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Messages - uniquorn

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1
Arctic sea ice / Re: The 2018/2019 freezing season
« on: January 16, 2019, 02:27:37 PM »
A further look at the amsr2 representation of ice on the atlantic front over the last few days where refrozen fractures show as higher concentration than older floes. This is apparent on both uni Hamburg and Bremen.
Comparing with worldview viirs, brightness temperature(band 15,night) with different palettes (green1 and rainbow1) there is a haze above the refrozen fractures, more visible on the rainbow palette. Perhaps it is mist due to heat escaping through the thinner ice. Snow would be unlikely where the ice meets the ocean.
worldview,viirs,bt15n,jan16  https://go.nasa.gov/2TWCNzh
amsr2-uhh, jan15 - high contrast on right

2
Arctic sea ice / Re: 2019 sea ice area and extent data
« on: January 16, 2019, 01:23:15 AM »
This animation is so messy that I wasn't going to post it, but I think it shows how volatile ice extent/area is over recent years, particularly when the peripheral seas are freezing.
amsr2-uhh, dec1-jan13 from 2015/16-2018/19

3
Arctic sea ice / Re: The 2018/2019 freezing season
« on: January 15, 2019, 12:21:58 PM »
January 6-13.
Not sure what makes amsr2 detect large floes as lower concentration than the 'glue ice' in between. Snowdrifts?
With the cold wind, I'd expected the ice to cross the warm current to Svalbard again but no, it still melts.
amsr2-uhh, atlantic front, jan7-14
worldview, viirs, bt15n, atlantic front, jan15  https://go.nasa.gov/2FvSg66

4
Arctic sea ice / Re: The 2018/2019 freezing season
« on: January 12, 2019, 12:26:43 PM »
Shame, would have spurred some interesting reading had it happened.

Forgive my naivety.
thanks for the research  :)  It's unlikely that this year's mostly first year ice is up to the job. Waves are over 3m today, forecast for over 4m tomorrow.
polarview, Greenland ice front closest to Jan Mayen, jan12 

5
Arctic sea ice / Re: The 2018/2019 freezing season
« on: January 11, 2019, 11:29:05 PM »
no

6
Greenland and Arctic Circle / Re: The Nares Strait thread
« on: January 11, 2019, 11:55:25 AM »
Looking a bit weak beyond the next arch.
Worldview,viirs,bt15,night,jan9-11

7
Arctic sea ice / Re: Arctic Ocean salinity, temperature and waves
« on: January 09, 2019, 11:32:50 AM »
Atlantic current beneath the ice on it's way to the Laptev.
Worldview, viirs,bt15,night,jan7-9.
Mercator 34m salinity, jan7

edit: polarview image, jan11 for future reference.

8
Arctic sea ice / Re: The 2018/2019 freezing season
« on: January 08, 2019, 02:10:49 PM »
Less cloud today. worldview,viirs,bt15n, northFJL, jan7-8.

ascat, day325-007. (3.6MB)
Hopefully ice on the Pacific side will be less mobile now the Bering Strait is plugged. The Beaufort arc of older ice bifurcated at the Chukchi while there was open water. The atlantic ice front made it to Svalbard only to be pushed back, possibly temporarily. Fast moving, quite fragile ice in the Greenland Sea due for another pounding tomorrow and 957 949hPa cyclone gfs forecast for thursday before thicker ice from the CAA makes its way across in the next few days (see Tealight https://forum.arctic-sea-ice.net/index.php/topic,2268.msg185799.html#msg185799).

windy ecmwf forecast for jan10
hmmm. 11m waves, >90km/h wind forecast along the Greenland sea ice front on friday. Like Meddoc (sort of) says, maybe a large short term extent gain coming.

9
Greenland and Arctic Circle / Re: The Nares Strait thread
« on: January 06, 2019, 08:39:35 PM »
New fractures. edit: Worldview,viirs,bt15,night,jan6-7  https://go.nasa.gov/2FcfPR7

10
Arctic sea ice / Re: Arctic Ocean salinity, temperature and waves
« on: January 05, 2019, 04:31:03 PM »
Polarview image north west of Svalbard jan5 showing some of the area of warm atlantic water upwelling and what may be evidence of surface currents.

Nullschool version of surface currents jan5.

11
Arctic sea ice / Re: AMSR2 Sea Ice Volume/Thickness
« on: January 04, 2019, 08:28:40 PM »
Comparison of Tealight's amsr2sit and 1day interference on ascat during december 2018.  Each interference image is created by combining images from three consecutive days in RGB, highlighting ice movement.
As the band of thinner or lower concentration ice along the old ice line is still visible on both animations, perhaps it is caused by the difference in movement of thicker and thinner ice.

edit:slowed the animation to 3days/s

edit:While talking my wife to sleep (helps insomnia apparently) I realised the interferometry animations were incorrect. Apologies to A-team whose method combines d1,d2 d2,d3 and d3,d4 but the last few I have posted combined d1,d2 d2,d3 and d1,d3 which compares 3 days, not 4 and over different time frames. While correcting the error I tried comparing d1,d2 d1,d3 and d1,d4 which seems to improve definition of the old ice line. I've updated this animation with latter version. Sleep well.

12
Arctic sea ice / Re: The 2018/2019 freezing season
« on: January 01, 2019, 12:56:51 PM »
SST's from the argo float are here
https://forum.arctic-sea-ice.net/index.php/topic,2417.msg184302.html#msg184302
though it hasn't surfaced since dec14 (or batteries may be flat).
Agreed, evidence of melt as far as FJL. Worldview, viirsbt15n, dec23-jan1. (3MB)

On a brighter note, Bering sea is freezing.
amsr2-uhh, dec1-31. (1.4MB)


13
Arctic sea ice / Re: The 2018/2019 freezing season
« on: December 31, 2018, 12:26:41 PM »
Ice on the Atlantic front reaches the Svalbard Islands.
Worldview, Atlantic ice front, viirs,bt15n, dec31 (click on image for full size)
Polarview, Svalbard, dec31

14
Arctic sea ice / Re: 2018 sea ice area and extent data
« on: December 29, 2018, 12:18:39 PM »
<snippage>Greenland Sea - export down the Fram?
amsr2-uhh and jaxa, Greenland Sea, nov9-dec27

15
Arctic sea ice / Re: The 2018/2019 freezing season
« on: December 28, 2018, 11:22:40 PM »
Yes, the ice front may make it across to Svalbard over the next few days.

An animation of the Kara/Barents using uni hamburg amsr2, oct18-dec27, 7days/sec (~3MB)


16
Arctic sea ice / Re: Arctic Ocean salinity, temperature and waves
« on: December 28, 2018, 11:02:24 PM »
A closer look using worldview, viirs, bt15n, dec23-28.
Low concentration area in the centre, Svalbard far right. Winds are forecast from the west for a few more days so the ice front may reach across the warm current to Svalbard again this year.  The cloud streets thickening up with the increasing temperature difference perhaps.

17
Arctic sea ice / Re: Arctic Ocean salinity, temperature and waves
« on: December 28, 2018, 12:42:13 PM »
Update on the persistent low concentration area north of Svalbard.
amsr2-uhh, aug1-dec28, contrast enhanced on rhs.

18
Arctic sea ice / Re: The 2018/2019 freezing season
« on: December 25, 2018, 04:17:24 PM »
same old same old.
bon fete :)

19
The rest / Re: Astronomical news
« on: December 21, 2018, 04:57:37 PM »
Mars Express beams back images of ice-filled Korolev crater
A composite picture of the Korolev crater in the northern lowlands of Mars, made from images taken by the Mars Express High Resolution Stereo Camera overlaid on a digital terrain model. Photograph: Björn Schreiner/FU Berlin/DLR/ESA

The stunning Korolev crater in the northern lowlands of Mars is filled with ice all year round owing to a trapped layer of cold Martian air that keeps the water frozen.
The 50-mile-wide crater contains 530 cubic miles of water ice, as much as Great Bear Lake in northern Canada, and in the centre of the crater the ice is more than a mile thick.

https://www.theguardian.com/science/2018/dec/21/mars-express-beams-back-images-of-ice-filled-korolev-crater

20
Arctic sea ice / Re: The 2018/2019 freezing season
« on: December 17, 2018, 12:21:03 PM »
Worldview, viirs,bt15n,dec16-17.  https://tinyurl.com/y75x8uxf
Westerly winds pushing large floes into the warm current north of Svalbard. Low concentration ice above the possible upwelling (just above centre) looks more like a whirlpool. Quite a turbulent forecast for this area tomorrow.

21
Arctic sea ice / Re: The 2018/2019 freezing season
« on: December 16, 2018, 02:44:56 PM »
An amateur attempt to match argo float 3901910 to amsr2-uhh to see how close to the ice edge it travelled, aug18-dec14. It reported weekly until december and has been reporting daily since. Report (cycle) numbers are overlayed onto Greenland, bottom left.
The main observation is that the warm current alongside the ice front is ~2.5C at surface recently.

More details and data here https://forum.arctic-sea-ice.net/index.php/topic,2417.msg184302.html#msg184302

edit: "These data were collected and made freely available by the Coriolis project and programmes that contribute to it (http://www.coriolis.eu.org)."


22
Arctic sea ice / Re: Arctic Ocean salinity, temperature and waves
« on: December 16, 2018, 12:53:29 PM »
An amateur attempt to match argo float 3901910 to amsr2 to see how close to the ice edge it travelled, aug18-dec14. It reported weekly until nov30 and has reporting daily since. Report (cycle) numbers are overlayed onto Greenland, bottom left.
edit:added temp labels

Approximate data based on eyeballing the attached charts is in text below. Timing the temp/salinity data to the animation makes the gif too large. Easiest to download both gifs and step them manually for analysis. (or even better, advice from someone with netcdf skills pls)

The main observation for ice watchers is that the warm current alongside the ice front is ~2.5C at surface recently.

cycle   lat              long          temp C    sal      date
60   80.06547      5.16783      2.75      32.4      0818
61   80.20849      5.23104      5      34.45   0825
62   80.38986      4.78623      2.6      33.65   0901
63   80.48555      6.0284      4.5      34.42   0908
64   80.49247      6.82373      3.8      34.1      0915
65   80.58095      7.16061      4.3      34.1      0922
66   80.44863      8.30625      3.8      34.4      0929
67   80.43952      9.16231      4      34.75   1006
68   80.37718      7.56771      1.5      34.4      1013
69   80.51731      11.28802      0.3      34.1      1020
70   80.84061      14.77375      3      34.75   1027
71   80.85687      16.35878      1.5      34.6      1103
72   81.43671      17.30993      1.6      34.64   1110
73   81.56787      21.71607      -1.2      34.15   1117
74   81.61883      26.34895      -0.7      34.35   1124
75   81.62392      31.29192      -1.5      34.26   1201
76   81.82774      34.03102      -1.1      34.32   1202
77   82.01424      35.80637      -1.6      34.26   1203
78   82.1778      38.04842      2.5      34.82   1204
79   82.28333      39.82095      -1.6      34.23   1205
80   82.29029      39.77042      2.3      34.77   1206
81   82.28489      39.64985      1.8      34.74   1207
82   82.29791      39.56938      2.7      34.86   1208
83   82.25532      39.58456      0.8      34.61   1209
84   82.22805      39.50098      2.7      34.86   1210
85   82.20667      39.35864      2.5      34.86   1211
86   82.21352      39.10944      1.2      34.45   1212
87   82.21687      39.05996      -1.2      34.29   1213
88   82.21415      39.16856      0      34.49      1214

data here http://www.argodatamgt.org/Access-to-data/Description-of-all-floats2
choose 3901910

23
Arctic sea ice / Re: Arctic Ocean salinity, temperature and waves
« on: December 13, 2018, 10:36:22 PM »
Thanks to Brigantine for the heads up on the ARGO float 3902910 currently north of FJL.
The first image shows the drift trajectory and the cycle (report) number. The projection could be better for the arctic but Svalbard is clearly identifiable centre left, FJL under the 80N text.

The animation shows temperature and salinity charts for cycle 65,70,73 and 83-87 (latest). From my limited understanding of the charts, this float appears to have drifted along the ice front in the warm current at depth, surfacing sometimes into cold meltwater, other times into the warm current.
2 days ago SST was 2.5C salinity34.85, today -1.6C salinity 34.15

http://www.argo.ucsd.edu/How_Argo_floats.html
Quote
Argo is an international collaboration that collects high-quality temperature and salinity profiles from the upper 2000m of the ice-free global ocean and currents from intermediate depths. The data come from battery-powered autonomous floats that spend most of their life drifting at depth where they are stabilised by being neutrally buoyant at the "parking depth" pressure by having a density equal to the ambient pressure and a compressibility that is less than that of sea water. At present there are several models of profiling float used in Argo. All work in a similar fashion but differ somewhat in their design characteristics. At typically 10-day intervals, the floats pump fluid into an external bladder and rise to the surface over about 6 hours while measuring temperature and salinity. Satellites or GPS determine the position of the floats when they surface, and the floats transmit their data to the satellites. The bladder then deflates and the float returns to its original density and sinks to drift until the cycle is repeated. Floats are designed to make about 150 such cycles.

data here http://www.argodatamgt.org/Access-to-data/Description-of-all-floats2
choose 3901910

"These data were collected and made freely available by the Coriolis project and programmes that contribute to it (http://www.coriolis.eu.org)."
edit: slowed the gif a bit

24
Arctic sea ice / Re: The 2018/2019 freezing season
« on: December 12, 2018, 01:06:38 PM »
In fact the entire Atlantic front + Kara seems to be increasing.
That's one way of describing it.  Worldview link, https://tinyurl.com/y6wyep2b

25
Greenland and Arctic Circle / Re: The Nares Strait thread
« on: December 11, 2018, 11:31:06 PM »
So the big floe looks like it popped out like a cork over the last 3 days.
Worldview, viirs bt15n, dec5-10
Polarview dec11

26
Arctic sea ice / Re: The 2018/2019 freezing season
« on: December 10, 2018, 11:24:33 AM »
SMOS is a good indicator of ice thickness up to 0.5m at this time of year. It doesn't look like it is only compaction in the Kara Sea. Too cloudy recently for viirs.
Uni-Bremen, dec1-9.

Worldview, Fram Strait, dec10 with mercator 0m temperature inset bottom left. Cloud over the warm current south of Svalbard, ice melting at it's northern end where it sinks into the depths.
https://tinyurl.com/ybrnrbyn
edit: Ice can also be seen melting along the ice front as the rest of the current turns east along the north Svalbard coast

27
Arctic sea ice / Re: Arctic Ocean salinity, temperature and waves
« on: December 08, 2018, 01:56:59 PM »
Worldview, viirs, bt15day doing a great job yesterday in relatively clear weather with a cyclone over the Beaufort gyre (click on the image for full size). Ice lifting off the CAA tending to confirm the mercator model indicating upwelling east and west of the Mclure strait.
Mercator, CAA, 0m and 30m salinity, nov1-dec7.
edit:added salinity scales. (some of the 0m salinity increase should be brine exclusion from freezing ice, but probably not in the Amundsen gulf or along the CAA coast)

worldview link: https://tinyurl.com/yaszxycm

edit2: Added ascat to the salinity animation.


28
Arctic sea ice / Re: The 2018/2019 freezing season
« on: December 07, 2018, 12:30:38 AM »
Agreed, patches of flash freezing already visible.... but the pack is so mobile, looking a bit wounded almost (obviously I'm reading too much into it ;) )
ascat, last 20days (enhanced contrast,clahe,unsharpmask)

29
Arctic sea ice / Re: The 2018/2019 freezing season
« on: December 06, 2018, 11:11:50 AM »
Worldview, viirs brightness temperature band15, night, dec6. https://tinyurl.com/y7s5h2hf
Greenland Sea looking a bit worse for wear after another storm and thick(ish) ice lined up for Fram export.
edit: Nares still open. That large floe rounding off its edges as it goes down.

30
Arctic sea ice / Re: The 2018/2019 freezing season
« on: December 05, 2018, 06:39:18 PM »
A comparison of Atlantic side using amsr2-uhh, nov1-dec4, 2018,2017,2016,2015.
2015 is missing a couple of frames due to poor data so the day before was duplicated. Date label is too small. edit:bigger date for 2018

31
Arctic sea ice / Re: AMSR2 Sea Ice Volume/Thickness
« on: December 05, 2018, 12:21:53 AM »
binntho, I doubt if it explains everything, but for a more valid comparison you need to compare PIOMAS to  NSIDC extent, which has much larger grid cells and lower accuracy.

I agree with Binntho. No gridded cells could explain that difference.

But in fairness, the PIOMAS is a better effort than the AMSR volume chart posted earlier by Tealight.

Look at the two areas circled in black. Parts of Area A in the Laptev were still not fully ice covered in early November and now it is supposed to be nearing 150cm thick ! PIOMAS puts the same area in the 75cm to 1m bin. Which is probably even a little generous.

Meanwhile Area B shows a river of blue going right up the centre of the Arctic Basin. That's less than 50cm thick. Clearly incorrect.
In defence of Tealights stalwart efforts, I ran interferometry on ascat for november (thank you A-Team) and there is a hint of lower concentration along the old ice front. Perhaps the newer, rapidly formed ice is more mobile than the older ice.

32
Arctic sea ice / Re: The 2018/2019 freezing season
« on: December 04, 2018, 10:56:46 PM »
<snippage>
The shrinking distance between the encroaching salty oceans
A reminder that warmer salty water tends to sink below colder fresh water. The atlantic side has a stronger current/larger incoming volume than the pacific but both tend to be limited in 'encroachment' by the depth of the arctic ocean (or sea or estuary).
At this stage it would appear that the ice gets thinner while attempting to cover historical extent.

33
Arctic sea ice / Re: Arctic Ocean salinity, temperature and waves
« on: December 03, 2018, 10:30:30 PM »
More stormy weather is forecast. I'll revisit this one in a few days.
windy-wam-dec3-forecast-for-dec12, atlantic side.

A comparison of mercator temperature at 0m and 34m depth with JAXA RGB from nov1-dec2 in the Chukchi sea. While the JAXA images that I can easily download are smaller (lower resolution) than amsr2 products they do give a better representation of differing ice types.
When the newer thin ice in the Beaufort meets the eddies on the edge of the gyre the interaction can be seen from ~10-17nov. After that, the thicker ice (in blue) is not so responsive and has picked up a lot of momentum from the continuous 25-40km/h winds over the last week.
Chukchi and Beaufort, Mercator temperature 0m and 34m, jaxa rgb, nov1-dec2

edit:added mercator temperature scales

34
Arctic sea ice / Re: The 2018/2019 freezing season
« on: December 02, 2018, 04:48:26 PM »
A closer look at the Atlantic ice front using amsr2-uhh and comparing with mercator temperatures 0m and 34m depth. The mercator model showing most of the warmer Atlantic water flowing east towards Novaya Zemlya, with a smaller current flowing north towards Svalbard then turning east towards FJL along the edge of the Nansen basin.
If I understand correctly, some of the warmer salty atlantic water will mix with fresher melt water in the choppy seas along the ice front but most is destined to sink into the depths of the Nansen basin, the salt making it denser, despite being warmer.

Notice how the thinner ice north of FJL melts even when blown northward onto the warmer current.

amsr2-uhh, mercator temperature 0m and 34m, nov1-dec1

edit: Lower concentration ice is still just discernible over the 'upwelling' north of Svalbard.

35
Arctic sea ice / Re: The 2018/2019 freezing season
« on: December 01, 2018, 02:59:35 PM »
The extent numbers look quite healthy so far, but thicker ice is still melting along the Atlantic front all the way to FJL and looks like it will continue to melt for a while longer in the Chukchi. Fram/NSvalbard export may make a bigger difference this freezing season.
jaxa 2018 and 2017, nov1-30

36
Arctic sea ice / Re: The 2018/2019 freezing season
« on: November 30, 2018, 06:25:38 PM »
Thick ice dragged back out of the Mclure Strait.
Worldview, viirs brightness temperature, band15, night, nov21-30. (1.1MB)

37
Arctic sea ice / Re: The 2018/2019 freezing season
« on: November 25, 2018, 03:52:21 PM »
A comparison of Chukchi ice extent from 2015-2018, nov1-24 using amsr2-uhh.
The main ice edge for each year from 2015-2017 has been extracted using edge detect in imagej, then splitting the colour channels to remove some of the concentration data, so it should be seen only as a rough comparison.

38
Developers Corner / Re: Creating Animated GIFs
« on: November 22, 2018, 09:49:37 PM »
amsr2-uhh, with overlaid ice edges of 2016 in red and 2017 in yellow (shows up well against blue but not too good over white)
edit:chose a neutral grey for 100% ice color - too much at once though

not too bad for a close up view

using ImageJ, Process>find edges. Image>color>split channels. Keep blue channel. Adjust color balance to choose color (must be a better way) make montage and save.
using gimp, layer>transparency>set color to alpha, merge down, repeat and save
back to imagej. image>stack>tools>montage to stack. crop, scale, repeat final frames.


39
Arctic sea ice / Re: The 2018/2019 freezing season
« on: November 22, 2018, 12:36:46 AM »
Very long leads across the CAB recently, best seen from nov14-16 on worldview bt15n.
https://tinyurl.com/ybynxmdl
A large catchment area for Fram Strait export as well

40
Arctic sea ice / Re: The 2018/2019 freezing season
« on: November 21, 2018, 08:57:52 PM »
Worldview, north of Svalbard, brightness temperature, band15,night, nov20-21.
The lower concentration ice near to the eddy (circled) still clearly visible over recent days. They look like goodbye waves and cloud streets along the ice front. Large floes on the ice edge ~-28C.

For those who missed it first time round, some cloud street info from A-Team

"cloud streets" in the Barents (associated with cold winds of a meandering central anti-cyclonic high) will continue out to March 25th and beyond, per GFS.

Twitter can confuse these with with blowing Antarctic ice needles or katabatic Greenland winds but Zach notes correctly today these are parallel bands of cumulus clouds that form as cold winds from the north blow off the ice edge onto warmer ocean waters.

OK, but why now, why cumulus mediocris, and what causes the street banding? 

The temperature differential between cold air blowing off the ice and the sea surface water, either open leads or more commonly beyond the ice edge, can easily exceed 20ºC in March. Thermal columns of moist heated air rise off the sea surface until they hit a denser warmer lid of air (provided a temperature inversion is present).

As the thermals are advected downwind and sink or rise according to ambient density differences, they form parallel pairs of counter-rotating cylinders of air. On the upper surface of rising air, water vapor cools and condenses into flat-bottomed, fluffy-topped clouds (ie cumulus: https://en.wikipedia.org/wiki/Cumulus_cloud). On the downdrafts, condensates evaporate giving clear skies on the sides of the clouds, the banding.

Surprisingly, the alignment of vortices alone does not reliably indicate wind direction. Stably stratified environments have lines 30° off CCW to the left; only an unstably stratified (ie convective) situation has bands parallel to mean wind.

Cloud streets are technically called horizontal convective rolls. The most favorable conditions for them occur when the lowermost layer of air is unstable, driven by a moderate wind and capped by a stable inversion, a common situation when upper air is subsiding, such as under recently prevailing anticyclonic conditions.

https://en.wikipedia.org/wiki/Horizontal_convective_rolls turbulent momentum flux in PBL
<snip>

Tech note: brightness/contrast adjusted and clahe applied to the worldview images

41
Arctic sea ice / Re: The 2018/2019 freezing season
« on: November 20, 2018, 11:41:05 PM »
Agreed. It looks like there is only movement in the Nares now.
Here is a comparison of 2017 and 2018, using amsr2-uhh, from oct1 to nov19. 2017 is outlined in green.

42
Arctic sea ice / Re: The 2018/2019 freezing season
« on: November 19, 2018, 10:22:08 AM »
amsr2-uhh, husdon bay, foxe basin, nov10-18
edit: added worldview-hudson-nov19

43
Arctic sea ice / Re: The 2018/2019 freezing season
« on: November 18, 2018, 01:29:02 PM »
Despite the low temperatures, Nares is still exporting and, surprisingly, there is still movement in the Mclure Strait.
Worldview brightness temperature,band15,night.

44
Arctic sea ice / Re: The 2018/2019 freezing season
« on: November 15, 2018, 08:33:25 PM »
esrl ice thickness forecast, nov14-21

https://floe.keytwist.net/esrl-daily-forecasts/2018-11-14

45
Arctic sea ice / Re: The 2018/2019 freezing season
« on: November 13, 2018, 05:48:05 PM »
amsr2-uhh, oct12-nov12, hudson bay, foxe basin and baffin bay (2MB)

46
Developers Corner / Re: Creating Animated GIFs
« on: November 12, 2018, 10:46:10 PM »
ascat interferometry, 1 day difference, with mask, 2018, day293-315
match width with land mask
contrast/brightness, clahe, unsharp mask before montage.

47
Greenland and Arctic Circle / Re: The Nares Strait thread
« on: November 12, 2018, 10:25:03 PM »
Worldview, viirs brightness temperature, band15n animation of Nares, nov3-12.



48
Arctic sea ice / Re: The 2018/2019 freezing season
« on: November 12, 2018, 09:38:22 PM »
Some clearer skies recently on worldview using viirs brightness temperature band15, day or night. Here is an example showing the area north Greenland, nov12, using 2 different colour palettes. Despite the cold temperatures, the ice to the east of Ellesmere still looks in bad condition.

https://tinyurl.com/ydbuy7aj
edit: according to worldview scale, yellow ~0C, light blue ~-46C
 

49
Arctic sea ice / Re: The 2018/2019 freezing season
« on: November 10, 2018, 02:42:56 PM »
Even with lower temps, more ice equals slower loss of residual summer heat accumulation.

Agreed, also rapid freeze at low temperatures probably means more brine in the ice.
Full size animation of ascat, oct18-nov9 as it is deliniating the different ice types so well at the moment (after enhancement).

The atlantic is still at work under the new ice front until the halocline/pynocline settles down.
amsr2-uhh, oct31-nov9, forward and back.

50
Arctic sea ice / Re: The 2018/2019 freezing season
« on: November 07, 2018, 07:14:34 PM »
Since the Beaufort, CAB, ESS, Laptev is pretty much ice covered now, here is amsr2-uhh for the current freezing season, sep24-nov6

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