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Messages - Stephan

Pages: [1] 2 3 ... 27
1
Arctic sea ice / Re: The 2020/2021 freezing season
« on: September 19, 2020, 09:52:34 PM »
Very nice animation. Thanks for all these great contributions.  :)

2
Arctic sea ice / Re: 2020 Sea ice area and extent data
« on: September 19, 2020, 06:58:50 PM »
The last evaluation of Arctic Sea Ice Area of this melting season "relative area wise"
Two seas still lost ice:
ESS       - 63%
CAB       -   1%
Three seas have already gained some ice:
Grønland + 4%
Beaufort  + 6%
CAA        + 8%
The other seas (almost completely melted out) were not analysed.

3
Arctic sea ice / Re: 2020 Sea ice area and extent data
« on: September 19, 2020, 07:19:01 AM »
From the image a further relevant increase should be expected. Large areas of newly formed ice in N Beaufort Sea.
But still no numerical data available.

4
Arctic sea ice / Re: 2020 Sea ice area and extent data
« on: September 17, 2020, 06:08:25 PM »
The second lowest minimum extent of Arctic Sea Ice was one of the topics in the radio news (Deutschlandfunk - a nationwide public radio programme in Germany). They also explained the higher than average temperatures in the Arctic were one of the reasons for this event.

5
Arctic sea ice / Re: When will 2020 JAXA extent cross 2012?
« on: September 15, 2020, 08:33:39 PM »
I subracted 0.45 M km² from the 2019 extent and this line crosses the 2012 path on October 10, 2020. I think the refreeze will be delayed this year (as it was 2019) because of all the warm water masses around the actual ice edge. Therefore 2020 should roughly follow 2019, but at a slightly lower level.

6
This calving event made it into the main TV news "Tagesschau" in Germany yesterday. I really wondered why they needed ten weeks to broadcast it...

7
Antarctica / Re: Sea Ice Extent around Antarctica
« on: September 15, 2020, 07:21:08 PM »
It should be 42 years (1979 to 2020).

8
Antarctica / Re: Pine Island Glacier (PIG) Calving and Discussion
« on: September 14, 2020, 06:25:25 PM »
Maybe we will have the answer in a few days, when (hopefully) clear Sentinel VIS pictures will be available.

9
Science / Re: 2020 Mauna Loa CO2 levels
« on: September 13, 2020, 05:42:11 PM »
Outlook:
Last year's next week has had an average of about 408.6 ppm. Extrapolating the actual values into the near future will lead to an annual increase of around 2.5 ± 0.25 ppm.
It is Sunday evening here in Germany, and the latest weekly average of Mauna Loa CO2 is available.

Week beginning on September 6, 2020:     411.37 ppm
Weekly value from 1 year ago:                  408.75 ppm
Weekly value from 10 years ago:              386.26 ppm
Last updated: September 13, 2020

The annual increase of 2.62 ppm is still higher than the 10 y average of 2.51 ppm/a.
Last week's values were highly variable intra-day with some hourly averages below 408 ppm. The lowest daily average was 410.8 ppm. With about 0.7 ppm until the annual minimum is reached there may be one or two days' average below 410 ppm, but I do not think that a whole week's average will go below that threshold.

Outlook:
Last year the following week had an average of about 408.4 ppm. The annual increase should therefore be in the range of 2.4 ± 0.3 ppm.

10
Antarctica / Re: Antarctic Icebergs
« on: September 12, 2020, 09:08:37 PM »
In addition to my post yesterday I examined the area between B-22 and Bear Peninsula which - even during winter - frequently shows open water (probably of polynya type). The last week saw an extension of open waters (orange arrows) into areas that were sea ice covered before.

In addition I discovered the western tip of B-22 that calved off B-22 some months ago. It lies grounded in shallow seas N of Bear Peninsula (circled in yellow). Size, position, shape and texture reveal that this is the "missing part". It might stay there for a while, I will watch it this melting season.

See attached picture.

11
Science / Re: Where are we now in CO2e , which pathway are we on?
« on: September 12, 2020, 08:42:21 PM »
A short explanation of this plot would be helpful, wdmn, including the designation of x and y axes.
I guess it is worldwide temperature the last 10,000 years?

12
Antarctica / Re: Thwaites Glacier Discussion
« on: September 12, 2020, 07:28:27 AM »
Comparison of movements of different parts of the Thwaites glacier between Nov 15, 2019 and Sep 11, 2020 using the "measure distance tool" in EOSDIS.

The first picture shows the points I analysed, the second picture is the screenshot from EOSDIS. Please do not take the second digit too seriously; scalingis too large, and exactly placing the mouse into the correct position is not possible with that precision.

TEIS is slightly moving into NE direction; but the very northern/northwestern tip has not changed its position in the last 10 months because it is grounded.
The other places have moved roughly 3-5 km in 10 months, the "peeling" of parts of the Thwaites Ice Tongue has resulted in a slightly varying flow direction, see little black bars in the first picture.
This "peeling off" of parts of the toungue led to a widening of the tongue itself.

I also measured the movement of icebergs, frozen in sea ice - their movement is roughly identical to that of Thwaites Glacier behind it.

See attached pictures.

13
Antarctica / Re: Pine Island Glacier (PIG) Calving and Discussion
« on: September 12, 2020, 07:27:46 AM »
A very short answer:
It is not about air temperatures and missing insolation during the Austral winter, but about sea water temperatures which are high enough to allow a continuous melting of the ice shelf from below.
Pine Island Bay partly has polynyas, which means that "warmer" (0, 1, 2, 3°C) waters upwell close to the calving front.

14
Arctic sea ice / Re: The 2020 melting season
« on: September 11, 2020, 10:30:35 PM »
"Central Arctic Sea at its lowest extent"  - - - So if it wasn't for the large chunk of ice in Beaufort and the partly filled channels in the CAA we would have beaten 2012 ??

15
Antarctica / Re: Antarctic Icebergs
« on: September 11, 2020, 09:38:41 PM »
The sun still does not shine at the South Pole, but Amundsen Sea is north and bright enough to allow EOSDIS to make new pictures.

So the first look I took was on my pet iceberg that has lost parts of its SW tip some months ago (details in the Thwaites Gl. thread).

I took the opportunity and evaluated the movement of B-22A between 15. Nov 2019 and 11. Sept 2020.
It moved slowly in NW direction (around 5 km). I checked different places and spots on this iceberg, measured the distance between the two dates and added them into the attached picture. As far as I evaluated there seems to be no turning around of the iceberg.

16
Arctic sea ice / Re: 2020 Sea ice area and extent data
« on: September 11, 2020, 07:19:14 PM »
I added the monthly extent value for August 2020 into my long-term plot where I calculate the extent anomalies from 1979 up to now.
The average (1979-2020) August extent is now 6.18 M km². August 2020 had an average extent of 5.09 M km², which is 1.09 M km² less than that long-term average.
The much higher than normal losses in July 2020 had pushed the actual value below the red long-term linear trend line, where it remains in August. The difference is -0.54 M km² (calculated from the linear trend line this August should have been at 5.63 M km²).
The slope of the long-term linear trend line has become steeper by two digits (-0.0553 instead of -0.0551).

See attached graph.

17
Arctic sea ice / Re: When will the Arctic Go Ice Free?
« on: September 11, 2020, 01:09:05 PM »
It is time for the monthly update of my extrapolation when the extent [Ausdehnung], volume [Volumen], thickness [Dicke] and area [Fläche] will reach zero. The extrapolation occured linearly and by a logarithmic function; the latter one almost constantly resulting in earlier times (valid for volume and thickness, not for extent and area in the winter months). The August value now includes 2020.
Volume in August 2020 is slightly above the long term trend, thickness for August 2020 lies almost at the long term trend lines, whereas extent and area dip slightly below it. The "BOE numbers" did not change (volume, thickness) and decreased by 1-2 years (extent, area) compared to August 2019.
So there is a tiny further convergence between the "late values" (area, extent) and the "early value" (volume).
The order (earlier → later BOE) generally is volume < thickness < area < extent.

Please note that this is not a forecast but a trend!
See attached table, now widened to see the linear function value (y-AA) at t = 0. stg = slope.

Click to enlarge it.

18
Science / Re: Where are we now in CO2e , which pathway are we on?
« on: September 10, 2020, 08:45:34 PM »
To finalize my update on greenhouse gases here is the summary of the four postings in the individual gas concentration threads.

More radiative forcing of the "NOAA gases" (CO2, CH4, N2O, SF6) in May 2020 than in Apr 2020 or in May 2019.

The values [W/m²], change to Apr 2020 and change to May 2019:
CO2 2.170   (+ 0.011)    (+ 0.031)   
CH4 0.520   (+ 0.000)    (+ 0.005)
N2O 0.205   (+ 0.000)    (+ 0.004)
SF6  0.0053 (+ 0.0000)  (+ 0.0002)
sum  2.900  (+ 0.011)   (+ 0.040)

The relative annual increase is 1.36 %.
It also means never before since we measure these gases has their radiative forcing been so strong.

19
Science / Re: Trends in Atmospheric N2O
« on: September 10, 2020, 08:39:25 PM »
Finally, the latest NOAA monthly average for N2O.

May 2020:     332.8 ppb
May 2019:     331.6 ppb
Last updated: September 05, 2020

The annual increase is 1.2 ppb. This is higher than the annual increase of most of the last years.

I set an index = 100 to the average of 1980 [301.1 ppb]. May 2020 has a relative value of 110.5 compared to 1980.

20
Science / Re: Trends in Atmospheric SF6
« on: September 10, 2020, 08:35:39 PM »
With a little delay also the latest monthly average for SF6 is available from NOAA:

May 2020:     10.23 ppt
May 2019:       9.90 ppt
Last updated: September 05, 2020

The annual increase is 0.33 ppt. It is about average of what has been observed in the last decade.

I set an index of 100 for the year 1980 [0.848 ppt]. May 2020 is at 1,206.

21
Science / Re: Trends in atmospheric CH4
« on: September 10, 2020, 08:32:31 PM »
Here is the latest monthly average of Mauna Loa CH4 concntration:

May 2020:     1874.7 ppb
May 2019:     1861.9 ppb
Last updated: September 05, 2020

This is an annual increase of 12.8 ppb. This is the highest annual increase since March 2015!

I set an index = 100 for the 1980 average [1601.2 ppb]. May 2020 is at 117.1 compared to that index.


22
Science / Re: 2020 Mauna Loa CO2 levels
« on: September 10, 2020, 08:27:48 PM »
Here is the official August average for Mauna Loa CO2:

August 2020:       412.55 ppm
August 2019:       409.95 ppm
Last updated: September 9, 2020

The annual increase is at 2.60 ppm. It is above the 10y average increase rate of 2.42 ppm. There is no constant increase rate, but it is slightly increasing. In this month the annual increase rate is even above the long-term trend line of annual increases, which should be at 2.46 ppm/a.

I set an index of 1980 = 100 (338.55 ppm). August 2020 has an indexed value of 121.8.

23
Greenland and Arctic Circle / Re: Greenland 2020 Melting Season
« on: September 08, 2020, 09:03:49 PM »
Seems like the melting season is finished - at least in higher altitudes. Freya Gletscher Webcam, East Grønland, from today.

24
Arctic sea ice / Re: 2020 Sea ice area and extent data
« on: September 08, 2020, 08:27:03 PM »
Evaluation of Arctic sea ice area "relative area wise" Aug 22 - Sep 07, 2020.
The list becomes shorter, as most of the seas have melted out more or less completely.
The others here in a list, ordered by relative losses:
CAB        -   2%
ESS        -   2%
Kara       -   7%
Beaufort - 15%
CAA        - 20%
Grønland - 23%

25
Antarctica / Re: Pine Island Glacier (PIG) Calving and Discussion
« on: September 08, 2020, 08:19:45 PM »
so now the last named pieces in the SZD are on their way out.
Wonder how long the NW piece of PIIS with P2 will stay in place.

26
Science / Re: 2020 Mauna Loa CO2 levels
« on: September 06, 2020, 05:52:46 PM »
Outlook:
Last year next week had an average of around 408.8 ppm. The annual increase should be in the range of 2.6 ± 0.3 ppm.

Another Sunday evening - here is the latest Mauna Loa CO2 data.

Week beginning on August 30, 2020:     411.59 ppm
Weekly value from 1 year ago:              408.82 ppm
Weekly value from 10 years ago:           387.59 ppm
Last updated: September 6, 2020

The annual increase is 2.77 ppm, higher than the 10y average (2.40 ppm/a).
This week has shown high intra-day variability, but the daily avarages were quite smooth. There are four more weeks until the annual minimum.

Outlook:
Last year's next week has had an average of about 408.6 ppm. Extrapolating the actual values into the near future will lead to an annual increase of around 2.5 ± 0.25 ppm.

27
Antarctica / Re: Pine Island Glacier (PIG) Calving and Discussion
« on: September 03, 2020, 06:08:15 PM »
Thank you baking and paolo,
almost no week passes by without a mini calving at either NSM or SSM. When will this stop? Until both zones of destruction are emptied??

28
Arctic sea ice / Re: When will the Arctic Go Ice Free?
« on: September 02, 2020, 09:14:09 PM »
I wonder what you are looking at. Yellow line is volume. Connect 1987 to 2019 and extrapolate.

And then insert some weather induced negative spikes like 1981, 2007 or 2010-2012, subtract them from the linear trend line and the BOE is reached even earlier than 2029...

29
Science / Re: 2020 Mauna Loa CO2 levels
« on: August 30, 2020, 05:45:47 PM »
Outlook.
The average CO2 level of the next week last year was around 409.4 ppm. Therefore an annual increase of 2.75 ± 0.25 ppm shall be expected.

Another Sunday evening. It is time for the latest CO2 values from NOAA / Mauna Loa.

Week beginning on August 23, 2020:     411.96 ppm
Weekly value from 1 year ago:              409.42 ppm
Weekly value from 10 years ago:           387.47 ppm
Last updated: August 30, 2020

The annual increase is at 2.54 ppm, higher than the 10y average (2.45 ppm). Unlike last week the measured values were very smooth.

Outlook:
Last year next week had an average of around 408.8 ppm. The annual increase should be in the range of 2.6 ± 0.3 ppm.

30
Arctic sea ice / Re: 2020 Sea ice area and extent data
« on: August 27, 2020, 07:20:19 PM »
Arctic Sea Ice Area - analysis "relative area wise" Aug 12-26, 2020.

The big laggard:
CAB    -10 %
Slow decrease:
CAA    -21%
Beauf. -23%
Kara   -24%
Grønl. -26%
Fast decrease:
ESS    -51%
Laptev -57%
The race winner:
Chukchi -98%

Hudson, Baffin and Barents not analysed, almost melted out completely.

31
Arctic sea ice / Re: Updating the ASIG
« on: August 24, 2020, 09:57:23 PM »
A while ago the "DMI N of 80°N temperature graph" gave the opportunity to look at older temperature curves on the left hand side. Now only the actual year is visible. Could you please return to the previous presentation? Thanks.

32
Science / Re: 2020 Mauna Loa CO2 levels
« on: August 23, 2020, 06:45:11 PM »
Outlook:
Next week last year had an average of around 409.9 ppm. An annual increase of 2.4 ± 0.25 ppm seems likely.
Sunday evening brings the latest CO2 data from NOAA (Mauna Loa)

Week beginning on August 16, 2020:     412.44 ppm
Weekly value from 1 year ago:              409.74 ppm
Weekly value from 10 years ago:           388.38 ppm
Last updated: August 23, 2020

The annual increase is at 2.70 ppm, higher than I expected last Sunday, and higher than the 10-y-average (2.40 ppm/a). The whole week was very bumpy, with large intra-day fluctuations, two days were "unavailable". The decline of the "valid" days was small. The next weeks until the annual minimum early October will see a slightly steeper decrease. I make a guess that 410 ppm as a weekly average is highly unlikely.

Outlook.
The average CO2 level of the next week last year was around 409.4 ppm. Therefore an annual increase of 2.75 ± 0.25 ppm shall be expected.

33
Arctic sea ice / Re: 2020 Sea ice area and extent data
« on: August 23, 2020, 05:22:43 PM »
Another daily loss of Chukchi Sea Ice Area like yesterday - and the ice area will become negative...

34
Arctic sea ice / Re: 2020 Sea ice area and extent data
« on: August 20, 2020, 08:51:41 PM »
If the decrease rate of Chukchi of the last week continues for two more days Chukchi Sea will be ice-free.

35
Arctic sea ice / Re: 2020 Sea ice area and extent data
« on: August 17, 2020, 09:58:24 PM »
I am impressed by the large relative ice area losses in Chukchi Sea in the last four days.

36
Science / Re: 2020 Mauna Loa CO2 levels
« on: August 16, 2020, 06:58:40 PM »

Outlook.
Next week of last year came in at 410.3. Best guess would be an annual increase of 2.5 ± 0.25 ppm.
Another week has passed, here are the latest NOAA numbers on CO2 (Mauna Loa):
Week beginning on August 9, 2020:     412.74 ppm
Weekly value from 1 year ago:            410.30 ppm
Weekly value from 10 years ago:        388.86 ppm
Last updated: August 16, 2020

The annual increase is at 2.44 ppm, the 10y average increase is at 2.24 ppm/a.
This week showed slightly decreasing CO2 values, in parts with a high intra-day variability.

Outlook:
Next week last year had an average of around 409.9 ppm. An annual increase of 2.4 ± 0.25 ppm seems likely.

37
Arctic sea ice / Re: 2020 Sea ice area and extent data
« on: August 16, 2020, 08:33:03 AM »
Still "No Data" for Aug. 15, 2020 available...

38
Greenland and Arctic Circle / Re: Greenland 2020 Melting Season
« on: August 15, 2020, 07:58:53 PM »
A short cool intermezzo during the melting season or the first sign of the coming freezing season?

39
Antarctica / Re: Pine Island Glacier (PIG) Calving and Discussion
« on: August 15, 2020, 07:50:15 PM »
Thank you baking and paolo.
It looks like the Almond is the "real cork" at the SSM as Cork III has disintegrated into three separate icebergs. It seems a wonder to me that it is still connected to the SIS. "Any day now" a calving of parts of the ZOD seems possible for me.

40
Arctic sea ice / Re: 2020 Sea ice area and extent data
« on: August 15, 2020, 07:42:39 PM »
NSIDC sea ice area - evaluation "relative area wise" Aug 01-Aug 14, 2020:

The big laggard:
CAB       -   3%
On the slow side:
CAA       - 13%
medium rate ice loss:
Beaufort  - 25%
Kara        - 28%
ESS        - 31%
Grønland - 36%
The front runners:
Laptev     - 55%
Chukchi   - 58%

Hudson, Baffin and Barents almost melted out - no analysis.

PS: Gerontocrat: Welcome back here - we all missed you!

41
Antarctica / Re: Sea Ice Extent around Antarctica
« on: August 14, 2020, 05:50:17 PM »
Yeah. The top ten list is the lowest top ten - as it is common for the Arctic Sea Ice.

JAXA Antarctic Sea Ice extent as of Aug 13, 2020. All values in M km²
2002: 16.82
2017: 16.87
1983: 16.98
1986: 17.01
2018: 17.09
2019: 17.24
1993: 17.28
2003: 17.32
1990: 17.37 (extrapolated)
1989: 17.38
2001: 17.40
2007: 17.41
2015: 17.47
2020: 17.55 (# 14 in the list after massive gains in the last days)

The decadal averages are
1980s ave: 17.57
1990s ave: 17.69
2000s ave: 17.75
2010s ave: 17.78




42
Arctic sea ice / Re: Global sea ice area and extent data
« on: August 13, 2020, 09:20:11 PM »
JAXA Global Sea Ice Extent as of August 12, 2020.
2020 now is #4 in the list. At average decreases in the Arctic and much higher than average gains in the Antarctic in the last days have forced 2020 to lose one further position.

All values in M km².
2019: 22.13
2017: 22.31
2018: 22.59
2020: 22.63
2012: 22.69
2007: 22.71
2016: 23.07
2015: 23.15
2011: 23.22
2010s: 23.26
2002: 23.39
2000s: 24.22
1990s: 25.05
1980s: 25.63

43
Glaciers / Re: Alpine Glaciers / Europe
« on: August 13, 2020, 06:59:41 PM »
The Turtmanngletscher in Wallis (Switzerland) has recently lost 600 m of its length.
https://www.wetteronline.de/wetterticker/klima-gletscherabbrueche-in-den-alpen-202008135095162
(in German)

44
Arctic sea ice / Re: 2020 Sea ice area and extent data
« on: August 12, 2020, 09:06:30 PM »
Juan C & Gerontocrat: seems like good odds that melting rate this month could be record low unless it doesn't speed up soon.
JAXA Arctic Sea Ice losses in August (31.7. to 31.8. of each year, values in M km²). Bold: Exceptional values, compared to the other years.
2005: -1.48
2006: -1.25
2007: -1.82
2008: -2.25
2009: -1.53
2000s ave: -1.61
2010: -1.63
2011: -1.83
2012: -2.59
2013: -1.64
2014: -1.54
2015: -2.12
2016: -2.20

2017: -1.77
2018: -1.69
2019: -1.70
2010s ave: -1.87

2020 has so far lost 0.53 M km². A little more than a third of the month has passed, and the slope of decrease decreases towards the end of the month. A place in the lower part of the ranking list seems possible.

45
Antarctica / Re: Sea Ice Extent around Antarctica
« on: August 10, 2020, 10:34:40 PM »
JAXA Antarctic Sea Ice Extent as of Aug. 09.
The top ten list, all values in M km²
1986  16.56
2002  16.58
2017  16.73
1983  16.88
2018  17.03
1993  17.08
2017  17.11
1989  17.18
2020  17.20
1997  17.22

2020 today is #9 and had recently higher than average increases (+0.08, +0.20 and +0.11 M km² per day) and was #4 in the ranking list on Aug. 06, 2020.

The average of the decades, all values in M km²
1980s 17.38
1990s 17.50
2000s 17.60
2010s 17.61

46
Glaciers / Re: Norway glacier retreat 2007 - 2013
« on: August 10, 2020, 10:12:16 PM »
Any update from the last seven years? Guess it must have retreated further since then...  >:(

47
Greenland and Arctic Circle / Re: Greenland 2020 Melting Season
« on: August 10, 2020, 10:03:59 PM »
Another sad picture from Freya 2 on a mild and rainy summer day.

48
Arctic sea ice / Re: Global sea ice area and extent data
« on: August 10, 2020, 07:41:46 PM »
JAXA Global Sea Ice Extent as of August 09, 2020.
2020 now is #3 in the list. At average decreases in the Arctic and much higher than average gains in the Antarctic in the last days have forced 2020 to lose its pole position.

All values in M km².
2017: 22.32
2019: 22.35
2020: 22.50
2012: 22.74
2018: 22.78
2007: 22.88
2016: 23.06
2011: 23.24
2002: 23.36
2010s: 23.37
2015: 23.50
2000s: 24.27
1990s: 25.07
1980s: 25.64

49
I already voted in June and haven't changed any of the bins since then...

50
Science / Re: 2020 Mauna Loa CO2 levels
« on: August 09, 2020, 05:25:53 PM »
Outlook:
The next week of last year had an average of around 410.3 ppm. Extrapolating this week's values into the near future will lead to an annual increase slightly below 3 ppm.
Sunday evening - time for an update of Mauna Loa CO2 levels.

Week beginning on August 2, 2020:     413.17 ppm
Weekly value from 1 year ago:            410.35 ppm
Weekly value from 10 years ago:         388.71 ppm
Last updated: August 9, 2020

The annual increase is at 2.82 ppm. The 10y average annual increase is lower, at 2.45 ppm.
This week's average should be taken with some grain of salt as most of the days were "unavailable".

Outlook.
Next week of last year came in at 410.3. Best guess would be an annual increase of 2.5 ± 0.25 ppm.

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