This is a new paper in Geophysical Research Letters by C. J. Schrijver, W. C. Livingston, T. N. Woods, and R. A. Mewaldt. WUWT readers may recognize Livingston as the creator of one of the datasets we regularly follow graphically on our Solar Data and Images reference page.
They reconstruct total solar flux all the way back to 1650, as seen below:
The implication is that in August-September 2009, when we saw such a dearth of solar activity, the sun dipped to a level similar to periods of the Maunder Minimum. Now that the sun is starting to rev up a bit, the question is: will it last? And, if it doesn’t will we see a cooler period on Earth as some suggest, or as the authors suggest, “drivers other than TSI dominate Earth’s long‐term climate change” dominate? Nature (not the journal) will eventually provide the final answer, all we can do is watch and wait.
The abstract:
Variations in the total solar irradiance (TSI) associated with solar activity have been argued to influence the Earth’s climate system, in particular when solar activity deviates from the average for a substantial period. One such example is the 17th Century Maunder Minimum during which sunspot numbers were extremely low, as Earth experienced the Little Ice Age. Estimation of the TSI during that period has relied on extrapolations of correlations with sunspot numbers or even more indirectly with modulations of galactic cosmic rays. We argue that there is a minimum state of solar magnetic activity associated with a population of relatively small magnetic bipoles which persists even when sunspots are absent, and that consequently estimates of TSI for the Little Ice Age that are based on scalings with sunspot numbers are generally too low. The minimal solar activity, which measurements show to be frequently observable between active‐region decay products regardless of the phase of the sunspot cycle, was approached globally after an unusually long lull in sunspot activity in 2008–2009. Therefore, the best estimate of magnetic activity, and presumably TSI, for the least‐active Maunder Minimum phases appears to be
provided by direct measurement in 2008–2009. The implied marginally significant decrease in TSI during the least active phases of the Maunder Minimum by 140 to 360 ppm relative to 1996 suggests that drivers other than TSI dominate Earth’s long‐term climate change.
I asked Dr. Leif Svalgaard about this paper, in particular this paragraph:
“Therefore, we argue that the best estimate of the magnetic flux threading the solar surface during the deepest Maunder Minimum phases appears to be provided by direct measurement in 2008–2009. If surface magnetic variability is the principal driver of TSI changes, then that same period yields a direct estimate of the TSI in that era, yielding values 140 to 360 ppmlower than in 1996 [Fröhlich, 2009; Gray et al., 2010].”
His response was:
Magnetic variability drives the variations of TSI on top of what the nuclear furnace in the core puts out. They are basically saying that there is no long-term background variations. There is a slight problem with the ~200 ppm lower TSI in 2008-2009 compared to 1996. I have shown that the lower estimates of TSI by Fröhlich in 2008 are likely due to uncorrected degradation of the instrument on which PMOD is based.
See:
that shows the difference between PMOD and the best calibrated instrument we have [TIM of SORCE]. All indications are that TSI at the past minimum was not significantly lower than in 1996 and that that level probably also was typical of the Maunder Minimum, in other words this
is as low as the Sun can go.
See also http://www.leif.org/research/PMOD%20TSI-SOHO%20keyhole%20effect-degradation%20over%20time.pdf
You can read the full Schrijver et al paper here (PDF)
BillyBob says:
March 20, 2011 at 1:05 pm
RGates: “the point here is that while CO2 is less potent a GH gas in that it traps a much more narrow bandwidth of LW radiation …”
H2O is undoubtedly the most potent GHG.
1) Is H2O measured at weather stations? Humidity? Pan evaporation?
2) Is it the same over the 20th century (when you claim CO2 caused warming)?
If the answer to #2 above is “I don’t know”, then how can you blame CO2?
The same is true for sunshine hours. Is it the same over the 20th Century? If the answer is no, or I don’t know, then how can you blame CO2?
If you cannot prove the #1 energy input to the climate system has not gone up, and you cannot prove the #1 GHG has not gone up, blaming CO2 is bizarre.
_____
You’d have to understand the relationship between CO2 and water vapor and hence to the hydrological cycle. The rock-carbon cycle is intimately connected to the hydrological cycle, and over the longer-term when CO2 increases so does water vapor levels as the hydrological cycle begins to accelerate– which is exactly what we’ve seen over the past several decades. This increase in the hydrological cycle increases rock weathering, which then removes CO2 from the atmosphere, thus acting as a natural negative feedback loop to both keep the earth’s temperature and CO2 within a range. The point is: it is CO2 that acts as the thermostat in this process and is integral to the control of water vapor and rock weathering, and it’s own limiting process to make sure this thermostat is always set to the range we’ve seen (and enjoyed as species) over the past 800,000 years. The interesting event has arisen in that suddenly the CO2 thermostat has been set 40% higher than it’s been during these past 800,000 years, and now we need to discover how sensitive the climate is to this sudden turning up of the CO2 thermostat…somewhere between 1.5 to 5 degrees C of warming for a doubling of CO2 seems to be the best current estimate.
Henry@R.Gates
It is alleged that due to increased green house gases heat is trapped that cannot escape from earth. So if green house gasses were to blame for the warming, it should have been minimum temperatures that must show the increase (of modern warming). But as shown in Pretoria, there has not been any warming in the past few decades when CO2 increased the most and minima declined by as much as 0.04 degrees C. It was the same in Spain and Northern Ireland (one line covering half the earth), I also found comparable results to that of Pretoria during the dry months in La Paz, Bolivia, minima declining by 0.05 degrees C per annum…. The conclusion is simply that it cannot be greenhouse gases that caused modern warming of the past 150 years.
It must be something else that caused it …..obviously.
http://www.letterdash.com/HenryP/assessment-of-global-warming-and-global-warming-caused-by-greenhouse-forcings-in-pretoria-south-africa
RGates: “The rock-carbon cycle is intimately connected to the hydrological cycle, and over the longer-term when CO2 increases so does water vapor levels …”
But that isn’t happening. Pan Evaporation, which should climb if AGW is true, is actually dropping all over ther world.
http://themigrantmind.blogspot.com/2009/11/does-pan-evaporation-indicate-cooling.html
The measurments are against your pet theory. Its a failure.
Sunshine Hours, on the other hand, are up. Up enough to account for the tiny bit of claimed warming. And it tracks the up/down/up cycle of warming in the 20th century.
Look up Global Brightening and Global Dimming and Pan Evaporation.
Quit focussing on that failed CO2 theory. Its a loser.
Lief,
It looks to me like you cherry picked the solar wind to make the claim that the solar wind today is higher than 1980.
http://wattsupwiththat.files.wordpress.com/2009/06/solar_wind_pressure_1963.gif
It seems to me that since 1992 the solar wind has dropped dramantically.
Leif Svalgaard said:
“TSI is just one of the many consequences of solar activity. What the article says is that all the other indicators also were the same during the MM as now, [in particular TSI which is the only variable that energetically has any chance of influencing the climate].”
i) One does not necessarily need to influence the climate ‘energetically’ (by which I assume you mean via radiative processes. It is enough to affect the atmosphere chemically. That has an effect on the radiative processes but only in so far as the radiative balance needs to adjust to accommodate the chemical effects and restore radiative equilibrium. So ‘energetic’ processes will change in response to chemical influences as a negative feedback rather than a climate driver.
ii) For a brief while recently the climate did return to something closer to Maunder conditions than we have seen for over a century with a remarkable intensification and equatorward shift of the polar high pressure cells and consequent flooding of the mid latitudes with cold polar air. The only difference with the Maunder period being that it has not yet had time to build up a thermal effect on the oceans from increased global albedo. If it goes on for as long as did the Maunder Minimum then the climate consequences will be just the same.
richcar 1225 said:
” The cooling of the thermosphere and the stratosphere is now being followed by the cooling of the troposhere”
The rest of your post is right in my opinion but not the above portion.
When the sun was active the thermosphere and troposphere warmed whilst the mesosphere and stratosphere cooled.
With the sun now quieter the thermosphere has cooled a lot, the troposphere has stopped warming and may start cooling whilsat the mesosphere and stratosphere have stopped cooling and have warmed a little.
Thus I have had to propose opposite responses to solar variability in the thermosphere/troposphere on the one hand and mesosphere/stratosphere on the other hand.
The prime candidate for such a phenomenon is ozone based chemical changes having different thermal effects at different heights. Lots of other chemical reactions at different levels also seem to be involved but we have yet to sort out the detail.
Leif,
I’d be interested to know a brief history of our understanding of TSI variation on the centennial/millenial scale. My understanding is that late 1990’s we had estimates of 6W/M2 (Crowley) and 3W/M2 (Lean) for the variation from MM to present. Recent studies had it at 1-2W/M2 (Steinhilber, Krivova and others). Now this paper has it about 1/3 of those estimates (~0.33-0.66W/M2). Does this sound correct?
The period pre-MM interests me. Would it be safe to assume that the multi-cennential variations in TSI are much lower outside the period this paper has studied as well? If so changes from MWP to MM seem problematic given there is no anthropogenic forcing then.
Leif says
“Any complex system has internal random fluctuations”
For decades or centuries? This sounds like something the AGWers reject, a nice measurable forcing seems like something they demand.
BillyBob’s link referred to this as regards the apparent decline in pan evaporation rates since 1945:
“So, what other alternatives (to explain the decline) exist? Humidity is one. If the air is more humid it will slow evaporation. The problem is that this is ruled out for the following reason:
“However, this explanation for decreasing pan
evaporation is unsatisfactory for two reasons.
First, it only predicts changes in pan evaporation
in water-limited environments. The
problem is that some areas are not waterlimited,
and in wet environments the evaporation
from pans and the surrounding environment
have both declined.”
I wouldn’t rule out increased near surface humidity on that basis. When the troposphere was warming there was more evaporation from the oceans and a faster water cycle so air over the land became generally a little more humid and pan evaporation would have declined. I suspect that the rates of pan evaporation have stabilised since around 2003 and may soon start to increase.
I don’t think that the reference to ‘wet’ environments is sound because 100% humidity is rare and localised over land and even when humidity is 100% evaporation continues in order to maintain that 100& humidity. Ground surfaces still dry out quickly even in shade in the equatorial regions.
R Gates said:
“it is CO2 that acts as the thermostat in this process and is integral to the control of water vapor”
The baseline amount of evaporation from the oceans is set initially by atmospheric pressure. The value of the enthalpy of vapourisation which is itself pressure dependent dictates the baseline rate of energy flow from ocean to air as a result of that rate of evaporation.
Other factors such as windiness, humidity, solar input to the oceans, internal ocean cycles and downwelling infra red from GHGs are capable of causing variation from the baseline amounts of evaporation and energy transfer.
However any changes other than a change in atmospheric pressure will only result in a change in the speed of the water cycle and NOT a change in the baseline rate of evaporation.
CO2 cannot alter that baseline rate and therefore cannot be said to be in control of water vapour. It can only be one of several variables that can alter the speed of the water cycle.
The speed of the water cycle is ALWAYS a negative feedback which works to prevent those other variables (including CO2) from causing a deviation from the baseline rate of evaporation.
The only effect of more CO2 in the air is to change the speed of the water cycle to a miniscule degree that is unmeasurable compared to natural changes in the speed of the water cycle.
@ur momisugly Leif Svalgaard says:
March 20, 2011 at 7:54 pm
CET since 1659 is not nonsense.
I think this is the key, solar varaiation. It’s unlikely that a trace gas CO2 can have such an appreciable affect on global temperature. I recommend anyone to check out the evidence, Professor Don Easterbrook presents, which shows a strong correlation between solar variation and global temperature.
http://myweb.wwu.edu/dbunny/research/global/glocool.htm
ichcar1225 says:
March 20, 2011 at 11:52 pm
It seems to me that since 1992 the solar wind has dropped dramatically.
No, it hasn’t:
http://www.leif.org/research/Solar-Wind-Flow-Pressure.png
HR says:
March 21, 2011 at 12:32 am
Now this paper has it about 1/3 of those estimates (~0.33-0.66W/M2). Does this sound correct?
It does to me.
Would it be safe to assume that the multi-cennential variations in TSI are much lower outside the period this paper has studied as well?
The cosmic ray record does not suggest that the recent period is abnormal.
“Any complex system has internal random fluctuations”
For decades or centuries?
Some people reject this for the Earth, but are perfectly happy with accepting this for the Sun…
HR wrote: “changes from MWP to MM”
Possibly due to Volcanoes. Zhong et al. (2010) have a nice model-based paper in Climate Dynamics http://dx.doi.org/10.1007/s00382-010-0967-z (Centennial-scale climate change from decadally-paced explosive volcanism: a coupled sea ice-ocean mechanism). Considering all model-caveats, the physics of that paper and discussions by Gleckler in Nature in 2006 and Ottera in Nature Geo last year and … a lot of other papers, give quite a consistent picture.
Sure, but that’s just a mis-application of the rule “See tiger, run”. A lot of human-made rules don’t have a very solid basis in reality, but I agree, they’re useful for preserving the species.
R. Gates, your constant drum of 40% higher needs a clearer statement. And in context. Please produce one. I am curious as to how you would word that, graph that, and maybe even picture it in terms of its relationship to the context it lives in: The atmosphere.
*****
Geoff Sharp says:
March 20, 2011 at 5:22 pm
Your observation is only looking at one climate driver. Climate is mainly driven by ocean cycles and solar activity, do not make the mistake of isolating one aspect. The PDO flipped during the 1940′s.
——–
Stephen Wilde says:
March 20, 2011 at 9:12 am
Most likely the slightly less active cycle 20 combined with a cool PDO resulted in a mild net cooling during a longer term strong warming trend.
The oceans introduce variability on a 60 year cycle (and possibly other time scales).
*****
Thanks for replying.
Yes, I’m aware of the ocean cycles. In fact, this strengthens my argument. The 20 & 60 yr ocean cycles are much longer than Earth’s temperature-response time-constant for a direct forcing change. So those ocean cycles are very difficult or impossible to link to solar magnetic/TSI changes IMO, even if those solar changes actually had a significant effect (which they apparently don’t when comparing global temps vs solar output) .
I agree the ocean-cycles changes are important — they are paramount to short & long-term climate changes. But those changes are internally generated, IMO. Why? Because there isn’t any credible evidence of what “outside” influence could be causing them as yet (Leif shows pretty convincingly that solar output changes have been trivially small over at least the last ~400 yrs). And the best evidence I’ve seen for long-term climate change is the correlation between ice-volume changes with solar insolation at ~50 to 65 deg north. Since this depends on the orbital configuration/eccentricity characteristics (not the sun’s output itself), it is “internally” generated.
Whoops, I need to correct this:
“The baseline amount of evaporation from the oceans is set initially by atmospheric pressure. The value of the enthalpy of vapourisation which is itself pressure dependent dictates the baseline rate of energy flow from ocean to air as a result of that rate of evaporation.”
It is actually the RATIO between the energy value of the enthalpy of vapourisation and the amount of energy required to provoke evaporation that is pressure dependent.
That is how atmospheric pressure ‘controls’ water vapour.
Lief,
Is not the decline in Solar wind flow pressure and magnetic field intensity directly associated with the decline in the magnetic intensity of the umbral magnetic field aka ‘Livingston and Penn’ effect?
http://www.leif.org/research/Livingston%20and%20Penn.png
I do not see a significant recovery here.
richcar1225 says:
March 21, 2011 at 10:11 am
Is not the decline in Solar wind flow pressure and magnetic field intensity directly associated with the decline in the magnetic intensity of the umbral magnetic field aka ‘Livingston and Penn’ effect?
First, there is no decline, the solar wind has recovered nicely. Second, the L&P effect is not really about the lack of magnetic flux on the Sun, but about the less efficient process of concentration of that flux into spots. The solar wind controls the modulation of cosmic rays and the 10Be data suggests that the modulation was vigorous during the Maunder Minimum: http://www.leif.org/research/Cycle-10Be-Maunder-Min.png and http://www.leif.org/research/10Be-Sun-Berggren.png
Beng: “Because there isn’t any credible evidence of what “outside” influence could be causing them as yet (Leif shows pretty convincingly that solar output changes have been trivially small over at least the last ~400 yrs). ”
Solar output that reaches the earth HAS changed over the 20th century, and it matches up with the PDO quite well.
” There is increasing evidence that the amount of solar radiation incident at the Earth’s surface is not stable over the years but undergoes significant decadal variations. Here I review the evidence for these changes, their magnitude, their possible causes, their representation in climate models, and their potential implications for climate change. The various studies analyzing long-term records of surface radiation measurements suggest a widespread decrease in surface solar radiation between the 1950s and 1980s (‘‘global dimming’’), with a partial recovery more recently at many locations (‘‘brightening’’).
There are also some indications for an ‘‘early brightening’’ in the first part of the 20th
century.”
http://www.leif.org/EOS/2008JD011470.pdf
Pamela Gray
R. Gates,
Trollus robusticus,
fervently believes
that the flea (CO2)
on the elephant’s tail
drives the elephant (H2O)
forward,
ignoring the sun
that sits
astride the elephant
wielding the goad.
He reminds me of the Texas Sharp Shooter fallacy: shoot at barn, hit barn (some times), paint target on barn, crow “what a good shot I am”.
BillyBob says:
March 21, 2011 at 11:45 am
Solar output that reaches the earth HAS changed over the 20th century, and it matches up with the PDO quite well.
” There is increasing evidence that the amount of solar radiation incident at the Earth’s surface is not stable over the years but undergoes significant decadal variations.”
Changes in climate or other environmental factors can change the incident radiation [called the insolation] without the sun’s output [its irradiance] changing.
Leif Svalgaard says:
March 20, 2011 at 8:55 pm
. .The issue at hand is whether there is any long-term variation of the background level of solar magnetism. Many climate models assume so [especially from the AGW crowd], but there is mounting evidence that there is not [as I have been saying for years now: http://www.leif.org/research/TSI-LEIF.png ]. Stick to the topic.
~
What about the solar Corona and extended coronal region. The toroidal and polodial forces magnetic and centrifuge must be an awful mess in that region of the solar atmosphere.
How far out is the Corona, must depend on solar activity cycle. Neat photos at different activity levels here:
THE SOLAR CORONA AT TOTALITY
Pg 3
Coronal morphology (depicted here out to 3 solar radii) is most
likely shaped by the sun’s magnetic field, which changes over an
11- year cycle of activity.
During a period of quiescence, coronal structure suggests that open lines of
the sun’s magnetic dipole field spread out from almost all solar regions except
those near the equator, where the corona is brightest and fairly uniform. These
regions of open field lines tend to be less
bright and may qualify as coronal holes, features characterized by drastically
reduced x-ray emission, low particle density, and possibly low temperature.
It is known that, during periods of solar inactivity, coronal holes extend
from the poles toward the equator and cover much of the sun’s surface.
Presumably solar wind flows strongly from coronal holes, thus depleting
particle and energy densities.
http://www.fas.org/sgp/othergov/doe/lanl/pubs/00416689.pdf
Some solar accretion models depict an X line over the solar corona as an active solar interstellar reconnection region complete with its own solar magneto pause around 16 solar radii. Sorta strongly resembles the “Helium Focusing Cone.” Could this be the elsewhere we should be looking? That X line piston moving in and out, up and down, not static.. all the way out from interstellar space.. oh my..
Leif, pretend you are on another star and you are looking back into the solar system. YOU can see “RINGS” of influence as your eyes move across the vast system. Those rings appear to brighten substantianally at 1 Au and brighten even more as your eyes moved near the corona..
Carla says:
March 21, 2011 at 1:01 pm
Some solar accretion models depict an X line over the solar corona as an active solar interstellar reconnection region complete with its own solar magneto pause around 16 solar radii.
There are no such models. The sentence is full of meaningless words that don’t belong together. The corona does have a ‘neutral line’ separating regions of different magnetic polarity [regions originating in the photosphere – we can calculate the shape and position of the neutral line from the magnetic field observed in the photosphere]. That warped neutral line is carrying out by the solar wind to form the sector boundary in space. It looks like this: http://wso.stanford.edu/gifs/helio.gif
Carla says:
March 21, 2011 at 1:01 pm
That X line piston moving in and out, up and down, not static.. all the way out from interstellar space
The neutral line [the sector boundary I showed you a picture of] is carried away from the Sun by the expanding solar wind. A vertical cut through the system looks like this: http://www.leif.org/research/HCS-Movie.gif The wobbling up and down is due to solar rotation.