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Messages - Stephan

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1
Science / Re: Where are we now in CO2e , which pathway are we on?
« on: January 25, 2020, 10:31:13 PM »
Don’t forget the halocarbons.
I didn't mention them because I only took the four "NOAA gases" that are reported on https://www.esrl.noaa.gov/gmd/ccgg/trends/index.html in a regular way. Of course the halocarbons are relevant and must be included into any realistic calculation of the GHG in Earth's atmosphere.

2
Science / Re: Where are we now in CO2e , which pathway are we on?
« on: January 25, 2020, 09:49:10 PM »
While writing these lines a further question came into my mind:
Is a simple addition right at all? Maybe the IR spectra of the molecules (especially CO2 and N2O) overlap and reduce each other by some interference?

3
Science / Re: Where are we now in CO2e , which pathway are we on?
« on: January 25, 2020, 09:26:33 PM »
Stephan, could you please post your calculation and the numbers you used?
I re-calculate for June 2019 (recommended by ASLR)
CO2
concentration 413.92 ppm
factor 1
resulting 413.92 ppm CO2 eq

CH4
concentration 1.8596 ppm
factors 84 (20 y) and 28 (100 y)
resulting 156.21 or 52.07 ppm CO2 eq
adjusting mole weight 56.80 or 18.93 ppm CO2 eq.
→ this was one of my questions whether this has to be done or is it already implemented in the GHG factor? This makes my CH4 value so low


N2O
concentration 0.3318 ppm
factor 264 (I didn't use factor 265 for 100 y, so I used 264 for both times)
resulting 87.60 ppm CO2 eq
no adjust of mole weight necessary

SF6
concentration 0.00093 ppm
factors 17,500 (20 y) or 23,500 (100 y)
resulting 0.17 or 0.23 CO2 eq
adjusting mole weight 0.58 or 0.77 ppm CO2 eq
(same question as above, makes SF6 value much higher because it is so heavy)


The sum of the bold written black lines gives me the same value as yours, nanning (apart from the different month used) 657.90 ppm CO2 eq (20 y) or 553.82 ppm CO2 eq (100 y)
Including the mole weights the values are lower: 558.89 ppm CO2 eq (20 y) or 521.22 ppm CO2 eq (100 y)

4
Science / Re: Where are we now in CO2e , which pathway are we on?
« on: January 25, 2020, 08:43:57 AM »
Re-posted from the 2020 Mauna Loa CO2 thread:
Thank you Stephan. Since you are regularly updating several GHG readings, would it be possible to add a CO2e figure?
In that way we'll have the cumulative GHG effect updated. I know it depends on assumptions but you can put those in.
nanning,
I will do it in the next time. I have the monthly reading of four gas concentrations (CO2, CH4, N2O and SF6) on my PC, in different files, and I can put them together.
I did it, but the sum differs from what I saw from gerontocrat's posting further upthread where he provides NOAA's annual table.
I took the monthly concentrations (beginning from 2000 on, before that date I do not have all the four gases) and multiplied CH4 with the factors 85 (20 years) and 28 (100 years), N2O with 264 (20 & 100 years), and finally SF6 with 17500 (20 years) and 23500 (100 years), using the conversion factors from the later IPCC report. Then I looked up the definition of these CO2 equivalents, which are not given in moles, but in kg and converted the numbers by taking their molecular weight.
I end up with the latest data (Sep 2019) with the following values (100 years equivalent):
CO2: 408.54
CH4:   19.05
N2O:   87.65
SF6    0.78
sum: 516.01
This sum is higher than the CO2 eq given further upthread. Also the proportions of the ratio CH4 to N2O differs completely from NOAA's table. Where is the error?

5
The rest / Re: Good music
« on: January 24, 2020, 10:08:04 PM »
And my favourite from Francesco Puccioni from Roma, aka Mike Francis
Don't Start Givin' Up from his "Flashes of Life" album 1988

Enjoy the music - surprising harmony changes:



6
The rest / Re: Good music
« on: January 24, 2020, 09:57:12 PM »
Back to the (early) eighties...

A Hot Summer Night With Donna
The "we want more" track from her tour 1983, supported by her daughter Mimi.

State Of Independence from her 1980 album "Donna Summer" sung all the way live and she can sing:


7
Science / Re: 2020 Mauna Loa CO2 levels
« on: January 24, 2020, 04:09:40 PM »
I have been thinking that it would be nice to have a thread here which tracked where we are wrt several scenarios.

So maybe we can combine the CO2e data + The Carbon Clock data in a thread where we also compare the outcomes to the RCP scenarios?

This would leave the Mona Loa Thread for the ML numbers and collect CO2e in a thread where it is directly useful.

Lets call it something like:
Where are we now in CO2e and which pathway are we on/how much budget do we have left?

Feel free to improve that title.
Good idea, kassy. I'd also prefer to have the CO2 / CH4 / N2O / SF6 concentration threads (comparable to the ASI Extent thread - bookkeepuing type of thread) and a separate thread about CO2 eq (how to calculate and evaluate with respect to carbon budgets and RCP scenarios).

8
Arctic sea ice / Re: 2020 Sea ice area and extent data
« on: January 24, 2020, 08:17:20 AM »
If 2020 marches further upwards, it will soon fall off of the "top 15" list. 2009, 2007 and 2004 are not out of reach, when increases well above average continue...

9
Arctic sea ice / Re: Global sea ice area and extent data
« on: January 24, 2020, 08:14:33 AM »
The season-typical decrease of Global Sea Ice Extent has stalled completely in the last days and increased from Jan 22 to Jan 23. It has almost matched the 2010s average and is only 0.76 M km² apart from the 2000s average. This is the smallest difference I have noticed since I started to watch global sea ice in 2016. Mainly the much less than average decrease in the last weeks on the Antarctic side has led to this situation.

10
Science / Re: 2020 Mauna Loa CO2 levels
« on: January 23, 2020, 10:20:39 PM »
Thank you Stephan. Since you are regularly updating several GHG readings, would it be possible to add a CO2e figure?
In that way we'll have the cumulative GHG effect updated. I know it depends on assumptions but you can put those in.
nanning,
I will do it in the next time. I have the monthly reading of four gas concentrations (CO2, CH4, N2O and SF6) on my PC, in different files, and I can put them together.
I did it, but the sum differs from what I saw from gerontocrat's posting further upthread where he provides NOAA's annual table.
I took the monthly concentrations (beginning from 2000 on, before that date I do not have all the four gases) and multiplied CH4 with the factors 85 (20 years) and 28 (100 years), N2O with 264 (20 & 100 years), and finally SF6 with 17500 (20 years) and 23500 (100 years), using the conversion factors from the later IPCC report. Then I looked up the definition of these CO2 equivalents, which are not given in moles, but in kg and converted the numbers by taking their molecular weight.
I end up with the latest data (Sep 2019) with the following values (100 years equivalent):
CO2: 408.54
CH4:   19.05
N2O:   87.65
SF6    0.78
sum: 516.01
This sum is higher than the CO2 eq given further upthread. Also the proportions of the ratio CH4 to N2O differs completely from NOAA's table. Where is the error?

11
Antarctica / Re: PIG has calved
« on: January 23, 2020, 07:37:11 PM »
I analysed the latest Sentinel image of the NW tip of the SW Tributary (SWT)
Grounded icebergs (I think we have lost one of them) are circled in yellow.
New and/or widened cracks are marked by red lines
Some minor or mini calvings have happened (green circles)
The zone of destruction S of the tip, adjacent to the much much slower mowing ice W of the SWT is circled in orange. It shows a general widening of the cracks, one of the smaller icebergs within the cracks has tumbled over. I wonder whether a further calving of the tip will open a way for open waters to reach that area. The general flow direction is noted by blue arrows.

See attached picture.

12
Science / Re: 2020 Mauna Loa CO2 levels
« on: January 19, 2020, 09:12:35 PM »
Thank you Stephan. Since you are regularly updating several GHG readings, would it be possible to add a CO2e figure?
In that way we'll have the cumulative GHG effect updated. I know it depends on assumptions but you can put those in.
nanning,
I will do it in the next time. I have the monthly reading of four gas concentrations (CO2, CH4, N2O and SF6) on my PC, in different files, and I can put them together. Before I do that I'd like to have widely accepted "exchange rates" [GHG factors] between the different gases. At least for methane there is a large variety of values - ranging from 20 to 160 - around. Maybe this forum can advice me which number to use?

13
Science / Re: 2020 Mauna Loa CO2 levels
« on: January 19, 2020, 09:09:05 PM »
Hefaistos,
you cannot over-interprete a predicted lower increase value in the next week than in this week and speculate about a change in the overall growth pattern. The annual increase is depending on the actual value and the value last year. If - like in this case - there was a jump last year, then, of course, the annual increase is lower.
Please check out the Keeling curve at NOAA. Take a ruler to follow the increase of CO2. You will find that this increase is not linear, but slowly accelerating. And so is it in 2020.

14
Science / Re: 2020 Mauna Loa CO2 levels
« on: January 19, 2020, 06:10:22 PM »
Outlook:
Last year next week had an average of 410.7 ppm. Extrapolating the actual values will result in a 2.3 ± 0.3 ppm increase. From mid January on the values generally rise much higher than in late autumn or December.

My Sunday evening CO2 information:
Week beginning on January 12, 2020:     412.82 ppm
Weekly value from 1 year ago:               410.66 ppm
Weekly value from 10 years ago:             388.41 ppm
Last updated: January 19, 2020

This week I got it right. The annual increase has shifted back to values we saw in December 2019. Nevertheless, an increase of "only" 2.16 ppm would have been unprecedented 30-40 years ago. So we got used to see these high values...

Outlook:
Next week last year averaged at 412 ppm with an extreme intra-day variability. This year it looks much smoother; I expect an annual increase around 1.75 ± 0.25 ppm.

15
Science / 2020 Mauna Loa CO2 levels
« on: January 12, 2020, 04:33:11 PM »
Last year next week had an average of 411.7 ppm. Extrapolating the actual values will result in a 2.3 ± 0.3 ppm increase. From mid January on the values generally rise much higher than in late autumn or December.

I got the weekly value last year wrong (I took the average value of the week later and did not carefully look at the scale of the y-axis - sorry). Therefore my Sunday evening CO2 posting begins with an excuse.

Week beginning on January 5, 2020:     413.37 ppm
Weekly value from 1 year ago:             409.94 ppm
Weekly value from 10 years ago:          388.21 ppm
Last updated: January 12, 2020

The annual increase stays above 3.4 ppm. This is no good news for this year. It has just begun - and unfortunately with this massive increase.
The high variability of the last weeks has disappeared. The values are much more in line, daily and hourly averages.
We have the same CO2 level than in April last year. This means we are three months before schedule.

Outlook:
Last year next week had an average of 410.7 ppm. Extrapolating the actual values will result in a 2.3 ± 0.3 ppm increase. From mid January on the values generally rise much higher than in late autumn or December.

16
Arctic sea ice / Re: Global sea ice area and extent data
« on: January 10, 2020, 08:46:16 PM »
I compared the actual JAXA extent values with the averages (1980s to 2010s) and determined the time difference, when today's values had the same value as the averages of the various decades.

For Jan 09, 2020 the difference in the Arctic to the 2010s average was 0 days. In the Antarctic the difference was 4 days (sum: 4 days)
This difference is larger compared with previous decades:
Arctic Jan 09, 2020 vs. 2000s average 12 days, Antarctic 5 days (sum 17 days),
Arctic Jan 09, 2020 vs. 1990s average 23 days, Antarctic 4 days (sum 27 days),
Arctic Jan 09, 2020 vs. 1980s average 31 days, Antarctic 3 days (sum 34 days).

This difference had been larger in the last years on this date - at the moment neither the Arctic Sea Ice Extent nor the Antarctic Sea Ice Extent is at record lows...

17
Science / Re: Trends in Atmospheric SF6
« on: January 10, 2020, 04:59:24 PM »
The monthly average for September 2019 is available:

September 2019:     10.00 ppt
September 2018:     9.66 ppt
Last updated: January 05, 2020

The annual increase of 0.34 ppt is comparable to the values we saw the last months.

18
Science / Re: Trends in Atmospheric N2O
« on: January 10, 2020, 04:57:46 PM »
The monthly average of September 2019 is available:

September 2019:     332.0 ppb
September 2018:     331.1 ppb
Last updated: January 05, 2020

This is an annual increase of 0.9 ppb, slightly less as in the last months.

19
Science / Re: Trends in atmospheric CH4
« on: January 10, 2020, 04:55:07 PM »
The September 2019 average is avialable:

September 2019:     1870.5 ppb
September 2018:     1860.4 ppb
Last updated: January 05, 2020

The annual increase is 10.1 ppbm, higher than before...

20
Science / Re: 2019 Mauna Loa CO2 levels
« on: January 10, 2020, 04:49:42 PM »
The December 2019 average is available:

December 2019:       411.76 ppm
December 2018:       409.07 ppm
Last updated: January 7, 2020

The annual increase lies at 2.7 ppm

21
Antarctica / Re: PIG has calved
« on: January 07, 2020, 09:50:51 PM »
the nothing that holds it all together
East of the Cork there is only about 700 m of ice left (measured from the new calving front to the western end of R2). How long will this "nothing" withstand the forces?

22
Antarctica / Re: PIG has calved
« on: January 07, 2020, 09:13:01 PM »
The latest Sentinel image shows the situation on 2020-01-06 at the western end of PIIS-MIS and on the eastern side the picture has been taken on 2019-12-27. Where these image match an estimation of flow speed is easy if identifiable features are visible on both sides of that "border".

I measured the speed at the R2 rift where both pictures are "matched". The southern rim moved ca. 150 m, whereas the northern rim had a shift of around 200 m. That means the rift R2 has further widened. The daily speed is calculated to 15 m/day, the soon-to-come iceberg moved by about 20 m/day. This movement of 200 m is constant through the northern part of the MIS until the calving front. These are higher values than measured ever before.
At R3 the values are: North rim moved by 150 m, the south rim by "only" 125 m, making this rift also wider, and revealing a speed of the MIS of 12.5 m/day even south of R3.
125 m is also the difference at the southern edge of PIIS-MIS where the zone of destruction begins.
Within the zone of destruction the shift is reduced to around 75-100 m.

At the southern end of the zone of destruction, where the slow Southern Ice Shelf begins, the pictures almost perfectly match (shift < 25 m), indicating that the positioning of the pictures is quite good.

23
Antarctica / Re: PIG has calved
« on: January 05, 2020, 10:44:59 PM »
Latest development on the tip of SW Tributary:
1. widening of the cracks at the calving front along the tip
2. a lot of microcalvings along the tip of the SWT as well as at the new calving front after the last calving
3. open water in the crack further inland (marked by a red ? in the picture)
4. one of the lately calved icebergs is now grounded (at least temporarily), marked in yellow

See attached picture.

24
Antarctica / Re: Where is D-26 headed?
« on: January 05, 2020, 10:35:38 PM »
Nov 19 to Jan 04: A progress in N direction of about 18 km. Its western edge still is very close to that persistent sea ice field which probably marks shallow waters.
It still has to move another 30 km to reach really open waters.

25
Arctic sea ice / Re: When will the Arctic Go Ice Free?
« on: January 05, 2020, 09:21:34 PM »
It is time for the monthly update of my extrapolation when the extent [Extent], 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, area and thickness, not for extent in the winter months). The December value now includes 2019.
Extent, area and - a bit less - volume for December 2019 lie above the long term trend lines whereas thickness almost matched it. The "BOE numbers" increased by averaged 7 years (extent and area) and left this number unchanged compared with December 2018 (volume and thickness). This differentiation is in contrast to the observation in the previous months, but easily explainable by the higher than average gains in area and extent compared to last year(s).
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. stg = slope.

26
Arctic sea ice / Re: Latest PIOMAS update (January 2020)
« on: January 05, 2020, 09:14:07 PM »
If you plot the annual mean value you get a linear (fits quite well) trend line with a slope of -0,305 kkm³ per year, which is roughly close enough to your estimation.

27
Science / Re: 2019 Mauna Loa CO2 levels
« on: January 05, 2020, 06:03:43 PM »
Outlook:
Last year next week averaged at 409.6 ppm. The annual increase is hard to predict as this week has been so bumpy. My best guess would be at 2.7 ± 0.3 ppm.
The Sunday evening Mauna Loa CO2 information is available:
Week beginning on December 29, 2019:     413.09 ppm
Weekly value from 1 year ago:                   409.55 ppm
Weekly value from 10 years ago:                388.67 ppm
Last updated: January 5, 2020

This annual increase (3.5 ppm) is way higher than expected. The individual days show a very high variability with a lot of ups and downs. I have no idea whether the huge fires in Australia have had an influence. Anyway, this is bad news for the climate.

Outlook:
Last year next week had an average of 411.7 ppm. Extrapolating the actual values will result in a 2.3 ± 0.3 ppm increase. From mid January on the values generally rise much higher than in late autumn or December.

28
Antarctica / Re: Antarctic Icebergs
« on: January 01, 2020, 09:48:15 PM »
What about B-22 in Amundsen Sea?

I chose five different remarkable points A, B, C, D, and E and calculated the changes of their position between 10.01.2019 and 27.09.2019 (Shift 1) as well as the changes between 10.01.2019 and 25.12.2019 (Shift 2) from clear Sentinel images.
B-22 lies north of Haynes/Smith Glacier and NW of Thwaites Ice Tongue, from which it broke off almost 10 years ago. It is not perfectly grounded, but almost stuck in shallow waters. But it moves slowly into NW direction. I present the position changes in the following table (numbers in km, direction indicated)

Point  Shift 1 [km]  - Shift 2 [km]
A       2,7 W 2,0 N  -  3,6 W 2,5 N
B       2,5 W 1,9 N  -  4,4 W 2,9 N
C       2,7 W 1,6 N  -  3,8 W 4,6 N
D       2,9 W 1,6 N  -  2,7 W 4,1 N
E       2,8 W 1,8 N  -  3,3 W 3,3 N
_____________________________
F       0,7 W 2,2 N  -  7,9 W 7,7 N (the "cork", see text below)

The westward movement, predominant in the first part (Shift 1) has turned into a more northward movement in the latter part (Shift 2), especially at the eastern end of B-22.
The western end is slowly eroding by calving. It loses maybe 100 m per year at some points. B-22`s length is around 85 km - please calculate by yourself how long it might take for a complete calving...

South of B-22 the compact sea ice has opened (area circled in blue). One of the larger icebergs south of B-22 has floated into NW direction (8 km in Shift 2). Now it seems to be stuck in shallow waters. It blocks the outflow of the sea ice in the blue circled region. Therefore it acts as a cork. I have no idea whether it will stay there for longer or whether it will be pushed through by the currents. Until that happens a complete clear-out of sea ice south of B-22 seems unlikely.

See attached picture.

29
Science / Re: 2019 Mauna Loa CO2 levels
« on: December 29, 2019, 05:54:45 PM »
Outlook:
Next week last year had an average of about 409.1 ppm. With the steady increase I expect this week the annual increase should rise to 2.8 ± 0.15 ppm. A bad sign for a further increase in 2020??

My Sunday evening CO2 posting is ready now:

Week beginning on December 22, 2019:     412.21 ppm
Weekly value from 1 year ago:                   409.24 ppm
Weekly value from 10 years ago:                388.17 ppm
Last updated: December 29, 2019

The annual increase rose almost back to 3 ppm, a little bit beyond the corridor I saw it in. After two-three weeks of steady and regular slight increase the last week shows heavy ups and downs, mostly on a day-to-day basis, but some days also had a very high noise in the hourly means. But all days had average values, so these changes passed NOAA's quality standards.

Outlook:
Last year next week averaged at 409.6 ppm. The annual increase is hard to predict as this week has been so bumpy. My best guess would be at 2.7 ± 0.3 ppm.

30
Antarctica / Re: PIG has calved
« on: December 25, 2019, 09:05:29 PM »
Paolo,
thank you for that clarification. Of course the speed of the calving front is the sum of the whole ice shelf plus the extra movement caused by the widening of the rifts. This is what I wanted to point out with my posting - the widening of the rifts (EOSDIS can't tell which one has the largest impact) is accelerating.

[I am a little bit of impatiently waiting for the major calving, although I know this is not good for the future of the PIIS]

31
Antarctica / Re: Thwaites Glacier Discussion
« on: December 24, 2019, 07:12:18 PM »
Analysis of Thwaites Ice Tongue as of 2019-12-22.

I compared the images between Nov 03 and Dec 22. The rift in the center of the Thwaites Ice Tongue has widened massively. Open water is visible in it. Yellowish green arrows show the flow direction. A new row of icebergs prepares for being peeled-off in the next weeks (red line). The grounded iceberg in the NW is still grounded (pale blue circle). I have no idea why there is open water in the SW of this picture. Looks like one of the small icebergs has sunk  ;) and has left open water behind (pale magenta circle).

See attached picture.

32
Antarctica / Re: Thwaites Glacier Discussion
« on: December 24, 2019, 03:14:07 PM »
Evaluation of the latest Sentinel-1 photo of TEIS.

The latest photo shows some new and widened cracks (marked in red). I added the movement direction with yellowish green arrows. The northern part seems almost immobile (= grounded). I see a shear zone (pale dotted line), SE of it a small movement in NE direction is apparent.
The "Thwaites Ice Tongue Cork" has been very mobile (compared with Nov 3, 2019), heading into NNW direction. All icebergs behind it follow in roughly the same speed.
Compared to PIIS everything here is much slower, but changes are obvious.

See attached picture.

33
Antarctica / Re: PIG has calved
« on: December 23, 2019, 10:47:11 PM »
Action also at the eastern end of the PIIS/PIG (the "blumencrack area").
The comparison shows the birth of a new zone of destruction (circled yellow) with a lot of fast widening cracks and many icebergs, held loosely together by sea ice. All relevant growing and lengthening of cracks are marked in red. The dashed pale line is approx. the grounding line (GL) from 10-20 years ago. The yellowish green arrows show the flow direction.

Having had the discussion earlier in this thread, could these features (or the change of these features) on the surface give information about the actual position of the GL? From Eric Rignot's presentations I heard how damn complicated it is to reliably find out the exact position of the GL.

See attached picture.

34
Science / Re: 2019 Mauna Loa CO2 levels
« on: December 23, 2019, 01:30:13 PM »
Outlook:
Last year next week has averaged a little bit lower than this week (409.2 ppm). With actually rising CO2 concentrations I expect an annual increase of around 2.5 ppm.

My Sunday evening Mauna Loa CO2 service (sorry about the delay - I forgot it last night  :() now on Monday noon CET:
Week beginning on December 15, 2019:     411.89 ppm
Weekly value from 1 year ago:                   409.32 ppm
Weekly value from 10 years ago:        -999.99 ppm (which obviously means "unavailable")
Last updated: December 22, 2019

The annual increase is as high as I expected last week.

Outlook:
Next week last year had an average of about 409.1 ppm. With the steady increase I expect this week the annual increase should rise to 2.8 ± 0.15 ppm. A bad sign for a further increase in 2020??

35
Arctic sea ice / Re: 2019 sea ice area and extent data
« on: December 22, 2019, 07:47:33 AM »
Thank you for keeping us up to date, Juan.  :)
It is one of the few days in 2019 with a daily value (slightly) above the 2010s average.

36
Science / Re: Trends in atmospheric CH4
« on: December 19, 2019, 09:56:16 PM »
Quote
I took the time and checked the average August annual methane increase. Apart from 1998 (the super El Niño year) there has never been such an increase since 1990.
Stephan, I assume the 1990 cutoff is because that is as far back as the data goes, right?
No. The data from NOAA begin in July 1983. Until 1990 the annual increase was above 12 ppb per year. Whether the collapse of the COMECON in 1990/91 was the reason for the slowdown of the CH4 increase rate or just a coincidence I do not know.

37
Science / Re: Trends in Atmospheric SF6
« on: December 19, 2019, 09:50:33 PM »
I think that SF6 would be completely absent without humans on this planet. It is no naturally formed molecule, but a product of chemical industry.

38
Arctic sea ice / Re: When will the Arctic Go Ice Free?
« on: December 17, 2019, 09:47:54 PM »
(quote from Glen Koehler) "July hitting zero before August in Stephan's table must be a mathematical fluke caused by a slightly steeper decline rate being extrapolated into the future."

Of course this a mathematical effect and not "real". July's Arctic Ice Volume was very close to December's volume when the measurements started in 1979. Since around 2010 it comes much closer to November's volume. Therefore its slope is much steeper than in any other month, leading to a "slightly earlier" BOE in the extrapolation.
Maybe in the mid 2030s July will be ice free before August - although August would have been ice-free anyway that same year. Let's see what happens...

39
Science / Re: 2019 Mauna Loa CO2 levels
« on: December 15, 2019, 06:08:15 PM »
Outlook:
Next week last year averaged at 409.3 ppm, which is a jump from this week last year by about 1 ppm. The daily values are on the rise, therefore an annual increase slightly above 2 ppm should be expected.
My Sunday evening Mauna Loa CO2 service is ready:
Week beginning on December 8, 2019:     411.32 ppm
Weekly value from 1 year ago:                 409.22 ppm
Weekly value from 10 years ago:              386.90 ppm
Last updated: December 15, 2019

This time I got it right - 2.1 ppm is slightly above 2 ppm. There was no daily average below 410 last week, but some hourly averages lay below this threshold line.

Outlook:
Last year next week has averaged a little bit lower than this week (409.2 ppm). With actually rising CO2 concentrations I expect an annual increase of around 2.5 ppm.

40
Arctic sea ice / Re: When will the Arctic Go Ice Free?
« on: December 15, 2019, 08:36:51 AM »
It is time for the monthly update of my extrapolation when the extent [Extent], 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, area and thickness, not for extent in the winter months). The November value now includes 2019.
Extent, area, volume and thickness for November 2019 lie at or slightly below the long term trend lines. The "BOE numbers" decreased by averaged 2 years (extent and area) and left this number unchanged compared with November 2018 (volume and thickness). This differentiation, already observed in Sep and Oct 2019, seems to continue and could thus merge in many years.
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.

41
Antarctica / Re: Sea Ice Extent around Antarctica
« on: December 12, 2019, 08:24:22 PM »
Thank you gerontocrat for keeping us updated.
A little note on the "projected minimum": If the above average ice losses continue the resulting minimum for the entry 2010/2011 will become negative.
We are on a bad track concerning sea ice area and extent.

42
Antarctica / Re: PIG has calved
« on: December 10, 2019, 10:58:41 PM »
I followed the track of the two new little icebergs (circled in orange) generated by the calving event last weekend. They traveled up to 37 km in the last three days - a sign for a strong current in Pine Island Bay. The third little iceberg (circled in yellow) that had been "almost broken off" on Dec 7 is now also floating freely close to the calving front.

See attached picture.

43
Science / Re: Trends in atmospheric CH4
« on: December 10, 2019, 10:35:35 PM »
The CH4 concentration values for August are available now:

August 2019:     1863.6 ppb
August 2018:     1851.9 ppb
Last updated: December 05, 2019

The annual increase (11.7 ppb) is significantly above from that of the last months. At the moment I have no clue whether this is just natural variability, an outlier or a trend change...
I took the time and checked the average August annual methane increase. Apart from 1998 (the super El Niño year) there has never been such an increase since 1990.

44
Antarctica / Re: PIG has calved
« on: December 09, 2019, 11:06:06 PM »
Paolo,

thank you for that gif. I'd like to see it playing somewhat slower so that I can focus more on the details of bathymetry and elevation. Would it be possible to put a scale on the elevation profile?  Thank you.

45
Science / Re: Trends in Atmospheric SF6
« on: December 08, 2019, 08:42:09 PM »
Finally, SF6 also received an update.

August 2019:     9.98 ppt
August 2018:     9.63 ppt
Last updated: December 05, 2019

The annual increase of 0.35 ppt is comparable to the values we saw the last months.
Interestingly, the relative increase (0.35 ppt = 3,6 %) is much higher than that of the other greenhouse gases. It is probably the lack of natural sinks that causes this effect.

46
Science / Re: Trends in Atmospheric N2O
« on: December 08, 2019, 08:38:57 PM »
As for CO2 and CH4 also the N2O concentration information was updated:

August 2019:     331.9 ppb
August 2018:     330.9 ppb
Last updated: December 05, 2019

This is an annual increase of 1.0 ppb, roughly the same value as in the last months.

47
Science / Re: Trends in atmospheric CH4
« on: December 08, 2019, 08:36:57 PM »
The CH4 concentration values for August are available now:

August 2019:     1863.6 ppb
August 2018:     1851.9 ppb
Last updated: December 05, 2019

The annual increase (11.7 ppb) is significantly above from that of the last months. At the moment I have no clue whether this is just natural variability, an outlier or a trend change...

48
Science / Re: 2019 Mauna Loa CO2 levels
« on: December 08, 2019, 08:32:02 PM »
Next week last year stayed around 408.5 ppm. At the moment the day-to-day changes are small, therefore an annual increase of slightly above 2 ppm is likely.
My Sunday evening weekly (and in addition today, monthly) CO2 service.
Week beginning on December 1, 2019:     411.07 ppm
Weekly value from 1 year ago:                 408.47 ppm
Weekly value from 10 years ago:              387.08 ppm
Last updated: December 8, 2019.
This is an annual increase of 2.6 ppm, more than I had expected last Sunday.

The month has finished and here is the monthly average for November 2019:
November 2019:       410.27 ppm
November 2018:       408.02 ppm
Last updated: December 5, 2019
The annual increase of 2.25 ppm is at the lower edge of values we saw this year.

Outlook:
Next week last year averaged at 409.3 ppm, which is a jump from this week last year by about 1 ppm. The daily values are on the rise, therefore an annual increase slightly above 2 ppm should be expected.

49
Antarctica / Re: Thwaites Glacier Discussion
« on: December 08, 2019, 12:13:13 PM »
I would be careful with such an interpretation. Baking has adjusted the pictures in that gif to the movement of the ice tongue (visible in the shift of the red latitude line). Depending on which floe he chose to make that adjustment it may be that others' flows slightly differs - therefore a kind of rotation appears, although it objectively doesn't happen.

50
Arctic sea ice / Re: When will the Arctic Go Ice Free?
« on: December 08, 2019, 08:09:11 AM »
Here are the regional data:
ftp://sidads.colorado.edu/DATASETS/NOAA/G02135/seaice_analysis/
click on "Regional monthly (or daily) data".

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