Guest post by Geoff Sherrington
The global problem.
In response to the threat of a global viral epidemic, countries announced lockdowns at various times near 25th March 2020. https://en.wikipedia.org/wiki/COVID-19_pandemic_lockdowns
This caused a reduction of industrial activity and hence a lower rate of emission of anthropogenic carbon dioxide to the atmosphere. An example of reduction from aircraft is given at https://en.wikipedia.org/wiki/Impact_of_the_COVID-19_pandemic_on_aviation
Numerous sources asked if the reduction in CO2 emission could be detected in analysis of air for CO2 content, which had been done for decades. Early questions and speculative answers came from many sources including –
https://www.esrl.noaa.gov/gmd/ccgg/covid2.html
By late May 2020, the emerging consensus was that the reduction would be too small to show at the main measuring stations such as Mauna Loa, Hawaii.
This CO2 event has some consequences for global warming alarmism. There has long been argument that the contribution of anthropogenic CO2 to air is tiny compared to natural sources and sinks. Another argument says that the decades-long increase in CO2, the Keeling Curve, is mainly due to mankind, because the estimated emissions from industry account for about double the increase measured each year. Here is part of that curve to mid-May 2020:

It follows that an absence of a fall in the curve in the 2020 lockdown could indicate that the emissions of mankind are dwarfed by natural emissions. Whereas, a fall can be interpreted as proof that atmospheric CO2 levels are directly and measurably influenced by man-made emissions.
In terms of global political action, there are numerous calls to lower CO2 emissions by reduction or removal of fossil fuel generators such as electric power plants, cement manufacturing, gas autos replaced by electric and so on.
If the lockdown causes a 10% reduction in man-made emissions and this does not show in measurements, what does this mean for models of global climate and their forecasts? How are we going to monitor progress from drastic cuts to fossil fuel use if we cannot see the result in the numbers?
CITIZEN SCIENCE INVESTIGATES.
You are an interested scientist seeking to do your own investigation of CO2 levels in 2020. You prefer daily reports of CO2 to preserve the fine texture of the measurements and their comparisons from one weather station to another. You seek data from other weather stations.
There are 4 stations typically listed as keys to the system. These are –
Barrow, Alaska
Mauna Loa, Hawaii
Cape Grim, Tasmania
The South Pole, Antarctica
There are many secondary stations such as these in the AGAGE (Advanced Global Atmospheric Gases Experiment https://agage.mit.edu/global-network
About 23rd March 2020 I started to download files of CO2 in air from some of these stations. There were problems. Almost none of them had daily data for year 2020, some had no 2020 data at all. NOAA, for example, had daily South Pole data to only 31st December 2019. Mauna Loa was the exception. It had data from two sets of instruments, one under the NOAA banner, the other from Scripps. I managed to download some NOAA daily data ending in March 2020, but when I tried again I could not find the original source. If I try the following URL, the data stop at 31st December 2019.
ftp://aftp.cmdl.noaa.gov/data/trace_gases/co2/in-situ/surface/
Ralph Keeling from Scripps was most helpful with data. By email of 27 April 2020, he sent a few years of past daily Mauna Loa data to 12th April 2020. I told him I would not use it unauthorised, but then later found it to be identical to data downloaded here.
https://scrippsco2.ucsd.edu/data/atmospheric_co2/mlo.html
This is the most up-to-date, comprehensive source of daily CO2 data that I have found for year 2020.
The other Mauna Loa people, NOAA, write in their read-me notes that –
These data are made freely available to the public and the
scientific community in the belief that their wide dissemination
will lead to greater understanding and new scientific insights.
The availability of these data does not constitute publication
of the data. NOAA relies on the ethics and integrity of the user to
ensure that ESRL receives fair credit for their work.
Sadly, I have not succeeded in finding daily CO2 data for Mauna Loa for much of 2020 despite perhaps 20 searches, except for the Scripps source and Ralph Keeling.
What did I do with the daily CO2 data from Mauna Loa, NOAA versus Scripps?
NOAA HAS A PROBLEM OR THREE.
First, I did a straight comparison. It was something of a shock, because it demonstrated there was strong circumstantial evidence that NOAA was making up numbers that went into their official historic record. I would not have detected this feature if I had not got daily data from Ralph Keeling, with gaps labelled NaN for missing data. Here is but one example of it.
YEAR MONTH DAY SCRIPPS CO2 NOAA CO2
2020 1 374 413.39 413.1
2020 1 375 413.46 413.15
2020 1 376 413.25 413.2
2020 1 377 413.23 413.25
2020 1 378 NaN 413.3
2020 1 379 NaN 413.35
2020 1 380 NaN 413.4
2020 1 381 NaN 413.45
2020 1 382 NaN 413.49
2020 1 383 NaN 413.54
2020 1 384 NaN 413.58
2020 1 385 NaN 413.62
2020 1 386 NaN 413.67
2020 1 387 NaN 413.71
2020 1 388 413.16 413.74
2020 1 389 412.58 413.78
2020 1 390 412.54 413.82
2020 1 391 413 413.85
2020 1 392 414.76 413.89
For reasons unknown to me, Scripps had 10 consecutive days when no data were reported. It seems like NOAA had a similar gap, because the NOAA numbers are a simple linear infill with synthetic numbers, each either 0.4 or 0.5 ppm apart.
It is reasonable to presume that some of the NOAA numbers are not real, but are guesses.
Here is another NOAA problem, problem number two, from a that graph follows with small annotations, from the public source https://www.co2.earth/daily-co2
Around 22nd March 2020, there is a gap of some 4-5 days of missing data. I have added pictorial yellow trend lines that indicate (roughly) that the observations had a step change of about 1 ppm CO2 over these 5 days. This type of change would alert any experienced analytical chemist, with a strong message like “What is going on here? The dots do not join.” This is rather significant jump when, as references above show, we are seeking a change of 0.2 ppm over some months as an indicator of an effect of the global lockdown.
Here we have a change of about 1 ppm in 5 days.

NOAA have a detailed explanation of how they manage their accuracy and errors at Mauna Loa.
https://www.esrl.noaa.gov/gmd/ccgg/about/co2_measurements.html
They note that
- The Observatory near the summit of Mauna Loa, at an altitude of 3400 m, is well situated to measure air masses that are representative of very large areas.
- All of the measurements are rigorously and very frequently calibrated.
- Ongoing comparisons of independent measurements at the same site allow an estimate of the accuracy, which is generally better than 0.2 ppm.
They have the following graph about rejection of observations that are unsuitable – or perhaps “inconvenient” as in truth?

The colour code for grey-blue, letter U, is said to represent
There is often a diurnal wind flow pattern on Mauna Loa driven by warming of the surface during the day and cooling during the night. During the day warm air flows up the slope, typically reaching the observatory at 9 am local time (19 UTC) or later. The upslope air may have CO2 that has been lowered by plants removing CO2 through photosynthesis at lower elevations on the island, although the CO2 decrease arrives later than the change in wind direction, because the observatory is surrounded by miles of bare lava. Upslope winds can persist through ~7 pm local time (5 UTC, next day, or local hour 19 in Figure 2). Hours that are likely affected by local photosynthesis (11am to 7pm local time, 21 to 5 UTC) are indicated by a “U” flag in the hourly data file, and by the blue color in Figure 2.
It is important to note that these words are conjecture. They are guesses at a mechanism. NOAA do not reference controlled experiments that confirm these conjectures. Another conjecture might be that the grey-blue dots are correct; and that higher values are from positive contamination of CO2 from elsewhere.
An important deduction is that NOAA have introduced subjective results into the official record. In hard analytical chemistry, this is not done. Some regard it as cheating. We have already seen an example of NOAA using invented numbers, another no-no. A double strike is hardly a compliment.
Three strikes and you are out? Yes, here is the third strike. It is about accuracy. NOAA claim that
Ongoing comparisons of independent measurements at the same site allow an estimate of the accuracy, which is generally better than 0.2 ppm.
The accuracy of measurements from a laboratory has long been calculated as if an unknown client walks off the street with a sample and asks the lab to analyse it. The lab does not have access to the history of the sample. In reference to the graph just above, selected hourly averages. you need to consider all of the colours of all of the points to calculate accuracy. If accuracy is expressed in customary terms of a normal distribution with 95% of measurements falling within the 2 sigmas of standard deviation either side of the mean, even a rough eyeball estimate puts the 2 sigmas at about +/- 2 ppm accuracy. This is really elementary, classical science. With extreme special pleading by NOAA, using only their black “accepted” points, we are looking at +/- 0.7 or so ppm 2 sigma. It is hard to fathom the source of their accuracy claim of 0.2 ppm, but then they might have created their own definitions for measurement and expression of accuracy.
Here is another graph, this one a comparison of Scripps and NOAA from the same location but using different instruments, calibration procedures and algorithms to treat data.

It is not hard to find reason to question both the NOAA claim of 0.2 ppm accuracy and the accuracy at Scripps. This graph shows results something similar to the “man off the street “ exercise noted above.
Three counts.
In the olden days, if my laboratory operators had these counts against them, they would have handed in their badges of professionalism and gone home before sunset. I see two factors at work here. First is a lack of accountability. My operators knew that they would be fired on the spot for transgressions like these, so they behaved in an accountable way. The performance of people in the work place improves when there are open measures of accountability. Second, there might be aspects of post-modern or post-normal science at work here. As Wiki explains it in summary – https://en.wikipedia.org/wiki/Post-normal_science
Post-normal science (PNS) represents a novel approach for the use of science on issues where “facts [are] uncertain, values in dispute, stakes high and decisions urgent”.[1] PNS was developed in the 1990s by Silvio Funtowicz and Jerome R. Ravetz.[2][3][1] It can be considered as a reaction to the styles of analysis based on risk and cost-benefit analysis prevailing at that time, and as an embodiment of concepts of a new “critical science” developed in previous works by the same authors.[4][5] In a more recent work PNS is described as “the stage where we are today, where all the comfortable assumptions about science, its production and its use, are in question”.[6]
WHAT OF LOCATIONS AWAY FROM MAUNA LOA?
By email of 3rd April 2020, I attempted to obtain CO2 results from the New Zealand Authority NIWA, for Baring Head near Wellington.
Hello from Melbourne,
Do you have a web site link from which I can download your daily measurements of the carbon dioxide concentration in the air as measured at Baring Head? I am seeking daily concentrations from about Jan 2015 to the present day or so, preferably in .csv of similar format Alternatively, can you advise me of the correct procedure to request this information, including that for recent weeks?
Thank you Geoffrey H Sherrington
Scientist
Their reply was –
Dear Geoff,
The Baring Head carbon dioxide data that are available publicly, on the World Data Centre for Greenhouse Gases (https://gaw.kishou.go.jp/), in our plots at https://niwa.co.nz/atmosphere/our-data/trace-gas-datasets and on our ftp site ftp://ftp.niwa.co.nz/tropac/, currently go through to the end of 2018.
Before we make our Baring Head CO2 data publicly available, we go through a very thorough validation process which is explained below. We do this annually and are very close to releasing the 2019 data. The above links will be updated with the 2019 data once it is available. The 2020 data will not be available until about this time next year as it needs to go through the same validation process before it is released.
Our data validation process involves scrutinising the calibration gas measurements for the previous year. Below is a quick description of the calibration process:
At Baring Head we have eight calibration gases that are used as long-term transfer standards providing a link for our measurements to the World Meteorological Organisation (WMO) mole fraction scale. The CO2 mole fractions for the eight long-term transfer standard calibration gases are determined by the WMO Central Calibration Laboratory (CCL), with an estimated uncertainty of ±0.07 ppm (1-sigma) with respect to the WMO scale. We use these eight calibration gases to determine the calibration response for our instrument. These eight calibration gases are usually run on a fortnightly basis. We also run another four calibration gases as short-term working standards, which are run several times each day. More details can be found in Brailsford et al., Atmos. Meas. Tech., 5, 3109–3117, 2012; www.atmos-meas-tech.net/5/3109/2012/ doi:10.5194/amt-5-3109-2012.
Kind regards, Caroline
By email of 30th March 2020, I requested daily data from CSIRO Australia, for Cape Grim.
Message: Can I please obtain data as .csv or similar, showing daily measurements of atmospheric carbon dioxide from start 2014 to today, or to the last day of measurement from Cape Grim? I have viewed some data for the years 2014-2019 incl., but the period of most interest is daily and it starts March 1 2020
There were several emails, the most recent from CSIRO being –
Hi Geoffrey,
Thanks for contacting CSIRO.
The Cape Grim monthly averaged baseline data is made available to the public on a monthly basis. It is provisioned at this frequency, rather than hourly or daily, because the high resolution data needs to be run through a process by our team that is not instant.
The monthly data is currently sufficient for all other publications, enquirers and users, and our robust and peer-reviewed data publishing process will not be changed based upon your request.
We trust that the recently published March 2020 monthly averaged data point will be of use to you.
These bodies seem keen to gatekeep their data for reasons unexplained. The Australian data are paid for by the Australian public, who have a reasonable expectation of being able to access the data. I know of no law or regulation that allows CSIRO to act as censor or gatekeeper against the public. Perhaps there are some acts & regs, but I have never found them or seen them quoted.
The whole sorry procedure takes me back to my friend Warwick Hughes, who received that shattering email from Prof Phil Jones back in 2004-5.
“Why should I make the data available to you,
when your aim is to try and find something wrong with it.”
Must one conclude, with a heavy heart, that there remain vested interests among the science community who simply do not know of the damage that can be done through failing to learn from the history of Science? And who are more willing to obscure than to learn?
And no, this essay is not a candidate for a formal, peer reviewed publication because it does not present any useful advance of Science. It uses methods little more complicated than addition and subtraction of simple numbers. It is not meant to advance understanding of Science, so much as to minimise the decline.
THE END.
Geoff Sherrington
Scientist
Melbourne, Australia.
21st May 2010.
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JAPAN WINS VIRUS FIGHT BY IGNORING RULEBOOK
https://www.bangkokpost.com/world/1923028/japan-wins-virus-fight-by-ignoring-rulebook
[excerpt]
TOKYO: Japan’s state of emergency is nearing its end with new cases of the coronavirus dwindling to mere dozens. It got there despite largely ignoring the default playbook.
No restrictions were placed on residents’ movements, and businesses from restaurants to hairdressers stayed open. No high-tech apps that tracked people’s movements were deployed. The country doesn’t have a centre for disease control.
And even as nations were exhorted to “test, test, test”, Japan has tested just 0.2% of its population — one of the lowest rates among developed countries.
Yet the curve has been flattened, with just 17,000 cases and 826 deaths in a country of 126 million — by far the best numbers among the Group of Seven developed nations.
Allan
And, they have one of the oldest populations in the world and some of the most overcrowded mass transportation systems. There are a lot of things we still don’t understand about this virus!
Hi Clyde,
The Diamond Princess cruise ship in Yokohama provided excellent data on the morbidity of the Covid-19 illness for different age groups – it had little or no effect on the majority younger healthier population, but was highly dangerous to the old and infirm. That was my confident conclusion by mid-March. I wrote that the full-lockdown was NOT necessary on 21Mar2020.
I concluded then that there was little or no justification for the full lock-down, but an obvious need to over-protect the elderly and infirm. Countries that did so did very well. In contrast, Britain and New York State did the exact opposite and killed multitudes of their high-risk populations – one has to wonder how anyone could be so utterly dysfunctional.
Best regards, Allan
Allan,
Please compare with Brazil, who did reasonably similarly to Japan.
Geoff – Totally different cultures and economies. Brazil has huge slums, Japan does not.
More differences than similarities.
https://volcano.si.edu/gvp_currenteruptions.cfm
Could it be the fact there are now 45 ongoing eruptions instead of the usual 20-25?
That’s an increase of 120%…
Would that not be a cause?
From the site:
“ Overall there are 45 volcanoes with ongoing eruptions as of the Stop Dates indicated, and as reported through the last data update (17 April 2020), sorted with the most recently started eruption at the top. Information about more recently started eruptions can be found in the Weekly Report.
Although detailed statistics are not kept on daily activity, generally there are around 20 volcanoes actively erupting on any particular day. The Smithsonian / USGS Weekly Volcanic Activity Report (WVAR) for the week ending on 19 May 2020 includes the 13 volcanoes bolded and shown below in the WVAR column (rollover for report).
An eruption marked as “continuing” does not always mean that the activity is continuous or happening today, but that there have been at least some intermittent eruptive events at that volcano without a break of at least 3 months since it started. An eruption listed here also might have ended since the last public data update, or at the update time a firm end date had not yet been determined due to potential renewed activity.”
Something to dig i suppose
Frederik,
Given the frequent assumption that volcanos can emit significant CO2, this has relevance to the task of tracking possible Covid/lockdown CO2 changes in the air.
More food for thought about the natural variation that is so much downplayed.
One would have thought that those interested in CO2 would be sending teams to each volcano to measure CO2 outputs. The ones above ground, at least. Or has it been proven beyond reasonable doubt that volcanic CO2 emissions are all together too small to worry about? I have not kept up with the literature.,
Geoff S
Geoff, continuous measurements around mount Etna, one of the most active volcanoes of the world showed that all above ground volcanoes together emit about 1% of what humans emit… Even if that doubles, it still is not measurable.
Deep ocean volcanoes are unknown, but most of then are deep enough to have all their emissions dissolved in the enormous pressure of under saturated seawater for CO2 at that depth.
See: https://www.nature.com/articles/351387a0
Ferdinand
You remarked, “… most of then are deep enough to have all their emissions dissolved in the enormous pressure of under saturated seawater …” True enough. But, that means transient underwater activity hundreds of years ago could be impacting the CO2 brought to the surface by up-welling. OCO-2 measurements show significant out-gassing in the tropics; however, we have no synoptic measurements prior to 2014. That is, we have no baseline measurements to compare against. Historical measurements of pH are officially untrusted.
Clyde,
Sorry for the late reply,
There are a few possibilities to know the past pH of the ocean surface and the exchange with the surface and atmosphere:
– Historical pH levels can be calculated from other measurements in the water samples, like total alkalinity, pCO2 or others which are more reliable than the glass pH electrode methods of that time…
– The amount of CO2 passing the atmosphere from the deep upwelling near the equator and sinking near the poles can be estimated from the “thinning” of the drop in δ13C caused by human emissions. Human emissions have an average δ13C level around -25 per mil, CO2 from the deep oceans (taking into account the water-air and air-water shift in isotopic ratio) of around -6.4 per mil.
That makes that about 1/3 of the original human emissions stay in the atmosphere, the rest is exchanged with mainly deep ocean CO2:
http://www.ferdinand-engelbeen.be/klimaat/klim_img/deep_ocean_air_zero.jpg
That means that some 40 GtC as CO2 is exchanged each year between deep oceans and atmosphere. Until about 1980, the biosphere might have been a small source of CO2, which gives the discrepancy before 1980, from 1990 onward, vegetation is a small, but increasing sink of CO2. That is not included in the calculation…
It doesn’t looks like that there was a huge change in deep ocean CO2 flux, but in the total mass of CO2 and its derivatives, that needs a lot extra to be measurable…
Frederik,
I agree with your conjecture.
My own suspicion is that undersea volcanoes & vents are the prime cause of global warming, rather than CO2 emissions. We can see that atmospheric CO2 follows, rather than leads temperature rises, from looking at the Scripps process. The resulting ‘Keeling Curve’ for each site shows a steady increase in temperature, overlaid by an annual seasonal variation that tracks the humidity (and hence temperature) of the respective sites.
Indeed, the effect of CO2 emissions causing an added increase in air temperature and hence humidity and consequent increased cloud formation and hence albedo, may have the effect of increasing the radiation of this added heat to space. In other words increasing CO2 might be adding to the control feedback that moderates global warming, rather than being the demon that needs reducing.
Thank you Geoff for that revelation. Having retired from exploration geophysics, I have spent the past decade applying my experience and knowledge to an analysis of publically available climate data. In the process, I have accepted that the data was sound. In particular I have analysed the Scripps Institution of Oceanography CO2 data from a number of their stations and compared it with the UAH satellite lower troposphere temperature data.
My most recent study was an analysis of the Scripps Mauna Loa Observatory 62 year long weekly data file for CO2 concentration up to 25 April 2020. It did not show any change in the regular seasonal variation that could be attributed to the current worldwide industrial shutdown.
The autocorrelation function of the annual rate of change of CO2 concentration showed a very definite cyclic pattern of near constant wavelength which I attribute to the El Niño event. The average wavelength from weekly lags up to 1500 weeks was 1322 days.
The Discrete Fourier Transform was also dominated by a maximum at 1308 days again attributed to the El Niño event. My conclusion is that this major climate event determines the rate of change of CO2 concentration in the Equatorial zone, that is, CO2 does not cause climate change, it is climate that causes the change in the rate of generation of atmospheric CO2.
In addition, the DFT amplitude spectrum gave local peaks relating to the 27.21 day draconic period and the 29.53 day synodic period of the Moon and integer multiples thereof. In the case of the draconic period, Moon passes through the two nodes marking the intersection of the Moon’s elliptic around the Earth and the Earth’s elliptical plane around the Sun every 13.6 days. While the DFT spectrum does not reveal this period from weekly data, it did reveal its integer multiples.
My conclusion here is that the Scripps Institution data was reliable enough to show the small changes in temperature bought about by the Moon’s orbit around the Earth which, in turn shows that it is temperature change that determines the rate of generation of atmospheric CO2 not CO2 causing temperature change.
Bevan: Interesting. Have you considered posting an article on wuwt? Seems like it would be a very good read.
Bevan Dockery,
Your analysis of the regular seasonal max-min variation should show an increase in amplitude,
as according to the orthodoxy it is caused by plant growth and decay. In other words, we should see a increase in the size of the annual ‘green wave’ of 30% or so over the last ~30 years.
If it does not , then the hypothesis that rising CO2 precedes Global temperature rises is in question.
https://www.nature.com/articles/nclimate3004
From the abstract:
” We show a persistent and widespread increase of growing season integrated LAI (greening) over 25% to 50% of the global vegetated area, whereas less than 4% of the globe shows decreasing LAI (browning). Factorial simulations with multiple global ecosystem models suggest that CO2 fertilization effects explain 70% of the observed greening trend”
Yes, TonyN,
The seasonal variation definitely shows an increase in amplitude with time although in a very irregular manner. However any farmer knows that the seasons vary unpredictably.
Would it were that Loydo could write something like this, he/she might be taken more seriously.
Bevan
Do you have any thoughts on how the moon might be affecting Earth’s temperature? I’d also like to encourage you to write an article for WUWT, and provide some speculation on how these correlations provide a mechanism for impacting weather and/or climate.
Anyone who has experienced a lunar eclipse of the Sun has felt the marked fall and rise in the local temperature during the eclipse. The Moon is passing through one of the two nodal points of its orbit as an eclipse takes place. In so doing, it scatters the Sun radiation away from part of the Earth’s surface thereby decreasing the temperature.
At other times we are not consciously aware of the transit through a nodal point but it is apparent on the DFT amplitude spectrum, indicating that life on Earth is very sensitive to temperature changes and that the Scripps Institution is doing a good job in tracking the atmospheric CO2 concentration.
Anyone who has experienced a lunar eclipse of the Sun has felt the marked fall and rise in the local temperature during the eclipse. The Moon is passing through one of the two nodal points of its orbit as an eclipse takes place. In so doing, it scatters the Sun radiation away from part of the Earth’s surface thereby decreasing the temperature.
At other times we are not consciously aware of the transit through a nodal point but it is apparent on the DFT amplitude spectrum, indicating that life on Earth is very sensitive to temperature changes and that the Scripps Institution is doing a good job in tracking the atmospheric CO2 concentration.
Has it occurred to you that they simply don’t have any data. That knowing what they know, they quit taking data points. They want an outcome and they don’t really care what the data is? Take a CO2 sample where you are, compare it to theirs. Sure, there is going to be a bit of difference but it will give you a start.
Donald: they do have data and that is exactly why they made this play. Desperate gambit that has failed to produce the desired results…in other words they proved them selves wrong. But that will be easy enough to paper away here on Planet Moron.
Come on gentlemen, the hourly data of several stations from the beginning of the measurements up to December 2019 are available on the NOAA and Scripps websites, including the standard deviation of the sampling over the past hour.
On simple request, I even received 10-second snapshots over the length of two days in 2006 from Pieter Tans, the head of the data management at Mauna Loa (at that time), so I could calculate the hourly averages and stdv myself with the methods used by NOAA, no difference with was reported…
Here how the hourly average was calculated for one hour sampling:
http://www.ferdinand-engelbeen.be/klimaat/mlo_raw_v_2006_11_17_00h.xls
As CO2 is measured at many “background” places in the world, by different people from different organizations from different countries, there is no way that one can tamper with the CO2 data…
We aren’t talking about temperature data here…
Geoff,
I had some spare time, so I downloaded the 2019 daily averages from MLO both from NOAA and Scripps.
So I compared them with each other and here are the conclusions:
– There are 33 NaN gaps in the Scripps data, thus without daily average
– There are 32 -999.99 value gaps in the NOAA data, thus without daily average
– Only 10 of these days were common for NOAA and Scripps.
That leaves 318 days with daily averages from NOAA and Scripps.
The average difference between these two data sets is 0.05 ppmv.
Wow! That difference for separate monitoring equipment, separate calibration gases, made by themselves (NOAA makes calibration gases for the whole world, Scripps makes their own) and own CO2 scales…
The standard deviation of the differences is 0.37 ppmv
If you leave out the 9 worst differences (> 1 ppmv), the stdv drops to 0.23 ppmv still over 309 days.
In near all cases, there is a difference in number of hours (deemed “background”) used to calculate the daily average between NOAA and Scripps. Even which hours were retained may be different, but that only can be checked in the hourly data of the same days. Anyway, that means that the daily averages from Scripps have not the same base as the daily averages from NOAA…
It seems to me that your stance against the CO2 data is not based on real problems with the methods used at NOAA or Scripps, but with the (a priori!) criteria used for retaining some data for averaging and others not.
I don’t have problems with that, as I am interested in real “background” CO2 data, not in what the Mauna Loa volcano does or what vegetation in the valleys of Hawaii do…
Geoff,
I have downloaded the daily data of Mauna Loa both by NOAA and Scripps for 2019.
What I have seen is:
– There are 32 data in the NOAA file with -999.99, that us their code for NaN
– There are 33 data with NaN in the Scripps file.
– There are only 10 days where both NOAA and Scripps have NaN
That gives that 318 days remain with daily data of both NOAA and Scripps.
If you take the difference between the two data sets, the average difference is 0,05 ppmv, despite difference in equipment, own calibration gases and CO2 scale.
The standard deviation of the difference is 0.37 ppmv
If you remove the 9 outliers with a difference > 1 ppmv. the stdev reduces to 0.23 ppmv for the remaining 309 daily averages.
Both datasets show the number of hours (deemed “background”) that they used to calculate the daily averages. Near always there is a difference in retained hours and retained hours are not necessary the same hours for both…
Conclusion, there is nothing that points to “infilling” of the data by NOAA. If they have no hourly data that fit the criteria, that day has no average.
NOAA and Scripps simply maintain their own equipment and criteria, which leads to differences in number of retained hours for the calculation of the daily average. That leads to small differences for the same days. For the bulk of the daily averages, that difference is below 0.2 ppmv (1 sigma). Only a few days give much larger (> 1 ppmv) differences…
My conclusion: much ado about nothing…
Geoff, the first of these two responses did remain in cyberspace for two days… So I prepared a second version and now they are there both…
Doesn’t matter…