From a new paper by Dr. Greg Kopp and Dr. Judith Lean, new finding on the solar minimum TSI in 2008:
The most probable value of total solar irradiance representative of solar minimum is 1360.8 ± 0.5 W m−2, lower than the canonical value of 1365.4 ± 1.3 W m−2 recommended a decade ago. This new value, measured by SORCE/TIM, is validated by irradiance comparisons to a NIST‐calibrated cryogenic radiometer in the new TSI Radiometer Facility. Uncorrected scattering and diffraction are shown to cause erroneously high readings in non‐TIM instruments.
That’s lower by 4.6 watts per square meter. This may mean that many climate models will have to be reinitialized if it is decided that this value they derive from SORCE is more accurate than the value established previously.
By way of a forcing comparison to this suggested revision, according to NOAA ESRL:
The total effective climate forcing for all GHGs including CO2 and ozone (O3) from the beginning of the industrial revolution in 1750 to the year 2000 is 2.63 watts per square meter.
So a change of 4.6 watts per square meter to the old baseline TSI is more than double the total GHG forcings. (Averaged over the earth’s curvature, it works out to about 0.85 watts per meter*) That’s still not chump change. It will be interesting to see how this shakes out in models. It is important to note this caveat from their abstract:
TIM’s lower solar irradiance value is not a change in the Sun’s output, whose variations it detects with stability comparable or superior to prior measurements; instead, its significance is in advancing the capability of monitoring solar irradiance variations.
Improved measurements of sun to advance understanding of climate change
From Eurekalert: WASHINGTON—Scientists have taken a major step toward accurately determining the amount of energy that the sun provides to Earth, and how variations in that energy may contribute to climate change.
In a new study of laboratory and satellite data, researchers report a lower value of that energy, known as total solar irradiance, than previously measured and demonstrate that the satellite instrument that made the measurement—which has a new optical design and was calibrated in a new way—has significantly improved the accuracy and consistency of such measurements.
The new findings give confidence, the researchers say, that other, newer satellites expected to launch starting early this year will measure total solar irradiance with adequate repeatability – and with little enough uncertainty – to help resolve the long-standing question of how significant a contributor solar fluctuations are to the rising average global temperature of the planet.
“Improved accuracies and stabilities in the long-term total solar irradiance record mean improved estimates of the sun’s influence on Earth’s climate,” said Greg Kopp of the Laboratory for Atmospheric and Space Physics (LASP) of the University of Colorado Boulder.
Kopp, who led the study, and Judith Lean of the Naval Research Laboratory, in Washington, D.C., published their findings today in Geophysical Research Letters, a journal of the American Geophysical Union.
The new work will help advance scientists’ ability to understand the contribution of natural versus anthropogenic causes of climate change, the scientists said. That’s because the research improves the accuracy of the continuous, 32-year record of total solar irradiance, or TSI. Energy from the sun is the primary energy input driving Earth’s climate, which scientific consensus indicates has been warming since the Industrial Revolution.
Lean specializes in the effects of the sun on climate and space weather. She said, “Scientists estimating Earth’s climate sensitivities need accurate and stable solar irradiance records to know exactly how much warming to attribute to changes in the sun’s output, versus anthropogenic or other natural forcings.”
The new, lower TSI value was measured by the LASP-built Total Irradiance Monitor (TIM) instrument on the NASA Solar Radiation and Climate Experiment (SORCE) spacecraft. Tests at a new calibration facility at LASP verify the lower TSI value. The ground-based calibration facility enables scientists to validate their instruments under on-orbit conditions against a reference standard calibrated by the National Institute of Standards and Technology (NIST). Before the development of the calibration facility, solar irradiance instruments would frequently return different measurements from each other, depending on their calibration. To maintain a long-term record of the sun’s output through time, scientists had to rely on overlapping measurements that allowed them to intercalibrate among instruments.
Kopp said, “The calibration facility indicates that the TIM is producing the most accurate total solar irradiance results to date, providing a baseline value that allows us to make the entire 32-year record more accurate. This baseline value will also help ensure that we can maintain this important climate data record for years into the future, reducing the risks from a potential gap in spacecraft measurements.”
Lean said, “We are eager to see how this lower irradiance value affects global climate models, which use various parameters to reproduce current climate: incoming solar radiation is a decisive factor. An improved and extended solar data record will make it easier for us to understand how fluctuations in the sun’s energy output over time affect temperatures, and how Earth’s climate responds to radiative forcing.”
Lean’s model, which is now adjusted to the new lower absolute TSI values, reproduces with high fidelity the TSI variations that TIM observes and indicates that solar irradiance levels during the recent prolonged solar minimum period were likely comparable to levels in past solar minima. Using this model, Lean estimates that solar variability produces about 0.1o Celsius (0.18o Fahrenheit) global warming during the 11-year solar cycle, but is likely not the main cause of global warming in the past three decades.
GEOPHYSICAL RESEARCH LETTERS, VOL. 38, L01706, 7 PP., 2011
doi:10.1029/2010GL045777
A new, lower value of total solar irradiance: Evidence and climate significance
Greg Kopp
Laboratory for Atmospheric and Space Physics, Boulder, Colorado, USA
Judith L. Lean
Space Science Division, Naval Research Laboratory, Washington, D. C., USA
The most accurate value of total solar irradiance during the 2008 solar minimum period is 1360.8 ± 0.5 W m-2 according to measurements from the Total Irradiance Monitor (TIM) on NASA’s Solar Radiation and Climate Experiment (SORCE) and a series of new radiometric laboratory tests. This value is significantly lower than the canonical value of
1365.4 ± 1.3 W m-2 established in the 1990s, which energy balance calculations and climate models currently use. Scattered light is a primary cause of the higher irradiance values measured by the earlier generation of solar radiometers in which the precision aperture defining the measured solar beam is located behind a larger, view-limiting aperture. In the TIM, the opposite order of these apertures precludes this spurious signal by limiting the light entering the instrument. We assess the accuracy and stability of irradiance measurements made since 1978 and the implications of instrument uncertainties and instabilities for climate research in comparison with the new TIM data. TIM’s lower solar irradiance value is not a change in the Sun’s output, whose variations it detects with stability comparable or superior to prior measurements; instead, its
significance is in advancing the capability of monitoring solar irradiance variations on climate-relevant time scales and in improving estimates of Earth energy balance, which the Sun initiates.
Received 7 October 2010; accepted 30 November 2010; published 14 January 2011.
Citation: Kopp, G., and J. L. Lean (2011), A new, lower value of total
solar irradiance: Evidence and climate significance, Geophys. Res.
Lett., 38, L01706, doi:10.1029/2010GL045777.
See the paper here (PDF)
big h/t to Dr. Leif Svalgaard
* UPDATE: from ClimateWatcher in comments:
The TSI averaged over the earth’s surface area and the amount not reflected to space:
1/4 ( 1 – a ) * S
1/4 – the ratio of circle through which radiation passes to the surface are of sphere.
a – albedo ( let’s use 0.3 even though nobody knows for sure)
So the comparison should be
0.25 * 0.7 * 4.6 W/m^2
or about 0.85 W/m^2
That’s still not negligible but not a doubler.
Interesting to note that 0.85 W/m^2 was the amount the earth was supposedly
out of balance by per Hansen and Trenberth.
Given the uncertainty in Solar constant, albedo and mostly thermal emission,
there’s no way anyone really knows if the earth is out of balance or not.
Now, for all you “electric universe” imbeciles, integrate that 1360 W/m^2 over a sphere with a radius of 93 million miles. All that energy is coming from where?
Regardless of the mechanism of the sun’s influence on climate, the study of the reconstructed temperatures from an ice core taken from the Altai Glacier demonstrate a twenty year lag between sunspot activity and temperature change.
http://www.science20.com/news_releases/siberian_altai_ice_cores_say_sun_drove_preindustrial_temperature_changes
If we take 1990 as the beginning of sunspot decline which is still continuing then we might expect temps to start declining in 2010 and continue for at least twenty years. Tropospheric temps have declined .7 degrees since a year ago. Although the Altai ice core reconstruction can only account for 50% of the recent warming due to sunspots, it turns out that the temperature increase at that location is twice the global average.
First off, second the comment from Climate Watcher; the forcing value is equivalent power density averaged over the whole earth and an entire day, rather than the peak value directly below the sun.
Second, I’m a bit surprised that Dr. Lean expects any change in model responses from the new, lower irradiance value. As far as I can tell, the models are concerned with changes over time; I don’t think they rely on the absolute value. There will be a small change in the sensitivity to albedo, equal to the fractional change in irradiance, but that’s only 4.6 / 1360 which is less than half a percent. Anyone have an idea why she thinks this is a significant change to GCMs? I can understand that more precise measurement of the variations in irradiance will be useful (but again I doubt these are very different from the prior best-estimates).
When I read the following: “TIM’s lower solar irradiance value is not a change in the Sun’s output, whose variations it detects with stability comparable or superior to prior measurements; instead, its significance is in advancing the capability of monitoring solar irradiance variations.”, I said to myself, “I wonder how long it will take to see a post from a believer that will ignore the statement and claim that TSI is lower but temps are higher seemingly to prove AGW.
Low and behold, it was the very first post!
richcar 1225 says:
January 14, 2011 at 6:13 pm
“If we take 1990 as the beginning of sunspot decline which is still continuing then we might expect temps to start declining in 2010 and continue for at least twenty years.”
_____________________________________________________________
Why take 1990? Sunspot numbers remained above their long-term average right up until the solar minimum in 2008-9. The Sun’s failure to come out of that minimum is really the first indication that things are changing.
As I see it, the sunspot decline is very recent phenomenon – 18 months to 2 years, at best.
If your 20-year lag theory is correct, it may be that the real “fun” won’t start until 2030…..
mike g says:
January 14, 2011 at 6:09 pm
Now, for all you “electric universe” imbeciles, integrate that 1360 W/m^2 over a sphere with a radius of 93 million miles. All that energy is coming from where?
=====
Bluetooth or WiFi, even us imbeciles’s know that.
Don’t know about “electric universe”, but I have electric.
I am not a climate researcher, and not a scientist at all though I have a technical background.
What I don’t understand is why the error limits of the ten year old 1365.4 +/-1.3 Watts/m^2 is so exclusive of the mean of the new figure of 1360.8 +/- .5 Watts/m^2. If these error limits given are actually 1sigma limits then the new mean is actually 4.6/1.3 = 3.5sigma outside of the older mean according to the error analysis of the earlier measurement….. And yet the claim is made that the sun’s output is not changed, but the new measurement is merely more accurate?
If this is true, why is the error analysis of the older measurement so innacurate? Isn’t it more reasonable to assume the sun’s radiance is variable and has changed?
rawdog
We’ve already established cloud cover as the primary climate driver. How does TSI and GCR affect cloud cover. We need data!
why would you even trust their data at this point? who reports it, NASA? too many crooks and liars in the mix….
anything is possible said:
“Why take 1990? Sunspot numbers remained above their long-term average right up until the solar minimum in 2008-9. The Sun’s failure to come out of that minimum is really the first indication that things are changing.”
Cycles 21 and 22 were fairly even but cycle 23 (2000-2001) declined from approximately SSN 160 (cycle 22, 1990) to about 110. Cycle 24 maybe about 60. The decline started from cycle 23 and has since accelerated.
Pray for GHG forcing. It might just be a coincidence but but the 1998 and 2010 El Ninos are 20 years from cycle 21 and 22 maximums. At any rate I do not believe we can expect a super El Nino for awhile.
When TSI is mentioned with respect to climate the fairly small changes are described as not enough to give rise to significant climate change. What I have not seen is any reference to spectral changes in solar radiation. Earths albedo should be wavelength dependent. Could it be that even though TSI remains constant spectral changes lead to much higher variations in albedo. This could explain the apparent link between sunspots and climate.
Studies such as this could signal a generational change in climate science.
I wouldn’t expect any of the “Old Dogs” to attempt any “New tricks” by getting involved in using the Sun as a baseline from which to work. The “Old Dogs”, I beleive, maybe too far committed with their existing dogma’s to be able to promote they’ve learnt “New Tricks” for anyone to be able to take them seriously.
I certainly wont.
Through their actions the “Old”Dogs” have already proven to be more leaders of faith based and emotive argument, using circumstantial and missleading information the majority of time which corrupts anything that may of value. 🙂
Using the Sun as a baseline for study may introduce some new blood into the field.
From there the science may develop and, hopefully, mature.
Leif Svalgaard says:
January 14, 2011 at 5:48 pm
Werner Weber says:
January 14, 2011 at 5:35 pm
I guess, Leif would insist that there are no such solar intensity changes from one solar minimum to the next.
What I would say [a bit more conservatively] is that such changes have not been demonstrated.
Leif, Your statement seems subjective. What evidence is there that the minimum has had no variance through time?
richcar 1225 says:
January 14, 2011 at 7:31 pm
“Cycles 21 and 22 were fairly even but cycle 23 (2000-2001) declined from approximately SSN 160 (cycle 22, 1990) to about 110. Cycle 24 maybe about 60. The decline started from cycle 23 and has since accelerated.”
____________________________________________________________
Fair point, but Solar Cycle 23 was still above-average (ranking about 9th. strongest) as compared to all 23 cycles. So the “decline” was really only relative to the strong cycles 21 & 22.
Essentially, just a quibble over data interpretation. I don’t disagree with your conclusions.
Eric Barnes says:
January 14, 2011 at 8:06 pm
Leif, Your statement seems subjective. What evidence is there that the minimum has had no variance through time?
Figure 1b has a grey band of uncertainty. The variation of observed TSI at minima falls within that band, hence as the paper itself states: “Disagreement among overlapping observations, as apparent in Figure 3, indicates undetected drifts that suggest the TSI record is not sufficiently stable to discern solar changes on decadal time scales.”.
I am curious how much the solar cycle has influenced Bastardi at AccuWeather to make the bet for the coming decade. It is brave to bet on a decade, but if the solar cycle truly is a major player and the current cycle is a bust, then he will clean up on the bet. This next decade will be an interesting one.
Personally I think once the cooling starts, it is going to be much greater than 0.2C in a decade.
http://theinconvenientskeptic.com/2011/01/bastardi%E2%80%99s-wager/
John Kehr,
‘Once to cooling starts’- hmmmm well temperatures continue to increase. Lets balance out those ENSO peaks and troughs over a five year period and plot against sunspot numbers, and for fun lets add the PDO………WOW!! Since 1980…Even mor WOW!!
http://www.woodfortrees.org/plot/gistemp/from:1930/to:2010/mean:60/plot/jisao-pdo/from:60/to:2010/scale:0.1/mean:60/plot/uah/from:1930/to:2010/mean:60/offset:0.2/plot/sidc-ssn/from:1930/to:2010/scale:0.0005
and some people on this site still think temperatures are cooling (wasn’t 2010 tied as warmest despite the sharp La Nina in the 2nd half of the year (from June/July)?) Hmmmm
Stevo says:
January 14, 2011 at 5:20 pm
“So a change of 4.6 watts per square meter to the old baseline TSI is more than double the total GHG forcings”
Good try, but no. 2.63*2=5.26. 5.26 is more than 4.6, not less. You also seem not to know that to calculate the solar forcing, you need to divide the change in TSI by 4, because solar radiation falls on half of a rotating planet,>>>
Wel;, if you are going to lecture others about math, at least get your own right. You divide the TSI by 4 because it falls on 1/2 the planet? LOL. Try you divide by 2 for half the planet and then again to account for curvature of the earth face as presented to the Sun.
and then multiply by 0.7 to account for the fact that 30% is reflected. So now we have not 4.6 but 0.805W/m². That’s quite a lot less than the greenhouse gas forcings.>>>
Is it now. Really? The classic number quoted by IPCC et al is 3.7 w/m2 for doubling of CO2 over the base line of 1750 AD. Of course they neglect to mention that after 260 years of fossil fuel use, CO2 has only gone up about 40%. Wait, no, don’t multiply 0.4 x 3.7 you will get too low a number! CO2 is logarithmic so once you figure out how to do that you should be at about 2.5 w/m2. But wait! The IPCC also neglects to spell out the fact that they aren’t modeling based on SURFACE temps, they are modeling based on the “effective black body” temperature of earth. That’s about -20 degrees C while the surface temperature of the earth is more like +15, or so the IPCC says. To get to a surface number you have to use THEIR ratio of 3.7/5.5*forcing at effective black body. So now, at surface, we’re talking in the range of 1.7 w/m2. So, the change in TSI measurement is about 50% of the modeled forcing from CO2.
And finally you seem not to have understand that this is not even a forcing, even though you manage to quote the bit about “TIM’s lower solar irradiance value is not a change in the Sun’s output”.>>>
It isn’t a forcing? Does the Sun’s radiance heat the planet or doesn’t it? If we’re going to argue about how much “forcing” CO2 causes in w/m2, then it has to be compared to other energy sources that cause changes in the amount of w/m2 that the earth receives from them and the amount that the earth radiates to space. Call it what ever you want, forcing is a lousy term for either. In this case the correction to base line appears to be in the same rough magnitude as change supposedly from CO2.
And don’t even get me started on this mythical “average” temperature of earth or the equally mythical “average” energy flux at earth surface from any source. That calculation is like taking the total number of bikinis being worn at any given time on earth and dividing by the area of the earth surface in order to estimate how many bikini clad women there at any given time, on average, at the North Pole. I suggest it is identical to the average number of bikini clad men at the North Pole. I don’t know for certain, Sports Illustrated always does their bikini shoot someplace not cold. And there aren’t any bikini clad men in those shots either. Odd that.
Will the figures in Trenberth’s famous diagram have to be altered? 1362 seems to be about the new average figure, divide by 4 and we get 340.5 instead of Trenberth’s 342 w/m^2 insolation which is used in nearly all the diagrams.
Ahh, I see SORCE puts in the altered figure and this important caveat:
I’d like a reminder of Scafetta’s position. I know he was hot under the collar about the splicing used between different satellite datasets and I’d trust him on the whole.
Forgot to add the SORCE url.
Leif, you have a great sense of humor.
Leif Svalgaard says:
Figure 1b has a grey band of uncertainty. The variation of observed TSI at minima falls within that band, hence as the paper itself states: “Disagreement among overlapping observations, as apparent in Figure 3, indicates undetected drifts that suggest the TSI record is not sufficiently stable to discern solar changes on decadal time scales.”.
HaroldW says:
January 14, 2011 at 6:25 pm
The GCM’s are not radically altered by the lower TSI baseline, to the extent that they will still spit out the same bad climate forecasts, as long as they are fed with tampered surface station data.
Cities and municipalities will continue to be mal-advised as to weather preparations.
The GHG’s 2.63 watts per square meter versus the 0.85 w/m2 reaching the ocean surface is far more similar when comparing both over land, but miles apart when over ocean. Despite these values quoted as supposed to cause more warming from GHG’s, when the planet doesn’t show this because of this mistake. About 71 percent of the planets surface of the 2.63 w/m2 when going back out to space only contacts the skin layer of the surface.
The 0.85 w/m2 reaches upwards to around 100m ocean depth, so comparing these two as comparable energy values to the planets energy budget is very wrong. This is the main reason why the planet is not complying to the calculations of computer models. That is why SWR has many orders higher influence then LWR with energy exchange compared, with the difference easily 200,000 times greater just to water compared with the atmosphere. This is so important because the ocean controls the temperatures of our atmosphere.
Likely a mistake also which should lead to a future change to the supposed 33c greenhouse effect theory. Why you wonder this is because the ocean in this context should also be treated as by far the biggest greehouse contribution of the planet. The greenhouse effect can’t be calulated just using the atmosphere it also needs the energy content processes involved with the oceans to achieve a correct value. The energy retained in the oceans makes the planet warmer and contributes significantly towards the greenhouse effect. (not only with water vapour, but also energy consistantly supplied like central heating to the atmosphere) Take away the ocean, but maintain the same atmospheric content and the greenhouse effect of 33c would be significantly reduced.
It would be great to have a solar page here, like the Sea Ice page and the sea level rise / SST pages. Including basic astrophysics links too. And though I may query his broad-brush rejection of EU, who better to do a solar page here than Leif.
(I think EU has important material even though I too query some of it. I would love to see nuanced studies and comments, looking at bits of evidence, rather than trench-warfare attitudes. For instance, IMHO it’s worth looking at planetary craters as the results of electrical discharges rather than mechanical impacts. Here’s a video study of Mars – also look at Mercury in this light)
@rushmike
“Hmmm, lower TSI, yet global temperatures keep increasing…hmmmm”
Why is it so hard for you pro AGW people to understand that there is a lag between solar activity, and that you need a prolonged period with lower solar activity for the effect to truly be seen?
During the last decades we have had the strongest solar cycles on average in over 8000 years. Even the weakest cycles in last decades have been pretty high in activity.
It is only in recent years that we have entered a deep grand minimum, so you cannot expect a immediate drop in global temperatures. But either way we already see some changes and global temps have started dropping like a rock since this summer.
Some of us who think sun is driver actually predicted the change in weather patterns seen over last years with jet streams moving more south, which is in exact contradiction to what should happen according to AGW theory.
It will probably take another decade before the full effects start to be seen.