When Eruptions Don’t

Guest Post by Willis Eschenbach

Inspired by Richard Keen’s interesting WUWT post on using eclipses to determine the clarity of the atmosphere, I went to the website of the Hawaiian Mauna Loa Observatory. They have some very fascinating datasets. One of them is a measurement of direct solar radiation, minute by minute, since about 1980.

I thought that I could use that dataset to determine the clarity of the atmosphere by looking at the maximum downwelling solar energy on a month by month basis. I’ve described my method of extracting the maximum solar energy from the minute by minute data in the appendix for those interested.

Now, according to Dr. Keen, the air is cleaner now than it’s been in a while:

“Based on the color and brightness of recent eclipses, we can say that Earth’s stratosphere is as clear as it has been in decades. There are very few volcanic aerosols up there,” he explains.

Now, the Mauna Loa Observatory (“MLO”) is a great place for taking measurements of a variety of things. Located at an elevation of 11,135 feet (3,394 m), it is above the low-lying clouds (although not all clouds, it gets snow …).

So what it is measuring is basically what Dr. Keen is measuring, the clarity of the upper part of the troposphere and the stratosphere above that. Any aerosols in the stratosphere will cut down on the maximum amount of sunshine that makes it through. With that as prologue, here is the record of maximum sunlight at MLO.

average max solar mauna loa with volcanoes.png

Figure 1. Maximum sunshine, month by month, at MLO. Vertical colored bars show a 2-year period starting at the eruption dates of the two volcanos, El Chichon and Pinatubo. Values are in watts/metre squared (W/m2).

To start with, we can see that whether Dr. Keen is right on a global basis about the atmosphere being as clear as it has been in decades, it is certainly not true at MLO. Other than after the volcanic eruptions, the clarity of the atmosphere is unchanged since 1980.

However, I had a deeper purpose. My theory, as I have discussed many times, is that the clouds respond to changes in total forcing in such a manner as to oppose them. Given that, I wondered what I could determine about what happens at MLO after big volcanic eruptions of the type shown in Figure 1.

To investigate this question, I looked at the minute by minute maximum solar energy and compared it to the average solar energy. I divided the dataset shown above into two parts—the two 2-year volcanic sections shown as vertical colored bars in Figure 1, and the rest of the data. Figure 2 shows just the part of the dataset that does not contain the eruptions. It lays out both the maximum solar energy and the average solar energy after losses due mostly to clouds.

daily max avg solar mauna loa no volc.png

Figure 2. Average minute-by-minute evolution of the daily maximum and average solar radiation at MLO.

Fresh powder snow in the Hawaiian Islands, what’s not to like? But I digress …

In Figure 2, you can see how the clouds start building up in the morning. By one in the afternoon, they are knocking the instantaneous solar radiation down to about 700 W/m2 from the morning peak about 1,100 W/m2

Now, that’s interesting in itself … but what is more interesting is what happens after a volcanic eruption. Figure three shows the same data as in Figure 2, with the addition of the maximum and average solar energy during the two-year period after each of the volcanic eruptions.

daily max avg solar mauna loa.png

Figure 3. As in Figure 2, with the addition of the maximum and average solar energy values for the two-year period following the eruptions of El Chichon (orange) and Pinatubo (yellow).

For me, the best part of doing scientific research is when I get surprised by my first view of the data. In this case what was surprising was how very similar the results of the two volcanoes were. Despite the difference of the size and location of the two eruptions, both the maximums and the averages of solar radiation after the two eruptions are very nearly identical … go figure. It makes me think that over a certain point, the stratosphere somehow maxes out and doesn’t cut out any more light.

As expected, the maximum energy making it through the upper atmosphere is significantly lower during the volcanic periods. And the averages were smaller as well. The average downwelling total solar radiation (direct and diffuse) was about 24.5 w/m2 less during the volcanic periods than when there were no volcanos.

So … how did my theory fare? My theory predicts that during the volcanic periods, the clouds would rearrange in order to cut out less sunshine, opposing the effects of the volcanic aerosols.

And in fact, this is exactly what they did.

During the time when there were eruptions, the clouds prevented the period from about 11AM to about 4 PM from decreasing at all … in fact, around 1PM the solar input during the volcanic periods was actually larger than during the non-volcano periods.

If the same percentage of sunlight had been cut out by the clouds during the volcanic periods as when there were no volcanos, instead of an observed loss of 24.5 W/m2, we would have expected a loss of 31.3 W/m2. This means that the rearrangement of the clouds increased downwelling solar radiation by about seven W/m2 …

However, despite the countervailing action of the clouds, there was still a significant loss of radiation, about twenty-five watts per square metre (W/m2). How much is 25 W/m2? The IPCC says that a doubling of CO2 will cause an increase of 3.7 W/m2. So to get the 25 W/m2 change seen during the eruptions, the CO2 would have to go from the current 400 ppmv to 43,250 ppmv …

So what difference did the loss of 25 W/m2 of sunshine make to the local temperatures? Now that’s an interesting question, and one which we can answer. The MLO also has taken temperature readings over that period, so we can compare apples to apples. Here is the result:

mlo temperature anomaly.png

Curious, huh? On average the MLO site received a full 25 W/m2 less solar radiation for an entire two years, and the temperature was unchanged …

I thought, well, maybe I’m reading things wrong. So I went and got some other temperature records from the Hawaiian Islands, because since MLO received less solar energy, all of Hawaii would have received less solar energy … here are the records that cover the times in question. Some don’t cover all of the volcanic periods, but there’s enough data to see if the eruptions actually affected the temperature.

I looked at other Hawaiian Island stations from the nearest to MLO to the furthest. Here’s the nearest station, Hilo, on the same island as MLO. It doesn’t contain the entire El Chichon record, but there’s enough there to see it didn’t cool down during the first year after the eruption. And there was obviously no effect from Pinatubo.

hilo temperature anomaly.png

Next, here’s the record from Molokai, a couple of islands over from MLO … no effect from either eruption on Molokai Temperatures.

molokai temperature anomaly.png

Next, Barber’s point on Oahu … same story. No effect.

barbers temperature anomaly.png

And finally, at the far end of the Hawaiian Island chain from MLO, here’s Lihue, on Kauaii. Like the other stations, Lihue apparently didn’t get the memo about the 25 W/m2 reduction in solar radiation …

lihue temperature anomaly.png

So … why was there no reduction in the temperatures anywhere in the islands from that large a change in forcing? That one is easy to answer …

I don’t know, and I doubt if anyone knows.

After all, in mainstream climate science it is accepted as an article of faith that the reduction in solar energy will and must cause a fall in temperatures … I’m the only person I know of who is heretical enough to seriously question this dogma. See, e.g. my posts called “Volcanic Disruptions” and “Missing The Missing Summer“.

My theory is that the climate system is not like a pool table, where you can calculate from the force applied to the cueball precisely how the other balls will move. Instead of being fixed, the climate system responds to any change in conditions in a number of ways, both seen and unseen. And following both the Constructal Law and Le Chatelier’s Principle, the changes all tend to restore the status quo ante.

But hey, that’s just my explanation why neither Pinatubo nor El Chichon affected Hawaiian temperatures. If someone else has a better idea why a drop in the amount of solar radiation reaching the ground of some 25 W/m2 for two years hasn’t affected the local temperatures, I’m all ears.

[UPDATE] Commenters asked about something I’d considered, whether it was a change in the wind speed that had affected the temperature. It appears that the answer is no.

average daily wind speed mauna loa

The difference between eruptions and no eruptions is well within the uncertainty of the data.


A foggy morning here. We’re six miles from the coast, and despite how far it is, the sea breeze brings me the distant sound of the surf and the foghorn on the breakwater … this is assuredly the most audacious and finest planet I’ve ever lived on.

Best wishes to everyone, my thanks to Richard Keen for setting off this train of thought,

w.

AS ALWAYS: I ask that when you comment, you quote the exact words you are referring to. This lets all of us be crystal clear about just who and what you are talking about. Can’t tell you how tired I am of comments that start with “You are …” when I have no clue who the “You” in the sentence refers to. Makes me want to tell the kids to get off my lawn …

DATA: The Hawaii temperatures are from GISS

The MLO data is available by FTP from here. Big files, because the data is taken every minute.

The MLO meteorological data (temperature, wind, pressure, etc.) is available by FTP from here. There is both minute and hourly data, I used the hourly data for the graph above.

There is also downwelling longwave data there … but unfortunately, it doesn’t start until 1994 … rats …

METHODS: The MLO solar radiation data is in two versions in different years—every three minutes in the early version and every ten minutes more recently. I first converted them all to ten-minute intervals, in part to reduce dataset size.

There are a couple of datasets of interest, the direct solar and the diffuse solar values.

For each month, I calculated the maximum and the average direct solar values for each ten-minute interval. Then, I took the time of the maximum direct solar, and I extracted the diffuse solar for that instant. That gave me the maximum total direct solar, plus the corresponding diffuse solar values.

Once I had the direct and diffuse maximum and average values I divided the datasets into volcano and no volcano sections by removing the data from the date of each eruption and for two years afterward. This let me compare average values for when there were and were not eruptions and their aftermath.

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139 thoughts on “When Eruptions Don’t

  1. Interesting post. I would have expected a clear effect on temperature from major eruptions, and there wasn’t one.

    • Tom Halla:
      On the other hand, Wordfortrees.org plots of average anomalous global temperatures for both GISS and Hadcrut4 clearly show a temperature decrease of about o.2 deg C. for both volcanoes.
      So why not over Hawaiii?

      • Hawaii are islands in a warm ocean. It takes a long time for an ocean to cool of significantly.

        • Exactly. We’re talking about Islands here far from any continental land mass with constantly changing generally warm waters around them. UAH shows noticeable drops in global temperature for the period after Pinatubo. So it would seem to me that SSTs around the islands would have a lot to do with the temps being recorded there.

        • I don’t believe that an ocean takes two years to cool off. Second, what happened to those 25 W/m2? It probably heated the atmosphere before it got a chance to heat the surface.

      • Burl,
        That’s within the margin of error for the instruments being used, so a 0.2C difference is not significant.

    • ” GISS and Hadcrut4 clearly show a temperature decrease of about o.2 deg C. for both volcanoes”
      It’s basically the noise that gets averaged out over many stations. A variation of, say, 0.2°C is very obvious in the global average, where year-year variations of 0.1°C (as in 2016) stand out. But a single site like Hilo has year-year variations of 1°C or more.

      • The noise cannot get averaged out over many stations – unless you can somehow prove that the noise is identical at each station and attach time of measurement.

        Measuring the same thing many times is not the same as measuring many different things.

  2. Hi Willis, is there any data available about incoming solar energy near the base of Mauna Loa, near sea level?
    If clouds are responding to counter change to incoming solar radiation, the response should be more pronounced at sea level than at Mauna Loa which is above much of the cloud cover.
    For what its worth I think you’ve made the case – the lack of temperature response is a good indication that some feedback is damping the temperature response to change in forcing. But it would be interesting to see how much low level clouds contribute to this response.

      • … lack of data is one of the biggest frustrations of working in climate science.

        That doesn’t seem to stop a lot of “climate scientists”. When you only have a few actual reporting stations in large areas of the globe like the arctic or central Africa, you just make it up (although they call it modeling).

        • Really, Just take the temperature of San Diego and propagate it into a 5000K x 5000K grid cell then project it over Hawaii. Isn’t that what Climate Science is all about??

    • Eric,
      The temperature data from Molokai, Oahu, and Kauai are almost certainly at lower elevations than MLO, and they appear (to me) to show lowered temperatures during the El Chichon event;

  3. Willis – great article! Thanks!
    However in the paragraph beginning “However, despite the countervailing…” just above unmarked Fig4, you mention “eclipses” when I guess you actually meant “eruptions”.

  4. Is there a seasonal signal? UK sunshine shows a big change in winter sunshine, not so much in summer.
    Is there a change in wavelength? UV penetrates deeper into ocean.

    • Sunshine, Mauna Loa is at about 19°N, so it’s in the tropics where summer and winter are not that different. As to the wavelengths, I don’t know of any spectrally resolved data. However, I assume that there would be a change in frequency from the presence of the volcanic aerosols.
      w.

  5. Thank you, Mr. E, you have a knack for writing with clarity
    One question came to my mind. The Hawaiian islands are surrounded by warm
    water. Heat spontaneously always flows towards cold. To maintain the “equilibrium” could the ocean have released heat to, perhaps, counter any potential cooling from volcanic aresols.

      • Willis, as we all know, water is much slower to cool than the atmosphere, so it is understandable that Hawaii would not see much change in temperature over just 2 years. The Pacific Ocean is something of a near neighbour to Hawaii, after all.
        Now a site in the central parts of North America, Europe, or Asia would very possibly show a different response in the same time-frame..

      • Thanks, Ray. In fact, the ocean warms and cools by quite a bit, several degrees per month. I just ran the numbers. In the Hawaiian waters, over the course of six months the average surface solar input changes by about 100 W/m2 and the ocean temperature changes by about 16°C … that’s about 4°C for 25W/m2 in six months.
        Given that we had a 25 W/m2 difference that lasted for two years, a clear dip in the ocean temperature greater than 4°C should have occurred.
        w.

  6. Given your findings that the clarity of the atmosphere is unchanged since 1980 (barring the eruptions) what might be causing Dr Keen’s observations of apparent clearing over time?

      • To clarify, so to speak, the point of my study is that the average aerosols since 1995 are less than the average for the 15 years before, i.e., the stratosphere is overall more clear.
        The quote from the Spaceweather article:
        http://spaceweather.com/archive.php?view=1&day=24&month=05&year=2018
        “Based on the color and brightness of recent eclipses, we can say that Earth’s stratosphere is as clear as it has been in decades. There are very few volcanic aerosols up there”
        does not say it’s *clearer* now than at some times prior to el Chichon and Pinatubo.
        The colorful poster does say:
        “… the global volcanic AOD remains at very low levels. A 22+ year period of a relatively clear stratosphere therefore continues, and is the longest such stretch since 1837- 1862. The stratospheric impacts of several climatically insignificant volcanoes during 1996-2018 are identified. There is no trend in AOD over this period, ruling out volcanoes as a contributor to the stable global temperatures during 1998-2015. Compared to the volcanically active period 1980-1995 (el Chichon and Pinatubo), the clear stratosphere since 1995 has contributed an increase of radiative climate forcing equal to that due to increasing greenhouse gases.”
        There is no contradiction between my eclipse data and the MLO data, and the big thing in both observed data sets is the ongoing 22+ year stretch without major volcanic events.
        So w’s statement that “Other than after the volcanic eruptions, the clarity of the atmosphere is unchanged since 1980” misses the entire point of my article, which is about those volcanic eruptions (and the subsequent lack thereof).

      • Richard Keen May 29, 2018 at 11:31 pm

        To clarify, so to speak, the point of my study is that the average aerosols since 1995 are less than the average for the 15 years before, i.e., the stratosphere is overall more clear.

        Richard, thanks for the comment. Of course the average aerosols are less since 1995 than in the previous 15 years, when El Chichon and Pinatubo erupted.
        In any case, the year 1980, before either El Chichon or Pinatubo, was as clear as the recent years.
        Finally, after both Pinatubo and El Chichon, the stratospheric aerosols were completely gone after a mere two years … so I find it difficult to believe that there was something that lasted for “decades” prior to those much larger eruptions.
        Next, you say:

        The stratospheric impacts of several climatically insignificant volcanoes during 1996-2018 are identified.

        There is absolutely no sign in the MLO record of the eruptions that you identified as having a “stratospheric impact”. Nor is there any sign of them in the UAH MSU Stratospheric Temperature record, which like the MLO record sensitively recorded the El Chichon and Pinatubo eruptions.
        https://i0.wp.com/wattsupwiththat.files.wordpress.com/2018/05/stratosphere-temperatures-and-volcanoes.png
        I see nothing but random fluctuations there, nothing of note.
        Best regards,
        w.

      • Mr Eschenbach, I think that there may be a couple of points about whether or not the Volcanoes have an effect.
        Fiirst of all Soufriere appears to have continued a downward trend.
        Whereas Ulawan on it’s own had no effect but when Reventador is added temps dropped.
        Like Soufriere, Rabaul also continued a downward trend.
        Puyene appears to have had no effect whereas Calbuco does.
        So could it be a combination of the “Content” of erupted material, the height that the material gains, the prevailing winds and therefore how quickly and how far the material gets spread?
        I also do not see Eyjafjallajökull on your chart, it certainly affected Europe, but I am not sure about world wide.

        • It takes a particularly short high-energy vertically-directed explosive impulse to project the particles and gases above the top of the troposphere. The other explosive eruptions, although very impressive, were weaker and achieved much lower altitudes.

      • @A C Osborn:
        You seem to be putting the cart before the horse by claiming that volcanic eruptions “cause” both heating and cooling without advancing empirical data to support the claim that the characteristics of the eruptions might be the root cause. We await your actual analysis with interest.

      • I’m sorry, mate, but I think you must have confused Farenheit when you said Hawaii water cools 16°C.
        No way does it cool that much in winter. Unless it is due to cold fresh water entering in the rainy season at the sight. Temperatures would range from 30-31°C to 21-24°C. People surf in boardshorts all year. There is no cold current in winter.
        Summer is hotter at 19°North than it is ever on the equator. The sun is just about directly overhead for about 50 consecutive days, twice as long as it is when passing over the equator. On the 27th of May the sun is a week away from being overhead. June 3rd it is directly overhead. June 20th it is 4.5° off being overhead. 17 days later it is directly overhead again. A week later it is 2° from being overhead. It is still mid summer.
        Can you see that in the readings? Does that shine light on anything?
        Like you, I don’t know. Maybe Tradewinds off the warm water keeps the air warm. Also, a lot of latent heat gets emitted when the moist surface air gets blown up the mountain into the cold where it condenses. Whatever it is, it is probably local, as a point of where to start looking, because the world did cool due to the volcanoes.

  7. Hmm.. I guess I have accepted the dogma that a major eruption is followed by 1 or more cool years. I need to go back and look at those studies again.
    Now I am wondering if Hawaii is insulated from such temperature dips due to the ocean surrounding it, acting as a temperature change buffer – seems reasonable. Or are the temperature dips an artifact of how they calculate the global average? For example, if a volcano impacts a temperature station that is used to fill in a large area, then it the volcano will seem to have a bigger impact than it really does.
    And I am wondering what the satellite data says about the same island over the same time period. This would be very interesting if you have found a divergence in computed satellite measurements versus recorded land data.

    • I would have to agree with the possible buffer item Robert. I would also wonder about the same measurements from other locations performing the same type of measurements as Mauna Loa during that time? Who else does what they do at Mauna Loa for comparison Willis? We surely don’t have all that data coming from just one basket….. I know, get on my mouse and go find it 😉

    • I wouldn’t be surprised if you are right about the impact of in-filled temperatures that are extrapolated to cover a large area. This is the fundamental reason that all of the earth-based measurements are utter nonsense and the global temperature trends of GISS, HadCRUT, etc. should not be used. Manufacturing data out of thin air is statistical prestidigitation, not science.
      The proper way to measure temperature trends over time is to compare each station to itself to determine a trend then perhaps average all those trends to come up with something approximating a reasonable picture of a global trend. In-filling is chicanery, the whole chicanery, and nothing but chicanery.

      • “The proper way to measure temperature trends over time is to compare each station to itself to determine a trend then perhaps average all those trends to come up with something approximating a reasonable picture of a global trend.”
        Virtually all our knowledge of the world is based on inference from samples. We can only measure finitely many things. Was the US cold in April? We only have a finite number of measures.
        This “proper way” is also sampling. You calculate trends in a finite number of places, and average trends to get a global. No different to averaging temperatures, and would give, as a matter of arithmetic, a fairly similar result.

    • Robert of Texas May 29, 2018 at 7:58 pm

      And I am wondering what the satellite data says about the same island over the same time period. This would be very interesting if you have found a divergence in computed satellite measurements versus recorded land data.

      Well, I suppose I should make this one a them “teachable moments” that the glitterati are always raving about …
      Start by going to the KNMI Climate Explorer. Click on the “Monthly Observations” link under “Select A Field”.
      Then scroll down to the “Lower Troposphere” section and click on the “1979-now: Spencer & Christy” link for Version 6.0.
      When the next page comes up, fill it in like this:
      https://i0.wp.com/wattsupwiththat.files.wordpress.com/2018/05/knmi-msu.png
      and click on “Make Time Series”. It will come up with a graph of the requested data from that area. Of course, being me, I figure that’s not good enough. I click on “Raw Data” under the graph, download the data, import it into R, and put it into a more meaningful and hopefully beautiful form as follows:
      https://i1.wp.com/wattsupwiththat.files.wordpress.com/2018/05/uah-msu-hawaii-eruptions.png
      No response to the solar change. Zip. Zero.
      w.

      • Really good article. Thanks.
        I just wondered that the Corialis Effect might have kept the air clear over Hawaii.
        Maybe check Southern Hemisphere temperatures during the volcanoes. Maybe only the North cooled, affecting average global temperature.

    • On ocean buffering – an interesting research project. Not for me, unfortunately, I have not the time to run a filter through my database on good stations that are not where they might be buffered. (It does have lat/long info, but I’d have to figure some kind of rather nasty spatial bounds for the filter).
      I can say, just looking at just one of the definitely unbuffered good stations (Tombstone, AZ) that any effect is definitely overshadowed by other weather patterns. El Chicon shows a -0.71 degree change in the annual mean 1982-1983 – but Pinatubo shows only a -0.05 degree change 1991-1992. (And post-Pinatubo, Tombstone’s annual mean was 2.0 degrees higher in 1993.)
      Oh, before I have to self-reply yet again – those are Fahrenheit. Business school stats class presentation, they would not have grokked Celsius. Although I do remember that I was tempted to use Kelvin at the time, to see if any of them actually were listening…

  8. The atmospheric transmission measurements at Mauna Loa Observatory form the longest data series at this premier site, even longer than the temperature series, which is fragmented in the early years. The measurements are made with an Eppley normal incidence pyrheliometer radiometer mounted on a sun tracker. The first system was installed by Jack Pales in the fall of 1957. Identical Eppleys are still used today. They are mounted on a tracker at the southeast corner of the solar deck. Extracting the atmospheric total transmission is tedious, for absorption by the water vapor column must be accounted for. There are subtle seasonal changes in the data caused mainly by dust and air pollution from Asia. While the stratosphere is currently very clean, there has been a slight reduction in transmission during the past several years. This has been discussed in the literature. The most likely reason is increased emissions from China. I have calibrated dozens of sun photometers and Microtops at MLO each summer for the past 25 years. During this time I have observed, measured and photographed a wide variety of aerosol events. I described the Eppley transmission measurements in “Hawaii’s Mauna Loa Observatory: Fifty Years of Monitoring the Atmosphere (University of Hawaii Press, 2012). I’ve lived at MLO some 229 days and nights. In 2016, NOAA hired me to calibrate the world standard ozone instrument (Dobson 83). This project required living at MLO for 64 days. I’ll be back later this summer to assist in conducting a major UVB survey of Hawaii Island.

  9. And what do the climate models predict in response to volcanic eruptions? Big dips in temperature – mmmm

  10. Not quite sure I understood. Are the maximum just spikes where little extra energy is added to the monthly average? You could then explain the results as patchiness of the cloud cover (then as it is).
    In the maximum plot, it appears, from the change with time, that you are less likely to get a very large spike with a greater path length (is this the case in winter?) and a drop in the average because of fewer spikes. The average also drops as there is more cloud forming at high altitudes as the day progresses. Very patchy though so less of an effect on the magnitude of the largest spike.
    The volcanic aerosols seem to affect the probability of getting a large spike, reducing the chance of a very large one and reducing the number so having an effect on the average. At 12 noon, the lower path length means that the very large spikes are less likely to get through but little reduction in the average, so the overall number getting through is still large. A bigger effect in the mid morning and late afternoon. A postulate (not theory) is that what seeds cloud formation differs a lot on patchiness depending on the mechanism.
    Really need to see the data spit into seasons, especially comparing months of mid winter with those around the spring equinox (or 60 days centred around it).
    After another 2000-3000 m of cloudy atmosphere, these spikes from clearer sky above are lost in the extra cloudiness but it would be interesting to see the if there is an effect on mid morning and late afternoon temperatures rather than mean of maximum and minimum. This could have a bigger effect on agriculture than the “climate” (mean of min and max).

  11. “quod erat demonstrandum” on the the climate temperature ‘governor’ Willis! Something like this fine article gives a sad demonstration of the lazy linear thinking of the mainstream consensus ‘science’.
    I recall you raising a similar point regarding the increase in solar insolation between the apogee and perigee of the earths orbit. The difference is greater than that from the 11yr solar cycle maxima and minima and yet the temperature record does to respond.
    I would say you have the makings of an article here that would strike the consensus dumb. If the earth can resist temperature increases with increased insolation, why not with increased CO2.

  12. Willis you said
    “There is also downwelling longwave data there … but unfortunately, it doesn’t start until 1994”
    It would be interesting to know how that downwelling longwave data looks like. Any trend?

  13. If daytime max incoming energy is reduced due to particulates I would think nighttime outgoing energy could also be reduced. This might lower the Max/Min temperature gap without showing much of a change in daily average since the highs might not be as high nor the lows as low. Might be too small to tease out of the Max/Min temperatures though due to variance caused by other natural processes.

  14. @Willis- I was wondering about the land station measurements of insulation last week. So your article is very timely and I appreciate it.
    You said- So … why was there no reduction in the temperatures anywhere in the islands from that large a change in forcing?
    I would claim while waving my hands wildly that the loss of solar forcing was sucked out of the ocean to make up for the difference.
    This is the document i found looking for ground Station solar insolation. It looks like one chart shows a cooling trend from 2000 of about 10 watts per meter squared per decade. So after this Micro Ice Age We may just keep stair stepping down for the next four thousand years. Stay tuned.
    from satellite and ground measurements: Comparisons and challenges
    Laura M. Hinkelman Paul W. Stackhouse Jr. Bruce A. Wielicki Taiping Zhang Sara R. Wilson
    First published: 15 August 2009
    https://doi.org/10.1029/2008JD011004
    Sandy minister of future

  15. Interesting data and a surprising result from your analyses, Willis!
    The largest Pinatubo eruption was coincident with Typhoon Yunya, the center of which passed about 47 miles north of the mountain. My conjecture is the heavy rains and winds associated with the typhoon ‘knocked down’ the height of the eruption plume through direct winds shear effects as well as rain transport of significant amounts of fine particulates and sulfur compounds to the ground/ocean. This reduced the impacts on high atmospheric transparency, making the net results closer to those of the El Chichon eruption.
    I’m a bit puzzled why the Mount St. Helens eruption in May 1980 do not show in the MLO data??!

      • And to boot, MSH had low-sulfur magma, while Pinatubo – and especially el Chichon – were high sulfur.

      • “And to boot, MSH had low-sulfur magma, while Pinatubo – and especially el Chichon – were high sulfur.”
        Answer to Willis’s question of why the 2 different volcanoes had similar effect even though they were different in magnitude?

  16. Are there wind speed/direction records matching your data Willis? Low and High Pressure systems moving heat around to stabilise?
    Like going down a rabbit warren when you start to contemplate all the different inputs to the system.
    Plus the erratics, volcanoes, earthquakes, meteors.
    Can you put this into your thunderstorms to show the results over time?
    Warren in New Zealand

  17. Question…isn’t direct solar irradiance including visible wavelengths that don’t cause heating? Meaning, the irradiance drops due to light reflection back in to space, but that drop in irradiance isn’t ALL energy that warms the earth…
    If only some fraction of total direct solar irradiance causes heating, then only the reduction in that fraction would have a cloud feedback effect. What is that fraction, and what is the reduction in that fraction? I don’t know, but gosh wouldn’t if be interesting to find out that the aerosols from the volcano eruptions only reduce heating irradiance by about the same amount your cloud cover decreased…
    I guess the missing down selling infrared info would have answered that?
    Thanks,
    Roland

  18. Since becoming enlightened just over a year ago (i.e no longer buys the ‘it’s all because of us’ dogma) I’ve developed a keen interest in Climate Change & whilst I do not yet have sufficient knowledge to offer an opinion on your findings, I want to thank you for having written it in such a readily understandable way that lay-people like me can continue to broaden our knowledge and think for ourselves

    • Thanks, Clare. My objective is exactly that—I envision my target audience as the “interested layperson”, someone who is fascinated by the world but may not have extensive scientific knowledge.
      Best regards,
      w.

  19. i wonder if the answer doesn’t lie in wind speeds. If the sun light increases in the islands, the ensuing warmth would create lower pressure which would in turn make for stronger walker cell trade winds (and visa versa). Walker trades follow the sun and, as such don’t kick up until the late morning/ noon hours. It would be interesting to see a comparison of temperatures in the islands as they evolve throughout the day. That might be the clue to the answer to the question at hand. (iow, book ’em Dano!… ☺) Looking at figure #3, it sure seems plausible. The greatest difference in solar radiation occurs during those morning hours when skies are clear and winds are calm. Keep in mind that those trade winds blow from east to west which means they are moving cooler air in the east to the west…

    • Fonz, I’ve wondered about the wind as well. A reduction in wind speed could be involved. Fortunately, I have the data, and it was next on my to-do list … well, after I fire up the weedwhacker and cut the grass on the lower acre. I’ll report back on the wind question when I can get to it.
      w.

      • Willis, hard to say how much walker trades affect wind speeds at 10,000+ feet. If they are mostly a surface phenomonon, then the data to look at would be winds at the surface. Most folks don’t realize that walker trades are not constant (like hadley trades), but only kick up in the hours around mid day, thus following the sun. And when they do, they’re rather strong. A difference might show up in those much higher wind speeds at the surface than high atop MLO (which may or may not see any effect from walker trades at all)…
        Sorry, if my comments seem a little half baked here. i used to live on the kehei coast of maui and always like wading into the conversation when the pacific region comes up (even though i don’t know my backside from a cinder cone when talking about it… ☺)

  20. The answer to the apparent conundrum is that the temperature is set by insolation reaching the top of the atmosphere and not the proportion that reaches the surface.
    Convection and conduction within the atmosphere always change to neutralise any radiative imbalances between atmosphere and space by adjusting the energy exchanges within the atmosphere and between surface and atmosphere in an equal and opposite direction.
    It works even when there is no water and no clouds but clouds in a water world do show up the processes in action.
    Thus the so called greenhouse effect is a consequence of atmospheric mass conducting and convecting within a gravity field and not a consequence of radiative imbalances.
    Stephen Wilde

  21. Willis,
    You are missing one key point: Both El Chichon and Pinatubo eruptions happened during strong El Nino. Thus, if you are assessing the effect of these volcanic eruptions, you need to consider the effect of simultaneous El Nino.

  22. Any science advisor to a President’s committee on climate change needs to read this. Remember how Obama’s Science Czar Holdren wanted to pump sulfur into the atmosphere to prevent warming? Doesn’t look like it’s going to work. It would be wasted tax dollars for sure.

  23. Interesting article as always, Mr E – many thanks for your endless curiosity. By the way, what is the humidity like at MLO? Its in the tropics, but at that elevation is there the same or less humidity than at sea level? Could the curious ‘no change’ effect be related at all?

  24. Interesting results indeed.
    It more or less confirms my suspicion that the amount of heat coming from the belly of our earth might be underestimated by all climatologists… You do not need a fancy GH theory to ‘make’ earth warmer. It is getting warmth enough from itself.
    However, we have to consider the fact that this is Hawaii, which is of course notoriously volcanic and might vent more a lot more heat than other places less volcanic. So, I am saying the result could be a bit biased.
    Do we have a similar observatory somewhere else?
    (I will check here in South Africa)

    • I’ve been impressed by the photos of the recent eruption and tried really basic calculations to see how much heat would have been emitted building Hawaii. I got around 400W continuously over the past million years but spread over the entire area of the island which I cheated and used 40 x 40km I think. Anyway, it was a fantastically trivial amount of heat compared to solar irradiance which just seems wrong, but I’ve found that before trying to work out the heat contribution from sea-floor spreading ridges. But of course volcanoes are nothing if not cyclical so averages over a million years may smooth things too much…
      But if geothermal heat contributions to Earth energy budget are off (or cyclical), I’d be looking in places like Greenland and Antarctica because there you can have some big changes with relatively small amounts of heat as you melt a lot of ice.
      Any temperate snow covered mountain ranges could get a big albedo shift too I suppose.
      I have always felt the dip in temps for the Pinatubo eruption was a bit of a trite explanation, sooner or later though, we’ll get another high altitude tropical eruption and this time we will all be watching the temp. Sucks to leave near them though.

      • Dixon
        I have also been looking at this eruption on Hawaii and I realized that this process is going on continuously in the Pacific- and Atlantic Rim at the bottom of the oceans. I am sure this produces a lot of H2O (g)?
        So, there is your answer why in the past many scientists thought that there must be a ‘GH’ effect.
        Even though I looked everywhere, I could not find any report giving me a balance sheet,
        i.e.
        how much energy is trapped (mainly by clouds) versus how much energy is deflected off from earth (mainly by clouds)
        So, what I am saying is that probably far too much energy is apportioned to the GH effect. Basically, there is no GH effect. My results show there is no manmade global warming.

  25. … and to continue;
    1982-1983 El Nino and 1991-1992 El Nino should have cause a similar upward peak in world temperatures as 1998 El Nino did. But instead, there was a small downward pit in the temperature record. If we assess this, the effect of these eruptions was at least 0.6-0.9 Celsius on temperature records.

    • And for Hawaii …
      “Hawaii tends to be drier than normal during the November-May period of a moderate to strong El Niño. Hawaii also tends to be warmer than normal during the October-March period in the year following such an episode.”
      https://www.ncdc.noaa.gov/sites/default/files/attachments/Pacific-Region-El-Niño-Impacts-and-Outlooks-Hawaii-2015.pdf
      So el Nino pumps up the Pacific Hadley circulation, strengthening the subtropical high, making Hawaii warmer, drier, and SUNNIER. So the compensating decrease in cloudiness that mitigates the volcanic reduction in solar radiation may be due to el Nino, in these two cases.
      Extracting truth from a sample of two can be tricky.

  26. Willis
    The link provides comment on why ozone congregates at the poles. Thickness of the stratosphere etc.
    http://www.arctic.uoguelph.ca/cpe/environments/climate/climate_future/ozone/ozone_what.htm
    Also MAK above refers to El nino years corresponding to the eruptions. During these periods there is strong upwelling at the equatorial region particularly the Pacific. These upwellings go into the stratosphere I understand, and head poleward. This would have a cleansing effect and move eruption particulate toward the the higher latitude’s.
    This may explain the limited effects at MLO.
    Regards

  27. There is also downwelling longwave data there … but unfortunately, it doesn’t start until 1994 … rats …

    The downwelling shortwave data is nonsense. It is fundamentally the temperature of near atmosphere that wrongly applies the Stefan-Boltzaman equation to arrive at some farcical radiation. Its bunkum. The pyrgeometers used incorporate a thermopile to measure temperature. They do not measure radiation despite how the data may be presented.
    Radiation is an electromagnetic field and energy cannot be transferred through that field from a lower temperature emitter to a higher temperature receiver.
    Actual downwelling IR is rare and associated with temperature inversions.

    • @RickWill said- ‘energy cannot be transferred through that field from a lower temperature emitter to a higher temperature receiver.’
      Actually it can. Consider 2 carbon spheres 1 m in diameter 4 m apart. One at 250 K, the other at 300 K. Neither is aware of the other and the radiation transmits outward from both. They will both intercept and absorb radiation from the other. They will then reradiate it.
      Sandy, Minister of Future

    • RickWill wrote, “Radiation is an electromagnetic field and energy cannot be transferred through that field from a lower temperature emitter to a higher temperature receiver.”
      Oh, good grief. More “slayer.” gibberish.
      No, RickWill, I’m sure you won’t believe me, but I’m telling you the truth: when an object absorbs EM radiation it doesn’t know or care whether its own temperature is warmer or colder than the temperature of the emitter of that radiation.
      If you live near a college or university, then please go find the physics department, and knock on the office door of a randomly chosen professor. Ask him or her about this. He’ll tell you what I told you.
      “A lie can travel halfway around the world before the truth can get its boots on.”
      – attributed to Mark Twain, and many others

    • RickWill

      You have confused radiation with conduction. Radiation is a transfer of electromagnetic energy, conduction is a transfer of energy in the form of heat. They are not the same and they behave differently. Above absolute zero, everything in the universe heats everything else in the universe. That is just how it is, and what is wonderful about electromagnetic radiation.

      Using it, you can even use energy to cool an object by cleverly controlling the energy level. That is how lasers cool gases to just about absolute zero.

    • It is quite obvious that those thinking that radiation is polydirectional do not understand fields and the Poynting vector. The linked paper might help you grasp the concept:
      https://www.osapublishing.org/oe/fulltext.cfm?uri=oe-18-19-19770&id=205485

      I have extracted the following text from the paper. You need to work through he maths to understand the conclusion.

      The traditional definition of the specific intensity in the phenomenological RTT states that 𝐼̃(𝐫, 𝐪̂ ) gives the amount of electromagnetic energy transported in the direction 𝐪̂ per unit area normal to 𝐪̂ per unit time per unit solid angle (e.g., Chandrasekhar 1950). This notion of the specific intensity implies that at the observation point r, electromagnetic energy propagates simultaneously in all directions and does it according to the angular distribution function 𝐼̃(𝐫, 𝐪̂ ).

      Our microphysical derivation of Eqs. (23) and (24) directly from the MMEs reveals that in the case of radiative transfer in a turbid medium this interpretation of 𝐼̃(𝐫, 𝐪̂ ) is profoundly incorrect. Indeed, the instantaneous local flow of electromagnetic energy is given by a monodirectional real Poynting vector 𝑆(𝐫, 𝑡) =𝐸(𝐫, 𝑡) × 𝐻(𝐫, 𝑡).

      At any point in space at a given time there is only ONE magnetic field vector and only ONE electric field vector. That means there is only one Poynting vector at that point in space at that given time so energy flows in only one direction at any time instant.

  28. Willis:
    Why does the temperature remain the same after an eruption?
    I don’t know the answer but here is a possible explanation.
    The clouds up there reducing the average radiation are boiling/evaporating and condensing at the same time.
    We all know that when we turn the heat up under the kettle it boils faster and visa versa. Also some know that the temperature (at sea level) remains at 100 C and does not alter.
    Thus when an eruption reduces the radiation (ie: turns the heat down), the rate of cloud boiling/evaporation reduces; but likewise the temperature remains the same.
    The temperature at which this happens is determined by gravity and the corresponding water vapour pressure (VP) at the resulting absolute pressure, with the actual rate being controlled by the pressure difference between this VP and the Partial Pressure of water (PP)in the atmosphere in accordance with Dalton’s Law of Partial Pressure relating to the ambient humidity at the interface.
    The result of this I expect? would be a reduction in the Albedo of the cloud formations which could match (relatively) the reduction in the radiation due to an eruption. Hence a balance in the radiation budget. All this, of course, operating in a somewhat narrow band of conditions.
    As I say: I DO NOT KNOW!
    As an aside: As both gravity and vapour Pressure are more or less relative constants the temperature at which my kettle boils will remain at 100 C, this being but one specific point on the lapse rate trace where the same applies, I am confident that so long as my kettle continues to boil at 100 C there is no danger of the Earth overheating. S’long the seas nae gang dry!
    Caveat:
    Sadly water is not very good at heating the planet should it be necessary; so getting cold is my main worry for future generations.
    As usual a brilliant thought producing article Willis. My thanks. Just wish I had your expertise.
    Regards.

    • @CogNog2 said-‘ so getting cold is my main worry for future generations.’
      That is my concern also, but more immediately, the next 30 winters.
      Up until two weeks ago I was thinking we are coming into a grand solar minimum. But I’ve reconsidered after rereading some articles on skeptic climate blogs. I now believe we entered a ‘Micro- IceAge’ in 2004 when Bob Weber’s fig.10 showed a drop in 10.7 cm solar flux, leading to ocean cooling. I’m calling this a ‘Micro’ because I don’t expect it to last more than solar cycle 24, 25, and 26. Then there will be 7 years to transition back to warmer global temps, but cooler than now, mabe 13 C; say by 2050.
      What the mainstream media is not highlighting is this last winter was the coldest in 40 years in many countries in the northern hemisphere. North Western European countries on the Atlantic coast reported last summer was the coldest in 40 Years also.
      This spring has been cold and longer than usual which will affect planting and the growing season.
      During the Little Ice Age the temperature dropped about half a degree globally. As you can see from the Delingpole essay, it has dropped by 0.56 degrees already.
      This is what we can expect starting from last Dec; some winters early and extremely cold, some wet cool springs to kill crops, later spring frost dates, some cold summers, and more frequent and severe storms. The storminess index went from 6.5 to 14 during the LIA. This slide into cold is showing up in German weather station records where the last 30 yrs of winter (DJF) are trending -19 dgC per 1000 yrs, much faster than the slow decline to normal glacials, -0.7 per thousand yrs. Also the USHCN chart of summer max for the last hundred yrs shows -13 C per thousand yrs trend. Ground Station solar insolation shows a cooling trend from 2000 of about -10 watts per meter squared per decade. So after this Micro Ice Age we may just keep stair stepping down for the next four thousand years.
      I expect in the next ten years one billion will actually starve due to crop failures*, and one billion will be eaten by stronger omnivores; feral dogs, cats, and … humans.
      Dont wait for the flames to die and rubble stops bouncing, the sooner you act, the better your chances of survival.
      Sandy, Minister of Future
      *NB- the WHO reports 800 mln suffer from hunger, 10 mln die from starvation each yr, 60 mln die from disease each yr.
      So now thats 70 mln / yr, plus more food stress, weakening immune system, more disease, amplified by cold climate / storm stress, could easily be 100 mln /yr … Thats 1 Bln / 10 yrs.
      Sandy, Minister of Future

      • My main worry is the cornbelt. The cold and drought will be similar to 87 years ago.
        That was the Dust Bowl drought.
        And 87 years before we had the droughts in 1845 that killed a lot of the bison
        …..

  29. Roy Spenser and others use a maximum forcing for Pinatubo of about -3 W/m2. http://www.drroyspencer.com/2010/06/revisiting-the-pinatubo-eruption-as-a-test-of-climate-sensitivity/
    You are discussing a change of -24.5 W/m2. Changes in solar radiation (TSI) are divided by a factor of 4 to convert them to forcing (because of the TSI is spread over a sphere with a surface area 4X larger than a disk. There might be another factor of 2 involved if you calculated an average change over daytime instead of a continuous average over 24 hour days.
    If you assume a mixed layer of 50 m, a 1 W/m2 imbalance is capable of warming the mixed layer and atmosphere at an initial rate of 0.2 K/yr. (I use the term initial rate, because – as soon as the planet starts to cool – it radiates less to space and the imbalance changes. If we assume Roy’s 3 W/m2 maximum forcing is correct, then the maximum cooling would be 0.6 K (and less if we account for the change in OLR with cooling), The natural variation in temperature at the sites you show may be masking the cooling due to volcanic aerosols.
    Also see: http://rankexploits.com/musings/2012/pinatubo-climate-sensitivity-and-two-dogs-that-didnt-bark-in-the-night/

    • Frank:

      Interesting points. However Willis was not trying to establish the magnitude of a drop in the global temperature, but the local one. If the -25W/m2 doesn’t cool things locally, why would it cool things globally?

      While Roy may be correct about the -3Q globally, it was -25W locally – from measurements, not calculations. So, where is the putative impact? The answer is the clouds compensated for it. End of short story.

      • Volcanic aerosols have a global effect because they are circulating around the world in the stratosphere. We should look for global effect. Local temperatures vary and Hawaii doesn’t represent global temperature. If there’s cooling in New York, we wouldn’t call it global cooling.

  30. Willis,
    As usual an interesting article.
    When I use my mark 1 eyeball to assess temperature changes, it would appear that there is all but no warming in most of the plots that you have set out in this article.
    It would be amusing to overlay Mauna Loa CO2 data upon the below plot.
    https://i1.wp.com/wattsupwiththat.files.wordpress.com/2018/05/uah-msu-hawaii-eruptions.png
    It would appear that Hawaii just like the contiguous US, shows no significant warming trend, as indeed is the case with Greenland and Iceland. It is remarkable that given that CO2 is a well mixed gas, there are so many places in the Northern Hemisphere that show no warming since the late 1930s/early 1940s (or in the case of Hawaii during the satellite era). I discount the Southern Hemisphere since it has no worthwhile data, and as Phil Jones so candidly pointed out, in the Cimategate emails, between the tropics and the continent of Antarctica, the Southern Hemisphere data is largely made up.

  31. Just like most data in ‘Climate Science’, we have no worthwhile historic data on aerosols in the atmosphere, and aerosol emissions (both natural and manmade)..
    Because of this, these are simply made up, and then this made up data is used as a fudge to input into the climate models because the models show far too much CO2 induced warming.
    Willis, I recall a long time ago you posted an interesting article on not being able to identify volcano eruptions from a quick look at the temperature record. Perhaps that interesting article should be linked to this present article.
    It appears that volcanoes have little impact on the temperature record and would appear to be short lived. One person who frequently comments on this blog often shows the satellite data detrended of volcanoes and ENSO and when so detrended, it shows no significant warming during the entirety of the satellite era!

  32. “So … why was there no reduction in the temperatures anywhere in the islands from that large a change in forcing? ”
    We do know that the planet cooled globally after the volcanic events. The most likely reason for the lack of discernible change in this region is either the ocean buffering effects or a reduction in low level clouds below the height of the observatory, or a mix of both. There are no other suspects in the case.

  33. Excellent work Willis. Additional evidence that Mother Gaia does not in fact sit on the knife’s edge of an irreversible tipping point. Our homeostatic home planet is an amazing system.
    I have one quibble with wording, if I may.

    My theory predicts that during the volcanic periods, the clouds would rearrange in order to cut out less sunshine, opposing the effects of the volcanic aerosols.

    Your meaning is clear, but I think it could be misunderstood by some readers as if the clouds “decide to take action” to oppose the changing conditions. Of course the clouds are a bunch of inanimate condensing water vapor with no power of agency.
    I’d suggest it’s better expressed as in the normal case with high incident solar radiation, there is a lot of evaporation leading to dense clouds. After volcanic eruptions dimmed the incident radiation, there was less evaporation, and fewer, less dense clouds formed as a result. The sun and the aerosols are the actors, the clouds are passive, right?
    If there is less evaporation, isn’t there less rain? How does that fit in the puzzle to potentially explain stable surface temperatures?

    • @Rich Davis said- ‘ I’d suggest it’s better expressed as in the normal case with high incident solar radiation, there is a lot of evaporation leading to dense clouds. After volcanic eruptions dimmed the incident radiation, there was less evaporation, and fewer, less dense clouds formed as a result. The sun and the aerosols are the actors, the clouds are passive, right?’
      In this instance I prefer Willis economy of words that ‘clouds would rearrange.’ Heh.
      Sandy, Minister of Future

    • @Rich- perhaps Mother Gaia’s clouds DO have agency. I wouldn’t be surprised.
      Sandy minister of future

    • But again, thinking through the mechanism of why there are fewer clouds that let in more warming sunlight when that sunlight is less intense, if there is less evaporation, isn’t there also less rain?
      Less evaporation from the ocean into the air gives us less water vapor and less dense clouds (and also cools the ocean less). The winds that Willis showed are not significantly changing, still blow over the island. That also makes sense doesn’t it? If the pressure is a function of the air temperature that isn’t changing, then the wind should not change either? If there is less water vapor in the clouds, is there less precipitation at the points where the surface temperature is being measured? It seems to me that when it rains, the latent heat released in condensation warms the cold air up at the cloud and the cold rain falls down through the air below the cloud and cools that warmer air until it finally equilibrates with the surface temperature. If there is less rain, then there should be less cooling of the surface and air. It could be the reason why the surface temperatures are not affected by the lower incident radiation.

      • This theory can be tested. It says that there should be less than normal rainfall in normally rainy regions after the eruptions and also that arid regions will see a significant cooling because you can’t reduce non-existent cloud cover or reduce non-existent rainfall.

  34. @Willis- I reread the article and the chart of MLO temperature chose a -1.8 just at the beginning of each eruption. Followed by a jagged rise up to +3 and +1.6. So maybe after the initial wave of particulates passed over, it subsequently got very thin globally.
    Sandy, Minister of Future

  35. HI Willis, excellent and interesting work/observation.
    Some thoughts:
    What, exactly, is being measured by the MLO instruments? I see “average solar radiation”. The incoming radiation from the sun has a distinct spectral form, then traverses the atmosphere…and ultimately affects the ground/atmosphere. Can the spectrum of the non volcanic incoming be compared to the volcanic affected period? No particular hypothesis there..just looking for change, ie data…and THEN work on a hypothesis (:)).
    How about comparing a couple “good” mainland temperature sets against the islands during the volcanic period…fraught with all kinds of problems…ie the plethora of other changing things….
    Can you look at the local affect of an eclipse? Since eclipse solar incoming attenuation is taking place outside the atmosphere (albeit for extremely short periods of time), perhaps a comparison might lead to some insights.
    How about night vs day temperature during the subject periods…ie did night temperatures not drop as much? Again, perhaps a distribution analysis of the 24 hour solar period during the eruption period vs “clear” periods.
    I absolutely love your remark…”the data surprised me.”. Aside from the scientific method, this should be a test of any real scientific endeavor..
    Best,
    Ethan Brand

    • This is where I was going with my previous question about total solar irradiance v/s actual heat produced by that full spectrum.
      A quick look online and I see that TOA irradiance is biased way more blue and green light than red and infra red. We also know that the earth reflects way more blue and green light than it does red (from oceans and vegitation). Therefore, those wavelengths should obviously have less “heating potential”, correct?
      I see lots of information online about albedo, but only as a percentage of total spectrum irradiance. It the aerosols are preferentially blocking blue green light, they obviously would have less of an impact on warming (cooling) of the planet. It also seems obvious to me that this could be the case, just from observations that close to the sources, the sky is often observed to be more reddish.
      Having said all this, we would need a albedo spectrum for the planet, subtract that from the irradiance spectrum and calculate total “effective” irradiance for non volcanic times and then the same for after an eruption. The difference between those two will be the actual energy input change between the two states.
      I have a hunch that green/blue visible light is over represented when using total irradiance as your base value. A portion of that is reflected back in to space anyway.
      Hope that makes sense,
      Roland

  36. The surface temperature of water or ice closely follows the measured atmospheric dew point/frost point because the air is saturated with water vapor at the interface. There isn’t much water vapor at the elevation of MLO but a lot of it nearer sea level around the islands. A lot more energy goes into the evaporation of water than goes into heating the atmosphere. The endothermic reaction of evaporation cools the surface of water or ice even in clouds.

  37. “One of [the fascinating datasets] is a measurement of direct solar radiation, minute by minute, since about 1980.”
    Do these datasets show any variance due to atmospheric tides? It seems to me that a ‘high’ atmospheric tide means that solar radiation (all radiation) must travel through more atmosphere than at ‘low’ atmospheric tide. More atmosphere would mean more CO2 as well right? Is there any discernable difference?

  38. This will be overly-long, so apologies in advance for being verbose:
    Excellent article, Dr. E. (even if you are not a DSc — — you write and analyze better than most that I’ve ever known [same goes for Anthony]). As a read it, one thought kept coming to me. Your statement about the apparent lack of a response was quite telling for me.
    In my science classes, we had to learn a concept called “stationarity”. Now, before we begin on this, let me state that I believe there are multiple definitions of stationarity. Other disciplines use alternate definitions from the one my classes needed, and used, as we studied and learned. If this is NOT the definition you know, be advised that it is likely an ‘ad hoc’ use. I respectfully request that we not quibble.
    “Stationarity” as I was taught, means that the impulse response of system is invariant (or slightly variant within some strict constraints, most of which are able to be accounted for). Let us take a simple example to illustrate:
    When I walk into the kitchen, I reach for the light switch, and when I activate it, the light comes on. Each time I repeat this, the same thing happens (and please do not bring in such things as defective light bulb, power outage, severed wires … … … ). When I do an action, the response is the same; this is “stationarity”.
    Now, suppose we consider a non-stationarity system: Same scenario, I walk into the kitchen, activate the light switch. Since my system no longer has stationarity, when I expect the light to come on, the dishwasher starts instead. Then, the next time, the window opens; next time, the refrigerator shuts off; or the spigot turns on, or … … …
    You get the idea: I apply an impulse, the result is a seemingly random, unassociated event.
    To tie this into your post, it seems to me that since the atmosphere is a non-stationarity system, the ‘expected’ response may not materialize at all. We know the eruptions have the potential to cause slight cooling world-wide, but the specific location you examined had other mitigating factors, such that the response was not “identical” to the two events.
    To further expand this comment, this is the prime failing of climate science, such as it is, in treating the global climate system as a system that exhibits stationarity, viz., if we apply an impulse (more CO2), then the response is an increase in temperatures. The premise is flawed (fatally) from the outset, since the atmosphere does not possess stationarity, and the ‘climate science’ community treats it as if it does.
    I welcome your comments as well, as we are all learners,
    Vlad

    • @Vlad
      It’s not satisfying to me to talk about a black box that does random schist. It makes me think of witch doctors doing rain dances and explaining that it works by magic. Surely you admit that the “stationarity” concept is an abstraction that expresses the concept that the real system is far more complex than some simplistic model of the real system, such that the model is sometimes correct and sometimes not? Like if the model is a stopped clock, it happens to give the correct time (in the real system), twice a day. The real system is ultimately explainable and works mechanistically. That isn’t changed by our knowledge or lack of knowledge.
      It always grates on me that in medical practice, things that are not understood at all are given a four- or five-word syndrome name, to cover up the fact that we have no clue. Doctors are not allowed to say you’ve got a problem that we don’t understand. They are paid too much not to give you an incomprehensible explanation. You have a pain when you do something where you didn’t have a pain doing that thing before, your body suffers from non-stationarity syndrome.
      No, it’s the mechanism that matters. If you can’t explain why, giving it a name is not really very useful. You can’t create a drug therapy except by trial and error, without understanding the biochemistry. Analogously, you can’t create a truly useful model of climate without really understanding the physical mechanisms sufficiently that “non-stationarity” is eliminated.
      At least in medical research, giving something a name even though you don’t understand it enough to realize that you’re lumping several unrelated disorders together based on similar symptoms, may enable you to come up with therapies that treat the symptoms. That is at least marginally useful. But in climate “science” we have the situation where the system that is too complex to model is simplified down to give the desired spurious answer needed by the politicians. Like Homer Simpson’s beer, is there nothing CO2 can’t do?

  39. The temperature didn’t change following the eruptions because the heat capacity of the oceans.

    • OK, maybe for Hawaii, but then how do we explain that temperatures did drop significantly on average across the globe, even if not on Hawaii?

  40. Willis,
    It makes sense to me that there is a cap on how much the incoming solar radiation can be reduced due to stratospheric SO2 – because like any gas, the stratosphere has a limit on how many particles it can carry per unit volume. And being quite thin, it can carry a lot less than the lower atmosphere. My conjecture is that you are seeing the stratosphere at its limit with these two eruptions.

  41. Not a single mention of the Kuwaiti Oil Fields burning for months in 1991.
    Well how could that have an impact on anything?

  42. Hello Mr Eschenbach. You say ”A foggy morning here. We’re six miles from the coast, and despite how far it is, the sea breeze brings me the distant sound of the surf and the foghorn on the breakwater …” I live several kilometres from a freeway and sometimes on a windy day the noise is almost unbearable. I have often wondered how wind can ”blow” a sound towards me. Any ideas?

  43. You were doing so well up to here:

    CO2 would have to go from the current 400 ppmv to 43,250 ppmv …

    Surely not.

  44. Excellent article. For some peripheral supporting analysis (not nearly up to WE quality or cloud feedback), see essay Blowing Smoke in eponymous ebook. Looked at some of the same data, deconstructing several AGW papers misconstruing/misreporting same. Looks like clouds rule.

    • Of course clouds rule. They control the most important variable, albedo, where and when it matters most (inter-tropics, daytime).
      Climate models acknowledge not having a clue about the way clouds would react to “GHG forcing”, that is, not having a clue about the most important.

  45. Simple. What happened to those 25 W/m2? It heated dust in the atmosphere before it got a chance to heat the surface.

  46. Excellent and well written.
    The small reaction to the lower sun inflow after eruptions might be sea dependent as stated above.
    I recall the fog that gave SF bay cooling during warm summer mornings and how the sun at noon started to shine.

  47. The graphs show “anomaly” – what is the base for calculating that? Does it include the period you are graphing?

    I think trying to show a relatively small effect in a multitude of effects is very unlikely to work. The volcano effect would have to overwhelm the other effects and then some.

  48. Hi Willis.

    My posts below support some of your hypo but do not support all of it. Please see my SUMMARY below.

    Regards, Allan

    [Note: The migration to the new server has rendered all my previous url’s within wattsup partly-obsolete – the old url locates the correct page, but that is all – then you have to manually locate my post. I’ve tried to update the url’s below.]

    https://wattsupwiththat.com/2018/05/climate-scientist-air-pollution-cleanup-may-be-major-driver-of-global-warming/#comment-2363299

    [excerpt]

    SUMMARY:
    Industrial pollution does not have much impact on global temperature. Major (century-scale) volcanoes like El Chichon and Pinatubo definitely do cool the planet – by up to about 0.5C, fully dissipating after about 5 years..

    The details are all here:

    https://wattsupwiththat.com/2017/09/report-ocean-cycles-not-humans-may-be-behind-most-observed-climate-change/#comment-2157696

    Formula:
    UAHLTcalc Global (Anom. in degC) = 0.20*Nino3.4IndexAnom (four months earlier) + 0.15 – 8*SatoGlobalMeanOpticalDepthIndex
    Sato Global Mean Aerosol Optical Depth at 550 nm https://data.giss.nasa.gov/modelforce/strataer/tau.line_2012.12.txt

    https://wattsupwiththat.com/2018/05/climate-scientist-air-pollution-cleanup-may-be-major-driver-of-global-warming/#comment-2363266

    Richard Keen wrote:
    “Compared to the murky decades of the el Chichon and Pinatubo, the clear stratosphere since 1995 has allowed the intensity of sunlight reaching the ground to increase by about 0.6 Watts per square meter,” says Keen. “That’s equivalent to a warming of 1 or 2 tenths of a degree C (0.1 C to 0.2 C).”

    “In other words,” he adds, “over the past 40 years, the decrease of volcanic aerosols and the increase of greenhouse gases have contributed equally to the total warming (~0.3 C) observed in global satellite temperature records.”

    I wrote a similar conclusion in 2016 – see my post below. From my graph, it is clear that the peak cooling effect of volcanic aerosols from El Chichon and Pinatubo was 0.4C to 0.5C, not 0.1C to 0.2C as Keen stated, and each volcanic aerosol event took about 5 years to fully dissipate.

    There is NO need to attribute any of the observed warming to increasing atmospheric CO2.

    https://wattsupwiththat.com/2016/07/spectacular-drop-in-global-average-satellite-temperatures/#comment-1813307

    I plotted the same formula back to 1982, which is where I [edit: 1982 is when the NOAA Nino3.4 data starts] started my first analysis. Satellite temperature data began in 1979.

    That formula is: UAHLT Calc. = 0.20*Nino3.4SST +0.15

    It is apparent that UAHLT Calc. is substantially higher than UAH Actual for two periods, each of ~5 years, BUT that difference could be largely or entirely due to the two major volcanoes, El Chichon in 1982 and Mt. Pinatubo in 1991.

    This leads to a startling new hypothesis: First, look at the blue line (a function of Nino3.4 SST), which shows NO significant global warming over the entire period from 1982 to 2016. Perhaps the “global warming” observed in the atmosphere after the 1997-98 El Nino was not global warming at all; maybe it was just the natural recovery in global atmospheric temperatures after two of the largest volcanoes in recent history.

    Comments?

    https://www.facebook.com/photo.php?fbid=1030751950335700&set=a.1012901982120697.1073741826.100002027142240&type=3&theater

  49. Hi Willis.

    My posts below support some of your hypo but do not support all of it. Please see my SUMMARY below.

    Regards, Allan

    Note: The post is in the spam filter because it contains several url’s.

    SUMMARY:
    Industrial pollution does not have much impact on global temperature. Major (century-scale) volcanoes like El Chichon and Pinatubo definitely do cool the planet – by up to about 0.5C, fully dissipating after about 5 years..

  50. A worldwide 25 W/m² is HUGE. That’s ~10% of usual 240W/m² you find in the flat-Earther Trenberth budget.
    In a full linear world, it means a ~7K drop in temperature! And even more, if the CAGW- postulated positive feedback were true.
    Obviously, Earth and humans barely noticed. You have to know beforehand that Pinatubo occurred to find some drop to explain.
    Meaning, there are NO positive feedback, but rather very strong negative, stabilizing feedback.

    Now, the nature of the feedback matters
    It could be just some sort of delay, meaning, it takes time to reach a new value. For instance, the thermal capacity of the Earth (mainly the ocean)
    Or it could be something directly opposite. For instance, the postulated cloud feedback.
    In any case, just looking at temperature isn’t enough to sort out the respective share of the 2 kind of negative feedback (both surely exist).
    Temperature is a SO bad metrics to study heat transfer.

  51. “If someone else has a better idea why a drop in the amount of solar radiation reaching the ground of some 25 W/m2 for two years hasn’t affected the local temperatures, I’m all ears.”

    I have an idea about that – essentially, low-lying clouds, and away from the mountain peak your 25 W/m2 in fact isn’t reaching the ground at all.

    The direct effect of volcanic gasses/particles was -31.3 W/m2.
    The feedback from clouds *above 3394m* was +6.8 W/m2
    The feedback from clouds *below 3394m* can be expected to be positive, and perhaps plausibly on the order of +24.5 W/m2?

    Even though the temperature is measured at 3394m, given it’s on a mountain surrounded by ocean, (and wind and convection), it would be mainly dependent on downwelling solar radiation at sea level in the upwind direction, right? (rather than in-situ at 3394m)

  52. As always, another interesting and thought provoking post by Willis. It is unfortunate that it happened to be timed with the site upgrades that caused some comments to be dropped and graphic presentations to be affected.

    I hope there will be a sequel follow-up unless Willis finds something else ‘shiny’. But then that will be interesting too.

  53. Hi Willis,

    When you graph ‘temperature anomaly’ are you using LIG Tmean, Tmax, Tmin or another instrument like Pt resistance?
    If you are using customary LIG Tmean as half of Tmax+Tmin, then you might get a different result by using just Tmax or just Tmin.
    In fine detail, one should not average Tmax with Tmin because these ‘special’ daily temperatures are set each day by a balance between some heating and some cooling effects that are not usually the same dominant effects for Tmax as they are from Tmin. The time of day when Tmax is reached can vary widely. Tmin, less so.
    Maybe you can extract more information by plotting time of day that Tmax happens, as well as what you have done with Average temperatures.
    I hope this helps to improve this rather fascinating set of observations, quite counter-intuitive ones, especially counter to the dominant CO2 control knob mechanisms.
    Geoff.

  54. As well as A C Osborn, I can’t find anything about the Eyjafjallajökull event in 2010. Is it missing data or was it just a quantité négligeable?

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