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Messages - Stephan

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1
Arctic sea ice / Re: 2018 sea ice area and extent data
« on: Today at 06:47:34 PM »
I think we all should wait a couple of days until the measurements are (then hopefully) settled again.

2
Thank you for having you back. We have missed your contributions.

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Arctic sea ice / Re: Arctic Image of the Day
« on: November 15, 2018, 06:46:17 PM »
As a man living in Germany it is hard to imagine to have only twilight around noon. The days here are also shorter now as in summer, but here sunset is around 5 PM.

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Arctic sea ice / Re: When will the Arctic Go Ice Free?
« on: October 12, 2018, 09:18:20 PM »
(This post is in the wrong thread but it must be said)
Here in Germany we suffer almost without exception from a too warm and too dry summer since beginning of April. We had almost no rain throughout June to October with a lot of crop failure and forest fires. And tomorrow daily max. temp is forecasted to be 27-29°C almost nationwide. Many people are alarmed, and the green party is really up in public polls. Diesel discussion and the end of coal mining is in every news show...

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Arctic sea ice / Re: The 2018/2019 freezing season
« on: October 12, 2018, 07:47:44 PM »
If this becomes true, it should be named "Abrupt Climate Change" for Bering and Chukchi Sea.

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Arctic sea ice / Re: When will the Arctic Go Ice Free?
« on: October 10, 2018, 04:47:35 PM »
Just a question for us all.
We already have seas that melt out completely (like Hudson or Kara). Would these seas be an example for a BOE? And has anyone ever monitored the rates of volume, thickness and area decline close before the end and compared these rates with the rates at about 30, 50, 70 % of ice coverage? This analysis (also the relation of the rates) could help to answer the questions that arose in this thread.

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Arctic sea ice / Re: When will the Arctic Go Ice Free?
« on: October 04, 2018, 09:11:24 PM »
It is time for the monthly update of my extrapolation when the extent [Extent], volume [Volumen] and thickness [Dicke] will reach zero. The extrapolation occured linearly and by a logarithmic function; the latter one almost constantly resulting in earlier times. September value now includes 2018, and BOE seems to appear later than extrapolated last year, mostly due to a slight increase in volume 2018 compared to 2017.
See attached table.

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Arctic sea ice / Re: 2018 sea ice area and extent data
« on: October 04, 2018, 05:47:40 PM »
Ned W,
thank you for the re-analysis of data around the yearly minimum. It is an interesting plot and shows that the last two weeks are not so unusual as they appear to be.

9
Arctic sea ice / Re: Global sea ice area and extent data
« on: October 03, 2018, 10:22:05 PM »
Once again the pen draws a line on previously untouched areas of this graph.
The closest years in global SIE are 2017, 2016 and 2012. This is not by chance, but a trend.
I wonder whether SIE loss in the Antarctic will start soon (then we may see a global SIE like 2016) or whether it will be delayed (then the global curve should more look like 2017).

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Arctic sea ice / Re: 2018 sea ice area and extent data
« on: October 03, 2018, 09:54:33 AM »
Step by step 2018 SIE comes closer to the value of 2007...

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Arctic sea ice / Re: 2018 sea ice area and extent data
« on: September 23, 2018, 09:13:46 AM »
This is the third lowest on record, being behind 2012 (lowest) and 2007 (second lowest).
Compared to the two previous years Sep 22 2018 has 0.21 mio. km² less ice than Sep 22, 2017 and 0.12 mio. km² less ice than Sep 22, 2016.
The highest value of the 2010s on this date were 2013 (5.00) and 2014 (5.04 mio km²)

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Arctic sea ice / Re: 2018 sea ice area and extent data
« on: September 07, 2018, 05:07:33 PM »
It is time for the monthly update of the comparison of actual data with the long term trend.
August 2018 is 0,16 mio. km² below the long term linear trend, see attached graph.

13
Arctic sea ice / Re: 2018 sea ice area and extent data
« on: September 07, 2018, 04:30:24 PM »
In my opinion, painting horizontal lines into the ice extent or volume data from 2007 to 2017 is cherry picking at its best. The same was done by AGW deniers with global temperatures, choosing 1998 as an extra warm year as start and drawing a line until 2013 (comparably cool), claiming the pause of global warming is the beginning of a forthcoming cooling. The T rise of 2015 and 2016 and 2017 has stopped them doing that.
It is the long term trend that is important. The natural variability which adds upon the decreasing trend has to be taken into account when interpreting or extrapolating the data.

14
Glaciers / Re: Alpine Glaciers
« on: August 24, 2018, 07:36:13 PM »
Here is a link to foto-webcam.eu of the Kleinfleißkees, Austria. You can switch from year to year from 2014 to 2018 to see the changes.
https://www.foto-webcam.eu/webcam/kleinfleisskees/2014/08/23/0900
The Goldbergkees, Austria is decreasing quite fast from 2016 to 2018:
https://www.foto-webcam.eu/webcam/goldbergkees/2016/08/23/0900.
The famous Pasterze is also melting. Use the year-to-year button to see it grow (backwards) or shrink (forward): https://www.foto-webcam.eu/webcam/freiwandeck/2018/08/24/0700

15
Thank you iwantatr for this animation. It is quite a big difference.

16
Thank you Espen for this impressive animation. Can you give us a rough scale of the size of the calved ice pack?

17
Arctic sea ice / Re: Latest PIOMAS update (August)
« on: August 06, 2018, 09:46:31 PM »
Thank you Juan for your work.
It clearly comes out that the major change in ASI happened in 2007. Since then only minor changes have occurred, expressed mainly in further reduction of volume, especially in OND due to later freezing / intrusion of warmth through the Atlantic side.

18
Arctic sea ice / Re: 2018 sea ice area and extent data
« on: July 27, 2018, 03:37:22 PM »
OK, I've finished reprocessing all the monthly NSIDC ice concentration data, to see what the effect would be of changing from a 15% threshold for extent to a 30% threshold. 
[...]
Yes, exactly.  Switching to a 30% threshold would delete 0.72 million km2 of extent on average, so we'd hit the "ice-free Arctic" threshold very slightly earlier.  But it would be an artificial distinction.
Thanks for this work. It seems like the difference between 15% and 30% extent is season-depending as mostly five peaks appear in almost regular manner in every five-year period.

19
Arctic sea ice / Re: 2018 sea ice area and extent data
« on: July 12, 2018, 06:51:49 PM »
The three most southern seas with significant ice are Baffin, Hudson, and Kara. I just compared their area (from Gerontocrat's actual post → THANK YOU FOR THIS VERY VALUABLE CONTRIBUTION!!) with their extent (from MASIE). All these seas show a very low compactness which makes them likely to melt out the next week(s):
Baffin area 0.23 extent 0.55 (compactness ~ 40%)
Hudson area 0.28 extent 0.70 (compactness ~ 25%)
Kara area 0.28 extent 0.50 (compactness ~ 55%)
The extents sum up to 1.75 mio. km² which should lead to further "century meltdowns" in the next days...

20
Arctic sea ice / Re: Don't read this thread
« on: July 08, 2018, 09:25:42 AM »
Personally I think the first year without summer ice will be quite unspectacular.

The preceding years will already have approached the arbitrary threshold of "ice free" and then one year it will just slip over this threshold. Interesting from a statistical and historical point of view but no more exciting than the years before.
I think that the first ice free year (from the extrapolation of volume data it should happen around 2025 ± 2 years) will be extremely spectacular because then the whole world will see that we are in deep trouble concerning climate change. I also believe that the distribution of heat, wind, air masses and ocean currents will change when there is (almost) no ice left in the Arctic Ocean.
The problem then is: It will be too late for a turnaround to a less warmer world...

21
Arctic sea ice / Re: 2018 sea ice area and extent data
« on: July 07, 2018, 08:10:11 PM »
East Siberian Sea had been "asleep" for almost the whole melting season this year. The extraordinary high temperatures that arrived there a week ago or so (max. around 20-30° according to Climate Reanalyzer) now start the big melt there...

22
Arctic sea ice / Re: The 2018 melting season
« on: July 07, 2018, 08:03:29 PM »
I would appreciate if these kinds of predictions are re-visited after the storm has left or faded.
Has the compact ice broken up? Were high waves eating away the edge of some floes? Did falling rain (or was it snow?) damage the surface? And a comparison of other less or non-affected areas close by (wouldn't all these things not have happened anyway?) should be included...

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Arctic sea ice / Re: "Stupid" Questions :o
« on: July 02, 2018, 10:40:34 PM »
Steam (water vapor) is the strongest GHG. From my studies in chemistry many years ago, I seem to remember that burning of fossile fuels create humidity. The primary products of complete combustion of e.g. kerosene or propane are carbon dioxide and water. Something like 15-20% of what goes up the flue on gas furnaces is steam. A lot of it is, however, condensed immediately in cooling towers.

My question is: How many gigatonnes of steam are created yearly from burning FF (net), and for how long does that additional steam remain in the atmosphere?
If you just assume, that oil is represented by octane (C8H18), then its burning will create carbon dioxide and water according to the formula below (mole weights multiplied with the numbers of molecules in brackets)
C8H18 (114) + 12,5*O2 (400) → 8*CO2 (352) + 9*H2O (162)
According to Wikipedia.de in 2016 a total of 4,384 Gt oil was produced worldwide. If this would have been completely combusted to CO2 and water this would sum up to an enormous amount of 4,384*162/114 = 6,23 Gt.

Water has a very short life in the atmosphere as it likely forms clouds and precipitates. So this increase will not be significant compared to the amount of water in the atmosphere.

A comparable calculation applies for natural gas.
CH4 (16) + 2*O2 (64) → CO2 (44) + 2*H2O (36)
Around 2,53 Gt were produced in 2015 (Wikipedia.de). This adds up to 2,53*36/16 = 5,69 Gt of water worldwide (a 100% combustion to water and CO2 assumed).

Another idea: This water also sums up to Global Sea Level Rise. 100 Gt lifts the oceans up by about 1 0,28 mm (corrected 3.7.2018). The two figures are around 12 Gt, meaning that the 360 Gt (= 1 mm) are reached within a 3 decades (corrected 3.7.2018).

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Arctic sea ice / Re: Arctic sea ice minimum early prediction
« on: June 04, 2018, 06:47:53 PM »
August has a weak correlation (see below)
September also correlates quite a little bit - even now it is definitively too late for an early prediction.
https://forum.arctic-sea-ice.net/Smileys/default/wink.gif

Therefore in my opinion the "most decisive time" for the level of the yearly minimum is the second half of June and July.
If anyone has the data by hand of beginning and end of each month a comparable month-by-month evaluation may be easily possible.

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Arctic sea ice / Re: Arctic sea ice minimum early prediction
« on: June 04, 2018, 06:44:35 PM »
I processed the arctic sea ice extent data by calculating the decrease from monthly averages for all years between 1979 and present. As the monthly averages are probably mid month values, these differences represent what is going on between the 15th of the previous month and the 15th of the actual month. These differences (on x-axis) are now plotted against the yearly JAXA minimum extent (y-axis) for all months between April and September for all years since 1979. The results are interesting:
April shows random values (see April.jpg)
May isn't better (see Mai.jpg)
June has a slight correlation (see Juni.jpg)
July correlates quite well (see Juli.jpg)
August and September follow soon.

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Arctic sea ice / Re: 2018 sea ice area and extent data
« on: May 28, 2018, 09:28:28 PM »
I analysed the last 38 years of JAXA extent date. I took the average values of the 80s, 90s, 00s and 10s (up to now) at each end of a quarter (first table) and in the middle of the quarter (second table) and looked for trends in differences from one season to the next one over these four decades.

Extent [mio km²]            
   March 31   June 30   Sep 30   Dec 31
80s   15,22   11,14   7,76           13,84
90s   14,83   10,48   7,10           13,48
00s   14,24     9,75   5,94           12,88
10s   13,94     8,95   4,95           12,35
Gains (+) and losses (-) [mio km²]            
80s   +1,38      -4,08   -3,38   +6,08
90s   +1,35   -4,35   -3,38   +6,38
00s   +1,36   -4,49   -3,81   +6,94
10s   +1,59   -4,99   -4,00   +7,40
            
Extent [mio km²]            
   Feb 15   May 15   Aug 15   Nov 15
80s   15,32   13,27   7,88           11,00
90s   14,96   12,87   7,24           10,54
00s   14,43   12,43   6,33             9,91
10s   13,84   11,99   5,40            9,26
Gains (+) and losses (-) [mio km²]            
80s   +4,32   -2,05   -5,39   +3,12
90s   +4,42   -2,09   -5,63   +3,30
00s   +4,52   -2,00   -6,10   +3,58
10s   +4,58   -1,85   -6,59   +3,86

From these values I see the sharp decrease in the melting over summer (July/Aug) in the latest decade, but also a pronounced increase in winter and early spring, and - surprisingly - a pronounced slower melting in the period between Feb 15 and May 15 in the latest decade. This is in line with the actual observations of a "slightly slower than average" decrease of sea ice extent in the last weeks.
The generally lower maximum (supposedly more in the periphery than in the CAB) could explain this behaviour (when less ice is available in the more peripherical parts which gain sun and warmth at first then the melting starts a little earlier).
The much lower minima in September also lead to a stronger increase towards the winter which explains the higher gains in the latest decade (compared to the earlier ones).

Just some points to discuss...

kind regards from Germany.



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