Incredible preparations were required of all who wished to come aboard, including photojournalists.

https://www.nationalgeographic.com/environment/2019/09/inside-training-for-mosaic-largest-arctic-expedition-in-history/

Ship & lines please. There are four lifeboats, emergency rafts and a small launch on the ship, lowered by lines not ropes. When Captain Schwarze says jump, you jump (even if it's just off the sofa at your WeWork). Or spend the rest of the cruise cleaning up engine room grease (1st figure, upper right).

Polar bears: German army soldier. Night vision googles. Remote guard tower. Trip line perimeter. Infrared-triggered game cameras. Blasts from ship's horn. Flares. Pepper spray. Rifle as last resort. 

On Svalbard, the most common rifle carried is a Mauser 30-06. It has a confusing 3-way safety with middle position only causing the shell to be ejected, not fired. That lead to a recent death in a scout camp. A Sabatti 308 or H&K G3 is more probable here. PBs bury themselves in snow drifts (eg lee side of pressure ridge) leaving only eyes and nose exposed, then snooze until they can ambush a passerby (as with that young woman in Sv).

The captain has a plan for everything, from fires aboard to abandon ship. The first high risk period is right now, with the ice too thin and the ice margin too close. The second is mid-winter when the ice is too thick for support icebreakers to reach them and at problematic range for helicopters. Fires are a serious risk througout the cruise.

That recent dive boat accident in California ‘raised awareness’ of the risks of lithium battery re-charge fires. Passengers had left them charging overnight by the thousands after the final night dive. I reckon the Polarstern has thousands of electronic devices aboard, plus all the electrical gear the ship would normally carry. Almost all ship fires are wiring, engine room or galley; lithium is new.

We are going to understand the Arctic system a whole lot better thanks to this fabulous effort. It’s not going to stop the sea ice — and everything contingent on it — from falling off a cliff the next few years, any more than posting another expository post here.

What is the shelf life of 2019-20 research, given the rapidity of change? They are building the Polarstern II as we speak.

https://www.globalsecurity.org/military/world/europe/polarstern-2.htm

The animation below runs up to Oct 6th. Although passing weather artifacts cannot be fully removed early on. it clearly shows the ice has not yet settled down in the area they needed to be in for a year's drift. They knew this going in but there were no better options.
« Last Edit: October 07, 2019, 10:51:04 PM by A-Team »

Niall Dollard

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Re: MOSAiC news
« Reply #92 on: October 08, 2019, 12:43:55 AM »
GFS forecast (from Nullschool) shows a yo-yo swing in temperature in the vicinity of Polarstern over the next 24 hours or so.

By 12 UTC on 8th Oct, a plume of mild arrives up from Svalbard, yielding temperatures slightly above 0 C but it is short lived and 12 hours later at 00 UTC on 9th Oct, it forecasts temperatures below -10 C as cold air is advected across the Pole from the American side towards Russia.

uniquorn

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Re: MOSAiC news
« Reply #93 on: October 08, 2019, 01:13:50 PM »
Excellent! Today's mosiaic multisensor map zooms in on the selected floe :) (click for full resolution)
Here is an updated overview of mosaic buoy locations/movement up to oct7, 81-87N 114-140E

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Re: MOSAiC news
« Reply #94 on: October 08, 2019, 03:36:41 PM »
The Polarstern is 'out of the woods' in terms of AMSR2_large sea ice concentration having solidified in their immediate vicinity to 100% yet the sea ice is still quite dodgy to their south and the ice edge with open water is not notably progressing south in the Laptev. The Polarstern is 142 nm (265 km) north of the nearest open water which surprisingly is still within the reach of long-reach swells. The water there is still too warm, anomalously so.

Although large format time series (3.215 km resolution) are inconvenient to work with, they are well-suited to other tasks such as following the formation of land-fast ice which was once extensive, very thick and perennial but now almost entirely seasonal.

We may think of ice formation in autumn as a phase change from liquid to solid but it is better considered as epitaxial crystal growth in a variably inhomogeneous medium (water + brine + algae). That is, new ice only forms on the bottom and laterally on the sides of existing older ice.

You will never see a block of new surface ice forming ab initio in Arctic Ocean open water with AMSR2. (Preconditioned sub-surface, yes, as in fast outreach coming on now in the Beaufort.) There is too much wind mixing, whereas on the bottom or sides of existing ice there is minimal stirring plus a locally colder mileau -- the preexisting seed ice wouldn't be there otherwise.

This is doubly true for internal regions of sub-100% concentration. Thus color-picking open water invariably yields a plain if wavy ice edge line rather than a topologically more complex boundary. (We did find an exception a couple years back of a stable, inexplicable internal polynya.)

The second time series shows the whole Arctic Ocean for the first week of October. The ice pack as a whole has some internal regions that have not settled down. It rocks forward and back; the split palette shows an equalization over the original AMSR2.

For Polarstern protection from ice-rubbishing swells, faster peripheral pack growth to the south is needed. But is it on the horizon? The blue line (Oct 7th) in the animation doesn't show consistent  progression over the last three weeks. Mosaic may be documenting the first season of a newer New Arctic.
« Last Edit: October 09, 2019, 01:16:48 AM by A-Team »

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Re: MOSAiC news
« Reply #95 on: October 08, 2019, 06:35:59 PM »
awww <3
Refugees welcome

uniquorn

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Re: MOSAiC news
« Reply #96 on: October 08, 2019, 10:39:47 PM »
Well fed bears :)
Following on from A-team's post, polarstern is also slowly drifting south at the moment which doesn't help their situation. Here is polarview's latest jp2 combined with the jpg which has the graticule overlay. Akademik Fedorov is brighter today further north. (click for full resolution)

The animation below is ice tracker buoy 300234068129990 showing the last 2 days drift roughly 2 degrees west of mosaic. North is up, west is left (does my head in). Temperatures aren't provided on the IT buoy.
« Last Edit: October 08, 2019, 10:49:36 PM by uniquorn »

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Re: MOSAiC news
« Reply #97 on: October 09, 2019, 02:23:18 PM »
Thinking about the persistent dip in the ice edge in the Laptev, here is amsr2-uhh, mosaic startup area overlaid onto gmrt bathymetry at 60% transparent, sep1-oct8
edit: moved the focus further south
https://www.gmrt.org/GMRTMapTool/np/
« Last Edit: October 09, 2019, 07:26:03 PM by uniquorn »

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Re: MOSAiC news
« Reply #98 on: October 09, 2019, 09:55:19 PM »
Quote
Polarstern drifting south and east
The ice shows no sign of getting its drift act together. Some of these autumn freeze season time series could be confused with spring melt season. Either way, great that the PS is out there observing it all.
« Last Edit: October 09, 2019, 10:33:57 PM by A-Team »

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Re: MOSAiC news
« Reply #99 on: October 09, 2019, 10:29:00 PM »
It's not entirely clear that melt season is over in some parts of the Arctic Ocean. The Polarstern is at 85ºN so quite a ways poleward (and west) of the scene below which straddles 80ºN. Mosaic is just now getting set up off-ship; it will be a week or two before we know if the ice at their floe is thickening at all and if so, at an expected rate.

The algal bloom may extend north to the PS's location and beyond under <1m ice once its snow cover is gone, especially under glassy melt pond sites. While sunlight is minimal now, algae may have captured its heat earlier in summer just below the surface of the ice (rather than letting it pass down in clear water to depth). Peak adsorption wavelengths for chlorophyll A are at 465 nm (blue) and 665 nm (red) whereas green is reflected back up. However algae have many secondary pigments and also backscatter.

This is one of the three main themes of Mosaic research but not one that likely to produce near real time outputs for us to illustrate or analyze.
« Last Edit: October 10, 2019, 03:19:27 AM by A-Team »