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Messages - uniquorn

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51
Arctic sea ice / Re: The 2020/2021 freezing season
« on: February 16, 2021, 06:36:55 PM »
Some other similar occasions from Februaries past. (2006/2014/2020)
So the large polynya recently was perhaps mostly due to wind.
56km/h in 2014, 78km/h in 2020 and 89km/h in 2021. (2006 not available)

Quote
DOI: 10.3390/rs71215807
The southern boundary of the polynya is not deļ¬ned that strictly, as it varies drastically in the course of the winter season [2]. After the initial formation of the ice bridge at Smith Sound, the sea ice south of it experiences a strong advection due to strong northerly winds from the Nares Strait and prevailing southerly ocean currents [8]

52
Arctic sea ice / Re: The 2020/2021 freezing season
« on: February 16, 2021, 11:43:42 AM »
mercator model shows a pulse of higher salinity at 34m depth down the nares strait recently, likely to mix towards the surface as it leaves the strait, possibly another on the way.

The arch lost a few chunks over the last few days.

53
Arctic sea ice / Re: What the Buoys are telling
« on: February 14, 2021, 06:21:18 PM »
Float ID 7900550.
Just a scratch of a halocline, and a 2-300m layer of Atlantic water still at ~2.5C.<<>>>
You probably know more than me... keeping an eye on it though

54
Arctic sea ice / Re: The 2020/2021 freezing season
« on: February 14, 2021, 11:44:40 AM »
AO decided to whiplash. Looks like it'll turn positive, from a winter low negative.<<>>
Yep, could be interesting over the Yermak Plateau for the next few days.
rammb, band I5, feb13-14  https://col.st/BvcZ5  (click 10MB)

Argo float 7900550 in the West Spitzbergen current north east of Svalbard reporting sea temperatures of around +1C down to 34m depth yesterday. Salinity here

Quote
PLATFORM_CODE   DATE (YYYY-MM-DDTHH:MI:SSZ)   DATE_QC   LATITUDE (degree_north)   LONGITUDE (degree_east)   POSITION_QC   PRES (decibar)   PRES_QC   PSAL (psu)   PSAL_QC   TEMP (degree_Celsius)   TEMP_QC
7900550   2021-02-13T05:11:20Z   1   81.83741   26.70286   1   0   1   34.614   3   0.954   3
7900550   2021-02-13T05:11:20Z   1   81.83741   26.70286   1   0.9   1   34.614   3   0.954   3
7900550   2021-02-13T05:11:20Z   1   81.83741   26.70286   1   1.8   1   34.62   3   0.952   1
7900550   2021-02-13T05:11:20Z   1   81.83741   26.70286   1   2.9   1   34.61   3   0.962   1
7900550   2021-02-13T05:11:20Z   1   81.83741   26.70286   1   3.9   1   34.59   3   0.983   1
7900550   2021-02-13T05:11:20Z   1   81.83741   26.70286   1   5   1   34.608   3   0.957   1
7900550   2021-02-13T05:11:20Z   1   81.83741   26.70286   1   6   1   34.596   3   0.937   1
7900550   2021-02-13T05:11:20Z   1   81.83741   26.70286   1   7   1   34.601   3   0.873   1
7900550   2021-02-13T05:11:20Z   1   81.83741   26.70286   1   8   1   34.596   1   0.876   1
7900550   2021-02-13T05:11:20Z   1   81.83741   26.70286   1   9.1   1   34.599   1   0.867   1
7900550   2021-02-13T05:11:20Z   1   81.83741   26.70286   1   10   1   34.597   1   0.899   1

55
Arctic sea ice / Re: Arctic Ocean salinity, temperature and waves
« on: February 12, 2021, 12:10:45 PM »
A close up of the ess break up edge, feb3-11  https://go.nasa.gov/3jJQe3B

Laptev, feb3-11.  https://go.nasa.gov/2Z9Q247

56
Arctic sea ice / Re: Arctic Ocean salinity, temperature and waves
« on: February 11, 2021, 04:28:34 PM »
Argo float 6903558 in the WSC west of Svalbard a little farther away from the ice edge recording SST of just over 2.5C on feb9. I suppose that is mixed layer to 200m.

57
Arctic sea ice / Re: Arctic Ocean salinity, temperature and waves
« on: February 10, 2021, 11:56:57 PM »
Following on from here in the freezing season thread, a few more observations on the february anticyclone event.

Close up on the siberian side, feb9-10

A wider view showing the engagement of the Beaufort into a larger drift. feb5-10

rammb band I5, feb7-10   https://col.st/YDzXQ

lol polarview



58
Arctic sea ice / Re: The 2020/2021 freezing season
« on: February 10, 2021, 07:33:02 PM »
The problem lies at the end of this ice circulation, where the CAB mass presses against Greenland and some of it is exiting the Fram, as shown in the Ascat animation a few posts above. Given the blob of thicker ice identified by Cryosat in that region, I find this concerning.
I don't very often run ascat backwards but it looks like that thicker ice came from just below last year's white band. Tricky to be sure with ascat's 'summer whitewash'.

2021 day40 to 2020 day28 (backwards)
Nearly everything between the pole and the fram goes down the fram or melts before it gets there.

59
Arctic sea ice / Re: MOSAiC news
« on: February 09, 2021, 09:18:29 PM »
update on mosaic tbuoy temperature profiles. Near surface temps lower than -40C on feb6.

60
Arctic sea ice / Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« on: February 09, 2021, 08:05:52 PM »
What is the effect on the water beneath the ice?
https://en.wikipedia.org/wiki/Ekman_transport#Ekman_pumping

Quote
The third wind pattern influencing Ekman transfer is large-scale wind patterns in the open ocean.[1] Open ocean wind circulation can lead to gyre-like structures of piled up sea surface water resulting in horizontal gradients of sea surface height.[1] This pile up of water causes the water to have a downward flow and suction, due to gravity and the concept of mass balance. Ekman pumping downward in the central ocean is a consequence of this convergence of water.[1]

Also found this:
https://www.researchgate.net/publication/5415676_Comment_on_EddyWind_Interactions_Stimulate_Extraordinary_Mid-Ocean_Plankton_Blooms#pf2

61
Arctic sea ice / Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« on: February 09, 2021, 04:49:20 PM »
It's generally accepted that anti-cyclonic winds cause ice to move towards the centre (ice to right of wind) sometimes described as compaction or compression.

What is the effect on the water beneath the ice?

62
Arctic sea ice / Re: The 2020/2021 freezing season
« on: February 09, 2021, 04:26:12 PM »
speed gyre. https://go.nasa.gov/3aMuP5D  feb1-8
might need to change some constants in that Brittle-Bingham-Maxwell sea ice rheology model soon  ;)
nullschool wind, feb1-8

63
Arctic sea ice / Re: Arctic Ocean salinity, temperature and waves
« on: February 09, 2021, 01:58:25 PM »
rough overlay of buoy positions onto amsr2-uhh, feb6 explaining the drop in temperatures at Argo float 6903547 on the tip of the tongue in the fram strait

float7900550, north of Svalbard also resurfaced on feb6, quite a chart. Will have to check some other days though it is right on the shelf break.


64
Arctic sea ice / Re: The 2020/2021 freezing season
« on: February 09, 2021, 10:51:45 AM »
amsr2-uhh view of the anomaly looks worse in the laptev but there is something disturbing about the ess break up. We'll see soon enough. The faux low concentration along the ESS coast occurred at the same time last year. It is similar to the surface features seen north of FJL/Svalbard. (discussed up thread)     feb1-8.

N Kara Sea. Note the crescent shaped floe top left. Lots of ice, alot of it drifting.
https://go.nasa.gov/2YWjkmI  feb7-9

65
Arctic sea ice / Re: Arctic Ocean salinity, temperature and waves
« on: February 09, 2021, 01:09:57 AM »
Argo float 6903547 a little further off the west coast of Svalbard showing colder temps of -1.727C at 6.1m depth on Feb6.

66
Arctic sea ice / Re: The 2020/2021 freezing season
« on: February 09, 2021, 12:41:58 AM »
Update on the ESS/Laptev anomaly.
Firstly an overview using 11 days of ascat day28-38.

A focus on the movement west of Wrangel Island feb7-8

rammb bandI5, ess/laptev feb7-8

67
Developers Corner / Re: Test space
« on: February 08, 2021, 04:38:17 PM »
<add an if statement>
At the moment I delete entries >0.99m/s but I think it's interesting to see the deployment, also some resupply vessels to mosaic and other expeditions. I was thinking the opposite so that all deployment journeys were visible but more accurate, rather than taking short cuts across land ;) . We'll see what's cleanest. I think the problems might be in the way I'm loading the data using rbind.fill. Plus I didn't really check much when I started using the daily full resolution data. I've been lazy just running the existing code in the background.
Busy looking at ess leads today.

here's 2017-2021, crf31 compression is getting higher to reduce 266MB down to 11MB, 3hrly so I can overlay nullschool at some point. Daily didn't really work for me.
2014-2021 is going to be a big file though...

68
Developers Corner / Re: Test space
« on: February 08, 2021, 11:48:07 AM »
Thanks. I'll see which of those options is easiest to code. I might take the velocity colours out altogether as they look pretty bugged.

69
Arctic sea ice / Re: The 2020/2021 freezing season
« on: February 07, 2021, 09:57:07 PM »
A closer look at the head of the break up traversing the ESS shows it progressing clockwise against the anti-clockwise drift.  https://go.nasa.gov/3tAizOa    feb4-7

I couldn't get many usable frames from rammb but it looks like a very large shear zone. Maybe weak ice that is drifting faster.
https://col.st/lVkVb  (It's too big for full zoom)

cmems modelling the break up further south where we would normally expect to see it, along the fast ice line.  https://tinyurl.com/y46o5h39

70
Arctic sea ice / Re: The 2020/2021 freezing season
« on: February 07, 2021, 07:25:16 PM »
This is different. A large wind driven break up roughly following the 50m bathy contour around the ESS. It's been growing for the last 5 days, the head now at roughly 74N 174.
https://go.nasa.gov/36Rnxwq

A break up shaped like that is normally associated with an underlying current but my understanding is that the current there is not believed to be very strong.

Ice around Wrangel Island looking broken up too. Feb3-7 (click)

The full picture just came in. Siberian side, feb7

Maybe it won't look so bad with a bit of snow on it.

71
Arctic sea ice / Re: The 2020/2021 freezing season
« on: February 07, 2021, 03:03:52 PM »
NSIDC Data
High Arctic Sea ice area losses in the High Arctic for a fourth day, especially along the Siberian shore
- just a wobble or an event unfolding?
What can be causing this? It doesn't look like it's drift since the edges have not been contracting significantly, and the temperature is also relatively normal in the high arctic (there's a high pressure area causing a mildly above average blob, but even that it still way below freezing so it shouldn't cause any drop in area).
A closer look at drift here. The area losses are not that large but there were strong winds across the Laptev feb2-4.

Update on Cryosat2 SMOS merged thickness oct22-feb4.


72
Developers Corner / Re: Test space
« on: February 07, 2021, 01:56:20 PM »
testing 3hourly iabp buoy drift 2018-2021
How to get rid of the permanent 'dead buoys'?
172MB gif to 7.8MB mp4 is not bad
updated below

73
Arctic sea ice / Re: Arctic Ocean salinity, temperature and waves
« on: February 07, 2021, 11:25:51 AM »
This constant high pressure with less clouds gives us a great winter view of ice movement.
https://go.nasa.gov/3cPUmNR, amsr2-uhh inset, Kara,  jan12-feb6

Much less fast ice than usual this year. Again, feb2-4 causing lift off.

74
Arctic sea ice / Re: The Rammb Slider Thread
« on: February 06, 2021, 08:49:53 PM »
Wind driven drift around New Siberian Islands, feb4-6. More details here
Band I4

A couple of shoals in there too.

75
Arctic sea ice / Re: Arctic Ocean salinity, temperature and waves
« on: February 06, 2021, 04:25:40 PM »
Laptev ice dynamics, jan7-feb5. The Polarview S1A sweep missing out the crucial frame.
40km/h surface winds at -16C close to NSI during feb2-3 with cloud. Up to 70km/h at 1000hPa

76
Arctic sea ice / Re: Arctic Ocean salinity, temperature and waves
« on: February 06, 2021, 12:50:52 PM »
Polarview S1B crop of WSC area above. (half size)

location of the image.
A lot of images of the white band area recently

77
Arctic sea ice / Re: 2021 Sea ice area and extent data
« on: February 06, 2021, 11:39:57 AM »
The sea of Okhotsk takes some responsibility for the high extent numbers.
Here using Wipneus UH AMSR2 3.125km data (up to feb4) but there shouldn't be a problem with boundaries in Okhotsk

78
Arctic sea ice / Re: Arctic Ocean salinity, temperature and waves
« on: February 06, 2021, 01:20:05 AM »
https://go.nasa.gov/3cFyViG
:bookmark for weak Laptev ice north and west of NSI

79
Developers Corner / Re: Test space
« on: February 06, 2021, 12:53:59 AM »
testing 3hourly presentation of iabp raw data, 2019-2021  6.7MB mp4
updated below
.

80
Walking the walk / Re: Gardening
« on: February 06, 2021, 12:09:05 AM »
Some that we stored have already started chitting so I planted them (beneath the ground for once) to see what happens over winter. Also put in some very early garlic as a test.

Seems a bit early, as the garlic could grow too big and then freeze over winter and also potatoes could start growing too early. Anyway, tell us later in spring what happened to them

Feedback on potatoes and garlic: The potatoes sprouted well but did get hit by frost and died back. We only had half a dozen -2C nights but it was enough. Maybe they will re-sprout. The garlic has done well and is well ahead of our regular crop. The cloves were very small though (too small to peel)  so we'll see what happens in a few months. It's very mild here so I'm thinking about early flax and coriandre (hasn't worked as a summer crop for a few years)

We already have a lot of hazel but a neighbour has been inspired enough to take some cuttings.

81
Arctic sea ice / Re: Arctic Ocean salinity, temperature and waves
« on: February 05, 2021, 08:32:09 PM »
Ice beginning to win the war of attrition with the West Spitzbergen current northwest of FJL.
rammb, jan26-feb4

added awi-amsr2-v103-feb1-5

and wv brightness temp, feb6  https://go.nasa.gov/3oTdw83

and argo float 3902108 reporting SST of well over 4C on Feb4. Holding that temp to a depth of 200m. Hopefully this float will stay with the WSC as it turns east.
Quote
PLATFORM_CODE   DATE (YYYY-MM-DDTHH:MI:SSZ)   DATE_QC   LATITUDE (degree_north)   LONGITUDE (degree_east)   POSITION_QC   PRES (decibar)   PRES_QC   PSAL (psu)   PSAL_QC   TEMP (degree_Celsius)   TEMP_QC
3902108   2021-02-04T20:23:30Z   1   77.84765   9.33892   1   2.9   1   35.015   1   4.27   1
3902108   2021-02-04T20:23:30Z   1   77.84765   9.33892   1   4.2   1   35.015   1   4.271   1
3902108   2021-02-04T20:23:30Z   1   77.84765   9.33892   1   5      1   35.014   1   4.274   1
3902108   2021-02-04T20:23:30Z   1   77.84765   9.33892   1   5.9   1   35.012   1   4.275   1
3902108   2021-02-04T20:23:30Z   1   77.84765   9.33892   1   6.7   1   35.017   1   4.27   1
.
.
3902108   2021-02-04T20:23:30Z   1   77.84765   9.33892   1   199.2   1   35.006   1   4.278   1   199.2   1   4.278
3902108   2021-02-04T20:23:30Z   1   77.84765   9.33892   1   201.1   1   35.01   1   4.274   1   201.1   1   4.274
3902108   2021-02-04T20:23:30Z   1   77.84765   9.33892   1   203   1   35.01   1   4.274   1   203   1   4.274
3902108   2021-02-04T20:23:30Z   1   77.84765   9.33892   1   205.4   1   35.008   1   4.274   1   205.4   1   4.274
3902108   2021-02-04T20:23:30Z   1   77.84765   9.33892   1   207.9   1   35.009   1   4.273   1   207.9   1   4.273
3902108   2021-02-04T20:23:30Z   1   77.84765   9.33892   1   209.8   1   35.008   1   4.269   1   209.8   1   4.269
3902108   2021-02-04T20:23:30Z   1   77.84765   9.33892   1   211.8   1   35.008   1   4.265   1   211.8   1   4.265
3902108   2021-02-04T20:23:30Z   1   77.84765   9.33892   1   213.8   1   35.007   1   4.259   1   213.8   1   4.259

82
Arctic sea ice / Re: Arctic Ocean salinity, temperature and waves
« on: February 05, 2021, 01:45:07 PM »
A small cyclone whipped over the Yermak plateau yesterday

83
Possible shoal sightings. amsr2-uhh ess, jan28-feb3
Ice to the north and west of NSI looking fragile.

84
Arctic sea ice / Re: The 2020/2021 freezing season
« on: February 04, 2021, 11:35:14 AM »
lol. Correction:
CMEMS (Copernicus Marine Environment Monitoring Service) are hopefully incorporating buoy data into their neXtSIM-F model soon edit: evaluated the  neXtSIM-F model with buoy data.
Quote
https://tc.copernicus.org/preprints/tc-2017-200/tc-2017-200-AC6-supplement.pdf
The forecast capability of neXtSIM is also evaluated using a large set of real buoys' trajectories, and compared to the capability of the free-drift model. We found that neXtSIM performs significantly better in simulating sea ice drift, both in terms of forecast error and as a tool to assist search-and-rescue operations, although the sources of uncertainties assumed for the present experiment are not sufficient for a complete coverage of the observed IABP positions.


Clearer weather over the Chukchi Sea today showing the expected refreeze. Now, how thick can it get before the end of the season? Still too cloudy to see much over the Bering Sea.

https://go.nasa.gov/3azNh1g  Chukchi (slight contrast)

Wipneus UH AMSR2 3.125kn extent, Bering

added yesterdays view of ice features close to Wrangel Island. Largely due to the persistent anti-cyclonic winds. We should get corrected reflectance (True color) view of these over the next few days.  https://go.nasa.gov/2MY9aPB

A wider view of the Siberian side from today  https://go.nasa.gov/2YRuby5. Anti-cyclone forecast to continue, winds easing off north of NSI. 

85
Arctic sea ice / Re: The 2020/2021 freezing season
« on: February 03, 2021, 02:09:29 PM »
Buoy velocity data appears to show that the ice in the CAB is at record high mobility, so even though the freezing season isn't spectacularly bad, I think Fram export is going to be a big problem this year

CMEMS (Copernicus Marine Environment Monitoring Service) are hopefully incorporating buoy data into their neXtSIM-F model soon. Here is the latest 6hourly drift forecast from nersc (thanks to A-Team for the link) suggesting Fram export picking up by the 10th.

The recent high pressure has lead to fairly clear weather, allowing a comparison of suomi/npp brightness temp with ascat from jan23-feb2 (7MB)

Also a quick follow up on the Chukchi using true colour from worldview, jan30-feb3 (amsr2-uhh inset)

86
Arctic sea ice / Re: What the Buoys are telling
« on: February 02, 2021, 11:54:04 AM »
The whoi itp113 profiler is struggling with shallower water and/or a low battery voltage. It really has done a great job since September 18, 2019. Would have been great if it could have recorded more of the changes crossing the chukchi plateau though.
All temperature and salinity profiles from jan1-feb2 (click 8.4MB, using x to help show single data points)
Profile contours, drift path (off the map) and rough latest location.




87
Arctic sea ice / Re: When will the Arctic Go Ice Free?
« on: February 02, 2021, 11:17:34 AM »
Thanks everyone. The discussion around yearly averages has been a real eye opener (for me).

88
Arctic sea ice / Re: The 2020/2021 freezing season
« on: February 02, 2021, 08:38:50 AM »
January Arctic sea ice extent over time.
extent on jan31?

A peek through the clouds at the Chukchi sea. https://go.nasa.gov/3jgmWJK
A possible opportunity for some quick refreeze perhaps. There is some very cold weather forecast over the next few days.

89
Arctic sea ice / Re: Arctic Ocean salinity, temperature and waves
« on: February 01, 2021, 10:22:32 PM »
Looking  more closely at the mixed layer depth in the West Spitsbergen current. Here the scale is set from 10m-350m so black is deeper than 350m as we are not clamping out of range values.
https://tinyurl.com/y2gkyfug

dec1-feb1 (7.2MB)

90
Arctic sea ice / Re: The 2020/2021 freezing season
« on: February 01, 2021, 06:28:18 PM »
Cryosat2 SMOS merged sea ice thickness for comparison, oct22-jan29.
This shows the ice between the pole and the Fram Strait a little thicker than Hycom but also some apparent thinning north of Ellesmere as the thicker ice moves west. It's also interesting how the ice further along the CAA, near Banks Island repeatedly thickens and thins. Probably due to lift off from the coast and new ice forming in leads in the older MYI.
click 4.8MB

91
Arctic sea ice / Re: What the Buoys are telling
« on: January 30, 2021, 02:13:45 PM »
5 years of daily iabp buoy drift and nullschool wind at 1000hPa. 2016-jan2021   11.3MB mp4 beware

Quote
ffmpeg -i buoy.avi -i wind.avi -filter_complex "
  • crop=w=448:h=438:x=4:y=20[c1]; [1]crop=w=448:h=438:x=0:y=0[c2]; [c2][c1]blend=all_mode='overlay':all_opacity=1[m];
  • [m]overlay=x=4:y=20" -crf 34 buoywind-crf34.mp4[/size]
interesting. Forum turns 0 in square brackets into bullet points

Best viewed at half speed. (four and a half minutes you'll never get back ;)  )

92
Developers Corner / Re: Test space
« on: January 30, 2021, 12:33:47 AM »
anyone know how to fix image scaling in ffmpeg when using overlay. The buoys are gif->mp4, nullschool wind is avi->mp4. Both are 452x458pixels then I use

ffmpeg -i wind.mp4 -i buoys.mp4 -filter_complex "blend=c0_mode='overlay'"

Nullschool starts at the right size but slowly enlarges.

nullschool wind over buoy drift 2016-2021
crf 37 is way too high but it's a big vid

edit: just figured it out. It's the borders and title on the buoys...that was wrong too. It was an auto increment on the nullschool url
removed

93
Arctic sea ice / Re: What the Buoys are telling
« on: January 28, 2021, 05:01:49 PM »
Great animation. While looking at it, the concept of a "Beaufort Gyre" seems more absurd than ever. Sometimes the buoys make a concerted effort to drift clockwise, but most of the time they just go every which way. And even when they do  follow a pattern, it's not the same pattern every time, the directions are different.
I think there's a hint of gyre there. An overlay of nullschool wind might show whether it's all wind drift or there is also an ocean current component.

Here's the full arctic ocean version, jan2016-jan2021.
January 1st data has been removed as it gives animation errors and some other data has been removed to clean things up a bit
Quote
data <- data[which(data$Lat < 90 ),]
data <- data[which(data$Lon > -180 ),]
data <- data[which(data$Lon < 360 ),]
data <- data[which(data$drift < 0.99),]
data <- data[which(data$drift > 0),]
Obviously many more things could be improved upon. Reluctant to increase compression to reduce file size any further.

94
Arctic sea ice / Re: What the Buoys are telling
« on: January 27, 2021, 10:30:05 PM »
Beaufort buoys jan2016-jan2021

95
Arctic sea ice / Re: The caa-greenland mega crack
« on: January 27, 2021, 08:40:48 PM »
Agreed, the downside these days being that large multi year ice floes get broken up into smaller and smaller parts held together by weaker first year ice. suomi/npp brightness temperature goes back to sep2017, allowing us to compare 4 years on roughly this date, depending on clouds. Lift off of fast ice deep into the Mclure Strait is probably the least desirable part of the 2021 image.

https://go.nasa.gov/3t2uofW  2018-2021

96
Arctic sea ice / Re: What the Buoys are telling
« on: January 27, 2021, 12:18:05 AM »
Slowly but surely making progress with animations spanning different years. Here is 20200921-20210126, roughly 1week per second.

97
Arctic sea ice / Re: Arctic Ocean salinity, temperature and waves
« on: January 27, 2021, 12:08:04 AM »
Haven't noticed turbulence west of FJL before. I hesitate to say that they look like standing waves...

98
Arctic sea ice / Re: The 2020/2021 freezing season
« on: January 26, 2021, 01:12:32 PM »
A quick animation comparing extent across different years on January 24th
The Sea of Okhotsk racing away this year with those cold northerly winds.

amsr2-uhh, dec1-jan25

amsr2 3.125km extent (wipneus' data)

99
Arctic sea ice / Re: The 2020/2021 freezing season
« on: January 26, 2021, 01:07:29 PM »
Clearer weather north of Greenland saves us from attempting to interpret S1B images. Brightness temperature tends to show thicker ice as colder. Here we see the 'low concentration' areas identified by amsr2 correlating mostly with the thicker ice. These are clearly ice features, but at this time of year over the CAB, especially this year, they don't appear to represent sea ice concentration.

Overlay of amsr2(colours inverted) on to suomi/npp viirs brightness temperature(band15), jan25/26
https://go.nasa.gov.3sWLTOH

amsr2-uhh atlantic side, dec1-jan25

100
Arctic sea ice / Re: The caa-greenland mega crack
« on: January 25, 2021, 07:14:23 PM »
Mclure strait leads, jan25
Wider view including the Beaufort for reference, jan26    https://go.nasa.gov/3iNWeaU
unusual swaths on that image

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