1. Mick West

    Mick West Administrator Staff Member

    Deadly UV Metabunk.

    In a paper titled "Deadly Ultraviolet UV-C and UV-B Penetration to Earth’s Surface:" J. Marvin Herndon, Raymond D. Hoisington, and Mark Whiteside write:

    Metabunk 2018-04-01 10-27-32.
    They get values for UV-C (their readings are shown in the graph above in red and black) that are much higher than found in space (the green line). The graph above is a comparison they make in their paper. I've corrected for the rather misleading log scale they used:

    Their readings obviously go wrong below 280 nm.

    Herndon's answer to this problem is that his cheap device is right and NASA's satellite measurements for the last couple of decades are wrong.

    I asked the manufacturers of the instrumente used, International Light Technologies, about this:

    They responded:

    (emphasis mine)

    So the rise in UV at the bottom of the range is due to the multiplication of noise from stray sunlight multiplied by a function that ramps up for low values of UV.

    i.e. it's a graph of the correction function made visible by not filtering out all the other light.

    Follow up from ILT:

    ILT say the only way to measure UV-C with this instrument is monochromator. This is a type of specialized filter that blocks out all stray light outside of one narrowly defined part of the spectrum. This was not done by Herndon, et. al, which is why they have the peak in UV-C. It's simply the calibration curve added in by the software. No UV-C was detected.

    It is unfortunate that the authors of the paper were seemingly unfamiliar with the problems of stray light in measuring UV-C. This is actually a well know problem in the field, and was in fact raised as an issue by of the peer-reviewers of the paper:

    The problem is well known to the manufacturers and experienced users of these instruments. Here's discussion from Instrument Systems, a division of Konica Minolta:
    They include this explanatory chart:
    Notice the most accurate readings (green) with the scanning double monochromator (as suggested by ILT) are around 0.001. Basically zero.

    Herndon, et. al, do mention "stray light"
    What they fail to realize is that 0.3% of very bright sunlight is still a lot of stray light falling on the UV-C portion of the sensor.

    [Note: this is a summary post of the thread below, original discussion follows]
    Last edited: Apr 3, 2018
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  2. Mick West

    Mick West Administrator Staff Member

    Metabunk 2018-04-01 11-27-48.

    Here's his problem in a bit more context. The larger blue graph is the actual solar radiation spectrum measured in space. Red and black are his measurements. Above 280 they are quote reasonable, being lower than the raw values above the atmosphere. The also (correctly) drop to zero at around 280. Then at around 250 down to 200 his readings ramp up to 20x times the value found in direct sunlight in space.

    Solar irradiance data from:

    UV data in the 200-400 range comes from the $122 Million SORCE satellite.

    Metabunk 2018-04-01 11-33-10.

    Similar errors were early reported on Geoengineering watch.

    Attached Files:

    Last edited: Apr 3, 2018
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  3. skephu

    skephu Senior Member

    Very reasonable explanation. Had Herndon (or his co-author Raymond Hoisington who was responsible for the spectral measurements) consulted the manufacturer, they would have saved themselves from an embarrassing mistake.
    But Herndon will never accept this.

    Interestingly, this former article on Geoengineeringwatch has been removed:
    "A new warning of deadly ozone layer collapse from a former NASA engineer"
    but is archived here: http://archive.is/yKgGQ

    The "former NASA engineer" writes that a scientist criticized his results on the basis that the high measured values are caused by stray light:
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  4. Clouds Givemethewillies

    Clouds Givemethewillies Active Member

    According to the above paper he did.

    " The initial order to International Light Technologies specified that solar radiation measurements were to be performed with this unit, and that power levels to be measured in μW/cm²/nm.
    International Light Technologies provided all training, and feedback analysis of initial data gathered to insure correct measurement process"
  5. Tedinoz

    Tedinoz New Member

    At face value, that would suggest that ILT have represented one thing to the authors, and another to Mick.

    However, in this technical paper, the authors disclaim that their technical competence and the reliability of interpretation of their data is/was subject to the prior interpretative/confirming work of others. Further, the results of the authors’ work is of ground-breaking significance. In such a case, would it not have been appropriate that the authors would disclose the details of the “initial data” and the “feedback analysis” for the purposes of ensuring their work could be tested and repeated?

    In the circumstances, I suggest that the onus falls on the authors, not ILT, to disclose that information.
  6. Ravi

    Ravi New Member

    Ah, handheld spectrometers are great! But not at 350nm and lower.. It is well known fact, if they would have the experience using them or any photometric device.. The authors should have asked a photonics engineer first, smh..
  7. Tedinoz

    Tedinoz New Member

    Quite possibly this is true. However, the authors claim that
    (Para 2 of the Introduction of their paper). So I would be very surprised if they felt that ANY other engineer could be trusted to give them impartial advice, particularly where it would have the effect of rendering their entire paper irrelevant.
    Last edited by a moderator: Apr 5, 2018
  8. Ravi

    Ravi New Member

    The paper explains a lot, but just not enough information is given about how the system works and if they (the operators) took care enough to prevent wrong data. The type of instrument they used is used everywhere, in labs and in the field. As I have used these type of spectrometers extensively in labs (I used OceanOptics USB4000), consists of a compact or "folded" optical design, where a small concave mirror is re-imaging the entrance slit via a small grating on a small CCD line-detector (8pix x 1064).

    Example: different company, same design:

    I am pretty confident that UV reaching our earth surface is not alarmingly increasing,
    it must have been caused by the instrument and/or the way it was used. I do not read in the paper that an expert (from the company) was present during the measurements, which leads me to believe that the measurement went wrong. Possible causes that I remember are:

    1-The spectrometer should have a "grating order cut off filter" inside. This is an optical filter, cutting off higher wavelengths than the range the unit measures. This is needed as the (sun) light is very much brighter around 700nm, a wavelength range that still enters the spectrometer and is diffracted by the grating. It will not directly hit the detector, but hit somewhere inside a (black) baffle of a wall. There the problem occurs: the light is scattered inside the unit and the scattering will hit the detector. When this is not taken in account observing the results, it gives a false result.

    2-Operation of the software might be wrong. The software has different settings for acquiring data: Absolute or Relative. When the Relative tab is used, the measured data is continuously referenced the the REF data taken earlier. This ratio is a tricky thing: if an angle is changed or the sun has moved somewhat it will immediately result in curves. The UV detectivity of Silicon also is very very low, and therefore a lot of "tricks" are needed to still spectrally observe UV light. Another fact is that the CCD arrays will not give you a larger dynamic range than ±12 bits.

    My money is on 1.
  9. Mick West

    Mick West Administrator Staff Member

    It think this is perhaps a case where we need to be careful not to understate both the implication of their claim and and the errors in their evidence.

    Obviously there is not an increase in UVC reaching the surface. Here's their graph again:

    Red&Black is theirs, green is the reference level of incoming solar radiation in space.

    They show what is now obvious is the calibration magnification of stray light in the range from 250 nm down to 200nm. This is increasing to 20 as the levels in space, with no filtering, direct from the sun, decrease down to less that 1.

    Not only that, but the levels appear to be increasing exponentially as the wavelength gets lower, but in the atmosphere the levels will decrease as the wavelength gets lower. Especially at 200nm, which is the start of "vacuum UV", so-called because it is strongly absorbed by the air - not just by ozone (O3) but by normal atmospheric oxygen (O2). Vacuum UV is used in science in a vacuum chamber, or in a pure nitrogen atmosphere. Here's the absorption rate:

    And here to scale:
    Metabunk 2018-04-06 08-55-19.

    So even if there was no ozone, as they suggest, then the UV would start going down (even more than it does in space), not up, at 200.

    AND, if there was no ozone, then where is the UV between 250 and 300? If it were not being blocked by the ozone layer, and if the oxygen was unable to block the much more blockable levels of UV-C below 250, then there would be vastly more UV between 250 and 300 than between 200 and 250.

    The are multiple other problems. Why are we not blind? Why has nobody noticed this unusual rise in UV. Why has nobody noticed thousands of tons of coal-fly ash being sprayed in the atmosphere. But these are almost irrelevant - the paper is fundamentally flawed and should never have been published. Let us not give it any more credence than it deserves.
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  10. Ravi

    Ravi New Member

    Fully agreeing with you there, Mick.
  11. Clouds Givemethewillies

    Clouds Givemethewillies Active Member

    Last edited: Apr 6, 2018
  12. Mick West

    Mick West Administrator Staff Member

    Exactly, if the UV starts to get attenuated in few feet then it's not going to make it through thousands of feet of atmospheric oxygen.

    And of course the ozone layer is still there. It's being observed by hundreds of scientists all around the world.
  13. Clouds Givemethewillies

    Clouds Givemethewillies Active Member

    Last edited: Apr 6, 2018
  14. Ravi

    Ravi New Member

    All has been said so far, but how could the paper have been accepted for publication? I cannot imagine the whole board reviewing the paper all agreed just like that?

    Found the peer-review history:
  15. Clouds Givemethewillies

    Clouds Givemethewillies Active Member

  16. marrowmonkey

    marrowmonkey Member

    Why would anyone try to publish such a spectacularly weird result without first confirming it with other measurement instruments/methods. Anyway, remarkable new findings, even if published in a renowned peer reviewed journal, are most likely just noise.
    Was this picked up by any mainstream media? It is unfortunate when that happens since it can undermine the public's confidence in the scientific process. Not until you have several independent teams coming to the same conclusion do you have a result.
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  17. Ravi

    Ravi New Member

    It is striking the group that made the findings, does not FIRST question their data, but directly concludes that it must be the light/atmosphere and not a faulty spectrometer and/or wrong measurement method. When there is huge "database" of measured spectral solar data, originating from many places on earth, measured with all kinds of different instruments, would it not be scientifically correct to doubt your strange findings?
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  18. Flint

    Flint New Member

    I agree that stray light is the most likely cause of their short wavelength values. I saw one comment speculating that the journal might retract the paper. As the senior author of the comment on the original D'Antoni paper (ref #28 in the Herndon paper), I naively thought that, by submitting that comment, the journal would think of retracting the paper. However, the editor was remarkably aloof and uninvolved in the controversy, and D'Antoni was permitted to publish a response to my comment (#29), and that was the end of things. The D'Antoni paper had been profiled by Nature Geosciences, and I couldn't get any response from them either. Any ideas how we should proceed with this paper?

    One other criticism of this paper is the photo of the tree in NYC. Classic "southwest winter injury." Ask a plant pathologist - I did. On a clear, cold winter day there is enough sunlight (very little UV) which thaws the vascular tissue just under the bark. Sun sets, goes behind a building, etc and the temperature drops quickly, refreezing the vascular tissue. Enough times during a winter and damage as seen in the picture results. That's why orchardists and horticulturalists paint trunks white or wrap them in white paper or perforated white plastic. I do that on my own fruit trees.
    Last edited by a moderator: Apr 13, 2018
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  19. skephu

    skephu Senior Member

    I don't think the journal would retract it, as the publisher seems to be one of those predatory types. However, they would probably publish a commentary, like they did previously with another paper by Herndon:
    Hopefully they would not charge a fee for a commentary paper.
    Wow, that's very interesting, and useful info.
  20. Clouds Givemethewillies

    Clouds Givemethewillies Active Member

    There is a review of ozone absorption cross sections here:
    eg. figure 5 and figure 6. ozone CS.PNG
    The absorption must increase towards shorter wavelengths until about 250nm. so there is no chance of the UVC at ground level increasing towards shorter wavelengths anywhere between 300nm. and 250nm. regardless of ozone concentration.
  21. Mick West

    Mick West Administrator Staff Member

    Metabunk 2018-04-13 21-30-08.

    Or given that it's in New York City, perhaps it's classic "bike lock injury". There's quite a few possible causes of tree injury.
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  22. Clouds Givemethewillies

    Clouds Givemethewillies Active Member

    And here is a handy converter to atmospheric transmittance, just in case anybody thinks it is proportional.. Looks about right to me, but Mick, or others can check. Transmittance v X section.PNG

    Attached Files:

  23. Ravi

    Ravi New Member

    Handy, but the transmittance of course depends on a lot more then only O3..

  24. Clouds Givemethewillies

    Clouds Givemethewillies Active Member

    ..but nothing attenuates quite like O3 between 300 and 250nm.
  25. Ravi

    Ravi New Member

    I agree here. I was not specifically talking about UV, so both our statements hold. :)
  26. Ravi

    Ravi New Member

    I found a great link explaining what I thought was indeed the case: the stray light on the ccd detector due to the compact design of the spectrometer.
    The link is from a competitor spectrometer company, but the specifications are the same: the Czerny-Turner Spectrograph.
    I used a similar one from OceanOptics, they are really great! But, when not aware of the limitations, it can cause errors.
    What happens is that the light from the grating, because it is a folded design, cannot be properly "baffled" to prevent stray light from hitting the detector.
    This is why compact spectrometers are more suitable for 400-1000nm. UV is tough.

  27. Clouds Givemethewillies

    Clouds Givemethewillies Active Member

    Another way to skin a cat. Don't know if, or how, they got it wrong as I can't see enough details. Capture.PNG
    https://books.google.co.uk/books?id...gUQ6AEIUDAI#v=onepage&q=KCl EU2+ UV-C&f=false
  28. Mick West

    Mick West Administrator Staff Member

    I have oak trees, and this morning it looked like one of them was on fire, with smoke pouring out of it.

    From the other side of the tree the "smoke" was invisible:
    Metabunk 2018-04-17 08-29-25.

    Of course it was just condensation, steam evaporating off the warming tree in the sunlight, and then condensing in the cold air, then evaporating again as it mixed more. We had a slight frost last night. You can quite easily understand how this cycle of freezing and sunlight can lead to injury on the sunward side.
  29. deirdre

    deirdre Moderator Staff Member

    yup. wilt disease kinda looks like that.
    wd2.JPG wd.JPG

    or woodpeckers

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  30. Fromage

    Fromage New Member

    Looks remarkably like a dead tree.

    Taking a photograph of a street tree under such horrid planting conditions as some conclusive proof of anything other than tree stress (or already being dead) is ludicrous.
  31. David Coulter

    David Coulter Active Member

    Sorry, I missed this thread when posted. I work with ground and airborne spectal radiometers all the time. I think Mick got the correct answer at the opening of the thread. Measurements outside the reliable wavelength response of a sensor are suspect. The radiometer setup is also preposterous as it should be aimed at a flatfield reflectance target, e.g. a Spectralon plate. I tend to blame instrument companies that record data outside the region of good signal to noise (SNR) of detectors. I have seen this in long wave (FTIR) instruments that are good in the 9-14 micrometer range but provide measurements down to 2 micrometers wherein the measurements are meaningless using FTIR technology and SNR is in the single digits. I also noted that "sciencedomain.org" is listed in Bealls List of Predatory Journals and Publishers as a pay to publish online journal (https://beallslist.weebly.com/). I have been asked to peer review at some of these dubious journals in fields totally outside my core scientific knowledge.