Messages

1

Arctic sea ice / Re: The caa-greenland mega crack

« on: September 19, 2020, 11:19:53 PM »

as the sunlight fades, https://go.nasa.gov/2FKBrpB

2

Developers Corner / Re: Maximising asif skills using near real time Mosaic data

« on: September 19, 2020, 10:42:08 PM »

tbuoy update

3

Arctic sea ice / Re: Arctic Ocean salinity, temperature and waves

« on: September 19, 2020, 10:38:32 PM »

@Bruce Steele, whoi itp117 temperature spike on SAMI
edit: similar spike on itp105, Mackenzie river water?

4

Arctic sea ice / Re: Arctic Ocean salinity, temperature and waves

« on: September 19, 2020, 09:58:07 PM »

mosaic iabp buoy names and relative locations for ref

5

Arctic sea ice / Re: MOSAiC news

« on: September 19, 2020, 05:53:55 PM »

EDIT: The speed of drift swings between 10% and 20% of normal walking speed. And the tidal swings are only a few hundred meters each way. The circular movement I guess has more to do with changing wind direction than anything else.

Great. As you guessed that one hopefully you will run the numbers to prove it. Hourly wind direction from PS is here   P169 is near if you need buoy data.
I suspect it is the combination of both since wind drift appears to be of the same order of magnitude as 'tidal drift' and it's a more likely explanation than continuous tight wind vortexes at multiples of walking speed. 

Here attempting to overlay the tight group of buoys onto bow radar. Maybe they are either side of a fault line or along a ridge. click for animation.

6

Arctic sea ice / Re: MOSAiC news

« on: September 19, 2020, 04:22:04 PM »

The default scale is utm km which may be reasonably accurate this close to the pole, though confusing to some, so I normally remove it. Recent location of most of the nearest buoys to PS

7

Arctic sea ice / Re: MOSAiC news

« on: September 19, 2020, 03:35:13 PM »

drift update from P176.
2 submarine landslides a day seems unlikely. I think I'll stick with tides.

8

Arctic sea ice / Re: The 2020 melting season

« on: September 18, 2020, 01:09:19 AM »

I see it differently, I think both years were eventually quite similar, when using generalizations:
2012 was sunny and warm and then windy and very stormy. It had some extra fluffy ice in the ESS but eventually it melted that ice and was left with a compact pack (and an extent record).
2020 too was sunny and warm and then very windy and somewhat stormy. It had some extra fluffy ice in the Chukchi and Siberian facing sections of CAB,  but eventually most of it melted and it was left with a mostly compact pack - except in the CA and the Beaufort arm (and a 2nd place extent finish).

I agree, only to stress that 2012 was an outlier and 2020 is almost normal as the global warming goes on.
Also I don’t see a paradigm shift at all, just a continuation of a warmer planet due to CO2. The ice is basically the same, only a lot less.

I agree too and would add that, with less ice, the arctic ocean is beginning to show itself more. Last year the CAA crack and this year the Greenland gap.

9

Arctic sea ice / Re: Arctic Ocean salinity, temperature and waves

« on: September 17, 2020, 05:09:01 PM »

Signs of turbulence north east end of the yermak plateau. https://go.nasa.gov/3iLPHNq

10

Arctic sea ice / Re: The 2020 melting season

« on: September 17, 2020, 01:01:16 PM »

AMSR2: Some recent days of 2020 compared to 2012

Rough overlay of 2012 vs 2020 using awi amsr2 v103, aug20-sep15 (am/pm)

gimp grain extract, the years were slightly different sizes so there is a small scaling error

11

Arctic sea ice / Re: Home brew AMSR2 extent & area calculation

« on: September 17, 2020, 12:42:07 PM »

I wonder if awi amsr2 sic v103 is using some of the SIC LEADS (experimental) processing.
Yesterdays worldview terra modis with v103 inset.

12

Developers Corner / Re: Test space

« on: September 17, 2020, 12:42:43 AM »

grain extract was better. Might try more accurate scaling tomorrow.
posted elsewhere

13

Developers Corner / Re: Test space

« on: September 17, 2020, 12:28:09 AM »

tried to do difference on seaice.de post here
Strange that the two years were different pixel sizes. A very rough resize produced this, so I think I've done something wrong. Interesting though.
removed

14

Arctic sea ice / Re: The 2020 melting season

« on: September 16, 2020, 11:12:06 PM »

Wipneus' regional extent chart for the CAB suggests there has been a physical limit for latest refreeze set by 2012. 2018 and 2019 tending to confirm that limit. 2020 is close to testing it.

15

Arctic sea ice / Re: MOSAiC news

« on: September 16, 2020, 10:05:08 PM »

A lot of good videos on https://twitter.com/seaice_de

The Polarstern is represented by the gray ball; it is moored with its starboard bow against the ice

Lars Kaleschke@seaice_de
12 Sep  Too much tension? Be careful with the anchor line. A very dangerous environment. @MOSAiCArctic  - April 28

16

Developers Corner / Re: Maximising asif skills using near real time Mosaic data

« on: September 16, 2020, 09:42:30 PM »

example of ice/ocean interface

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Arctic sea ice / Re: MOSAiC news

« on: September 16, 2020, 09:36:21 PM »

Probably best with VR headset but you can use the mouse (or finger) to look around. Look up first to  lose the auditorium.

18

Developers Corner / Re: Maximising asif skills using near real time Mosaic data

« on: September 16, 2020, 12:07:02 PM »

latest t78 and t81. T78 is an algo nightmare

19

Arctic sea ice / Re: The 2020 melting season

« on: September 15, 2020, 11:32:08 PM »

relative "compactness" of the ice pack compared to say 2016

Laptev/atl ice edge has been subjected to a few weeks of southerly wind so yes, relatively compact compared to 2016 and at the same time a short cyclone leaves the pack riddled with leads north of CAA while the Greenland gap slowly recovers (a large polynya is visible today at 85.2N-10)
https://go.nasa.gov/2Rycjog  (light contrast enhancement)

20

Arctic sea ice / Re: MOSAiC news

« on: September 15, 2020, 09:32:47 PM »

That 25km² of bow radar might overlay nicely onto buoy drift now that it is relatively static. A shame it's not hourly.
This is a wider view of the previous animation here with the tight cluster at the centre.

intermittent light snow

  Lat  Long  YY-MM-DD  UTC     Wind       T(C)  N  h  VV  wwWW  ICE  Pnn(hPa)
  89.1  108.3 20-09-15 20:00    4  230     -4.6  /  /  //  //// ///// 1005.2
  89.1  108.1 20-09-15 19:00    5  210     -4.9  /  /  //  //// ///// 1005.2
  89.1  107.9 20-09-15 18:00    5  200     -4.7  /  /  //  //// ///// 1004.9
  89.1  107.6 20-09-15 17:00    4  220     -4.7  /  /  //  //// ///// 1004.8
  89.1  107.3 20-09-15 16:00    4  230     -4.9  /  /  //  //// ///// 1004.8
  89.1  107.1 20-09-15 15:00    4  200     -4.9  8  2  98  7082 49/9/ 1004.7

21

Developers Corner / Re: Maximising asif skills using near real time Mosaic data

« on: September 15, 2020, 08:15:32 PM »

They were probably just spam on the mosaic thread.
@SimonF92 is it possible to take surface temperature into account when using the heat files in the algo?So that it amplifies the stdev in some way.

22

Arctic sea ice / Re: MOSAiC news

« on: September 15, 2020, 07:54:21 PM »

drift speed increased during sep13-14. click for motion

23

Developers Corner / Re: Maximising asif skills using near real time Mosaic data

« on: September 15, 2020, 04:32:35 PM »

t78 and t81 temp proc

24

Arctic sea ice / Re: When will the Arctic Go Ice Free?

« on: September 14, 2020, 09:20:26 PM »

Last four years.

You have a reasonable point that the ice age product shows a possible increase in 4+ year ice.
A technical graphics question. What made you choose to insert a transition that ignores the other 51 weeks into that animation? It makes no sense (and increases the file size).

25

Arctic sea ice / Re: MOSAiC news

« on: September 14, 2020, 03:46:39 PM »

Somewhere up-forum, all the weather commentaries for the entire expedition was extracted into a flatfile database and a MS Word-type glossary system proposed to stub in the code lookups to eliminate tedious and error-prone code lookups. No one picked up that baton.

63 downloads, quite popular. Though no further analysis from them.
Looking at some thread stats is valid as we near the end of the mosaic project. Gauging popularity of areas of analysis can be useful to determine viewer interest and whether sizing an animation to fit the forum's tight limits is worth the effort

Thanks, I hadn't  heard of diamond dust or graupel before.

26

Arctic sea ice / Re: When will the Arctic Go Ice Free?

« on: September 14, 2020, 01:24:20 PM »

nsidc ice age for the week to sep1 (or sep2), 1984-2020

27

Arctic sea ice / Re: Home brew AMSR2 extent & area calculation

« on: September 14, 2020, 01:01:35 PM »

It might make sense to make an avi using each consecutive pass as a frame.

That might be a more efficient than the am/pm. A daily avi of swaths which could be compiled by the user, one daily tiff compiled with lut, one compiled png and one compiled .nc
Avi might not be the best option. I think a tiff can contain multiple 'pages' which might retain the lut.

28

Developers Corner / Re: Maximising asif skills using near real time Mosaic data

« on: September 14, 2020, 12:34:11 PM »

t78 and t81 heat120 temps
t78 has some odd features

29

Arctic sea ice / Re: MOSAiC news

« on: September 14, 2020, 11:33:22 AM »

Sorry about that. I mixed up the ww and the WW
I should have said snow or mixed rain and snow moving to with less significant rain

W1 -- Most significant weather in past 6 hours
W2 -- Less significant weather in past 6 hours

    0 -- cloud covering less than half of sky
    1 -- cloud covering more than half of sky during part of period and more than half during part of period
    2 -- cloud covering more than half of sky
    3 -- sandstorm, duststorm or blowing snow
    4 -- fog, or thick haze
    5 -- drizzle
    6 -- rain
    7 -- snow or mixed rain and snow
    8 -- showers
    9 -- thunderstorms

76 -- diamond dust

Recent weather is hovering around 0C with continuous light drizzle.

30

Arctic sea ice / Re: MOSAiC news

« on: September 13, 2020, 10:54:08 PM »

Sub -12 C now:

  88.7  105.8 20-09-10 22:00      -12.4 
  88.7  106.0 20-09-10 21:00      -12.1 
  88.7  106.1 20-09-10 20:00      -12.6 
 

And then back to above 0C with freezing rain and 'diamond dust'

31

Arctic sea ice / Re: Arctic Ocean salinity, temperature and waves

« on: September 13, 2020, 10:29:48 PM »

nsidc ice age update

32

Arctic sea ice / Re: Tides

« on: September 13, 2020, 04:04:08 PM »

Some buoys near the pole

33

Arctic sea ice / Re: Home brew AMSR2 extent & area calculation

« on: September 12, 2020, 11:25:50 PM »

We are looking on this forum for an explanation of what visible, infrared and radar satellite imagery and drifting buoys have been showing for months above Greenland, Ellesmere and CAA which are nowhere near major rivers or their plumes yet the ice has been melted out to the point of oblivion by insolation and MDD this summer. We have direct confirmation from the captain of the transiting Polarstern.

Hopefully not too far off topic, this long term view of mercator 34m salinity could provide an explanation. There is a noticeable acceleration during the 2020 strong tpd event pushing higher salinity atl water? towards the greenland coast.
sep2018-sep2020

34

Arctic sea ice / Re: Arctic Ocean salinity, temperature and waves

« on: September 12, 2020, 10:57:14 PM »

mercator 34m salinity, jun1-sep11
Mercator not showing anything unusual north of greenland at 34m (short term)

35

Arctic sea ice / Re: Arctic Ocean salinity, temperature and waves

« on: September 12, 2020, 10:04:20 PM »

yes, I used to get told off for posting animations without the scale but including it in the animation makes the file size larger so I post it separately, if I remember. hmm

36

Arctic sea ice / Re: MOSAiC news

« on: September 12, 2020, 10:01:12 PM »

My sense is that buoy data needs a lot more edu: arrows drawn on stills, longer prose accounts of basics, fewer assumptions that such and such is obvious, tutorials even

You're probably right. Arrows on things no one looks at. Post some buoy data once a month.

37

Arctic sea ice / Re: MOSAiC news

« on: September 12, 2020, 09:38:10 PM »

The drone photo is both beautiful and shocking because of the blue water in the ponds apparently on 6 September. Because the basic info identifying the photo has been stripped, I'm left wondering if it was actually taken in the month of September at the pole.

Air temperature was mostly below 0C at PS location for a week before sep6. The pond water would have to be quite fresh saline.

aug25 was first full day on the floe according to fomo. Pics of fog. A lot of days with fog in awimet weather report
88.7  117.6 20-09-06 12:00    8  100     -2.8  8  2  99  0372
03 -- clouds developing 72 -- intermittent moderate snow
The camps and tracks look quite well developed.

38

Arctic sea ice / Re: MOSAiC news

« on: September 12, 2020, 09:31:43 PM »

I think we may be too harsh on mosaic. We have had loads of buoy data but it seems few are interested in it (or are willing to share their analysis). 1.4% of viewers can be bothered to look at recent ice temperature data to estimate thickness when it is practically spoon fed to them.
We need to up our own game and get some planks out of our eyes.

Im working on the stuff from last season but the data is pretty poor to be honest. There are 4 'active' thermistor buoys, but only T78 is providing reliable data at this point. The thickness for that one seems to be 90cm-1m.

Had a look at T81 and the data is challenging. The colder weather is helping at the surface but not really at the ice/ocean interface yet. Dropped to -1.69C on sep10.

39

Arctic sea ice / Re: MOSAiC news

« on: September 12, 2020, 04:13:16 PM »

I think we may be too harsh on mosaic. We have had loads of buoy data but it seems few are interested in it (or are willing to share their analysis). 1.4% of viewers can be bothered to look at recent ice temperature data to estimate thickness when it is practically spoon fed to them.
We need to up our own game and get some planks out of our eyes.

40

Arctic sea ice / Re: Arctic Ocean salinity, temperature and waves

« on: September 12, 2020, 03:22:11 PM »

mercator 0m salinity(SSS), jun1-sep11

41

Arctic sea ice / Re: The 2020 melting season

« on: September 12, 2020, 03:05:51 PM »

Probably not. We haven't had the teasing ups and downs yet.
mercator 0m temperature(SST) with amsr2-uhh sic overlay, jun1-sep11

42

Arctic sea ice / Re: MOSAiC news

« on: September 10, 2020, 10:43:50 PM »

It's probably going to take a while so moving delaunay development to the dev thread

thickness update. t81 may be showing some snow.

p234 drift speed

43

Developers Corner / Re: Maximising asif skills using near real time Mosaic data

« on: September 10, 2020, 10:11:10 PM »

continuing from mosaic thread
squared up the grid and added some labels. Looking at adding some distances but tracking them is difficult as the delaunay lines move around. It is in the code somewhere though.

44

Arctic sea ice / Re: The 2020 melting season

« on: September 10, 2020, 05:09:49 PM »

I bet there is a nice rebound of 4+years  MYI this year <>

Ice age updated on the 7th of last month but nothing new yet. There was a reasonably clear view of, what must be some of, our soon to be 4+yr ice yesterday on noaa-20. https://go.nasa.gov/2DS1v1m

45

Arctic sea ice / Re: The 2020 melting season

« on: September 09, 2020, 11:57:55 PM »

amsr2-awi dev v1.03 latest
amsr2-uhh, sep8 for comparison.
awi dev possibly using later swaths.

46

Arctic sea ice / Re: The caa-greenland mega crack

« on: September 09, 2020, 11:11:23 PM »

The caa-greenland mega fracture https://go.nasa.gov/2FoXSQY

47

Arctic sea ice / Re: The 2020 melting season

« on: September 09, 2020, 10:52:09 PM »

Remember the JD storm in June UCMiami? That storm was weaker over then still a solid thick ice pack, and it did leave a mark. The difference was persistence of the wind, and it was a speculation of mine before this storm that the frozen melt ponds would leave the wind without much to grab onto. The ridges - that must have been still present in June - are all gone now. The ice must be dead flat right now right? And that is a lesson learned for me...

I think a mark has been left. Better unlearn that one.
https://go.nasa.gov/33gEmhs

More analysis here

48

Arctic sea ice / Re: Home brew AMSR2 extent & area calculation

« on: September 09, 2020, 10:49:00 PM »

I think it's real. Noaa-20  https://go.nasa.gov/33gEmhs

49

Arctic sea ice / Re: MOSAiC news

« on: September 09, 2020, 09:37:02 PM »

First attempt at delaunay triangulation on the close Pbuoys. This only uses the hourly locations. lat/lon scale is in metres.
Lateral movement at this scale is too fast to view the small changes in position so one buoy's lat/lon (in metres) has been subtracted from all buoys. That buoy is at 0,0.

We should be able to tell when freeze sets in.
The 3d version might be interesting on this close set

Adding a fine grid adds another 5MB to the file size. Either there is quite a lot of movement within this 1.44km² area or we are at the limits of gps tracking this far north. I forgot that the presentation is not square, will look into that (squashed it horizontally).
Data is from iabp The conversion from lat/lon to utm is from plot-svalbard, saved as csv. Delaunay is run in octave. data is attached below as text.

oops, now it's less than 500px (unsquashed)

50

Arctic sea ice / Re: MOSAiC news

« on: September 09, 2020, 03:14:35 PM »

drift update using T78.
Tbuoy temperature data. Not long to wait till core temp drops to allow us to get a clearer idea of where the ice/ocean interface is. updated below
P234 drift speed update

Thinking overnight about the Pbuoy deployment, we know that there were many more local buoys on the first floe. Perhaps they are sharing even more buoy data this time. I haven't had time to calculate any distances yet, but a close array of buoys might be useful for documenting reduction of motion during the early stages of the freeze cycle in relation to other measurements being taken.

Agreed, possibly a missed opportunity with the north greenland gap. Maybe they thought they had to get through it before it closed up.