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Messages - Steven

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The politics / Re: The Alt Right
« on: October 11, 2020, 01:01:41 PM »
Any attempt to shift the discussion to the "alt-left" is disingenuous and should be treated as such.

It's the usual trolling by Tom_Mazanec.  That guy has been spouting far right-wing propaganda all over this forum. 

I'm glad I live in Western Europe and not in the USA.  Here in Belgium we had an openly gay prime minister a few years ago and now we have a transgender minister, and nobody had a problem with that.  And we have very liberal laws on abortion, euthanasia etc.  I cannot imagine any of that happening in the USA: there would be nonstop protests from right wing religious zealots.

Unfortunately, the far right-wing party here in the rich northern part of Belgium has been steadily gaining support in recent elections and polls.  They're thriving on anti-immigration rhetorics.  They're pretty much the same people spouting conspiracy theories, climate denial and anti-science, and they are increasingly derailing facebook and twitter threads.  Not as bad as in the USA, but it's becoming increasingly worrysome.

Arctic sea ice / Re: PIOMAS vs CryoSat
« on: October 10, 2020, 07:48:49 PM »
That big red blob from Cryosat (+2m ice??) is not there in PIOMAS.
Cryosat issue?

I'm not sure.  That red blob looked quite strong in the 2020 melt season.  The ice there seemed compact and apparently it had a relatively late melt onset and weaker surface melting than other parts of the Arctic Ocean.  Compare e.g. with the average SMOS map for the peak insolation months June and July, here.

Or maybe some other factors are messing up the CryoSat results: snow depth, ice surface roughness and whatnot.

The CryoSat data file includes an uncertainty map, suggesting that the uncertainty of the sea ice thickness data is less than half a meter for most of the Arctic Ocean:

Arctic sea ice / Re: PIOMAS vs CryoSat
« on: October 10, 2020, 01:00:14 PM »
First results from CryoSat this Autumn:

(Image created by opening the nc file with panoply software.)

Arctic sea ice / Re: Glossary ... for newbies and others
« on: October 03, 2020, 09:46:19 PM »
CAS = Central Arctic Sea.  Used by NSIDC.

Where does NSIDC call it "Central Arctic Sea"?  On their website they call it Central Arctic Basin (or briefly Central Arctic), just like everyone else. 

There are different ways to define the CAB (Wipneus uses a different definition than the NSIDC).  But I see no reason to add some non-existent "CAS" terminology that was made up by gerontocrat.  By that logic, you may as well rename Hudson Bay to Hudson Sea...

Arctic sea ice / Re: Accuracy of poll predictions
« on: October 01, 2020, 07:31:20 PM »
I've updated the graphics to include 2020.  The poll predictions were pretty accurate this year.

JAXA June polls:

NSIDC June polls:

NSIDC poll medians:

The rest / Re: Good music
« on: August 30, 2020, 04:43:37 PM »
Youssou N'Dour and Neneh Cherry - 7 Seconds (1994)

(Lyrics mostly in English, but some parts in French and Wolof)


Weezer - Island In The Sun (2001)

Arctic sea ice / Re: The 2020 melting season
« on: August 30, 2020, 04:32:13 PM »
SMOS remains lowest on record for the date, by a large margin.  This suggests there is still substantial surface melting going on.  Weather forecasts show colder air in the next few days, so presumably (hopefully) the curve will get back upward to more normal values for the time of year.

JAXA AMSR2 melt graphs show similar results: surface melting in August has been very strong this year.

The rest / Re: Good music
« on: August 23, 2020, 08:15:51 PM »
It seems that more than 90% of the content of this thread are oldies, which is overly repetitive in my opinion.  Anyway here are a couple more recent songs: 

Tame Impala - Let It Happen (2014)


The Raconteurs - Many Shades Of Black (2008)

The forum / Re: Forum Decorum
« on: August 17, 2020, 10:23:59 PM »
Signal-to-noise ratio is quite high in the melting season thread.

I think it has improved recently, as usual at this time of year.  It's an annual pattern: in June and July the melt season thread is a mess, due to a very loud minority of folks who think every year that the September extent will be a new record low by a huge margin.  Next, at some point in July or August it becomes obvious that that isn't going to happen, and then those folks disappear or change their tone and the signal-to-noise ratio improves.

Arctic sea ice / Re: The 2020 melting season
« on: August 17, 2020, 10:08:39 PM »
I've long predicted this year would be exceptional, looks like it still will be.

(for me, that means being top 3 in at least 3 of the following 4 areas: extent, area, volume, eye test)

A top 3 rank for the September minimum is not exceptional at all.  In fact, most years were "exceptional" by your definition.  Five of the last 10 years had a top 3 minimum for both extent, area and volume at the time.  And 16 of the last 30 years.

The forum / Re: Forum Decorum
« on: August 16, 2020, 03:39:02 PM »
It's true that last year saw consistently more users, but the drop hasn't been what it seems

I agree that page views are an unreliable metric. 

But there are other indicators.  Participation in the sea ice minimum polls has plummeted this year.  The June and July polls had the lowest number of participants ever in the history of this forum, by far.  Participation in the August poll was the lowest since 2014.

Either it's because people are getting tired of those sea ice polls, or because there is general discontent with the forum.  Personally, I'm getting increasingly tired of the forum.  I think there are too many clowns on the forum and too many childish, nonsensical or hyperbolic comments.

Arctic sea ice / Re: The 2020 melting season
« on: August 09, 2020, 08:29:09 PM »
The image below shows the 5-day median (pixel-wise) of the latest Bremen images.  I think this kind of smoothing helps to reduce cloud interference and other artefacts in the daily Bremen images.   (Another member of this forum, petm, used to post similar images frequently last year, but I haven't seen him on the forum recently.)

And here is the 3-day (rather than 5-day) median:

Arctic sea ice / Re: 2020 Sea ice area and extent data
« on: August 05, 2020, 09:49:29 PM »
NSIDC daily sea ice area: 2020 is lowest on record for the date, basically tied with 2012.

I created the graph using data from Wipneus' site.

Ranking of the NSIDC daily area values for 4th August:

Arctic sea ice / Re: SMOS
« on: August 01, 2020, 11:07:59 PM »
Can you show maps after June 1? Thank you in advance.

Here is the average over the past two months, for 2020 (left) vs 2012 (right):


And here are the averages for the month of July only:

July 2020 average map: 
July 2012 average map:

Arctic sea ice / Re: SMOS
« on: August 01, 2020, 10:01:24 AM »
You were right, it was an interesting week.  Surface melting ramped up in the Central Arctic due to warm air advection.  And I guess the cyclone on the Pacific side brought a lot of rain.

Average for the past week for 2020 (left) vs 2012 (right):


Here is the difference map (2020 minus 2012):

And here is the anomaly map for 2020 relative to the 2010-2019 average:

Arctic sea ice / Re: 2020 Sea ice area and extent data
« on: July 30, 2020, 11:02:27 AM »
I have to check the numbers more carefully.
At a fast look, I get on July 28th.:  4.04M km2 for area, excluding lakes.
It is an interesting data set.

It should be 3.89 million km2 for 28 July 2020.  I'm not sure how you got 4.04 million km2?

Here are the single-day NSIDC area values for the last 10 days.  The table also shows the change from the previous day and the anomaly relative to the 1981-2010 average, in million km2.

Arctic sea ice / Re: 2020 Sea ice area and extent data
« on: July 29, 2020, 10:28:18 PM »
You can find the single-day NSIDC regional extent and area values on Wipneus' site.  I think this is the file you're looking for:
Thank you, Steven.
I will look at them.  :)

Glad it's useful. 

Maybe I should add that Wipneus uses a somewhat different definition of the regions than on the NSIDC website.  In particular, the CAB region as defined in Wipneus' data is about 38% larger than on the NSIDC website.

In addition, he has a spreadsheet with the daily regional NSIDC data for all previous days and years:

Arctic sea ice / Re: 2020 Sea ice area and extent data
« on: July 28, 2020, 07:35:04 PM »
Seems that they don't make public the single day value.  :(

You can find the single-day NSIDC regional extent and area values on Wipneus' site.  I think this is the file you're looking for:

Arctic sea ice / Re: The 2020 melting season
« on: July 26, 2020, 10:37:10 AM »
Here is my current prediction for the sea ice min.

I'd love to see everyone's thoughts.

The region you indicated in that map is about 2.0 million km2 (based on pixel count).  I would be very surprised if the minimum extent is that low.

Take that graph with a grain of salt.  Thickness should not be calculated by dividing volume by NSIDC area.  It is known that NSIDC area substantially underestimates the real sea ice area, by about 10 to 25% in September.  So the "thickness" in that graph is an overestimate.

I have understood that area data was badly affected by melt ponds when insolation was high in early to mid-summer, and that produced the underestimates. But I also thought I had read that this effect diminished in the late Arctic summer, (starting around now) by which time melt ponds had drained, and as insolation quickly reduced in the high Arctic, melt ponds would no longer form to any great extent. So I always thought that by the minimum, the area data was less out of wack.
But I cannot find a study / science paper with the 10% to 25% figure. Can you point me to it?

So, as **Wipneus stated that the PIOMAS uses NSIDC Area data as input, for the time being for me  it's "Thickness = PIOMAS Volume divided by NSIDC Area".

If you had bothered to compare your thickness graph with the official PIOMAS thickness graph, you would have noticed that your numbers are systematically too high during Summer and Autumn, by about the percentages I posted.  Even as late as November there is still a discrepancy.

PIOMAS uses NSIDC concentration as some kind of replacement for melt ponds: PIOMAS doesn't model melt ponds explicitly, but only implicitly by assimilating the NSIDC concentration data.  But that does not mean that you can divide the volume by NSIDC area to get the average thickness.

NSIDC area is useful for making predictions about the minimum (Slater, Dekker, Tealight etc).  But if you want to know the real sea ice area, you're better off using the Hamburg AMSR2 sea ice area.  It's available on Wipneus' site.

NSIDC area underestimates the real sea ice area, not only in Summer but also in Autumn.  This was discussed several times in the Home Brew thread.  Last year I posted some graphs about this: see here.  Below is a similar graph, showing the ratio of NSIDC and AMSR2 area, averaged over the past 7 years.  Looking at individual years, the daily ratio in September ranges between 0.76 and 0.91.

The rest / Re: Good music
« on: July 21, 2020, 12:00:13 PM »
Somewhat related to the Arctic...

Within Temptation - Ice Queen (2000)  (symphonic metal song)


Pixies - Caribou (1987)  (alternative/rock)

Arctic sea ice / Re: SMOS
« on: July 18, 2020, 11:33:12 AM »
Average for the past week, for 2020 (left) vs 2012 (right):


The left image below shows the difference map: green = less melting in 2020 than in 2012, blue = more melting in 2020 than in 2012.  The right image shows the anomaly map for 2020 relative to the 2010-2019 average:


Arctic sea ice / Re: SMOS
« on: July 11, 2020, 10:55:43 AM »
Average for the first 10 days of July, for 2020 (left) vs. 2012 (right).  This suggests that recently there has been more surface melting than in 2012 on the Atlantic side of the CAB (including the north pole), but less on the Pacific side of the CAB.


Arctic sea ice / Re: The 2020 melting season
« on: July 09, 2020, 08:11:17 PM »
While extent continues to drop, area has actually stalled for the last 4 days. More draining melt ponds?

The JAXA AMSR2 melt graphics also show a reduction in surface melting in the last few days.  I guess the lack of warm air advection from lower latitudes is playing a role.

Arctic sea ice / Re: SMOS
« on: July 04, 2020, 09:32:18 PM »
I wrote some code to take weekly averages of the SMOS images

Can you average from the beginning of June?

Here is the average for the past 33 days for 2020 (left) vs. 2012 (right).  The large difference between those two years is mainly due to the fact that 2012 was way ahead in the first half of June.

Arctic sea ice / Re: SMOS
« on: July 04, 2020, 07:39:50 PM »
I wrote some code to take weekly averages of the SMOS images, to reduce the daily noise and fluctuations in those images. 

The left image below shows the average for the past week, 27 June to 3 July 2020.  For comparison, the right image shows the same period in 2012.  FWIW, this suggests that the Beaufort Sea and northern ESS had less surface melting than in 2012 during that period whereas the Canadian Archipelago and the Atlantic side of the CAB had more surface melting than in 2012.

Arctic sea ice / Re: SMOS
« on: July 01, 2020, 08:19:51 PM »
June monthly average:

The June monthly average has a good correlation with the September NSIDC sea ice extent.  The correlation coefficient is 0.86 over 2010-2019  (and even 0.95 if 2010 is excluded).  FWIW, this would give a prediction for the September 2020 NSIDC extent of 4.49 +/- 0.52 million km2 (95% prediction interval).

Here is a similar graph for the number of beige pixels in June, rather than the weighted pixel count.  In this case the correlation with the September NSIDC extent is 0.82 over the past 10 years, and the prediction for September 2020 extent would be 4.44 +/- 0.58 million km2.

Arctic sea ice / Re: SMOS
« on: June 20, 2020, 12:54:00 PM »
As the beige pixels are running out, it may be interesting to include information from the other pixel colors as well.  The graph below plots a weighted sum of all the sea ice pixels in the SMOS images, as discussed upthread last year:

Arctic sea ice / Re: SMOS
« on: May 16, 2020, 11:40:48 AM »
Just like last year, I will be running a pixel counting algorithm on the SMOS images.  The beige pixel counting graph will be updated daily:

Consequences / Re: COVID-19
« on: May 09, 2020, 02:29:18 PM »
As of 5/6, according to NY DOH, NYC had 47 deaths. 47!!!! Down from 171 the week prior. My statement that NYC deaths are nearing zero is absolutely CORRECT, considering we are now at 47 a day, which is 72% down from the number a week prior.

From your link: "Due to delays in reporting, recent data are incomplete".

Using the history data of their github repository, this is how their data changed over the past 10 days:

Science / Re: Where are we now in CO2e , which pathway are we on?
« on: May 09, 2020, 11:23:10 AM »
I add the graph for the NOAA gases (20y and 100y CO2 equivalents) from 2000 to 2020.

That graph doesn't make sense.

I suspect you've been using GWP multipliers in your calculations.  But those can only be used in the context of emissions, not in the context of concentrations.  The GWP approach can not be used to calculate the CO2 equivalent for the entire atmospheric amount of CO2/methane/N2O etc.  The only meaningful way to do that is to calculate radiative forcing and use a logarithmic transform, e.g. see here.

There seems to be a lot of confusion about this topic on this forum.  I think the source of confusion is a poorly written wikipedia page that discusses two very different definitions of "CO2 equivalent": one definition for emissions and another one for concentrations.  Discussions on GWP and 20-year timescales etc are only relevant to the former definition but are not related to the latter definition.

Consequences / Re: COVID-19
« on: April 25, 2020, 08:12:36 PM »
Early results of antibody tests in Belgium:

The number of people with antibodies has doubled in two weeks: 4.3% of blood samples taken on 14 April had antibodies, compared to 2.1% of samples taken on 30 March. 

Anyway, it's still a long way from herd immunity.

Back-of-envelope calculation: this would suggest the IFR is around 1%.  Population in Belgium is 11.5 million, so a 4.3% prevalence would suggest about 500 thousand people in Belgium had been infected.  There were about 5000 excess deaths in Belgium by 14 April.  Deaths are a lagging indicator, but so are antibodies, and in both cases the lag seems to be about 2 or 3 weeks on average.

Consequences / Re: COVID-19
« on: April 16, 2020, 11:48:12 PM »
Dutch Study Suggests 3 Percent of Population May Have Antibodies

There was a similar antibody study in Finland:

The Finnish study has a small sample size, but the preliminary results are in line with studies in other countries.  For the samples taken in the last week of March and first week of April, less than 1% of them had antibodies.  But for the samples taken in the second week of April,  3.4% of them had antibodies.

Arctic sea ice / Re: When will the Arctic Go Ice Free?
« on: April 13, 2020, 01:22:20 PM »
the second two graphs look at 365 day trailing average volume
But IFF** that linear trend continues, by 2050 85% of the ice is gone, and by 2060 the Arctic would be virtually ice-free apart from some bits and pieces in winter.

It's meaningless to extrapolate an annual average in that way.

If you do the same analysis for individual monthly data, the September ice volume would reach zero in the year 2033 whereas the April volume would reach zero in the year 2101.

Your annual average extrapolation reaches zero somewhere halfway between, in 2065.  That is because it implicitly assumes that the summer ice volume can drop below zero into negative territory.  The "negative volume" in summer would cancel out the "positive volume" in winter by 2065 in the annual average.  It's clearly meaningless.

There was a commenter called Viddaloo who did the same thing on this forum a few years ago (except that he used quadratic rather than linear extrapolations) and these problems were already pointed out back then, e.g. see here.

Consequences / Re: COVID-19
« on: April 08, 2020, 09:43:32 PM »
While I am in favor of the lockdown, this does bring up a pertinent point:

Once again you're linking to an extreme right-wing propaganda site.  Moreover, that story is based on a video from 27 March and doesn't take into account the increase in coronavirus deaths that occurred in the meantime.

Consequences / Re: COVID-19
« on: April 02, 2020, 09:59:48 PM »
I suggest a quick look back in time on 538 to get a sense of the value in the quoted experts.
Total cases Sunday 29 march 143,491.
Not worth reading if they don't drop of the "experts" who are so wrong.
If they had a filter so you only keep those who have some handle on how things are progressing  it would have value.

The dates in that 538 article were wrong.  If you look at the original survey (which is linked inside the 538 article), you'll see that the question was the number of cases reported on Monday 23 March, rather than Sunday 29 March.  Also, the USA was ramping up testing at that time, which is part of the reason for the very rapid increase in reported cases back then.

Consequences / Re: COVID-19
« on: March 30, 2020, 08:56:49 PM »
Is there a way to see how many people are tested in Italy and New York ?

In the last few days, New York state has been testing about 15,000 people per day and Italy about 30,000 people per day.  Daily numbers here:  (tamponi = swab tests)

Consequences / Re: COVID-19
« on: March 22, 2020, 11:32:43 AM »
Chinese economy gradually restarting: air pollution increasing again

The new data analysis by the Copernicus Sentinel-5P satellite reveals significant changes in the air pollution across China. Data analysis between late December and mid-March shows a significant decline in nitrogen dioxide (NO2) emissions during China’s national lockdown in January and February, followed by an increase of air pollution once the national lockdown is canceled as life and industrial activity is returning back.

The rest / Re: Good music
« on: March 21, 2020, 10:52:16 PM »
Playlist with 5 Italian songs:,RFpyhzQVhPk,FpOEN93LX-E,4kDZXHmC4Cs,OxhAadfBUsU

  • Amedeo Minghi & Mietta  -  Vattene Amore  (1990)
  • Franco Battiato & Alice  -  I Treni Di Tozeur   (1985)
  • Laura Pausini -  La Solitudine (1993)
  • Paolo Conte  -  Max (1987)
  • Zucchero  -  Il Volo  (1995)

Consequences / Re: COVID-19
« on: March 21, 2020, 07:50:54 PM »
But that would not account for the low recovered numbers, i get that.

The German number of recoveries that is listed on wikipedia (and on the worldometers website) comes from the following source:

...which says that the official number of recoveries is a lower bound, as there is no obligation to report recoveries:

209 wieder gesund*
*Mindestwert (keine Meldepflicht)

Consequences / Re: COVID-19
« on: March 21, 2020, 05:15:23 PM »
Testing in the USA has increased eightfold over the past week.  About 12% of the tests were positive.

Consequences / Re: COVID-19
« on: March 14, 2020, 11:37:41 AM »
"Coronavirus Health Advice - James Robb, MD FCAP
Retired professor of pathology at UC San Diego
05 March 2020-20

1. If you have a runny nose and sputum, you have a common cold

2. Coronavirus pneumonia is a dry cough with no runny nose.

3. This new virus is not heat-resistant and will be killed by a temperature of just 26/27C (78-80F) degrees. It hates the sun.

4. If someone sneezes with it, it takes about 10 feet before it drops to the ground and is no longer airborne.

5. If it drops on a metal surface it will live for at least 12 hours - so if you come into contact with any metal surface - wash your hands as soon as you can with a bacterial soap.

6. On fabric it can survive for 6-12 hours. Normal laundry detergent will kill it.

7. Drinking warm water is effective for all viruses. Try not to drink liquids with ice.

8. Wash your hands frequently as the virus can only live on your hands for 5-10 minutes, but - a lot can happen during that time - you can rub your eyes, pick your nose unwittingly and so on.

9. You should also gargle as a prevention. A simple solution of salt in warm water will suffice.

10. Can't emphasize enough - drink plenty of water!

You are spreading fake news.

There are several versions of the above text circulating on social media.  Some versions say it's from James Robb, other versions say it's from Stanford researchers, yet other versions say it's from Chinese researchers.  None of that is true.

See here for fact-check:

Consequences / Re: COVID-19
« on: March 13, 2020, 09:01:26 PM »
Coronavirus: Nitrogen Dioxide Emissions Drop Over Italy

New data from the Copernicus Sentinel-5P satellite reveal the decline of air pollution, specifically nitrogen dioxide emissions, over Italy. This reduction is particularly visible in northern Italy which coincides with its nationwide lockdown to prevent the spread of the coronavirus.

The animation shows the fluctuation of nitrogen dioxide emissions across Europe from 1 January 2020 until 11 March 2020, using a 10-day moving average.

Consequences / Re: COVID-19
« on: March 08, 2020, 11:09:26 AM »
Seems like a plausible explanation for the low South Korean CFR.

The main reason why South Korea has a lower case fatality rate, is that they are doing very extensive testing.  They are detecting lots of mild cases that would have gone unnoticed in other countries.

Arctic sea ice / Re: MOSAiC news
« on: March 02, 2020, 10:17:16 PM »
Perhaps it was something lost in translation but I'm wondering what is implied by "fast ice" in the above paragraph ?

The original German article says "festes Meereis".  I think what they mean in this context is compact sea ice.

Consequences / Re: COVID-19
« on: March 01, 2020, 12:41:44 PM »
People keep bringing up the demographics of the Diamond Princess yet I have seen no evidence for the demographics.

See here  (updated on 20 February):

The demographics for the Diamond Princess is heavily skewed towards older people.  The majority of them are more than 60 years old.

Antarctica / Re: PIG has calved
« on: February 12, 2020, 07:48:40 PM »
From Stef Lhermitte on twitter:  an animation showing the retreat of the PIG calving front from 1973 to 2020, including the calving that happened a few days ago:

Arctic sea ice / Re: The 2019/2020 freezing season
« on: February 06, 2020, 11:18:15 PM »
You showed above that there is no correlation of March to September, but surely there must be correlation by August.

As an addition to grixm's graphs, below is a table showing the correlations between detrended monthly sea ice extent data for each possible combination of months, from January to December.  For the calculation, I used the NSIDC extent data for 1979-2019.  The detrending that I'm using is slightly different from the one used by grixm, but the results seem to agree very well with his.

Note that the table shows the monthly correlation coefficients R rather than the squared correlations R^2, and it  has some grey background colors to indicate the strength of the monthly correlations, with darker colors indicating stronger correlations:

(click to enlarge the image)

The most noteworthy feature to me is the lack of correlation between May and June.  I guess it's because the weather conditions and preconditioning in late May and in June play a very important role for the rest of the melt season.  That time of year is basically the start of the melt pond season in the Arctic proper.

And here is a similar graph for monthly PIOMAS volume data, rather than extent.  As expected, the correlations are much stronger in that case.

Consequences / Re: Global Surface Air Temperatures
« on: January 13, 2020, 08:02:14 PM »
two new methods say it is likely

Only 1 of those 2 methods predicts that a new El Niño will emerge in 2020:

The other method predicts ENSO neutral conditions throughout 2020:

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