SORCE Says Sun Did It

SORCE in a clean room

SORCE in a clean room

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Well, maybe not ALL of it, but something unsettling was found that points to a solar involvement.


We have:

Much of recent global warming actually caused by Sun
By Lewis Page

New data indicates that changes in the Sun’s output of energy were a major factor in the global temperature increases seen in recent years. The research will be unwelcome among hardcore green activists, as it downplays the influence of human-driven carbon emissions.

But the interesting bit is that it focuses on the way different parts of the spectrum of solar output changed over time. As sunspots dropped, we didn’t just get lower solar output, we also got DIFFERENT solar output. And as the different frequencies of sunlight penetrate the atmosphere to different degrees, this goes a fair ways toward explaining why “Sunspot count” doesn’t have a 1 to 1 relationship to heating / cooling.

Now, however, boffins working at Imperial College in London (and one in Boulder, Colorado) have analysed detailed sunlight readings taken from 2004 to 2007 by NASA’s Solar Radiation and Climate Experiment (SORCE) satellite. They found that although the Sun was putting out less energy overall than usual, in line with observations showing decreased sunspot activity, it actually emitted more in the key visible-light and near-infrared wavelengths.

These shorter wavelength forms of radiated heat penetrate the atmosphere particularly well to heat up the Earth’s surface – just as the same frequencies get in through car windows to heat up its interior. The hot seats and dashboard – in this case the seas, landmasses etc – then radiate their own increased warmth via conduction, convection and longer-wave infrared, which can’t escape the way the shortwave energy came in. This is why the car, and the planet, become so hot.

Thus the Sun, though it was unusually calm in the back half of the last decade, was actually warming the planet much more strongly than before.

So we have an interesting wrinkle to add to “The Sun Did It” models. How does the color of the sun change with the progression of the sunspot drought?


Instruments similar to TIM have made daily irradiance measurements of the entire solar spectrum for more than three decades, but the SIM instrument is the first to monitor the daily activity of certain parts of the spectrum, a measurement scientists call solar spectral irradiance.

In recent years, SIM has collected data that suggest the sun’s brightness may vary in entirely unexpected ways. If the SIM’s spectral irradiance measurements are validated and proven accurate over time, then certain parts of Earth’s atmosphere may receive surprisingly large doses of solar radiation even during lulls in solar activity.

“We have never had a reason until now to believe that parts of the spectrum may vary out of phase with the solar cycle, but now we have started to model that possibility because of the SIM results,”
said Robert Cahalan, the project scientist for SORCE and the head of the climate and radiation branch at NASA’s Goddard Space Flight Center in Greenbelt, Md.

Cahalan, as well as groups of scientists from the University of Colorado at Boulder and Johns Hopkins University, presented research at the American Geophysical Union meeting in San Francisco in December that explored the climate implications of the recent SIM measurements.

Cahalan’s modeling, for example, suggests that the sun may underlie variations in stratospheric temperature more strongly than currently thought. Measurements have shown that stratospheric temperatures vary by about 1 °C (1.8 °F) over the course of a solar cycle, and Cahalan has demonstrated that inputting SIM’s measurements of spectral irradiance into a climate model produces variations of that same magnitude.

Without inclusion of SIM data, the model produces stratospheric temperature variations only about a fifth as strong as would be needed to explain observed stratospheric temperature variations. “We may have a lot more to learn about how solar variability works, and how the sun might influence our climate,” Cahalan said.

Yes, indeed. A LOT more to learn…

Some of the variations that SIM has measured in the last few years do not mesh with what most scientists expected. Climatologists have generally thought that the various part of the spectrum would vary in lockstep with changes in total solar irradiance.

However, SIM suggests that ultraviolet irradiance fell far more than expected between 2004 and 2007 — by ten times as much as the total irradiance did — while irradiance in certain visible and infrared wavelengths surprisingly increased, even as solar activity wound down overall.

I can attest to that. About a year ago? Maybe two… I commented that when working in the garden I did not have nearly as much tendency to sunburn as in the past. That something was wrong in the UV range. Didn’t need a whole lot of satellite data, just some garden time and noticing the lack of a sunburn. Guess Redheads can be useful as Solar Barometers ;-)

At any rate, it’s pretty clear that the change of spectral output is going to have a whole load of impacts that folks have not thought through. Perhaps we can use sunscreen sales or even skin cancer rates as a proxy for solar output… It certainly looks like we can use sunspots to predict the skin exposure to UV…

The steep decrease in the ultraviolet, coupled with the increase in the visible and infrared, does even out to about the same total irradiance change as measured by the TIM during that period, according to the SIM measurements.

The stratosphere absorbs most of the shorter wavelengths of ultraviolet light, but some of the longest ultraviolet rays (UV-A), as well as much of the visible and infrared portions of the spectrum, directly heat Earth’s lower atmosphere and can have a significant impact on the climate.

In Conclusion

Golly. I never expected to see folks saying “It’s The Sun” quite so quickly…

I’d also note that there may be even more subtile impacts. Many folks have Seasonal Affective Disorder, or SAD. This is treated with low dose UV. ( I have a “Lizard Lamp” set up for a family member. It raises the vitamin D level and cures several issues, including SAD. Though you must be careful to stop before you get a ‘sun’ burn…)

I would speculate that as UV drops, we will have more mood swings and more moody people as a greater number of folks develop SAD earlier and to a more severe degree. Expect more Vitamin D deficiency symptoms to show up globally.

So, less sunburn, more rickets… And maybe more folks being depressed and / or emotionally ‘touchy’. Hope the North Koreans can buy a Lizard Lamp for their petty dictator Dear Leader. Don’t need them getting any more sad and touchy than they already are…

Finally, I also have to note that perhaps this will have some significant impacts on the question of AGW Model validation. Changes in relative heating with altitude are part of their predictions, and here we have them driven by the sun. So… how long until those models are updated and we can see what they predict project next? Somehow I think I’m seeing a bit of a “spanner in the works” moment in the modelers future…

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About E.M.Smith

A technical managerial sort interested in things from Stonehenge to computer science. My present "hot buttons' are the mythology of Climate Change and ancient metrology; but things change...
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5 Responses to SORCE Says Sun Did It

  1. Baa Humbug says:

    Would not that possibly also explain the cooling of the stratosphere, a subject that comes up often in discussions about the missing hot spot.

    Also, I recall reading many times that the UV output of the sun various much more than TSI, a phenom observed on other variable stars.

    Thanx for this E M

  2. E.M.Smith says:

    @Baa Humbug:

    Yup. Ties up that loose end (and possbily a couple of others). Then adds a bunch of complications….

    So now we’ve got to allow for the various changes in opacity of the various layers of the atmosphere, along with their differential heating as the sun changes output. Oh Joy…

    This, then, will play Hobb with the models that make assumptions that Just Arn’t So.

    Then there is the question of how variable IS our star? We now know that TSI isn’t going to cut it as a metric all by itself. So if we’ve really GOT a fairly variable star, but just didn’t realize it as we were measuring the wrong thing, that’s got a load of implications.

    Finally, for the Electric Universe folks, we’ve got this little observation: When arc welding, the workpiece gets very hot. White hot even. LOADS of IR and visible comes off of it, including a boat load of UV (that’s what the special eye cover is for, so you don’t sunburn your eyes…). But when you stop the arc, the UV ceases immediately. The visible and IR go on quite a bit longer.

    So what makes the UV dive while the rest keeps on going just fine? Like someone extinguished or “turned down” an arc… It’s not like you can just say that the sun cooled off. It didn’t exactly. It’s not like you can say the total energy out dropped. TSI says it didn’t much. But a factor of 10 drop in UV compared to the rest? Kind of like someone turned down the power on an electric discharge….

    Who knows if there is any merit to the idea. But it will certainly give the Electric Universe folks some new toys to play with ;-)

    Maybe the Standard Model has an explanation for it. Would be interesting to see how they get around the sun not changing color much but the UV taking a dive.

    One thing is certain, though: The science is very much NOT settled.

  3. Ken McMurtrie says:

    This might be a bit oversimplified but seems relevant to me.
    The Sun is undoubtedly THE SOURCE of our planet’s heat supply.
    It’s ability to drastically alter our surface temperatures is exhibited by the temperature variations we get relatively stable from pole to equator to other pole. Then the seasonal changes due to the angle of our planet’s rotational axis cause many degrees variation. Also the day night variations showing instant surface air temp shifts. Also the instant response to cloud cover and precipitation.
    I understand that the long term planet heat content, having significant ‘inertia’ results in major smoothing of all these variations. Also that the surface temperature is greatly modified by the greenhouse effect of our atmosphere.
    However, the greenhouse effect does little to modify those huge short term variations discussed above.
    There are also many other factors, but it is difficult for me to accept that the miniscule percentage of CO2 in the atmosphere, even as a part of the greenhouse system, can over-ride all the other relevant influences.
    To me, the solar energy input is the greatest factor.

  4. E.M.Smith says:

    @Ken McMurtrie:

    And the paleo record confirms that “other stuff” dominates and CO2 just doesn’t have the drivers seat.

  5. pyromancer76 says:

    CO2 just doesn’t compute. It is a silly issue and one that certain interests are using to undo industrial societies, especially those that encourage freedom, transparency, accountability, and representative democracy. It is amazing to think about what we do not know about our Sun because we only recently developed our instrumentation to really KNOW. What was Sun like during Maunderor Dalton Minimums? No one knows. Now we can get an inkling.

    Much appreciation, E.M., for pulling together this info on the SOURCE. (At the same time, I won’t forget the heat from the interior plus the ocean, the ocean, the ocean. We life forms are so fortunate that we have an immense body of H2O (70%) making do with what Sun offers.)

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