New Sun-Watching Instrument to Monitor Sunlight Fluctuations

From Physorg.com

March 23rd, 2009 in Space & Earth / Space Exploration

New Sun-Watching Instrument to Monitor Sunlight FluctuationsEnlarge

During periods of peak activity (front three images) sunspots, solar flares and coronal mass ejections are more common, and the sun emits slightly more energy than during periods of low activity (back images). The amount of energy that strikes Earth’s atmosphere — called total solar irradiance (TSI) — fluctuates by about 0.1 percent over the course of the sun’s 11-year cycle, even though the soft X-ray wavelengths shown in this image vary by much greater amounts. Credit: Steele Hill, SOHO, NASA/ESA

(PhysOrg.com) — During the Maunder Minimum, a period of diminished solar activity between 1645 and 1715, sunspots were rare on the face of the sun, sometimes disappearing entirely for months to years. At the same time, Earth experienced a bitter cold period known as the “Little Ice Age.”

Were the events connected? Scientists cannot say for sure, but it’s quite likely. Slowdowns in — evidenced by reductions in sunspot numbers — are known to coincide with decreases in the amount of energy discharged by the sun. During the Little Ice Age, though, few would have thought to track (TSI), the amount of solar energy striking Earth’s . In fact, the needed to make such measurements — a spaceborne radiometer — was still three centuries into the future.

Modern scientists have several tools for studying TSI. Since the 1970s, scientists have relied upon a collection of radiometers on American and European spacecraft to keep a close eye on solar fluctuations from above the atmosphere, which intercepts much of the sun’s radiation. When launches the Glory satellite this fall (no earlier than October 2009), researchers will have a more accurate instrument for measuring TSI than they’ve ever had before.

The Total Irradiance Monitor (TIM) on Glory is more sophisticated, but still related in concept to the very earliest ground-based solar radiometers, which were invented in 1838. Where those radiometers used sunlight to heat water and indicate the intensity of the sun’s brightness at the Earth’s surface, Glory’s TIM instrument will use a black-coated metallic detector to measure how much heat is produced by as it reaches the top of the Earth’s atmosphere.

New Sun-Watching Instrument to Monitor Sunlight FluctuationsEnlarge

Scientists have compiled a three-decade record of total solar irradiance by patching together data from U.S. and European satellites. Fluctuations in irradiance correspond well with the cycling of sunspots. To ensure continuity, data from Glory’s TIM instrument must overlap with data from an earlier TIM (in red on this plot), which launched in 2003. Credit: Greg Kopp, LASP

Solar bolometers, as this subset of radiometers is called, have been flown on ten previous missions. Nimbus-7, launched in 1978, included one of the first spaceborne bolometers, and progressively more advanced instruments have followed on other NASA, National Oceanic and Atmospheric Administration, and European Space Agency missions.In 2003, a first generation TIM instrument went aloft with the Solar Radiation and Climate Experiment (SORCE) satellite. Learning from that instrument, engineers have tweaked the optical and electrical sensors to make the Glory TIM even more capable of measuring the true solar brightness and its fluctuations.

“The Glory TIM should be three times more accurate than SORCE TIM, and about ten times more accurate than earlier instruments,” said Greg Kopp, a physicist at the University of Colorado, Boulder, and leader of the TIM science team.

“There’s no doubt that’s an ambitious goal, but I wouldn’t be surprised if they pull it off,” said Joseph Rice, a physicist at the National Institute of Standards and Technology in Gaithersburg, Md.

Beyond engineering improvements, the Glory irradiance monitor has another advantage: access to the one-of-a-kind TSI Radiometer Facility. Funded by NASA and built by the Laboratory for Atmospheric and Space Physics in Boulder, Colo., the new facility has allowed Kopp’s team to calibrate the instrument in the same configuration and under the same conditions as it will endure in space. In January 2009, the Glory TIM instrument underwent a rigorous battery of tests while being compared to a highly accurate ground-based radiometer.

“This was the first time a TSI instrument has ever been validated end-to-end,” Kopp said. “The improvements in accuracy will make it possible to detect long-term changes in the sun’s output much more quickly.” The data will help scientists say more definitively whether the sun’s output is gradually trending upward or downward, and whether the trend is influencing the pace of climate change.

Existing measurements offer a rough sketch, but they’re not quite accurate enough over decades to centuries to paint a clear picture of whether changes in TSI reflect real changes on the sun or just artifacts of different instrument designs. That’s because the radiometers that have measured TSI so far have all reported values at slightly different levels and have all been calibrated differently, injecting a degree of uncertainty into the record.

The new TIM should be sufficiently accurate to quickly yield definitive data on whether solar irradiance is trending up or down. Modelers estimate that TSI increased roughly 0.08 percent as the Sun exited the Maunder Minimum, which lasted for much of the 1700s. But even if TSI radiometers had been available at the time, the increase in irradiance was so gradual that identifying the trend would have been difficult.

Detecting such subtle changes is where the Glory TIM shines. Prior to SORCE, most TSI instruments had only 0.1 percent accuracy, and could not have reliably detected a 0.08 percent change over a century, Kopp explained. The improved accuracy of the SORCE TIM (0.035 percent) would detect such a change in about 35 years. The Glory TIM, meanwhile, should reduce the time needed to nearly ten years.

Getting TSI right has profound implications for understanding Earth’s climate. Thanks to previous orbiting radiometers, scientists know TSI varies by roughly 0.1 percent through the sun’s 11-year magnetic cycle. Such a variation cannot explain the intensity and speed of the warming trends on Earth during the last century, explained Judith Lean, a solar physicist at the U.S. Naval Research Laboratory in Washington, D.C. But, that’s not to say that the sun has no influence on climate change.

While total solar irradiance changes by 0.1 percent, the change in the intensity of ultraviolet light varies by much larger amounts, scientists have discovered. Research shows such variations in the Sun’s emissions can affect the ozone layer and the way energy moves both vertically and horizontally through the atmosphere.

After examining the historical TSI database, some scientists have suggested that solar irradiance could account for as much as a quarter of recent global warming. But without a continuous and reliable TSI record, Kopp and Lean point out, there will always be room for skeptics to blame global warming entirely on the sun, even when most evidence suggests human activities are the key influence on modern climate changes.

Beyond that, there’s a big “what if” percolating through the scientific community. The 0.1 percent variation in solar irradiance is certainly too subtle to explain all of the recent warming. “But, what if — as many assume — much longer solar cycles are also at work?” said Lean. In that case, it’s not impossible that long-term patterns — proceeding over hundreds or thousands of years — could cause more severe swings in TSI.

Could a modern day Maunder Minimum offset the warming influence of greenhouse gases or even throw us back into another little ice age? “It’s extremely unlikely,” said Lean, “but we won’t know for sure unless we keep up and perfect our measurements.”

Provided by NASA’s Goddard Space Flight Center (news : web)

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Hopefully, Glory does not also end up in Antarctic.

tallbloke

Let’s hope it has some variation to monitor.
A sleeping sun gets a bit monotonous.
Come on Sol, give us a sign
Bring it forth and let it shine
Put your hat on and shout hooray
Tell us you’re coming out to play.

Pearland Aggie

speaking of sunlight fluctuations, Mt. Redoubt is rumbling again…
Huge Explosion Rocks Alaska’s Mount Redoubt
http://www.foxnews.com/story/0,2933,510718,00.html
and there’s a new report highlighting the importance of atmospheric dust with respect to Atlantic ocean temperatures. for years we’ve been hearing that North Atlantic SST anomalies were the result of AGW…now, maybe that’s not really the case.
http://www.physorg.com/news157296711.html

Anthony — would be great to get Facebook integrated into your posts. Would help “spread the word” bit faster.
-John

Adam from Kansas

I wonder if TSI is connected to climate by first dragging SST’s down then temps. go down with it, SST’s peaked not long after solar max according to the monthly SST data.
If anything, I don’t know if this is connected to a possible massive snowstorm forecast for Wichita starting tomorrow (according to my city paper), and the other one that dumped tons of snow up north less than a week ago, there’s also the big and rare snows the past year as well.
I had a dream around the latter half of fall where I look at the forecast and it said ‘catostrophic snow’ on a day and cold, I had no idea that it could end up coming true, probably won’t be as cold as in the dream, but the truckload of snow part will seem to be.
The part that seems wrong about this picture is that there’s dandelions popping up, plants popping up, trees starting to leaf out, spring coming overall, guess Winter can’t go without a possible grand finale.

Ray

The relatively small change in irrandiance does not account for the major changes in weather and climate on the earth. Irradiance is only a small part of the puzzle. There is much more than photons coming out of the sun that affects us and the rest of the solar system.

Tim L

TSI, whether the trend is influencing the pace of climate change.
!!!!! wow they maybe right sun has an influence. sarc/ off

tallbloke (12:39:41) :
Let’s hope it has some variation to monitor.
A sleeping sun gets a bit monotonous.
Come on Sol, give us a sign
Bring it forth and let it shine
Put your hat on and shout hooray
Tell us you’re coming out to play.

Round and round I go,
the barycenter longing to find and rest,
because the farthest I go
the most furious I become
The Sun

Dennis Wingo

Could a modern day Maunder Minimum offset the warming influence of greenhouse gases or even throw us back into another little ice age? “It’s extremely unlikely,” said Lean, “but we won’t know for sure unless we keep up and perfect our measurements.”
The problem that I have with this perspective is that it does not take into account the wavelength specific absorption and emission of radiation from the sun. We speak all the time about the absorption of infrared radiation from the Earth, caused by the addition of 0.01% of the atmosphere’s CO2 content, but we never discuss the effect of the wide variance in short wave radiation on the absorption and emission of radiation of oxygen (why the sky is blue) or other short wavelength absorbers/emitters.
As a designer of spacecraft solar power systems as well as terrestrial solar power systems, I am aware on a daily basis that the 1364 watts/m2 that is at the top of the atmosphere decreases to less than 1000 watts/m2 at sea level. The difference, over 300 watts/m2 is not absorbed by CO2 to any significant percentage.
The entire physics of the CO2 phenomenon is based upon the increase in kinetic energy of a CO2 molecule due to the absorption of an infrared photon. Why is it that the absorption of a far more energetic photon by oxygen or other visible light absorbers does not overwhelm any CO2 signature?
Secondarily, the USAF has a spacecraft in orbit today, that measures the expansion and contraction of the atmosphere. It has found that in this current extended minimum that the atmosphere has contracted to a greater extent than at any time in the history of the space age (52 years). Why is it that no one is investigating this effect on the overall radiation balance of the atmosphere?
I am asking these things as questions as I would sincerely like to know why these things are not investigated as to their contribution to global climate.

There is an apparent correlation between solar activity anomalies, including Maunder Minimum and planetary resonance of the two major planets of the Solar system.
On the graph numbers are rounded off from 95.88247 and 118.628
http://www.geocities.com/vukcevicu/CycleAnomalies.gif
http://www.vukcevic.co.uk/

I wonder if the spectrum at sea level of TSI varies, because during the big 1998 nino and years afterwards, sun’s radiation as felt by our skin was really aggresive, as UV was supposedly higher. Now it is different.

Scott Gibson

@Ray
I’m not sure about that. Although Leif tells us that there is not enough change in solar irradiation to explain weather and climate changes, there is no question that factors that seem tiny do have major effects. It is easy to understand warm days and cool nights. On the other hand, if I told you that changes in the angle of incidence of the sun could cause greater than 50 degree F swings in temperature, you might be skeptical if you didn’t know about winter and summer. In short, I’m still open to the possibility that small solar changes could cause major climate variations.

Scott Gibson: “small solar changes could cause major climate variations.”Not forgetting those “heralds of the times to come” as the Snow Owl posted not long ago here at WUWT or the recent appearance of increased numbers of sea bass and flounder fishes on the west coast of SA, which are better than NOAA or any computer model in forecasting cold sea waters.

Are you guys sure there was no sunspot today? My cell phone kept dropping calls…:+)

Ron de Haan

Dennis Wingo (13:13:36) :
Forget the CO2 BS (Bad Science)
http://www.ilovemycarbondioxide.com

Ohioholic

“Secondarily, the USAF has a spacecraft in orbit today, that measures the expansion and contraction of the atmosphere. It has found that in this current extended minimum that the atmosphere has contracted to a greater extent than at any time in the history of the space age (52 years). Why is it that no one is investigating this effect on the overall radiation balance of the atmosphere?”
I have wondered this myself. If the atmosphere is contracting is it also condensing?

Adam from Kansas

More on the blizzard that is supposed to be of ‘historic’ proportions around here (if this is sun related I wouldn’t want to think what would happen if TSI keeps on a downward trend), events like this seem to suddenly be getting more common as sun activity continues to decline.
up to 2 feet of snow forecast for southwestern Kansas, likely including Liberal, Garden City, and Dodge City
http://www.accuweather.com/news-story.asp?article=2
A weather update video and page
http://www.accuweather.com/news-top-headline.asp?partner=accuweather&date=2009-03-26_18:50

Adam from Kansas

Oh, here’s the link to the actual story
http://www.accuweather.com/regional-news-story.asp?region=southwestusnews
Here in Wichita, we could get very close to the biggest snowfall we ever had which is 15 inches, the way things are going and with snow forecasts increasing, I wouldn’t be entirely surprised if we break that.
Unfortunately for the kids here who got their hopes up for a snow day Friday the snow will really start falling AFTER they get home from school.

“While total solar irradiance changes by 0.1 percent, the change in the intensity of ultraviolet light varies by much larger amounts, scientists have discovered. Research shows such variations in the Sun’s emissions can affect the ozone layer and the way energy moves both vertically and horizontally through the atmosphere.”
Cool, finally getting to the real cause of ozone production and destruction as well. Back from the grave, UV-A and UV-B. To the grave with CFCs and the ozone ho;e junk science joke.

Robert Wood

P1*V1/T1 = P2*V2/T2
If the volume has contracted, and the pressure hasn’t really changed much (that being determined rather by gravity), then T must change!!

Robert Wood

Let me expand upon that statement. The pressure of the atmosphere is determined by the mass of gas in the planetary atmosphere and the planetary mass.
If the atmosphere heats up, it will expand in volume.
We currently see a reduction in the volume of the atmosphere. The mass of the atmosphere and mass of the planet have not changed, so there must be a decrease in the temperature of the atmosphere.

Robert Wood

The pressure of the atmosphere, AT THE SURFACE, …

Ohioholic (14:18:08) :
I have wondered this myself. If the atmosphere is contracting is it also condensing?
What do you mean by ‘condensing’? That the Oxygen gas is turning into a blue Oxygen liquid running down the window panes? :~)

Mr Lynn

. . .without a continuous and reliable TSI record, Kopp and Lean point out, there will always be room for skeptics to blame global warming entirely on the sun, even when most evidence suggests human activities are the key influence on modern climate changes. (From the NASA article; my emphasis.)

And what, pray tell, exactly isthat evidence, aside from a very rough correlation in the 20th century?
/Mr Lynn

VG

For Leif: from above quote “After examining the historical TSI database, some scientists have suggested that solar irradiance could account for as much as a quarter of recent global warming. But without a continuous and reliable TSI record, Kopp and Lean point out, there will always be room for skeptics to blame global warming entirely on the sun, even when most evidence suggests human activities are the key influence on modern climate changes… ect
So… at this stage…looks like its going from “no effect” whatsoever to now possibly 25% and then quote below to “long term changes in TSI” in fact could be 50%, 66% (effect on climate…), LOL
“Beyond that, there’s a big “what if” percolating through the scientific community. The 0.1 percent variation in solar irradiance is certainly too subtle to explain all of the recent warming. “But, what if — as many assume — much longer solar cycles are also at work?” said Lean. In that case, it’s not impossible that long-term patterns — proceeding over hundreds or thousands of years — could cause more severe swings in TSI”.

davidcobb

Really ,really crude calculations. A 1000w microwave oven will raise the temperature of one litre water 10 degrees in one min. Spread that out and one w/m3 will raise the top 250mm (1 foot) 6 degrees in one year. This is assuming 8 hrs of irradiance and a static system.

Bill Illis

Leif,
Has anyone examined what happened to temps etc. in the really big drop-outs which happen in TSI when the biggest sunspot groups occur.
In solar cycle 23, the biggest, longest one was at the end of October 2003 where TSI dropped from 1,361.7 W/m2 to 1,357.3 W/m2 for more than a week.
http://lasp.colorado.edu/cgi-bin/ion-p?ION__E1=PLOT%3Aplot_tsi_data.ion&ION__E2=PRINT%3Aprint_tsi_data.ion&ION__E3=BOTH%3Aplot_and_print_tsi_data.ion&START_DATE=100&STOP_DATE=500&TIME_SPAN=6&PLOT=Plot+Data
There was small decline in temps in November 2003 and what looked to be a rebuilding El Nino dropped off to neutral conditions. Anything else of note happen?

J.Hansford

Dennis Wingo, Robert Wood…..
That’s what I would have thought. If the satellite instrumentation is measuring a contraction of the atmosphere, without a corresponding drop in surface pressure….. Then there is only one explanation in physics…. A decrease in temperature.
…. But the AGW beat goes on. The simplistic laws of Thermodynamics no longer apply. The Hypothesis is now bigger than Ben Hur…..

Jack Green

The NASA measuring the atmosphere altitude would be a direct measure of Temperature if the Volume and Mass were relatively constant. Neat idea.
Here’s another curve ball: could an asteroid hitting the atmosphere rip off enough of it to cause it to shrink and allow more of the heat to escape thereby causing an ice age? We should look at the temperature record after the Tunguska event and see. Tunguska may not be a good example.

papertiger

In the TSI graph run a straight edge along the lowest point of the 87 minimum.
The 85-87 minimum as measured by ACRIM I V1 is a full notch lower then the 96 min as measured by ACRIM V3, and the current minimum as measured by TIM V9.
Unless it is somehow possible to be less then zero ACRIM I, ERBE, and in my opinion ACRIM2, are FUBAR.
Maybe not it the bandwidth they are measuring, but certainly in the splicing.
ACRIM I is set too low. ACRIM 2 is a dab too high. Aren’t the splicings a bit of subjective Xlimate changie hokus pokus?

Mike Ramsey

While total solar irradiance changes by 0.1 percent, the change in the intensity of ultraviolet light varies by much larger amounts, scientists have discovered. Research shows such variations in the Sun’s emissions can affect the ozone layer and the way energy moves both vertically and horizontally through the atmosphere.
This is interesting because previous satellites designed to monitor solar UV show that the UV intensity rises and falls in lockstep with the rise and fall of the solar sunspot cycle. See, for example http://wwwsolar.nrl.navy.mil/susim_uars.html
Once there, click on the “Mg II Index” hyperlink.
Also important is the fact that solar UV radiation is almost totally absorbed by the earth. The gamma rays, X-rays, and ultraviolet radiation less than 200 nm in wavelength are absorbed by oxygen and nitrogen. Most of the radiation with a range of wavelengths from 200 to 300 nm is absorbed by the ozone. Only 0.05% of this very short wavelength radiation is reflected back into space. Contrast this to the longer wavelengths greater than 300 nm where roughly a third is reflected back into space as earth shine.
Even if TSI as measured in outer space only varies by 0.1% the amount of that TSI that heats the earth varies greatly by wavelength. Given that all of the UV is absorbed and that 1/3 or more of the visible light is reflected back into space that varying UV has a greater impact on the temperature than its contribution to TSI would at first indicate.
–Mike Ramsey

Ohioholic (14:18:08) :
“Secondarily, the USAF has a spacecraft in orbit today, that measures the expansion and contraction of the atmosphere. It has found that in this current extended minimum that the atmosphere has contracted to a greater extent than at any time in the history of the space age (52 years). Why is it that no one is investigating this effect on the overall radiation balance of the atmosphere?”
I have wondered this myself. If the atmosphere is contracting is it also condensing?

This expansion and contraction is of the thermosphere (60 – 300 miles) not the lower atmosphere.

John F. Hultquist

Dennis Wingo (13:13:36) : You ask:
Why is it that the absorption of a far more energetic photon by oxygen or other visible light absorbers does not overwhelm any CO2 signature?
Oxygen and nitrogen do not absorb, they scatter blue light. Okay, oxygen does absorb a very small amount of some wavelenght, but the blue light
process is called Rayleigh Scattering, here:
http://hyperphysics.phy-astr.gsu.edu/Hbase/atmos/blusky.html
The scattering does not involve a change in the energy of the molecule. To be infrared active a molecule has to stretch or bend in special ways; N2 & O2 don’t. Within the above page, follow the link to Raman Scattering for a bit more info.
Water vapor does absorb and does swamp the CO2 effect as you expect.

Mark

Leif,
Can you enlighten us a little bit on these two excerpts:
“While total solar irradiance changes by 0.1 percent, the change in the intensity of ultraviolet light varies by much larger amounts, scientists have discovered. Research shows such variations in the Sun’s emissions can affect the ozone layer and the way energy moves both vertically and horizontally through the atmosphere.”
“soft X-ray wavelengths shown in this image vary by much greater amounts”
I guess I’m curious as to what how much energy and the amount of changes and what they can affect.

Mark Wagner

Given that all of the UV is absorbed and that 1/3 or more of the visible light is reflected back into space
so even a small % change in cloud cover would significantly affect temperatures.
Once again, ignoring those pesky indirect (magnetic) effects. We’ll soon know much more, I think.

DaveCF

“Modelers estimate that TSI increased roughly 0.08 percent as the Sun exited the Maunder Minimum” and “TSI varies by roughly 0.1 percent through the sun’s 11-year magnetic cycle. Such a variation cannot explain the intensity and speed of the warming trends on Earth during the last century” in the same article? That’s twenty-five percent more solar radiation in eleven years than was needed to break the Maunder Minimum and it doesn’t have much effect. How much solar energy does it take to boil away the Kool-Aid?

Gary P

.. J.Hansford (17:00:47)
The average surface pressure over the earth cannot change unless the mass of the atmosphere changes. Pressure = (mass x gravity)/area *
PV=nRT does not really apply here because we do not have a constant density throughout the volume.
* I am assuming the variation of gravity through the atmosphere is zero.

Yet Another Pundit

About that graphic, why so much noise? Or maybe it isn’t measurement noise, since the deep spikes seem to be multicolored (seen by multiple detectors). The variations seem to line up with the sunspot numbers (which wouldn’t be surprising), but is it measuring just the effect of sunspot brightness variations, or is it measuring that and something more? It seems like a better sunspot count than the actual sunspot count. The TSI can drop below minimum value even if the sunspot count can’t drop below zero. But why is the sun (TSI) so noisy?
And what happened recently? The value is low (as expected), but the variation is also much lower than in the previous minimums.

Dennis Wingo
Dennis Wingo

I am assuming the variation of gravity through the atmosphere is zero.
Actually this is not correct. I don’t know what the numbers are at the surface of the ground but in low orbit the gravity gradient is about 1 microgee per meter.

anna v

Mike Ramsey (17:35:27) :
.
Even if TSI as measured in outer space only varies by 0.1% the amount of that TSI that heats the earth varies greatly by wavelength. Given that all of the UV is absorbed and that 1/3 or more of the visible light is reflected back into space that varying UV has a greater impact on the temperature than its contribution to TSI would at first indicate.
–Mike Ramsey

I have been trying to find a link with numbers , i.e. the variation of the short wave spectrum with time.
I was given a link to a plot by Leif that shows that in percentage of the total energy coming from the sun, a small part is from short waves. I really would like to see a time dependence plot per wavelength intervals.
The reason is that if one looks at the map in http://earthobservatory.nasa.gov/Features/UVB/uvb_radiation3.php which shows the penetration of UV in the ocean, there are distinct spots in the oceans where the penetration is deeper.
So, handwaving the numbers I was able to glean, if the “blue to UV” has 5% of the energy, but it varies by 30%, that means that in those spots of the ocean there will be a 1.5% change of energy coming from the sun, much bigger than the general average of 0.1% change between minima/maxima. It is like having a localized heater which varies with total insolation right at the spots where the PDOs etc are created. Now Leif says that the variation during time is large but the percentage of total energy falls faster and the effect is neutered.
If anybody has any relevant links I would be grateful.

Jerry

“The improvements in accuracy will make it possible to detect long-term changes in the sun’s output much more quickly.” – Er, actually no. Long-term changes can, by definition, only be observed in the long term. You can certainly observe low rate changes, but you then have to assume that these will accumulate over the long term – i.e. predict the future. Anybody got a crystal ball?

Mike Ramsey

anna v (21:31:45) :
I have been trying to find a link with numbers , i.e. the variation of the short wave spectrum with time.

Be careful because the term “short wave spectrum” has different
meanings. The shorthand used by many scientist refers to
infrared as “long wave” and anything with a shorter wavelength
(e.g. visible light) as “short wave”. I try to be explicit
in my usage by defining the range of wavelengths. I hope
that this isn’t confusing. I did the following back of the envelope
calculation a little less than a year ago to try to see what impact
varying UV intensity might have on global heating.
The only part of the solar spectrum to have significant variation
in intensity is the UV, X-Ray range (i.e., wavelength = 300nm
is reflected right back into space. The detailed shape is vaguely
parabolic with the wavelength and amplitude of the peak varying
depending on the surface (e.g. cloud, ice, ocean, desert, forest).
But a 30% figure is widely accepted as an average.
This leaves 70% of 92% =.7 * .92 = .644 = 64.4% of the total
insolation with wavelength >= 300nm that is actually absorbed and
contributes to global heating.
That 8-9% represented by UV, X-Ray (wavelength < 300nm) accounts
for ~12% of the insolation heating the earth.
The remaining 91-92% varies by only 0.1%. Lean (2000) gives a
slightly higher historical variation of about 0.3% but let us stick
with the conservative 0.1% number.
Now consider that the UV, X-Ray (wavelength =300 nm, 0.1%
Shorter wavelengths are absorbed in the earth’s upper atmosphere and
see even larger variations:
120 nm, 50%
140-200 nm, 10-15%
See: http://www.atmos-chem-phys.org/7/5391/2007/acp-7-5391-2007.pdf
So I conclude that ~12% of the sun’s energy heating the earth is
being pumped directly by the solar cycle.
8% * 12% = 0.96% which is still larger than the 0.1% variation that
gets kicked around.
–Mike

Mike Ramsey

Well, that didn’t work. I’ll do it the hard way. 🙂
Anthony, please delete the previous versions of this post. Thanks, Mike
anna v (21:31:45) :
I have been trying to find a link with numbers , i.e. the variation of the short wave spectrum with time.

Be careful because the term “short wave spectrum” has different
meanings. The shorthand used by many scientist refers to
infrared as “long wave” and anything with a shorter wavelength
(e.g. visible light) as “short wave”. I try to be explicit
in my usage by defining the range of wavelengths. I hope
that this isn’t confusing. I did the following calculation
a little less than a year ago.
The only part of the solar spectrum to have significant variation
in intensity is the UV, X-Ray range (i.e., wavelength less than 300nm).
This portion of the spectrum accounts for only 8-9% of the total energy
content of insolation. http://squ1.org/wiki/Solar_Radiation
What I realized is that less than .05 percent of that solar UV,
X-Ray radiation impinging on the earth’s disk is reflected back
into space. The rest (99.95%) is totally absorbed by the earth.
On average, 30% of the remaining 91-92% with wavelength greater than
or equal to 300nm is reflected right back into space. The detailed
shape is vaguely parabolic with the wavelength and amplitude of the
peak varying depending on the surface (e.g. cloud, ice, ocean, desert,
forest). But a 30% figure is widely accepted as an average.
This leaves 70% of 92% =.7 * .92 = .644 = 64.4% of the total
insolation with wavelength greater than or equal to 300nm that is
actually absorbed and contributes to global heating.
That 8-9% represented by UV, X-Ray (wavelength less than 300nm) accounts
for ~12% of the insolation heating the earth.
The remaining 91-92% varies by only 0.1%. Lean (2000) gives a
slightly higher historical variation of about 0.3% but let us stick
with the conservative 0.1% number.
Now consider that the UV, X-Ray (wavelength less than 300nm) radiation
varies across a solar cycle (in lock step) by about 8%. Below is a sample:
200 nm, 8%
220-260 nm, 5%
greater than or equal to 300 nm, 0.1%
Shorter wavelengths are absorbed in the earth’s upper atmosphere and
see even larger variations:
120 nm, 50%
140-200 nm, 10-15%
So I conclude that ~12% of the sun’s energy heating the earth is
being pumped directly by the solar cycle.
8% * 12% = 0.96% which is still larger than the 0.1% variation that
gets kicked around.
–Mike

Jon H

A warmer world by additional 1-3 degrees equates to a rise in food production, and an ability to sustain more human population.
A cooler world by 1-3 degrees equates to a drastic fall in food production, and an inability to sustain our current population.

anna v

Mike Ramsey (03:17:28) :
Thanks.
Now consider that the UV, X-Ray (wavelength less than 300nm) radiation
varies across a solar cycle (in lock step) by about 8%. Below is a sample:
200 nm, 8%
220-260 nm, 5%
greater than or equal to 300 nm, 0.1%

Where did you get those numbers from?
You are making a point that the real difference in the energies coming from the sun are about nine times more from peak to valley of the sun cycle than what is being generally accepted.
I am looking at the localized effect of the 5% or 8% according to your numbers, in the oceans where the currents, PDO and ENSO and whatnot develop which according to The Tsonis et al thread here ( synchronized chaos) are enough to explain the temperature variations observed.
Have you had a look at the map in http://earthobservatory.nasa.gov/Features/UVB/Images/z10uvb.gif , of how the UV is absorbed to different depths in the oceans?
The change in the incoming UV could give a mechanism by which the sun cycle can tie up with the temperatures, because an 8% variation in the amount of heat penetrating to large depths might trigger an effect in the ocean currents.

anna v (06:17:47) :
Have you had a look at the map in http://earthobservatory.nasa.gov/Features/UVB/Images/z10uvb.gif , of how the UV is absorbed to different depths in the oceans?
The change in the incoming UV could give a mechanism by which the sun cycle can tie up with the temperatures, because an 8% variation in the amount of heat penetrating to large depths might trigger an effect in the ocean currents.

This increase of the harmful UV radiation is causing reduction in bio-mass of the oceans’ surface phytoplankton, the largest absorber of CO2 on the Earth’s surface, either through direct destruction of its cells or process of sterilisation by irradiation. Result of this is a reduced uptake of CO2 from the atmosphere and rising in the ‘green-house’ effect. There are already quantifiable evaluations of reduction in the efficiency of phytoplankton.
(just a comment).

Mike Ramsey

anna v (06:17:47) :
Where did you get those numbers from?

See: http://www.atmos-chem-phys.org/7/5391/2007/acp-7-5391-2007.pdf
You are making a point that the real difference in the energies coming from the sun are about nine times more from peak to valley of the sun cycle than what is being generally accepted.

Only at those specific frequencies so no I don’t think that the numbers I quoted are in dispute.
Have you had a look at the map in http://earthobservatory.nasa.gov/Features/UVB/Images/z10uvb.gif , of how the UV is absorbed to different depths in the oceans?

No but I will tonight.
–Mike
–Mike

gary gulrud

Mike Ramsey (03:17:28) :
Good info, looks sensible and is consistent with current compact Ionosphere.

Scott Gibson 13.31.05
” On the other hand, if I told you that changes in the angle of incidence of the sun could cause greater than 50 degree F swings in temperature, you might be skeptical if you didn’t know about winter and summer. In short, I’m still open to the possibility that small solar changes could cause major climate variations.”
Simple, but you may be onto something here. One rough measure of TSI on the ground would be to take two cities – say one in Saskatchewan and one in Texas with the same elevation and look at average temp differences (say summer months) and calculate the w/m sq. for each. Also, a small increment in TSI over an extended period would tend to accumulate heat, would it not? Talking about variation by season, look at the moon where day to night it goes from +100C in day to below -150C at night. It would be interesting to see if there is a discernible variation of mid day temp with varying TSI on the moon. Any data?