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Messages - Wipneus

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101
Arctic sea ice / Re: Latest PIOMAS update (October 2019)
« on: October 06, 2019, 10:51:53 AM »
Finally the thickness map comparisons. Here are thickness map, compared with previous years and their diff's on the 10th of September (approximate day of annual minimum).

102
Arctic sea ice / Re: Latest PIOMAS update (October 2019)
« on: October 06, 2019, 10:38:20 AM »
Finally a linear trend. The 2019 data point lies near perfect on the trend line. That means that the zero ice extrapolation has not shifted either and stays at 2032. That, and the fact that is has not changed much for many years gives some confidence to this date.

So for comparison I have added the same graph that I posted in 2012: also a 2032 zero ice extrapolation. The 'prediction' for 2019 is spot-on.

103
Arctic sea ice / Re: Latest PIOMAS update (October 2019)
« on: October 06, 2019, 10:29:10 AM »
Same as the previous but now a Gompertz regression, preferred by some. The Gompertz function approaches but never reaches zero, but still the same postponement to later and later dates is clear.

104
Arctic sea ice / Re: Latest PIOMAS update (October 2019)
« on: October 06, 2019, 10:24:20 AM »
Continuing discussion this, here is an attempt to show how the estimates of zero ice have been shifting. It is the same graph as in the previous post with extrapolations form former years added.
Here the dark blue line is the extrapolation using data up to 2018; The next greenish line data up to 2017
And so fort.
Many years the zero ice prediction was close to 2015 but that has been postponed, on average 1 year every year for the last 6 years or so.
 

105
Arctic sea ice / Re: Latest PIOMAS update (October 2019)
« on: October 06, 2019, 10:15:12 AM »
Here is the exponential fit. The 2019 minimum is above the trend, shifting the extrapolated zero ice after  2025 where with only data up to 2018 it was 2014.

106
Arctic sea ice / Re: Latest PIOMAS update (October 2019)
« on: October 06, 2019, 10:07:36 AM »
The graphs updated with the annual minima.
Here is my collection of possible math fits to the timeline.

This graph was originally as a reply posted on the ASI blog. In those days the minima closely followed an exponential decline.
Not so in recent years. Every year the extrapolated day of zero ice is postponed about one year. Similar for most other mathematical functions. More about that in the next posts. 

A click will give you a slightly better image.

107
Arctic sea ice / Re: Latest PIOMAS update (October 2019)
« on: October 06, 2019, 09:57:04 AM »
Continuing with the graphs...

Here is the updated Fram volume export graph. September export was below normal.

108
Arctic sea ice / Re: Latest PIOMAS update (October 2019)
« on: October 05, 2019, 09:13:14 AM »
More graphs to prepare (the ones with annual minimum), but that will be much later. Paint job to do.

110
Arctic sea ice / Re: Latest PIOMAS update (October 2019)
« on: October 05, 2019, 09:04:04 AM »
The volume and volume-anomaly graphs.

111
Arctic sea ice / Re: Latest PIOMAS update (October 2019)
« on: October 05, 2019, 08:57:45 AM »
PIOMAS gridded thickness data has updated. Volume calculated from thickness was 4.57[1000km3] on 30th September, second lowest for the day.
The 2019 minimum was around the 10th, 4.06[1000km3]. As these number are not exactly the same as the official PIOMAS volume numbers, wait for the release of those.

Here is the animation.


112
Antarctica / Re: PIG has calved
« on: September 26, 2019, 09:37:24 AM »
Progress report: cracks are extending and widening everywhere. Animation ( images should differ 12 days) scaled to 50m/pix for an overview. Images are aligned at the glacier front.


113
Some people have use for the updated regional data files:

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

114
And the Fram volume export.

115
Here are the updated volume and volume-anomaly graphs. Click to enlarge.

116
The PIOMAS gridded thickness data was updated to the 15th of September. Volume (calculated from thickness) on that date was 4.06 [1000km3], second lowest for the day. The number  have been nearly constant at 4.05-4.06 for several days. Because my calculation sometimes differ with the official volume data by 0.01 I do not know if we have reached the minimum (my feeling is, it has).

Here is the animation of September thus far. 

117
Antarctica / Re: PIG has calved
« on: September 16, 2019, 07:04:01 AM »
Wipneus, thank you very much.
Could you give me a link to that Sentinel B source - if I open this programme, there is no actual photograph available (https://apps.sentinel-hub.com/sentinel-playground/?source=S2&lat=-75.17015590641843&lng=-101.28536224365234&zoom=11&preset=1-NATURAL-COLOR&layers=B01,B02,B03&maxcc=100&gain=0.2&gamma=1.0&time=2018-08-01%7C2019-02-16&atmFilter=&showDates=true)


Stephan, I list and download from ESA's scihub using scripts provided by them.
The full flename of the download is:
S2B_MSIL1C_20190914T151259_N0208_R139_T14CMB_20190914T180019.zip
of use may be the productid:
'3ddd27b9-4efa-4bfb-a5b8-22cb80cd0662'

118
Antarctica / Re: PIG has calved
« on: September 15, 2019, 11:12:36 AM »
First visible light images from Sentinel 2 of the Pine Island Glacier.
The first image present the overview in reduced resolution (50m/pix). Then a detail in the native resolution of 10m/pixel.

119
Antarctica / Re: PIG has calved
« on: September 04, 2019, 04:07:09 PM »
Sorry for the confusion. The images are 2019-08-20 and 2019-09-01 (12 days is the return time of the Sentinel satellite for the same orbital position).

120
Arctic sea ice / Re: Home brew AMSR2 extent & area calculation
« on: September 04, 2019, 02:55:55 PM »

That is a very good animation, really shows the bad state of the ice. How do you get the original pictures? Can you send a link?
Thanks

V. these are "original pictures" generated by me from binary data from the University of Hamburg.

Perhaps have a look at the first few posts in this thread for more explanations. The current location of the data files are here:
ftp://ftp-projects.cen.uni-hamburg.de/seaice/AMSR2/3.125km

121
Arctic sea ice / Re: Home brew AMSR2 extent & area calculation
« on: September 04, 2019, 09:07:31 AM »
A late century drop in extent shows there are still possibilities for second lowest place ( in my limited data set).

Here is an animation of the Arctic Basin compared with 2012. Click to start.

122
Arctic sea ice / Re: Home brew AMSR2 extent & area calculation
« on: September 04, 2019, 09:02:49 AM »
The Google API that I am using to automatically update data and graphs has stopped working for me  ("Internal Server Error"). For the moment I am updating some files manually. Send me a PM if you favorite file is still from the 8th of August.

124
Arctic sea ice / Re: Latest PIOMAS update (September 2019)
« on: September 04, 2019, 08:52:08 AM »
The thickness map on 2019-08-31, compared with previous years and the differences. All need a click for full size.

125
Arctic sea ice / Re: Latest PIOMAS update (September 2019)
« on: September 04, 2019, 08:47:03 AM »
Looking at the graph I think 2019 is now guaranteed a 2nd place finish?

Yes

126
Arctic sea ice / Re: Latest PIOMAS update (September 2019)
« on: September 04, 2019, 08:46:25 AM »
Fram volume export was about normal for August: low.

127
Arctic sea ice / Re: Latest PIOMAS update (September 2019)
« on: September 04, 2019, 08:42:20 AM »
The volume and volume-anomaly graphs.

128
Arctic sea ice / Re: Latest PIOMAS update (September 2019)
« on: September 04, 2019, 08:28:36 AM »
PIOMAS gridded thickness data has updated (official volume data not yet). Volume on 31st August was 4.17 [1000km3], second lowest behind 2012 (3.93[1000km3]).

Here is the animation for August.

129
Antarctica / Re: PIG has calved
« on: September 03, 2019, 09:52:14 AM »
Update, compare with https://forum.arctic-sea-ice.net/index.php/topic,429.msg220359.html#msg220359

Crack keeps getting wider, very fast in comparison with usual speeds.

130
I have trouble uploading data and graphs to the 'arctischepinguin' google site. So the updates will be delayed until the google errors are resolved or I have found time to do it manually.

131
And the updated Fram volume export graph.

132
The volume and volume-anomaly graphs.

133
Here is the animation for August until now.

134
PIOMAS gridded thickness data was updated., last date was 2019-08-17. Volume calculated from thickness was 4.81 [1000km3], second lowest behind 2012 (4.68 [1000km3]).

graphs are being prepared...

135
Antarctica / Re: PIG has calved
« on: August 09, 2019, 08:48:20 AM »
The cracks are still widening as this detail shows.

136
Arctic sea ice / Re: Latest PIOMAS update (August 2019)
« on: August 04, 2019, 07:43:34 PM »
Wipneus, the thickness map in your post #2992 is last year's map not this year's.

Fixed, thanks for the notice.

137
Arctic sea ice / Re: Latest PIOMAS update (August 2019)
« on: August 04, 2019, 09:22:53 AM »
2019-0-31 thickness map, a comparison with previous years and their differences (need clicks for the true size).

139
Arctic sea ice / Re: Latest PIOMAS update (August 2019)
« on: August 04, 2019, 09:16:23 AM »
Fram volume export is low as expected for July.

140
Arctic sea ice / Re: Latest PIOMAS update (August 2019)
« on: August 04, 2019, 09:12:40 AM »
Updated volume and volume-anomaly graphs.

141
Arctic sea ice / Re: Latest PIOMAS update (August 2019)
« on: August 04, 2019, 08:52:00 AM »
PIOMAS gridded thickness data was updated. I calculate volume from the thickness data, gives 6.46 [1000km3] on 2019-07-31. Lowest for the day with a small margin with 2012 (6.68 [1000km3]).

Here is the animation.

142
Indeed, thanks.

Unfortunately I can't get Sentinel images as I'm getting a JSON error message saying "RATE_LIMIT_EXCEEDED".

I have not been able to download any images either. The Sentinel hub says:

Quote
t has been observed a decrease of the performances related to the products download following the Security Maintenance on 29-30 July.

Downloads might be slow and/or interrupted on the following services:

    Copernicus Open Access Hub (including API Hub)
    Collaborative Data Hub Node-1
    Copernicus Services Data Hub

Investigation is on going.

We apologise for any inconvenience caused to your activities.

https://scihub.copernicus.eu/news/News00585

Keep trying...

143
Arctic sea ice / Re: Home brew AMSR2 extent & area calculation
« on: August 04, 2019, 08:26:23 AM »
Total extent drop -93.6k, it is eating into the CAB now as well (-38.2k). Here is a diff with the previous day.

Bright red/blue: loss/gain of extent (crossing the 15% concentration limit). Light red/blue:  concentration change more than 7%. 

Click for the hi-res picture.

144
Arctic sea ice / Re: 2019 sea ice area and extent data
« on: August 02, 2019, 02:34:22 PM »
While at it, a near double century extent drop today. Here is the latest diff map to answer the question "where?".

145
Arctic sea ice / Re: 2019 sea ice area and extent data
« on: August 02, 2019, 02:28:40 PM »
The NSIDC NT Arctic Sea Ice Area annual minimum is now (2019-07-31) lower than any year before 200 with still 5-6 weeks to to go.


Below 2006?

2007, I have no idea where I lost that "7".

I report daily data always as daily.

BTW, extent is now (1st August) 20th lowest. Only 1999 (rank #15) of the previous century is still lower.

146
Arctic sea ice / Re: 2019 sea ice area and extent data
« on: August 02, 2019, 10:20:51 AM »
The NSIDC NT Arctic Sea Ice Area annual minimum is now (2019-07-31) lower than any year before 2007 with still 5-6 weeks to to go.

Here are the bottom 20 rankings:

NH Area
1 2012-09-12 2.228429
2 2016-09-06 2.463209
3 2011-09-05 2.916451
4 2007-09-07 2.954993
5 2017-09-11 3.000742
6 2010-09-07 3.071674
7 2008-09-08 3.079552
8 2015-09-07 3.139137
9 2018-09-09 3.235357
10 2009-09-08 3.547109
11 2014-09-09 3.576643
12 2013-09-08 3.607877
13 2019-07-31 4.026394
14 2006-09-22 4.082958
15 2002-09-05 4.098445
16 2005-09-03 4.134433
17 2003-09-05 4.155104
18 2000-09-03 4.235279
19 1999-09-16 4.318875
20 1998-09-11 4.346996

Extent is a bit less extreme: 2019 has not entered the bottom 20.

NH Extent
1 2012-09-16 3.339905
2 2016-09-07 4.144993
3 2007-09-14 4.146931
4 2011-09-08 4.332572
5 2015-09-08 4.387092
6 2008-09-18 4.548265
7 2010-09-19 4.589683
8 2018-09-21 4.630291
9 2017-09-13 4.634885
10 2014-09-16 4.988244
11 2013-09-13 5.039617
12 2009-09-12 5.046571
13 2005-09-20 5.314284
14 2002-09-18 5.625038
15 1999-09-12 5.676431
16 2006-09-14 5.746404
17 2004-09-18 5.770495
18 2000-09-11 5.942586
19 2003-09-17 5.969052
20 1990-09-21 6.010841
21 1995-09-04 6.012446
22 1993-09-13 6.161196
23 2019-07-31 6.192291
 

147
Arctic sea ice / Re: 2019 sea ice area and extent data
« on: July 27, 2019, 02:13:57 PM »
Today NSIDC's diff map (dark blue/red shows ice extent in/decreases. Light blue/red where ice concentration increased/decreased more than 7%) shows the ice pack retreating along the Beaufort/Chukchi/ESS ice edge.

148
Some people have use for the updated regional data files:


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

149
Daily Fram volume export graph. Little export as expected in July.

150
Updated volume and volume-anomaly graphs.

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