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Messages - Wipneus

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51
Arctic sea ice / Re: Latest PIOMAS update (March 2020)
« on: March 04, 2020, 07:06:43 PM »
Thickness map, compared with previous years and their diffs.
That is on the 29th of Feb, admittingly looks a bit silly for the other years.

Images to click for size.

52
Arctic sea ice / Re: Latest PIOMAS update (March 2020)
« on: March 04, 2020, 06:58:37 PM »
Fram volume export was above average this month.

53
Arctic sea ice / Re: Latest PIOMAS update (March 2020)
« on: March 04, 2020, 06:41:40 PM »
Volume and volume-anomaly graphs. Click for larger and clearer images.

54
Arctic sea ice / Re: Latest PIOMAS update (March 2020)
« on: March 04, 2020, 06:29:58 PM »
PIOMAS has updated. Last date was actually day 60 of 2020. Now that would be entirely consistent with 29th of February, except that the PIOMAS year has only 365 days every year. So it could be tagged as 1st March in PIOMAS time scale. For now, I stick to 29th of February. That may change silently later this year.

Anyway here is the animation.

55

Wipneus - thanks for all the efforts - how about a double thickness line for the current year - or a dashed version?

Good suggestion, I will go for the thicker current year (like in some area/extent graphs).


Quote
Equally maybe the ones say before 2010 could be finer / dotted lines so that even if they are  roughly same colour its easy to spot that they in a different category?

Yes, like all suggestions to use different line styles (like dotted or dashed) it takes some experimenting and may not be usable in all my graphs. Eventually as the number of years in the graphs grow it will be necessary at some time.

56
Some people have good use for the updated regional data files.

daily:
https://sites.google.com/site/arctischepinguin/home/piomas/data/PIOMAS-regional.txt.gz

Sorry to say Wipneus but the .txt file is dated 4/2/2020 with data to 31 Jan.

My apologies! It should be corrected now.

57
Arctic sea ice / Re: Latest PIOMAS update (February 2020)
« on: February 19, 2020, 10:14:10 AM »

Hi Wipneus, you asked the same question a year ago and I replied then with a suggested colour palette.

Did you try those colours and, if so, did they work OK?

[sorry for the late reply]

Hi slow wing.

Yes I have been using that approach: create an ordered set of colors nicely spaced out in RGB space. Unfortunately nice spaced in RGB is not perceived as such by our eyes. So I start tweaking colors, not to my complete satisfaction. 

58
Some people have good use for the updated regional data files.

daily:
https://sites.google.com/site/arctischepinguin/home/piomas/data/PIOMAS-regional.txt.gz

59
The gridded velocity data was not updated (yet?), so Fram export graph cannot be updated.

Here are the volume and volume and volume-anomaly graphs. Colors have been a bit tweaked, a light grey background added to make the yellows a bit readable, and shared with existing area/extent graphs.

[edit: gave 2020 a thicker line as suggested by charles_oil]
 

60
PIOMAS has updated the gridded thickness data upto the 15th. Calculated volume at 2020-2-15 was 19.67 [1000km3], This is fifth lowest for the day, exactly the same as the volume on that day in 2016, the "final official" volume data may change that exact match.

Here is the animation for February so far.

62
Arctic sea ice / Re: Latest PIOMAS update (February 2020)
« on: February 04, 2020, 08:19:07 PM »
Here are volume and volume-anomaly graphs.

It is getting harder to find a new color for a new year. I am trying a new color scheme that I found here:
https://sashat.me/2017/01/11/list-of-20-simple-distinct-colors/

Have a look, I am not sure myself yet, comments are welcome.


63
Arctic sea ice / Re: Latest PIOMAS update (February 2020)
« on: February 04, 2020, 07:21:45 PM »
Thickness map on 2020-01-31, compared with recent years and the diff's. Click for full size.

64
Arctic sea ice / Re: Latest PIOMAS update (February 2020)
« on: February 04, 2020, 07:11:15 PM »
PIOMAS has updated. Volume on 31st January was 18.282[1000km3], this is fifth lowest behind 2011,2013,2017 and 2018.

Here is the animation.

65
Arctic sea ice / Re: Latest PIOMAS update (January 2020)
« on: January 04, 2020, 10:09:31 AM »
Thickness map on 31st December 2019, compared with recent years and their diffs.
Clicks are needed for full size.

67
Arctic sea ice / Re: Latest PIOMAS update (January 2020)
« on: January 04, 2020, 10:02:35 AM »
Updated Fram volume export.

68
Arctic sea ice / Re: Latest PIOMAS update (January 2020)
« on: January 04, 2020, 09:59:48 AM »
Here are the updated volume and volume-anomaly graphs. Click for full size.

69
Arctic sea ice / Re: Latest PIOMAS update (January 2020)
« on: January 04, 2020, 09:31:31 AM »
PIOMAS gridded thickness data was update. On the last day, 31st December, volume is calculated to be 14.52 [1000km3], which is fourth lowest behind 2016, 2012 and 2017.

Here is the December animation.

70
Antarctica / Re: PIG has calved
« on: December 23, 2019, 07:59:04 PM »
A clear Landsat 8 image, with low solar elevation (8.2 degrees) shows more and more thin cracks have developed.

Click to see in full resolution (15m/pix).

71
Antarctica / Re: PIG has calved
« on: December 22, 2019, 10:06:55 AM »
Surface melt blackens the Sentinel 1's radar images. Some finer cracks become visible in this (medium resolution) dual polarization (Red=horizontal,Green=vertical) image. Needs a click to show in native (40m/pix) resolution.

72
Antarctica / Re: Latest GIOMAS/PIOMAS volume data for Antarctica
« on: December 22, 2019, 10:01:33 AM »
Hi,

I'm looking for Antarctic sea ice thickness and volume from PIOMAS - do you know where I can find the data?


There is no Antartctic PIOMAS, P is Pan-Arctic. GIOMAS is the a (G=) Global model, restricting the data to the Southern Hemisphere gives you the Antarctic data. GIOMAS has a courser grid, be careful with comparing to PIOMAS.

See my GIOMAS page (link my second post above) for the sources of GIOMAS data, that is gridded thickness data. Calculated volume is at the bottom of my page, in spreadsheet form and a link to a text file.
 

73
Some people have use for the updated regional data files:


daily:
https://sites.google.com/site/arctischepinguin/home/piomas/data/PIOMAS-regional.txt.gz

74
Updated Fram volume export graph.

75
The updated volume and volume-anomaly graphs.

76
PIOMAS gridded thickness data was updated. last day 15th December. Calculated volume on that day was 12.345 [1000km3]. That is still third lowest for that day after 2016 and 2012.

Here is the animation for the first half of December.

77
Antarctica / Re: PIG has calved
« on: December 08, 2019, 08:02:03 PM »
The new crack is getting longer and better visible in this Sentinel 2 image (contrast enhanced, 20m/pix).

78
Antarctica / Re: PIG has calved
« on: December 07, 2019, 12:22:22 PM »
Indeed, very little support left on this side left. The darkening has reversed again (Sentinel 1 SAR, at least for the PIG) and we can make a decent animation again.

79
Antarctica / Re: PIG has calved
« on: December 05, 2019, 04:13:44 PM »
Two more details of the crack discussed in the previous post. The first is the Sentinel 1 SAR image in native 10m/pix resolution. The second is from an earlier Sentinel 2 optical image, scaled to 5m/pixel (from native 10m). Here the contrast was enhanced to bring out the linear feature, that I had missed if not for the Sentinel 1 image.

80
Antarctica / Re: PIG has calved
« on: December 05, 2019, 03:54:53 PM »
End of November, all the Sentinel 1 images of the PIG area (and far beyond that) are turning a darker shade of grey. Happens every year, surface melting is cause no doubt. The reduced scattering makes some previously undetected  cracks  more visible, see the arrow drawn in the second frame.
For the overview I scaled the image to 50m/pix (from 10m/pix in the original). I will show some hi-res images in another post.

81
Arctic sea ice / Re: Latest PIOMAS update (December 2019 )
« on: December 04, 2019, 01:09:52 PM »
Thickness map compared with previous years and their diff's. Click to size.

83
Arctic sea ice / Re: Latest PIOMAS update (December 2019 )
« on: December 04, 2019, 11:45:22 AM »
The Fram-volume export graph. Average export was low, compared with average November export.

84
Arctic sea ice / Re: Latest PIOMAS update (December 2019 )
« on: December 04, 2019, 11:39:10 AM »
Updated volume and volume-anomaly graphs. Click for the better picture.

85
Arctic sea ice / Re: Latest PIOMAS update (December 2019 )
« on: December 04, 2019, 11:29:36 AM »
PIOMAS has upgraded the gridded thickness data. Last date, 30th Nov, the calculated volume was 10.35[1000km3]. That is third lowest for the day (behind 2016 and 2012).

Here is the animation for November 2019.

86
Some people have use for the updated regional data files:

daily:
https://sites.google.com/site/arctischepinguin/home/piomas/data/PIOMAS-regional.txt.gz

87
Fram volume export. Big negative spike on the last day can be seen in the animation above.

88
Updated volume and volume-anomaly graphs.

89
PIOMAS has upgraded its gridded thickness data upto 15th November. Calculated volume at that date was 8.54 [1000km3], which is third lowest behind 2012 and 2016.

Here is the animation of the first half of November.

90
Antarctica / Re: PIG has calved
« on: November 06, 2019, 08:18:59 PM »
The cracks are so wide now that we can see an iceberg breaking off and toppling over, withing the crack. If I am not mistaken of course.

92
Arctic sea ice / Re: Latest PIOMAS update (November 2019)
« on: November 04, 2019, 09:42:14 AM »
Thickness map, comparisons with previous years and their diff's. Click for full size.

93
Arctic sea ice / Re: Latest PIOMAS update (November 2019)
« on: November 04, 2019, 09:35:13 AM »
Update Fram volume export graph. The export is increasing, not quite as fast as expected.

94
Arctic sea ice / Re: Latest PIOMAS update (November 2019)
« on: November 04, 2019, 09:30:19 AM »
Update volume and volume-anomaly graphs. 2012, 2016 and 2019 are very close.

95
Arctic sea ice / Re: Latest PIOMAS update (November 2019)
« on: November 04, 2019, 09:20:44 AM »
PIOMAS gridded thickness data has updated. Volume calculated from thickness was 6.52[1000km3] on 31st October, third lowest for the day. 2012 and 2016 had a lower volume.

Here is the animation.

96
Some people have use for the updated regional data files:


daily:
https://sites.google.com/site/arctischepinguin/home/piomas/data/PIOMAS-regional.txt.gz

97
Fram volume export is still summer-low.

98
Updated volume and volume-anomaly graphs.

99
PIOMAS has updated the gridded thickness data up to 15 October. Volume was 5.16 [1000km3], second lowest (after 2012) for the day.

Here is the animation for October thus far.

100
Antarctica / Re: PIG has calved
« on: October 19, 2019, 07:55:14 PM »
Crack detail, images 12 days apart. The widening getting faster mainly from the Wesy side.

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