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Messages - uniquorn

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1
I find it particularly interesting that the leads and apparent wave structures move through the ice rather than with it, the PS' slow progress is the best indication of this I've seen. The emergent double features indicates an acceleration?
Long version probably off topic for the mosaic thread.
Kaleschke Sic Leads, oct1-feb20 for further perusal. Lead motion likely wind based, will try a nullschool overlay sometime.

2
Arctic sea ice / Re: MOSAiC news
« on: Today at 01:19:29 PM »
drift as noted above

3
Arctic sea ice / Re: The 2019/2020 freezing season
« on: Today at 10:03:48 AM »
New maximum extent.
[ADS NIPR VISHOP (JAXA)] Arctic Sea Ice Extent.
February 20th, 2020:
     14,099,241 km2, a century increase of 114,662 km2:o
     Source: https://ads.nipr.ac.jp/vishop/#/extent
Less running commentary ;)

4
Developers Corner / Re: Test space
« on: February 20, 2020, 10:23:13 PM »
That is of course if you plan to ever make another...
rough and ready, date position moved in 2015/6 so you have to guess some of those.
pls download

5
Arctic sea ice / Re: The 2019/2020 freezing season
« on: February 20, 2020, 05:59:58 PM »
Drift on the Atlantic side before the forecast warm spell.
uni-hamburg amsr2-uhh, atl, feb10-19

6
Arctic sea ice / Re: The 2019/2020 freezing season
« on: February 20, 2020, 12:19:52 PM »
https://go.nasa.gov/37EBZFr, Okhotsk sea (north), feb10-20, unihamburg-amsr2uhh inset. ctr

edit: Early maximum extent just about hanging in there. Probably dependent mostly on possible increases in Okhotsk and Baffin/Newfoundland (still at all time low). Bering still high for recent years and Barents/Kara forecast for southerly winds, so drifting north. Very little MYI in Greenland and Baffin Seas.
Wipneus regional extent, feb18. updated to feb19 - barentsz/kara drop, baffin/nfld rise, okhotsk slightly up, bering(very southerly) likely over reached with the continuous drift.
hmm St Lawrence

7
Another candidate (seen before) further east of NSI. 2 are visible on these images. ctr

8
Arctic sea ice / Re: MOSAiC news
« on: February 18, 2020, 01:27:40 PM »
New Snowbuoy 2020S99. A touch south east of p207.

9
Arctic sea ice / Re: Arctic Ocean salinity, temperature and waves
« on: February 17, 2020, 01:32:19 PM »
osisaf drift, beaufort, sep21-feb15

10
Arctic sea ice / Re: Arctic Ocean salinity, temperature and waves
« on: February 16, 2020, 09:49:51 PM »
or not

11
Arctic sea ice / Re: MOSAiC news
« on: February 13, 2020, 11:36:31 PM »
Now, where to put that airstrip?
Here showing most Mosaic IABP buoys that report on the hour. Some report only on the half hour. Inset is nullschool wind isobaric at 1000hpa. Frames are repeated twice to match the hourly buoys. Projection is done using PlotSvalbard in R. Delaunay triangulation in Octave.
 

12
Arctic sea ice / Re: Arctic Ocean salinity, temperature and waves
« on: February 12, 2020, 09:47:20 PM »
a rough and ready view of ascat, jan1-feb11 (no clean up, bad labelling)
The beaufort arch appears to have stalled. Hopefully normal service will be resumed in a couple of days.

13
Arctic sea ice / Re: The 2019/2020 freezing season
« on: February 12, 2020, 12:26:36 PM »
It's normal to see polynya and ridging along the fixed ice line. Not so sure about the large radial leads. https://go.nasa.gov/39ujJ38 (suomi/npp only goes back to sep2017)

Animation here

14
Arctic sea ice / Re: MOSAiC news
« on: February 12, 2020, 11:38:10 AM »
drifted west and north. Map from FoMo inset
250 frames@24fps. Interesting that the map is Greenland down (Perhaps it is a Nansen original)

15
Arctic sea ice / Re: MOSAiC news
« on: February 11, 2020, 01:12:41 PM »
drifted westnorth yesterday ;)

Quote
Christian Katlein@CKatlein
26 Jan
When he realized, that he won't drift to the pole, #Nansen went North by
skis. As we likely passed our northernmost point, we did the same ... As
we are already 150km further north than he ever reached, we only walked
for 1 hour and camped only 1 night to test our survival
Maybe they'll go camping again  https://twitter.com/CKatlein

tech note: nullschool locations are from p207, the northernmost buoy. The title is incorrect. It should say P201, 204 and 207. P193 often, but irregularly, misses ~2hrs of data so I went back to 201.

16
Arctic sea ice / Re: MOSAiC news
« on: February 10, 2020, 02:16:59 PM »
drift update, still headed north west, picking up speed again.
No polarview of KD area today so here is best I could find through cloud on rammb day/night band ctr
Lat line is 82.5N
KD at 83.7N 79.73 at 2020-02-10 19:00 local time https://www.cruisemapper.com/?imo=7824405

17
Arctic sea ice / Re: MOSAiC news
« on: February 09, 2020, 11:25:08 AM »
Headed steadily north west
155franes@12fps
Chaperone? 82.85N76.0 and 82.88N76.77


18
Arctic sea ice / Re: Arctic Ocean salinity, temperature and waves
« on: February 08, 2020, 09:50:07 PM »
Ran the numbers on itp113 also. https://www.whoi.edu/page.do?pid=165156

19
Arctic sea ice / Re: MOSAiC news
« on: February 08, 2020, 12:12:41 PM »
PS drifted gently north yesterday, shorter timescale, feb1-8
256frames@12fps -updated below
KD heading for a lead at 0320utm this morning, 88 82.25N 68.77E, barely visible on the jpg
https://www.polarview.aq/arctic, not sure how long this link to the jp2 viewer will last
Latest position from cruisemapper is 82:39'35", 74:23'58". It appears to be following the line of the lighter, probably newer ice

edit: Cruisemapper Local time 2020-02-08 19:31, sailwx data stops on feb4


20
Arctic sea ice / Re: Arctic Ocean salinity, temperature and waves
« on: February 07, 2020, 01:19:38 PM »
chukchi export. Ice movement revealing underlying current or bathy perhaps. ctr

21
Arctic sea ice / Re: MOSAiC news
« on: February 07, 2020, 10:47:39 AM »
drift update, headed north west again yesterday. Here showing only points and coordinates. ctr

22
Developers Corner / Re: Test space
« on: February 06, 2020, 08:52:41 PM »
and the size for posting longer series - removed

23
Arctic sea ice / Re: Arctic Ocean salinity, temperature and waves
« on: February 06, 2020, 07:41:43 PM »
From the rammb thread
Now that polar night is descending on the arctic, it's time to switch to band I04, shortwave IR discerns temperature.
link to location.
North of Svalbard/Yermak Plateau. The (hopefully) never ending battle between sea ice and the warm west spitzbergen current

24
Arctic sea ice / Re: MOSAiC news
« on: February 06, 2020, 12:13:25 PM »
data updated today, drift headed north west over  the last 2 days. Forgot to change the frame size so the ani is larger. ctr
770 frames@24fps
edit: corrected the longitude labelling.

25
Arctic sea ice / Re: MOSAiC news
« on: February 06, 2020, 01:44:39 AM »
Nice aspect ratio for wide screen. Some leads persist for a long time as lower concentration blobs.

Not many buoy 'proc' files were updated today. There are other unprocessed files providing latlon that we can use. Example from p201
DataId,CommId,DeviceName,DeviceDateTime,BatteryVoltage,GpsQuality,Latitude,Longitude,SubmergedBoolean,Temperature0cm,AccelerometerVariance,SamplingRate
24309464,"300234068912800","OSU-IT-0014",2020-02-05 21:00:25,10.5,3,87.524023,94.845873,0,,3,30
24309463,"300234068912800","OSU-IT-0014",2020-02-05 20:30:54,10.5,3,87.52297,94.856868,0,,3,30
https://data.meereisportal.de/download/buoys/2019P201_300234068912800.csv

Will look at that if they don't come back tomorrow. Different format so would require some small code changes.

26
Developers Corner / Re: Test space
« on: February 06, 2020, 12:58:00 AM »
testing oct1-21 with daily movement of PS loc where available. Probably have to change to white graticule
or..testing with less compression. much better but way too big a file size for forum. It'll just have to be smaller or ditch the nullschool layer.
removed

27
Developers Corner / Re: Test space
« on: February 04, 2020, 09:46:10 PM »
buoys in wychspace
need to add the nullschool data and get the labelling sorted. Maybe best to use daily PS loc, though it will partially obscure the close buoys
looks like my original labelling is incorrect. There are quite a few other errors.
nullschool labelling is incorrect-forgot to triple the frames - had enough for one day
removed

28
Arctic sea ice / Re: The 2019/2020 freezing season
« on: February 04, 2020, 11:04:23 AM »
A quick look at the Atlantic side, jan10-feb3, uni-hamburg amsr2uhh

29
Arctic sea ice / Re: MOSAiC news
« on: February 03, 2020, 08:28:50 PM »
The km/hr scale has tripled (or typo)?
The scale is auto calculated by R. 0.481m/s(1.73km/hr) is pretty quick. Extract from P193 below.
2020-02-01T06:30:25,87.4429,98.2130,0.467,NaN,0.0,3.0,1800.0
2020-02-01T07:00:30,87.4355,98.1605,0.481,NaN,0.0,4.0,1800.0
2020-02-01T07:30:27,87.4283,98.1003,0.478,NaN,0.0,3.0,1800.0
2020-02-01T08:00:28,87.4213,98.0384,0.463,NaN,0.0,4.0,1800.0
2020-02-01T08:30:35,87.4148,97.9766,0.438,NaN,0.0,6.0,1800.0

I don't think that there are many previous buoys to compare to in this area. Perhaps someone will search a couple out. Drift may appear faster when hourly reports are missing, for example on jan31

Here showing most mosaic iabp buoys that report on the hour from sep29 to feb2. R was used to calculate utm lat and lon and the graticule as in the drift animations. The data was then run in octave to present the delaunay triangulation. A small mismatch in image size required rescaling of the  graticule so this is best efforts and should be seen as a guide only.
edit: The longitude labels are incorrect, they should be one place to the left. 135E is vertical.

30
Developers Corner / Re: Test space
« on: February 03, 2020, 12:37:57 AM »
tomorrow's another day -removed

31
Arctic sea ice / Re: Arctic Ocean salinity, temperature and waves
« on: February 02, 2020, 11:04:52 PM »
Heat loss in the Laptev Sea, https://go.nasa.gov/2RSLf44 , jan14-feb1

32
Developers Corner / Re: Test space
« on: February 02, 2020, 08:45:48 PM »
testing iabp buoys with projection, working on scales labelling and grat
crf31 removed

33
Arctic sea ice / Re: MOSAiC news
« on: February 01, 2020, 01:21:10 PM »
Very nice amsr2 arctic lead product.
Some Pbuoy data yesterday was every 3 hours instead of 30mins.
2020-01-31T00:00:33,87.4500,95.7151,0.012,NaN,0.0,3.0,1800.0
2020-01-31T03:00:33,87.4516,95.7237,0.017,NaN,0.0,3.0,1800.0
2020-01-31T06:01:08,87.4552,95.7420,0.039,NaN,0.0,4.0,1800.0
2020-01-31T09:01:05,87.4651,95.7013,0.103,NaN,0.0,4.0,1800.0
2020-01-31T12:01:05,87.4851,95.5790,0.215,NaN,0.0,3.0,1800.0
2020-01-31T15:00:36,87.4989,95.5017,0.147,NaN,0.0,7.0,1800.0
2020-01-31T18:02:07,87.5078,95.5309,0.092,NaN,0.0,11.0,1800.0
2020-01-31T21:01:04,87.5147,95.5807,0.076,NaN,0.0,6.0,1800.0
2020-02-01T00:00:54,87.5176,95.6063,0.032,NaN,0.0,4.0,1800.0

Only showing 204 and 207 as there are some other odd data on p193 and p201
updated below

34
Arctic sea ice / Re: The 2019/2020 freezing season
« on: February 01, 2020, 10:22:15 AM »
Higher extent could imply more export.
unihamburg-amsr2-uhh, pacific side, jan22-31

35
Arctic sea ice / Re: MOSAiC news
« on: January 31, 2020, 08:55:31 PM »
I dug out the old delaunay test program written using octave for an overview of buoy drift from 66 iabp buoys, jan1-31
No projection. - removed
Projected version below

36
S1 close up of the lower candidate in the above post. The small island in blue, something just visible in the possible shoal area (marked, top left).  cffr

37
Arctic sea ice / Re: The 2019/2020 freezing season
« on: January 28, 2020, 01:35:20 PM »
The sea of Okhotsk doesn't feature much in this thread but affects extent at this time of year. Here is a comparison using uni-hamburg amsr2-uhh from 2013-2020, jan27
added Bering Sea comparison
combined them

38
Arctic sea ice / Re: MOSAiC news
« on: January 28, 2020, 11:22:49 AM »
Drift update, testing the brakes before a hairpin bend. :updated below
Added a close up from 27th onwards of the nearest Obuoy (to the north east) which report location every 10 minutes. No drift speed but the ani has 6 frames/hr (at 7fps)
O4 temp/salinity/pressure chart from meereis. That still doesn't make sense to me, a sharp salinity increase but temperature goes down. (legend position is unfortunate, see #521)
edit:Looking more carefully, the spike in salinity is at 20m. At 100m salinity dips with the drop in temperature.

39
Arctic sea ice / Re: The 2019/2020 freezing season
« on: January 27, 2020, 09:45:53 PM »
Bering Sea looking beautiful at the moment. Extent racing away to the sunlit uplands :)
https://go.nasa.gov/3aPDKSW  jan22-26, click to run

40
Arctic sea ice / Re: Arctic Ocean salinity, temperature and waves
« on: January 27, 2020, 02:55:39 PM »
Nice. I expect we will see more of that over the next couple of days. This paper noted on the mosaic thread suggests there may be a small current through the Yermak Pass..

https://agupubs.onlinelibrary.wiley.com/doi/10.1002/2016JC012391
Quote
Regional circulation schematic of Atlantic Water inflow in Fram Strait and Nansen Basin, west and north of the Svalbard Archipelago following Sirevaag and Fer [2009] and Polyakov et al. [2012]. Dashed arrows represent uncertain Atlantic Water pathways around the Yermak Plateau and across the Plateau through the Yermak Pass

41
A new row of candidates in the ESS further south.

42
Arctic sea ice / Re: MOSAiC news
« on: January 26, 2020, 04:59:52 PM »
Similar activity on a macro scale from rammb, jan22-26. The latitude line is unlabelled but sits between 85 and 90, so should be 9 87.5.  https://col.st/yci9q
edited to attempt to get the centre closer to current mosaic location
Corrected: 97.5 off the planet ;)

43
Arctic sea ice / Re: Arctic Ocean salinity, temperature and waves
« on: January 26, 2020, 03:53:52 PM »
Looking closer at the breakaway ice edge north of FJL/Svalbard. FJL coast very top left.
rammb, very heavy contrast, jan22-26     https://col.st/ib7ix
GFS indicating wind fairly constant northeasterly at -28C or lower so it has to be warm water rising from depth doing that. Movement suggests tidal.

44
Arctic sea ice / Re: The 2019/2020 freezing season
« on: January 26, 2020, 01:46:20 PM »
uni-hamburg amsr2-uhh, atlantic side, dec1-jan25

45
Arctic sea ice / Re: Arctic Ocean salinity, temperature and waves
« on: January 26, 2020, 11:01:06 AM »
https://go.nasa.gov/2TX24MY, jan7-26, rotated, north down, FJL(left) and Svalbard(right)

46
Arctic sea ice / Re: Arctic Ocean salinity, temperature and waves
« on: January 26, 2020, 10:54:37 AM »
Also interesting from the mosaic thread: https://www.nature.com/articles/s41598-017-15486-3
Quote
To summarize, we have used co-located acoustic and CTD data to unequivocally demonstrate that there is a one-to-one correspondence of thermohaline stairsteps and acoustic layering. We were able to track a staircase continuously (with some interruptions due to ice breaking in between drift stations) for 36 h over a ship track of 91 km (Fig. 4a), and identify an isolated staircase, extending about 100 km laterally, in the Nansen Basin (Fig. 5). We also present observations of layers forming/disappearing and splitting/merging within a thermohaline staircase (Fig. 5d–f). Finally, we present, for the first time, continuous high frequency vertical displacements of individual steps within an Arctic thermohaline staircase caused by internal waves. It is hypothesized that a sudden transition within an internal wave, where much of the high frequency energy at the trailing side of the wave suddenly disappears, is related to shear instabilities.

The data presented here suggest that in order to fully understand vertical heat fluxes, not only the presence of staircases must be considered, but also the mixing caused by decaying internal waves, which is likely not accounted for in laboratory measurements, numerical simulations, or very localized (i.e., discrete profile) measurements. A synoptic view is needed where, ideally, acoustic observations similar to the ones presented here are augmented by concurrent CTD and microstructure observations. This acoustic observational technique should offer new insights into the mechanisms controlling layer formation and evolution, and eventually allow for greater understanding of interactions between double-diffusive convection and shear-induced turbulence, as well as their control on diapycnal fluxes.

47
Antarctica / Re: Antarctic images
« on: January 25, 2020, 11:35:25 PM »
Antarctic
Endurance swimmer Lewis Pugh swims under an ice sheet. Pugh, 50, swam for 10 minutes and 17 seconds in the river underneath the melting ice sheet in an attempt to raise awareness of the climate crisis at the poles

Photograph: Lewis Pugh/PA
https://www.theguardian.com/artanddesign/gallery/2020/jan/25/20-photographs-of-the-week

48
Arctic sea ice / Re: MOSAiC news
« on: January 22, 2020, 10:23:12 PM »
Temperature gradient through snow and ice from T56, T62 and T66. ctr
data2

Quick analysis of T62 on jan22
Therm1-40 above snow
Therm41-47 snow/ice
Therm48-111 ice
Therm111-> ocean see inset


49
Arctic sea ice / Re: MOSAiC news
« on: January 22, 2020, 09:12:35 PM »
The animation colours don't really display enough detail. The charts show a lot more variation. The cold, occasionally salty, fingers appear to be quite local. O6 really struggling. ctr
tech note: should have picked a later start date, unexpected autoshrink makes text barely legible

50
Arctic sea ice / Re: Arctic Ocean salinity, temperature and waves
« on: January 22, 2020, 12:00:34 PM »
PSY4 animations available here. Be aware that the scale is not static.
Individual static scale maps are here (just edit both dates in the address)

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