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Author Topic: Is there new observational evidence for solar-climate coupling?  (Read 3610 times)

Offline frethack

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Didnt want to hijack the geomagnetic activity thread.

Yes...there is evidence from instrumental data.  No...the sun is not the only determinant factor in regards to the climate system.
As a disclaimer, positive evidence for a solar effect on climate is not negative evidence for the effect of CO2 on climate.  These are two separate subjects, and the validity of one is not dependent upon the invalidity of the other (except among ideologues).

yor_on...if you cannot access these through google scholar, please let me know and I will be happy to email the .pdf files to you (or anyone for that matter).  I cant openly post copyrighted material without risking trouble.  These are all from well respected, peer reviewed journals and are leading authors in the field of solar-climate coupling.  None of these authors believes that because the sun has an effect on climate that CO2 does not, however some (not all) of the recent climate changes attributed to CO2 are now being shown to be attributable to solar variability...not because previous authors were dishonest, but because CO2 and solar activity were increasing at the same time...this is the scientific method.  To dig deeper, just look up more papers by the lead authors...it will help if you have access to a scientific search engine such as Web of Science...if not, google scholar will do.

Bond, G., B. Kromer, J. Beer et al. (2001), Persistent solar influence on North Atlantic climate during the Holocene, Science, 294, 2130–2136.

Gleisner, H., and P. Thejll, (2003). Patterns of tropospheric response to solar variability. Geophys. Res. Lett., 30, 1711.

Haigh, J. D. (2003), The effects of solar variability on the Earth’s climate, Philos. Trans. R. Soc. A, 361, 95–111.

Haigh, J. D., M. Blackburn, and R. Day (2005), The response of tropospheric circulation to perturbations in lower stratospheric temperature, J. Clim., 18, 3672–3685.

Lockwood, M., C. Bell, T. Woollings, R. G. Harrison, L. J. Gray, J. D. Haigh (2010b), Top down solar modulation of climate: Evidence for centennial scale change, Environ. Res. Lett., 5, 034008.

Poore, R.Z., Quinn, T.M., and Verardo, S., (2004), Century-scale movement of the Atlantic Intertropical Convergence Zone linked to solar variability: Geophysical Research Letters, v. 31, p. L12214.

Roy, I., Haigh, J.D. (2010) Solar cycle signals in sea level pressure and sea surface temperature. Atmos. Chem. Phys. 10, 3147-3153.

van Loon, H., Meehl, G.A., Shea, D.J., (2007). Coupled air-sea response to solar forcing in the Pacific region during northern winter. J. Geophys. Res. 112.

There are literally hundreds of papers on the subject...keep digging.

« Last Edit: 13/05/2011 15:36:26 by frethack »


 

Offline yor_on

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It's interesting Frethack :)
I will see what I can find, as I'm sure more than me will.
 

Offline yor_on

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Okay, I really like that one with the flares :) It's a little star trek to me but also real and incredibly fascinating. I've been thinking a little, well, I can't sleep so what the he* should I do else?

1a. Assuming that we're talking a energy transfer here, that builds up heat, directly or indirectly? How much would be needed for making a discernible impact on the gas layer surrounding Earth, (1b) also put in perspective relative the absolute output of solar radiation we receive from the sun every year?

That's the first two questions that's needed to be answered. Would you have any figures on that?

2. The next question that will be needed to be answered if we can see a correlation between those and the warming we've had since 1850? Before that, as I understands it, the planet actually seemed to be in a slow cooling process, not discussing the little ice age there.

It seems obvious that the energy transfers possible by such magnetic 'tunneling' should contribute, but to make it correlate to this warming we will need to find evidence for it having either increased in magnitude, or coming much more often.

As you point out there is definitely a lot of couplings and feedbacks, so many that I doubt that anyone really have a clear understanding of them all, but if we would assume the Sun to drive the warming then it has to deliver more energy now that before, as I see it, no matter what other feedbacks that steps in.

You could naturally assume that what is needed is just that 'kick start' and then some slower amplification through those flares, as the rest of the ecosystem now might start to 'oscillate' and self-reinforce that first energy delivered through earths CO2 cycles, oceans cycles, etc. But then we would need to assume that this 'kick start' also was a recent one, won't we? And that would also mean we already have passed the so called 'tipping point' for how the climate will become the next ? millenniums ? whatever. So I really hope that one is wrong as the idea of a 'tipping' is what really makes me nervous.

For those that don't know what a 'tipping' is seen as, it's when a non-linear system, as earth, suddenly change its balance, falling into a new and semi-stable phase. It can go very quickly as I understands it, once started, and it will only fluctuate in one direction once 'tipped', that is increasing the warming. The opposite effect would be a cooling, like 'snowball earth'. And 'non-linear' just mean the you can't count on the effects, they are not 'linear' instead growing infinitely, more or less, with all other things changing by that first effect, reflecting back on it changing it even more etc etc. Most things we see are actually non-linear in nature. But we've made a civilization trusting in 'linearity', as Newtons work is a prime example of. And it worked perfectly for the longest time:)

The third option is to assume a slow build-up where a lot of interactions come to play, and that one seems the most hopeful as we then also might be able to change the situation by, for example, reducing our CO2, as that is a major 'forcing' any which way we look at it.

But the concept as such is truly fascinating. Makes me think of supra conduction, and I can see why you take it seriously. But those first question needs to be answered before one can draw any conclusions it seems to me.
« Last Edit: 14/05/2011 03:57:04 by yor_on »
 

Offline frethack

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It seems obvious that the energy transfers possible by such magnetic 'tunneling' should contribute, but to make it correlate to this warming we will need to find evidence for it having either increased in magnitude, or coming much more often.

The magnetic tunneling is a completely different subject.  I dont know of any evidence that this contributes to climate change, though that doesnt necessarily mean that it isnt a factor is some way.  Its just not my area of expertise.

1a. Assuming that we're talking a energy transfer here, that builds up heat, directly or indirectly? How much would be needed for making a discernible impact on the gas layer surrounding Earth, (1b) also put in perspective relative the absolute output of solar radiation we receive from the sun every year?

There is very little change in solar output over the course of a solar cycle, on the order of 0.1%.  It isnt the change in total output that is important, but instead it is the change in output in specific wavelengths across the radiation spectrum.  For example, the following is a plot of spectral irradiance anomalies from the previous solar maximum until the current deep solar minimum.  The data comes from the SOLSTICE and SIM instruments on board the SORCE satellite.  The plot marked "Lean model" is the current solar anomaly model used worldwide in GCMs and by the IPCC.  The Lean model underestimates changes in the ultraviolet spectrum by as much as 600% or more, something we had never detected before.  Because ozone absorbs radiation in this band, this has implications on ozone organization and abundance, which is the main driver of stratospheric circulation. 

In explanation, visible light is in the range of about 700nm wavelengths to about 400nm.  Ultraviolet begins at around 400nm.


This is another plot showing changes in ultraviolet over the past three solar cycles.  Note that the most recent solar minimum is very deep, something we had not detected before.  Until the past few years, it was comepletly unknown to us that the sun reacted in this way.

It is thought by some researchers that we may be ending a Gleissberg cycle, which is about a 100 - 120 year cycle (previously thought to be about 87 years).  It forces us to rethink what the range of solar variability may be, especially extreme events like grand minima such as the Maunder, Sporer, Wolf, and Oort Grand Minima of the Little Ice Age.


Ill post more as I have time. 
 

Offline yor_on

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Very interesting, thanks for your explanation Frethack. and it is perfectly reasonable that it have to do with the 'right' frequency's for different atoms/molecules, that we already know .  I will take a look around and see what I can find myself. And yeah, please find the time to post. I'm also thinking of the, so far, unexplained stratospheric water forcing. Not that I see how that would work out, but maybe?

"Since 2000, water vapor in the stratosphere decreased by about 10 percent. The reason for the recent decline in water vapor is unknown. The new study used calculations and models to show that the cooling from this change caused surface temperatures to increase about 25 percent more slowly than they would have otherwise, due only to the increases in carbon dioxide and other greenhouse gases." This vapor exist in a little researched narrow altitude region of the stratosphere that exist from about 17 km (56,000 ft) up to 51 km (32 mi; 170,000 ft). Temperature increases with height due to increased absorption of ultraviolet radiation by the ozone layer, which restricts turbulence and mixing. While the temperature may be -60 −60 C (−76 F; 213.2 K) at the troposphere, the top of the stratosphere is much warmer, and may be near freezing.

"An increase in stratospheric water vapor in the 1990s likely had the opposite effect of increasing the rate of warming observed during that time by about 30 percent, the authors found. Susan Solomon, Karen Rosenlof, Robert Portmann, and John Daniel, all of the NOAA Earth System Research Laboratory  (ESRL) in Boulder, Colo.; Sean Davis and Todd Sanford, NOAA/ESRL and the Cooperative Institute for Research in Environmental Sciences, University of Colorado; and Gian-Kasper Plattner, University of Bern, Switzerland. "

Sorry about me presuming in the post above, I must admit that I assumed that it was the tunneling you were going to take up, but you just whetted our/my appetite there huh? :)
 

Offline frethack

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"Since 2000, water vapor in the stratosphere decreased by about 10 percent...

This is another enigma that is currently under heavy research.  The stratosphere in the equatorial regions extends from about 17 to 50 km above the surface, and though water vapor is scarce in the stratosphere, it does create a surface warming effect through polar stratospheric clouds.  These clouds are transparent to incoming solar radiation, but translucent/opaque to outgoing longwave radiation. 

Over the decline of the past solar cycle, the stratospheric ozone peak abundance shifted locations from about 35km to nearly 50km (top of the stratosphere).  This has the effect of cooling the lower stratosphere and reducing its capacity to carry water vapor.  Whether this can entirely explain the water vapor decline, there is not enough information to say, but it is certainly a contributor.  It is likely to take decades to determine all of the mechanisms for water vapor loss in the stratosphere. 

As for the solar-geomagnetic conduits, Ill see what else I can find.  I cant speak competently on this subject, but Im sure there is someone at the university who will know much more than me.  At the end of the summer Im meeting with one of the solar physicists from the astronomy department, and maybe he will have a better idea.
 

Offline yor_on

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Good on you :)

The Suns variations and possible cycles is a truly tricky business. It would have been nice if we had more human-made records going back in history, or, lacking that a time machine would be highly appreciated.

So the Ozone might be stronger driver than the IPCC considers. Not that it surprise me, they seem to be very wary of stepping out of 'bounds' extrapolating. In this case I don't know if that's the best approach, to me it's a little like not wanting to see, hoping it to go away if one just ignore it.

You're in a interesting field of research Frethack.

 

Offline frethack

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So the Ozone might be stronger driver than the IPCC considers. Not that it surprise me, they seem to be very wary of stepping out of 'bounds' extrapolating. In this case I don't know if that's the best approach, to me it's a little like not wanting to see, hoping it to go away if one just ignore it.

The IPCC serves a good purpose as a scientific body that uses established and well tested research to make policy recommendations, but because it is large and cumbersome, the body as a whole has a difficult time adjusting quickly to new information, especially in rather controversial fields.  To my knowledge, Judith Lean is the only solar physicist that contributes to IPCC reports...at least for the reports up to AR4...maybe AR5 will be different, I dont know.

A little more info.  The two plots below are the result of multiple regression analysis of NCAR-NCEP reanalysis data sets from 1979 to 2002.  They do not include the most recent deep solar minimum.  Multiple regression analysis is basically finding the equation of a line [y = mx + B], but with multiple x values [y = m1x1 + m2x2 + ...mnxn].  It is used to determine the contribution of multiple independent variables on one dependent variable.  In this case to save space, Ive included only the effects of solar activity from 1979 - 2003 on temperature and zonal wind (average latitudinal wind).  the X axis is latitude, and the y axis is atmospheric pressure level in mb (or hPa).

The unshaded areas are those that are within the 95% confidence level.  As solar maximum is approached (the "11 year" cycle), the lower equatorial stratosphere warms, and two vertical columns of warming extend from the tropopause into the lower troposphere at mid-latitudes.


In this study on zonal wind, done by the same author, it shows that the subtropical jet cores weaken, expand, and shift poleward as solar maximum is approached.  A similar study done on vertical wind (convection) detects a weakening and expansion of the Hadley Cell, and poleward movement of the Ferrel Cell, which is in line with the study shown below.


These two studies were done before the current solar minimum and it is possible that the effect is more pronounced with drastic changes in UV radiation, but we will not know that until longer data sets are available.  The effect on the jet cores, Hadley Cell, and Ferrel Cell were attributed solely to increases in CO2 before, but it is now known that solar variability is also a significant contributor to this change.  What are the contributions of each?  There is no way to tell at the moment.  Paleoclimate evidence suggests that the solar effect could be large...we will see.



« Last Edit: 15/05/2011 18:13:05 by frethack »
 

Offline yor_on

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Yeah, the simplified way of thinking of it as a linear process, coming from the sun acting on our ground, but as you point out it also has to do with the molecules/atoms spectra, with that I mean that narrow 'frequency window' from where they can receive 'energy'. So I think that in reality it's not as simple as assuming that the suns rays goes from 'A' to 'B', it's more as a constant flux of interactions, changing depending on what atmospheric mix we have, also depending on the frequencies received.

And for the moment it seem as the atmospheric content are changing. From that we can extrapolate to the 'slower' feedbacks as the way the oceans treat CO2 etc, and the way they do will also reflect on the atmosphere. So to me it seems as a very difficult field to oversee, where we will have all kinds of time induced oscillations and changes, short time and long time, all reflecting on each other and changing each other.

Does that make sense :)
 

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